Important things learned at yesterday's otherwise frustrating range session with the 485g Lee mold "narrow ogive" bullet

[JimGnitecki]

Yesterday's range session was frustrating overall, as it failed to identify a handload that shoots well beyond 100 yards using the 485g Lee mold bullet that has a very narrow sharply pointed ogive. But I learned a LOT, AND I finally got the bullet to group at 150 meters = 163 yards, although the grouping is still completely unsatisfactory.

It was a very complicated session to manage, but in shooting 6 different loads of 5744 powder, 5 of them using my new Track of the Wolf expander setup, and after studying my 6 different Labradar logs, here sre some of the things I verified or learned:

- This bullet needs to be chambered so that it is in contact with the rifling. When in prior sessions I had some "jump", it would shoot great at 100 meters = 108 yards (as good as 0.62" 3-shot groups), but would not group at all at 150 meters. Based on forum info I had acquired from buffalo rifle websites, bullets with sharp narrow ogives rattle around too much and destabilize when allowed to jump. This is because a long narrow ogive necessitates a shorter bullet SHANK, and it is the shank that stablizes the bullet. If the bullets are in contact with the rifling BEFORE ignition occurs, they tend to fly better.

- The safest way to achieve a repeatable amount of rifling contact, despite slight variances in COAL and in case length, is to use an expander size and shape that secures the bullet enough to enable sensible no-shock handling and transport, but allows the bullet to "slide back" in the case once it has touched the rifling, and maintain JUST that light contact while the case is completing its chambering.

- The above expander's specific shape also eliminates the need to UNflare each cartridge after seating the bullet, thus eliminating one handloading operation.

- Having the bullet touch the rifling enable me to, for the first time ever with this bullet, get actual groups at 150 meters. The group size was still way too large (2 to 3 inches at 150 meters = 163 yards), but at least it was progress.

- The elimination of the jump apaprently also eliminated the funny transonic variance in bullet velocity versus distance from the muzzle that existed before, atfter 125 yards, which at my 3000 foot elevation, just happens to be the local speed of sound:

Before (i.e. with jump):


After (with no jump):



I assume this is furrther evidence of the improved bullet stability with the elimination of the jump.

By the way, the reason that the muzzle velcoties on the 2 graphs are different is because the first graph shows ALL the handloads in one graph while the 2nd graph shows one specific load. All the specific loads generate a graph like the 2nd graph, after I removed the jump.

- None of the handloads generated what I could honestly call "bad" average / SD / ES statistics, and some were pretty excellent (like SD = "2"). Basically, with the 5744 powder and this bullet, you really cannot generate bad SDs and ESs. 5744 really works well with the 45-70 caliber at loadings suitable for buffalo rifles. Notably, ALL buffalo rifle loadings for use with heavy, cast bullets, that you actually want to obturate to the barrel, WILL involve transonic velocities. You cannot load those heavy bullets to velocities low enough, or high enough, to aovid the transonic zone if you want to shoot long distances.

- The ballistic coefficient for this bullet changes dramatically with velocity. I used an online BC calculator that determines BC by comparing the bullet velocities at two different known ranges. That was an eye opener. At one extreme (the highest powder load and speed), the calculated BC was as low as 0.4. At the other extreme (the lowest powder load and speed) the calculated BC was just over 0.5! This might be why some BPCR shooters keep their muzzle velocities in the 1000 to 1100 fps region for use at some ranges.

- Loading these cartridges that enable the bullet to slide back into the case after hitting the rifling was NOT hard to do. Simple thumb pressure on the base of the cartriudge was sufficient to get the cartridge chambered sufficiently that the Sharps replica FALLING BLOCK was able to slide back up over the cartrudge base to seal the chamber. On a bolt action rifle this would have been even simpler and would have allowed for a tighter fit between case and bullet. Apparently, there are BPCR shooters who use "pusher tools" to do this, and some even load JUST the bullet first into the rifling, and then add the case with powder as a separate step. No kidding.

- In the handloads tried so far, I have found 3 muzzle velocity "nodes" located at 21.7g, 24.0g, and 25.5g of 5744. I now need to make way more cartridges at each of the 3 powder levels in order to ensure a large enough sample size to draw valid accuracy conclusions from.

I am still not sure if I can EVER get this bullet to shoot adequately at the longer ranges I want to shoot at (up to 600 yards available at our club facility). It certainly has not been easy so far.

