Gentlemen, lend me your knowledge. (Very long winded 300blk content)

Status
Not open for further replies.

Trashyshoots

Member
Joined
Jul 12, 2019
Messages
598
Going to post this here due to being a longer range 300blk question.

First of all, let me start by thanking this forum, I have lurked for a long while, and soaked up a lot of great information that has helped me.


I would like to test a few theories about my next build im considering in the quest of a 1000 yard pistol. Yes, pistol.


I will also take this time to apologize, because I over explain things, and I am long winded, while not being particularly interesting.


I have been into long range pistol shooting since I was young but have only gotten serious about it in the last few years. I have dabbled in precision shooting, but my heart lies with handguns. I have been known to terrorize my local blm shooting ranges with 357s out to 400+ yards, but quickly became tired of the front sight covering the target due to elevation and the mechanical accuracy limits of revolvers themselves, also as (my) luck would have it, my favorite revolvers having issues unusually unheard of (for these particular models), putting them out of commission for months. However, this post isn't about 686 locking mechanisms turning revolvers into loaded paperweights or gp100s with bent pawls and cracked forcing cones(all with factory 158gr ammo I didnt reload then), its about the journey and theory. (Protip NEVER buy "run of the mill" revolvers used)


I knew rifles were vastly superior in terms of accuracy, but I'm stubborn. Thankfully there were guns out there that were tempting. Remington xp100s were always an answer, but typically out of my budget and the 223 models having 1:12 twists weren't ideal for heavier 223 loads. I even went so far as to consider a ground up build of a bolt action pistol, using something like a kelby action, but again, way out of the budget.


And then the answer hit me. A contender build. The frames were affordable and there were plenty of custom barrel makers that would help me out in my quest of long range pistol shooting out to 500 yards.


I bought a frame, and had a trigger job done, I also spec'd out two barrels, one in 22lr match (I'm not anywhere near rich so I shoot .22s 95% of the time) and a 12 inch 223 barrel with built in muzzle brake (more on that later) and a 1:7 twist to stabilize 80gr bullets or higher.


Both barrels are incredible, they both will print sub moa groups rested at 100 yards (I'm tickled pink about my 22lr barrel being that accurate) the 223 has made those 400+ yard shots on steel almost easy. Crosshairs are much better than bulky sights for distance shooting, and instead of aiming 12ft over the target, its just down to the next notch in the scope when zeroed @ 100.



But there are negatives to it.

1. The concussion is outrageous

A 12 inch 223 barrel with a muzzlebrake might not have been the best idea. Its unpleasant to shoot groups with and actually target practice with. Outside of about 50 rounds spaced out in groups of 5, it's honestly too rowdy.


2. I now have access to 1,000 yards on blm land that I learned about through mutual friends. And I'm worried the 223 will get pushed by wind, and I'm worried about the transonic instabilites. And that concussion is just too much to hone my skills further. I tried it a few times at a 24x24 plate and was having a lot of issues.


So need less to say, I've been on a search for a new caliber, and I think I've come to a conclusion but its based on a lot of theories I need help with. I thought about a 38 special, 357 mag, 357 max, 44 mag, 45acp, 9mm, 40s&w, 10mm and 9x25 dillon, but ruled them out due to awful ballistic coefficients, I thought about 6.5 grendel, 224 valkyrie, and even considered an encore in 308, but recoil, concussion and my desire for a short barrel (I like to offhand pistols not just rest them) ruled them out. And then it hit me. 300blk shooting subsonics


Heres my idea and reasoning behind it, and theories.


Subsonic: so that dreaded concussion will be reduced (this barrel will not have a muzzlebrake), and no worries about the round going transsonic and "wobbling" if it starts subsonic. Also checking ballistic calculators it seems to retain quite a bit of energy.

Recoil: should be very manageable in a 5+ pound pistol. My personal recoil limit is hot 44 mags, I'm willing to bet heavy 300blks are less recoil than normal 44 mags

Short barrel efficiency: I have read subsonic 300blk is most efficient in shorter barrels.

Wind resistance: heavy 30 cals have ballistic coefficients smaller calibers dream about. Especially at "pistol" speeds, I know that the looong flight time gives wind more of a chance to mess with trajectory, but the weight and coefficient, seem to help a ton vs punching in 80gr 223s

Ammo availability: a non issue since I reload, but its always a nice option for informal plinking with the family.

And 30 cal holes are just easier to see on paper.