Jim G

 

[MEHavey]

Get/use this mould/bullet.
Paul Jones 45001 Creedmoor Clone

.459

This is a copy of one of my Paul Jones moulds that I have used very successfully over the years. The bullet has a bearing surface length of .700" and an over all length of 1.430". A great design for silhouette and long range shooting. BULLETS CAST FROM THIS MOULD WERE USED BY THE WINNER OF THE...

www.buffaloarms.com

Close 2nd
Classic Postell

.458

Lyman Single Cavity Cast Bullet Mould produces Lyman Rifle bullet #457132, .458" nominal diameter, 535 grain, Postell bullet. Designed by Postell for long range target shooting. One of the best long range target bullets ever designed, widely used for B.P.C.S.. Lyman Top Punch #132...

www.buffaloarms.com

 

[JimGnitecki]

Get/use this mould/bullet.
Paul Jones 45001 Creedmoor Clone

.459

This is a copy of one of my Paul Jones moulds that I have used very successfully over the years. The bullet has a bearing surface length of .700" and an over all length of 1.430". A great design for silhouette and long range shooting. BULLETS CAST FROM THIS MOULD WERE USED BY THE WINNER OF THE...

www.buffaloarms.com

Close 2nd
Classic Postell

.458

Lyman Single Cavity Cast Bullet Mould produces Lyman Rifle bullet #457132, .458" nominal diameter, 535 grain, Postell bullet. Designed by Postell for long range target shooting. One of the best long range target bullets ever designed, widely used for B.P.C.S.. Lyman Top Punch #132...

www.buffaloarms.com

Thank-you. BUT, I am almost afraid to spend the money on yet another (3rd) mold, since I have had 2 in a row strike out, despite very careful handloading and great SD and SE statistics. I'd really prefer to somehow get some sample bullets before I buy a 3rd mold.

Jim G

 

[MEHavey]

Send me a PM,
I'll cast up/size (460), DGLube, and send a dozen Creedmoors

 

[JimGnitecki]

Send me a PM,
I'll cast up/size (460), DGLube, and send a dozen Creedmoors

Thank-you, MEHavey! I really appreciate it. I sent you a PM. The landed and taxed current cost of that mold to me in Canada would be $195 US / 0.705 x1.05 + $35 = $325 Canadian, PLUS the cost of buying a Saeco handle for it! Hence my reluctance to buy molds to try.

Jim G

 

[GooseGestapo]

NOW Jim, I’m going to throw you an another curve ball, and a bit more of that mold’s history…..!
First, you discovered what I already knew about shooting accurately with both a Sharps style rifle and THAT bullet. They NEED to be seated in contact with the rifling.
Second, we only shot them cast from soft lead, and lubed with SPG (except for some I shot from a NEF single shot). Also, only Pyrodex or GOEX 2F BP. Sized .458”. I’ve gone to a .460” sizer since.

THIRDLY, on one occasion, we were able to shoot at some gongs at 385 and 550yds.
The bullets tended to “go to sleep”, meaning they wobbled like an unstable top until somewhere about 300-350yds, where after they went “smooth” and groups quit spreading. We got groups on the 550yd gong that were little different from the 385yd gong, Observing with a quality 60x scope, you could watch the bullets arc down range. When the light was angled right, they looked like “strobe lights”, then a solid streak. The 405 FNGC did similarly but not as bad. The 400gr HBFN Nose pour mold didn’t, but at 385 and 550 shot better, but dropped a bit more. Our velocities were slightly less than yours at about 1,100fps MV.

Do continue shooting and reporting! My “investment” in your mold has been worth it!
Mike Venturino, who wrote/writes for Rifle Magazine can tell you that buying additional molds is a deep, expansive (and expensive) rabbit hole. He shot BPCF competition for years. Has wrote extensively about it. I suggest you research his articles and perhaps reach out to him. He’s a VAST wealth of information.

 

[JimGnitecki]

NOW Jim, I’m going to throw you an another curve ball, and a bit more of that mold’s history…..!
First, you discovered what I already knew about shooting accurately with both a Sharps style rifle and THAT bullet. They NEED to be seated in contact with the rifling.
Second, we only shot them cast from soft lead, and lubed with SPG (except for some I shot from a NEF single shot). Also, only Pyrodex or GOEX 2F BP. Sized .458”. I’ve gone to a .460” sizer since.

THIRDLY, on one occasion, we were able to shoot at some gongs at 385 and 550yds.
The bullets tended to “go to sleep”, meaning they wobbled like an unstable top until somewhere about 300-350yds, where after they went “smooth” and groups quit spreading. We got groups on the 550yd gong that were little different from the 385yd gong, Observing with a quality 60x scope, you could watch the bullets arc down range. When the light was angled right, they looked like “strobe lights”, then a solid streak. The 405 FNGC did similarly but not as bad. The 400gr HBFN Nose pour mold didn’t, but at 385 and 550 shot better, but dropped a bit more. Our velocities were slightly less than yours at about 1,100fps MV.

Do continue shooting and reporting! My “investment” in your mold has been worth it!
Mike Venturino, who wrote/writes for Rifle Magazine can tell you that buying additional molds is a deep, expansive (and expensive) rabbit hole. He shot BPCF competition for years. Has wrote extensively about it. I suggest you research his articles and perhaps reach out to him. He’s a VAST wealth of information.

Ok, this is JUST a THEORY, but it builds upon what you have said above, and what I have previously theorized based on circumstantial evidence:

This bullet may indeed be particularly susceptible to reacting badly to transonic disturbances. Look at the circumstantial evidence so far:

- My Labradar says it cuts through the local (eleveation 3000 ft) speed of sound of 1130 fps at about 125 yards. "Coincidentally", it sharps with tremendous accuracy at 100 meters, but then failed to group by 150 meters.

- You guys saw it wobbling on its way to the 300 to 350 yards but then stabilizing

- Using an online calculator that estimates BC based upon speed of a bullet at 2 different distances from the muzzle, I have found that the BC of this bullet VARIES with its muzzle velocity: LOWER MV gives HIGHER BC, and HIGHER MV gives LOWER BC. So, your low 1100 fps muzzle velocity gives this bullet a relatively very high BC which means it takes LONGER for it to get to a low enough velocity to escape from the transonic effects (which sort of peak around the local speed of sound and fade slowly as the velocity either increases above or below the speed of sound.

- An online ballistics calculator that provides, among other things, the estimated velocity at specific ranges, says that a bullet woth the physical characteristics of this bullet will hit a velocity of about 950 fps at about 300 to 350 yards. At that 950 fps velocity, yes, I would expect transonic disturbances to become rather small or insufficient to "buffet" the bullet. Is that maybe why you observed it recovering stability at that range of 300 to 350 yards?

- You and I both noting that the bullet requires seating into the rifling to get better results (better, but still not great) makes sense if indeed marginal stability is the issue, because seating into the rifling gives the bullet a more stable "start" than a jump to the rifling does. This is why my rnage results were BETTER yesterday with the bullet seated into the rifling, but still not sufficient.

One way to test this "instability" theory would be to launch the bullet at a high enough muzzle velocity to keep it out of the transonic speed zone to at least the distance you want to shoot to. However, I cannot do that test with Accurate 5744, the only powder I have for this cartridge. None of the load tables I have found goes above 28.0g for a CAST bullet if needing to maintain Trapdoor pressures AND keeping velocities low enough to prevent leading of the barrel. The combination of the safety issues, the leading issues, and the recoil issues put such a test outside my sphere of comfort.

So, again, I am led to the conclusion that this bullet, like the Lyman "bulbuous" bullet, appear to be unsuitable for my objectives.

Jim G

 

[JimGnitecki]

By the way, I tried this morning to see how short a COAL would be required to actually enable chambering a cartridge loaded with the Lyman 457125 bullet (the one I call the "bulbuous" bullet). I prepped a dummy cartridge using the successful .460" expander setup that allows me to push the bullet further into the case without damaging the bullet.

I had to seat the bullet to a COAL of 2.716" in order to be able to finally close the falling block on the chamber. The COAL recommended for this bullet by Lyman itself, in the load table in their Cast Bullet Handbook, is 2.835". So, I had to make the COAL .119" shorter than the recommended COAL!

Even THEN, I had to push pretty hard on the falling block's lever. And, I was unable to extract the unfired (dummy) cartridge from the chamber. I had to use a rod pushed down from the muzzle to dislodge the bullet from the rifling.

That (brand new) Lyman 457125 mold I got clearly produces a bullet with an ogive too large to fit my Pedersoli SAAMI-compliant chamber.