So heres the plan for the next barrel

12 inches to get 230-250 gr bullets up to speed with out pressure issues, and to keep things matching, my other barrels are 12 inches.

1:7 twist, for stabilizing those heavy pigs. I think mgm used to offer 6.5 twist for 300blk, so if they can still do that twist thats also an option.

No muzzlebrake (learned my lesson)

Full bull, no contour.

Built on 6 inch 20moa rail


Ontop of said barrel an ivey 200moa base. I like to shoot from 100 yards on out, so I dont want to go with fixed rails, even though, I know theyre "better"


And scope choices I have many handgun and rifle scopes in drawers. It will probably get an swfa fixed 10x42HD. The way I hold pistols makes rifle scopes work.


Is there anything in my thinking thats completely wrong? I know its outlandish, but it all seems sound as individual theories. I know my powder throws will have to be perfect (trickler ftw) I know that my drops will be upwards of 170moa, and wind will effect it more than if it was cruisin supersonic, but I feel like I've thought of it all. If im wrong somewhere, or haven't considered something please, let me know.
 
I have a Remington 22lr pistol my father acquired in the 70's and I enjoy shooting it at 100yrds and the wind messes with it, I also have a TC in 223 that is a moa shooter at 100 with lighter bullets. Basically the extra muzzle velocity makes the 223 one I would shoot out to 2 or 300yrds I can't imagine trying for 1000yrds, I think the subsonic speed will make it more of a 300-500yrd than a 1000
 
I really think you are highly under estimating the amount of drop that a 220g .308 bullet is going to have at 1,000 yards when fired at roughly 1,000 fps. I mean you are talking about a drop of over 158 FEET.

View attachment 849929

Agree with @beeenbag. Even with one of the highest BC bullets (210 gr. SMK @ .645 BC @ 1,000fps with rifle zeroed at 300 yards) the drop would be 1,500+ inches or 125 FEET.
 
Last edited:
Anything subsonic is going to be a mortar at 1000 yards. Flight time will be ~3 seconds.

Also, 300 BO is designed to compromise EVERYTHING in the interests of AR action compatibility.

This is not the cartridge you are looking for.
 
I know 44 mag has been used as far as 600. Elmer Keith claims to have hit and finished off a deer at 600 yards for a client who wounded it and was out of ammo for his rifle. Bob Munden duplicated the shot to prove it could be done.



Jerry Miculek did 1000 yards with a 9mm. I'm not a 300 BO fan, but if a 9mm can do it, the 300 can.

 
I really think you are highly under estimating the amount of drop that a 220g .308 bullet is going to have at 1,000 yards when fired at roughly 1,000 fps. I mean you are talking about a drop of over 158 FEET.

View attachment 849929

I have thought of that, I have an ivey 200moa adjustable base on its way. Worst case scenario, my cousin will buy it off me for creedmoor shots out past 1 mile, or I put it on a .22 rifle and see what I can do vs the wind



https://precisionrifleblog.com/2018/08/05/extreme-long-range-tips-optics-mounts/
 

Attachments

  • Ivey-Rings-Adjustable-Scope-Mount-645x475.jpg
    Ivey-Rings-Adjustable-Scope-Mount-645x475.jpg
    38.9 KB · Views: 7
Yes, it will have a lot of drop. So what? That is what the knob on top of the scope, the spots on the bottom crosshair, and slanted bases are for.

Berger says their 215 gr Hybrid at 1050 fps will arrive at 1000 yards at 836 fps, stability 2.16 where 1.5 is adequate.
 
Call MGM and have a new 14" non brake .223 barrel made for your heavier bullets.

Or step up to a G2 frame and go w a higher pressure cartridge

iMHO the Encore frame is just too big/ clunky.

Another option would be a Savage Striker bolt rig. Think they headapace w barrel nut like the rifles.
 
My dad has a 7mm 08 for IHMSA. My daughter likes shooting it w the brake closed ( striker )

While any handgun is mean on thw ears....muffs were good enough for my .223 old style Contender and non brake 14" bbl wasnt blasty.

My peference is Contender. Less bulky. Since i like the old style....am limited in cartridge.

Oh well. Currently have 35 rem Super 14. Its a hoot.


Want to shoot long range? Proly run an angled base and rifle scope. Which will limit cartridge selection. Some guys run magnums so equipped....but theyre braked.

Long D and subsonic? Never tried it and wouldnt. Maybe im FOS....but that sounds like making square tires for your truck.
 