Jim G

 

[AJC1]

Ok, this is JUST a THEORY, but it builds upon what you have said above, and what I have previously theorized based on circumstantial evidence:

This bullet may indeed be particularly susceptible to reacting badly to transonic disturbances. Look at the circumstantial evidence so far:

- My Labradar says it cuts through the local (eleveation 3000 ft) speed of sound of 1130 fps at about 125 yards. "Coincidentally", it sharps with tremendous accuracy at 100 meters, but then failed to group by 150 meters.

- You guys saw it wobbling on its way to the 300 to 350 yards but then stabilizing

- Using an online calculator that estimates BC based upon speed of a bullet at 2 different distances from the muzzle, I have found that the BC of this bullet VARIES with its muzzle velocity: LOWER MV gives HIGHER BC, and HIGHER MV gives LOWER BC. So, your low 1100 fps muzzle velocity gives this bullet a relatively very high BC which means it takes LONGER for it to get to a low enough velocity to escape from the transonic effects (which sort of peak around the local speed of sound and fade slowly as the velocity either increases above or below the speed of sound.

- An online ballistics calculator that provides, among other things, the estimated velocity at specific ranges, says that a bullet woth the physical characteristics of this bullet will hit a velocity of about 950 fps at about 300 to 350 yards. At that 950 fps velocity, yes, I would expect transonic disturbances to become rather small or insufficient to "buffet" the bullet. Is that maybe why you observed it recovering stability at that range of 300 to 350 yards?

- You and I both noting that the bullet requires seating into the rifling to get better results (better, but still not great) makes sense if indeed marginal stability is the issue, because seating into the rifling gives the bullet a more stable "start" than a jump to the rifling does. This is why my rnage results were BETTER yesterday with the bullet seated into the rifling, but still not sufficient.

One way to test this "instability" theory would be to launch the bullet at a high enough muzzle velocity to keep it out of the transonic speed zone to at least the distance you want to shoot to. However, I cannot do that test with Accurate 5744, the only powder I have for this cartridge. None of the load tables I have found goes above 28.0g for a CAST bullet if needing to maintain Trapdoor pressures AND keeping velocities low enough to prevent leading of the barrel. The combination of the safety issues, the leading issues, and the recoil issues put such a test outside my sphere of comfort.

So, again, I am led to the conclusion that this bullet, like the Lyman "bulbuous" bullet, appear to be unsuitable for my objectives.

Jim G

I have and continue to push engagement of cast boolits into the lands. The reason is that cast has no ability to resist bullet deformation when jumped. Each bullet would deform differently based on how they made initial contact with the lands.

 

[JimGnitecki]

I have and continue to push engagement of cast boolits into the lands. The reason is that cast has no ability to resist bullet deformation when jumped. Each bullet would deform differently based on how they made initial contact with the lands.

Sounds reasonable when I think about it.

Jim G

 

[jmorris]

It was a very complicated session to manage,

One of the most helpful tools I have in this area is fairly new to me but really is a game changer, eliminating wasted time as well as recovering the information later, it’s the shotmarker system.

Its intended to be used for scoring at matches, there are hundreds of different targets to choose from and you just calibrate where the actual center of the target is in the frame to the target image you matched with it.


When the bullet passes (must be super sonic) the location of its passing is calculated and sent back to a tablet you have at the bench with you. It numbers your shots, records down range velocity for each as well. It really eliminates the need to go down range as long as you don’t shoot out your aim point. If you want a “new target”, just save the old one and a fresh screen pops up.



Makes it super easy to go back and see what you did and you can export the data file if needed.

 

[JimGnitecki]

One of the most helpful tools I have in this area is fairly new to me but really is a game changer, eliminating wasted time as well as recovering the information later, it’s the shotmarker system.

Its intended to be used for scoring at matches, there are hundreds of different targets to choose from and you just calibrate where the actual center of the target is in the frame to the target image you matched with it.

View attachment 1171709
When the bullet passes (must be super sonic) the location of its passing is calculated and sent back to a tablet you have at the bench with you. It numbers your shots, records down range velocity for each as well. It really eliminates the need to go down range as long as you don’t shoot out your aim point. If you want a “new target”, just save the old one and a fresh screen pops up.

View attachment 1171710

Makes it super easy to go back and see what you did and you can export the data file if needed.