@Jim Watson
I plan on hopefully building a load in the 230 range, either berger, smk, or hornady. I wouldn't be opposed to even trying hornadys 250gr atip. If it works price be hecked.

@Hookeye
I currently have a g2 contender, I was considering an encore in 308, but muzzle blast and recoil are 2 things I would like to avoid.

Here she is running a reddot for upsetting the AR boys at the local desert spot.
 

Attachments

  • IMG_20190701_182359_280.jpg
    IMG_20190701_182359_280.jpg
    119.2 KB · Views: 21
60* from what?
People toss around "mortar" but the angle is not severe.
Dan Theodore MEASURED the angle of a .45 BPCR, probably a .45-110, as 4.5 degrees at 1000 yards.

Which brings up a question, how do you know where you are hitting at long range in unimproved land?
 
60* from what?
People toss around "mortar" but the angle is not severe.
Dan Theodore MEASURED the angle of a .45 BPCR, probably a .45-110, as 4.5 degrees at 1000 yards.

Which brings up a question, how do you know where you are hitting at long range in unimproved land?

I was saying it more in jest, but by my calculations there is a 35 foot drop from 900-1000 yards (.645BC, 210gr., 1,000 fps muzzle velocity, no wind) so based on my calculations thats about a 11.66% angle (35' / 300' = 0.116666 or 11.6%). The angle would actually be slightly greater than 11.6% as I was taking in account the last 100 yards. If one were to measure the last 10' of distance versus altitude loss it would be a greater angle, albeit not a big difference.

I would think it would be noticeable on paper as a slight elongated hole.

It's a worthy endeavor the OP is on, just wanted to make sure he knew the ballistics, as I don't know him from Adam and what his experience is; it seems like he is experienced in the matter enough to make the decision to attempt it.
 
Last edited:
Too bad Hornady dropped the 180 gr single shot pistol bullet. Wonder how that would work in a . 357 max
 
I shoot the wussy Leverevolution 200gr in my Super 14 .35 rem.

There is a range not too far..,that goes yo 700. Have yet to try that cartidge out past 150. Might be fun
 
I was saying it more in jest, but by my calculations there is a 35 foot drop from 900-1000 yards (.645BC, 210gr., 1,000 fps muzzle velocity, no wind) so based on my calculations thats about a 11.66% angle (35' / 300' = 0.116666 or 11.6%). The angle would actually be slightly greater than 11.6% as I was taking in account the last 100 yards. If one were to measure the last 10' of distance versus altitude loss it would be a greater angle, albeit not a big difference.i

11.6% slope is 6.6 degrees.

I am surprised it is that steep.
That .45 BP was probably doing 1450 fps with cast elliptical nose bullet. Just goes to show mass and speed count.
 
@<*(((><
Paper will be out to 300 yards, past that steel plates. At 1k im hoping to get a 24x24 steel plate.

@Hookeye
357 max was definitely considered for this wild ride, unfortunately the bc and supersonic retention wasnt there for that cartridge.

If I was a hunter, outside of popcans and clays I would use a 357 max. Perfect for Arizona medium game.
 
Well people shoot 1000 yards with black powder 45-70's all the time so it can certainly be done with a 300 blackout, but yeah there are much better solutions than a 300 blackout at least in the ballistics department. I would honestly be amazed if you could hit a 24 x 24 plate at that distance with any repeat-ability, but it would be super cool if you could.

I did some rough math and at that distance the bullet is going to be on like a 7 degree downward trajectory so it will be dropping 2 feet every 5 yards
A 10 FPS spread in muzzle velocity will have nearly 3 feet of vertical dispersion
A 1 mph change in wind speed will be 10" difference in drift
 
Last edited:
Which is why BPCR shooters go to great lengths to minimize velocity variation. Single digit spreads are feasible.
The OP will have to strive for similar consistency.

And he needs a bigger target.
The NRA LR target has a 20" ten ring in a 44" black which covers 8, 9, and 10 rings on a six foot backer.

And some way to spot his shots. A good spotting scope will see bullet splash on a freshly painted plate at 500m - 600 yds. I doubt at 1000. But I have seen great claims, maybe there are better ones to be had.
 
@Jim Watson
@someguy2800
Absolute perfection in reloading will be critical. Counting powder granules is in my future. Haha. And yes I will probably need a larger target, at least vertically. Spotting scopes or target cameras are another venture I need to delve into, but for the time being I'm checking that my theories are correct. Im going to go halvsies in on a spotting scope and or camera set up.
 
Status
Not open for further replies.
Back
Top