Yes, my best friend has this target system. And the club he belongs to uses a fleet of them, some owned by both the club and others by individual members, for its matches. It is VERY impressive and reduces a lot of time, work, and error. The cost is not that bad either, and it was designed and is being sold by a Canadian shooter. I have been considering getting one, but there are currently as-yet unsolved impediments for me:

- Cost obviously. It's over $1000 for the basic kit to which you need to add your own "target structure" - the frame to which you attach the sensors, black box, etc - and the REAL cost of that target structure gets pretty high if done right.

- The target structure must be large enough to enable the 4 sensors at each corner of it creating at LEAST a 48" x 48" physical array. Anyhting smaller introduces significant errors in the actual reported shot locations, due to the way the system works. This is a serious obstacle for me, as only one of our family vehicles (Ford Maverick pickup) could transport such a structure, even if it folds up (as my friend's one does), and that vehicle is used pretty much daily by my wife. Our other vehicle is a Magnuson supercharged Camaro hotrod, and its cargo capacity, even with the joke-of-a-rear-seat folded down, is laughably inadequate to handle ANY design concept I have been able to visualize. Being restricted to using the truck to go to the range would not work logistically at all well.

- As you pointed out, the system only works with supersonic bullets, so it would work with my 6.5 Creedmoor PGW rifle (2750 fps) and my 9mm handgun (1350 fps). It would definitely NOT be usable at all with my Cowboy Action shooting where the rifle and handguns are all subsonic. Most importantly, it would not work with my 45-70 Pedersoli Sharps replica at the very ranges where it would be most useful, since long rnages with that rifle require a 500g or heavier bullet that starts out supersonic but is subsonic by the time it gets to the ranges of interest.

- In addition, my friend tells me that the system requires the bullets to be traveling within a few degrees of horizontal, in order to detect them properly. The trajectories of 45-70 buffalo rifle bullets won't fit within that restriction.

For me, some sort of target camera system that can transmit a target image of suitable resolution might be far more practical. Something like a "trail camera" but with very SIGNIFICANTLY better image resolution seems like a conceptual starting point. Such a system would have the signfiicant advantages of compact size, light weight, and universal usability for ALL my shooting. But it would lack the instant group analysis that the Shotmarker system offers.

I really have not yet figured out how to move ahead on a better target system than my current one, which consists of two target arrays, each 24" wide by 40" high, consisting of inexpensive lightweight corrugated plastic sign material from Lowes, held together and upright by 5/32" steel rods run THROUGH the corrugated panels, backed by a 48" high piece of cheap wooden lath on each side, and supported by quick-folding 2x4 wooden stands:



Each "frame" when setup holds EIGHT 8.5" x 11" paper targets, or fewer larger targets for longer ranges. With the 8 letter size targets on each frame, I can fire 8 x 2 = 16 groups of shots without having to walk down range, These are very lightweight (I actually use some of my wife's weightlifting weights as ballast in windy conditions), they are very inexpensive, have very easily replaceable individual components when damaged, andthey actually fit inside the supercharged hotrod:



The unusual combination of Pedersoli Sharps replica with Leatherwood Hi-Lux semi-authentic 1870s full length telescopic sight, resting for ladder testing on a Rempel bipod, Labradar capturing the bullet velocities, spotting scope on tripod, the 2 magical unfolding target systems, and the sleeper white supercharged 650 hp hotrod with lipstick red leather interior, draws a lot of curious looks at the range.

The other day, the Royal Canadian Mounted Police (our Canadian national police force) were at the range at the same time, practicing with their full auto suppressed weapons, while I was trying to get the buffalo rifle to finally group at 150 meters. So the contrasts were particularly vivid that day.

Jim G

 

[jmorris]

Cost obviously. It's over $1000 for the basic kit to which you need to add your own "target structure" - the frame to which you attach the sensors, black box, etc - and the REAL cost of that target structure gets pretty high if done right.

- The target structure must be large enough to enable the 4 sensors at each corner of it creating at LEAST a 48" x 48" physical array. Anyhting smaller introduces significant errors in the actual reported shot locations, due to the way the system works. This is a serious obstacle for me, as only one of our family vehicles (Ford Maverick pickup)

They are a couple hundred bucks cheaper than that.

ShotMarker One

Price in USD. Production lead time ~12-16 weeks. This package includes everything you need to set up a ShotMarker system with one target frame. Access Point Sensor Hub Cable Pack 4 Sensors with Brackets 2 Calibration Targets Carrying Case User Manual

autotrickler.com

Big frames, you have to haul around is an issue for sure but not one that can’t be over come. This 8x8 one breaks down so I can haul it in the mule.



Pitch and yaw are also recorded for each shot.



If you need to adjust you can quantify in the field how much and in what direction.



I made it as simple as I could, I did machine the ends of the box tube to ensure identical lengths and square ends. 1/4-20 thread inserts mean I only need a 7/16 nut driver for the 4 bolts that assemble the frame.



How far out does you load stay super?

 

[JimGnitecki]

They are a couple hundred bucks cheaper than that.

ShotMarker One

Price in USD. Production lead time ~12-16 weeks. This package includes everything you need to set up a ShotMarker system with one target frame. Access Point Sensor Hub Cable Pack 4 Sensors with Brackets 2 Calibration Targets Carrying Case User Manual

autotrickler.com

Big frames, you have to haul around is an issue for sure but not one that can’t be over come. This 8x8 one breaks down so I can haul it in the mule.

View attachment 1171728

Pitch and yaw are also recorded for each shot.

View attachment 1171727

If you need to adjust you can quantify in the field how much and in what direction.

View attachment 1171736

I made it as simple as I could, I did machine the ends of the box tube to ensure identical lengths and square ends. 1/4-20 thread inserts mean I only need a 7/16 nut driver for the 4 bolts that assemble the frame.View attachment 1171737

View attachment 1171726

How far out does you load stay super?

Thanks for the good ideas, jmorris. Your frame looks well thought out. My 45-70 heavy bullet handloads VARY in how far out they stay supersonic, depending upon ballistic coefficient AND muzzle velocity in TWO interacting ways:

1. Higher muzzle velocity normally means the bullet can stay supersonic longer

BUT

2. The Ballistic coefficient DROPS for the heavy cast bullets as their muzzle velocity is increased!

This means each handload will have a different distance it can go before dropping below the speed of sound. And of course, the transonic effects, and the BC chnages are occurring simultaneously. But the drop to subsonic speeds is pretty quick with a heavy 45-70 cast bullet.

The loads I have tried so far , per the Labradar, formally drop through the 1120 fps local speed of sound at about 125 yards! It's hard to imagine the Shotmakrer system detecting most 45-70 cast loads at any meaningfully long ranges.

My HOTTEST load so far, 27.0g of 5744, which is only 1 grain below laod table maximum, starts with a muzzle velocity of 1376, and its chart of distance versus velocity looks like this:



(edited to better show 1100 fps velocity and 600 yard desired range) Hmm. since the BC will continue to reduce, MIGHT actually still be supersonic at 500 yards?? The Labradar is limited tom only the 150 yards maximum, even with this very large bullet, so I have no way of measuring velocity past that.

Jim G

 

[Blue68f100]

I've used wifi video cameras to view targets in the past, 200 & 300 yrds. Just need to add a beam antenna to the camera and setup using adhoc network to your phone or tablet. Most all my cameras are 12vdc, so small 12vdc batteries works well and solar chargers if you want to leave the camera setup. Even some of the game cameras using cel service may work if you have a way to remote trigger the camera after each shot.

 

[JimGnitecki]

I've used wifi video cameras to view targets in the past, 200 & 300 yrds. Just need to add a beam antenna to the camera and setup using adhoc network to your phone or tablet. Most all my cameras are 12vdc, so small 12vdc batteries works well and solar chargers if you want to leave the camera setup. Even some of the game cameras using cel service may work if you have a way to remote trigger the camera after each shot.

The camera idea merits further research to see what is available, at what cost, and what capabilities!

Jim G

 

[JimGnitecki]

Anyone out there who has a Shotmarker system AND a 45-70 buffalo rifle AND bullets in the 475 to 525g weight rnage who could try a test to see if the Shotmarker will see the bullet at long ranges, like 400, 500, and 600 yards?

Jim G

 

[MEHavey]

Shotmarker doesn't "see" the bullet like Labradar,
Rather, it senses the supersonic shockwave passage
right there at the target.

If subsonic... No-see-um.

A traditional 535gr Postell bullet starting out at 1,500fps (which is hauling a$$), goes subsonic ~300yds
A 405 starting at 1600 may stay super to 350.

 

[JimGnitecki]

Shotmarker doesn't "see" the bullet like Labradar,
Rather, it senses the supersonic shockwave passage
right there at the target.

If subsonic... No-see-um.

A traditional 535gr Postell bullet starting out at 1,500fps (which is hauling a$$), goes subsonic ~300yds
A 405 starting at 1600 may stay super to 350.

I don't know about that! Take another look at my graph in posting no. 14 above. See that reduction in BC that starts to occur when the bullet eaches 150 yards? (See the little "upward hook" in the shape right after that? And, as the speed decreases, the BC also CONTINUES to improve. Hard to believe that line will touch 1120 fps by 300 yards. I'd predict maybe quite a ways beyond 300 yards.

And this bullet has a lower BC claim from lee than the other Lee mold I just snapped up when Western Metal here in Alberta, Canada offered it at $37 CAN + $20 shipping + tax = $59 CAN = $43 US delivered at the current currency exchange rate (including the mold handle):



I grabbed it online yesterday morning and Canada Post delievered it this morning.

THIS bullet claims a signficiantly higher BC than the one in my graph. Hmmm . . .

I would have preferred a single cavity version, but Lee only offers this mold in 2-cavity configuration. At $59 delivered, it would be foolish to not at least try it.

Jim G

 

[JimGnitecki]

Shotmarker doesn't "see" the bullet like Labradar,
Rather, it senses the supersonic shockwave passage
right there at the target.

If subsonic... No-see-um.
. . .

Does the supersonic shock wave it sees occur, literally, only at or above the local speed of sound, or can the Shotmarker detect a transonic effect? (Transonic effects occur over a RANGE of velocities, not just at the exact local speed of sound)

Jim G

 

[Blue68f100]

The camera idea merits further research to see what is available, at what cost, and what capabilities!

Jim G

Small bullet surveillance cameras are pretty cheap these days. You will need the external directional antenna and a small battery source. Then you need knowledge on setting up a Adhoc network between the 2 devices. Kind of like having a high power spotting scope via wifi. There is a commercial system made for doing this but they want way too much $$$ for it.

 

[MEHavey]

I'm running QuickLoad/QuickTarget for downrange ballistics for these kind of exercises.

FWIW: my 2-velocity LABRADAR-measured 1,100fps@muzzle subsonic BC for the Lyman 457125 520gr (soft 30-1) ... is 0.445 actual.
It ain't gonna get better than that the faster it goes. But I'll pretend:
0.445 starting at 1,500fps and slower.

The ballistics show it hitting subsonic at 375 yards after starting at 1,500




Wither that Lee 459-500-3R you may stay super to 350/375, but I'd very much doubt over 400.

,

 

[JimGnitecki]

I'm running QuickLoad/QuickTarget for downrange ballistics for these kind of exercises.

FWIW: my 2-velocity LABRADAR-measured 1,100fps@muzzle subsonic BC for the Lyman 457125 520gr (soft 30-1) ... is 0.445 actual.
It ain't gonna get better than that the faster it goes. But I'll pretend:
0.445 starting at 1,500fps and slower.

The ballistics show it hitting subsonic at 375 yards after starting at 1,500




Wither that Lee 459-500-3R you may stay super to 350/375, but I'd very much doubt over 400.

,

Thanks for the useful data, MEHavey!

Jim G

 

[JimGnitecki]

Small bullet surveillance cameras are pretty cheap these days. You will need the external directional antenna and a small battery source. Then you need knowledge on setting up a Adhoc network between the 2 devices. Kind of like having a high power spotting scope via wifi. There is a commercial system made for doing this but they want way too much $$$ for it.

I knoiw how to USE local networks, but have no expertise at all in setting one up without its own provided app. I'll have to see what what systems might be offered in the marketplace.

I got a free Security camera system from Amazon a few months ago to test. It was a 120v plug-in powered unit that I set up in my garage. It reacts to movement, takes 1060P video, and transmits it to my iPhone in the house. But, it de4pends upon my home wifi. It retails for under $100 Canadian.

Jim G

 

[Blue68f100]

I knoiw how to USE local networks, but have no expertise at all in setting one up without its own provided app. I'll have to see what what systems might be offered in the marketplace.

I got a free Security camera system from Amazon a few months ago to test. It was a 120v plug-in powered unit that I set up in my garage. It reacts to movement, takes 1060P video, and transmits it to my iPhone in the house. But, it de4pends upon my home wifi. It retails for under $100 Canadian.

Jim G

Go into the wifi setting on the camera and see if adhoc is a option? Also look at the ac pack to see if it's outputting 12vdc. Most night vision cameras use 12vdc. If it does not have adhoc option you can use a AP as a repeater to extend the distance.