Differences in Recoil but Same Bullet Weight

[Rule3]

Again, I asked what other factors if any could cause it, besides velocity. I wasn't looking for a definitive answer to what did cause it, only if other variables existed of which I was not aware. I'm struggling to understand why that is such a hard concept. Could it have been velocity? Sure. I never said it couldn't be the reason. But that's not the answer to my question, because my question specifically excluded velocity.

For a short quick down and dirty answer to you question of:

"Now I didn't chronograph these rounds, but I felt an obvious increase in recoil with my reloads to the DT ammo. And I'm wondering, other than velocity, what could cause that? Different powders, jacketed vs coated lead, or something else?"

Yes, different powders CAN make a difference if everything else is exactly the same. different bullet composition maybe sort of ,a little but that is pretty minor, of course it can always be SOMETHING else. If someone can "feel" the difference between a coated lead bullet and aFMJ then they must be a ZEN master or Jedi.
But again it is is perceived or felt recoil not necessarily ACTUAL recoil.

Kinda like the song "More than a Feeling"

 

[murf]

finally got the second test done: ruger blackhawk new model 357 magnum, 158 gn lrnfp bullet, cci 500 primer, 1.590" col, no crimp except to take the bell out (there is no cannelure on this bullet), 15.7 grains of h4227, 8.4 grains of longshot, both loads chrony @ 1180 fps.

same blind test only this time the rounds were single loaded to prevent bullet pull (tested this later on and found no change in col). my friend said the h227 load rolled a bit more in ihis hand, but the recoil wasn't much more than the longshot load. i noticed a slight increase in felt recoil when i shot a couple rounds. note: we shoot heavy loads in handguns and that may skew our opinions. we like recoil!

conclusion: my friend and i can't tell a difference in recoil with the two grain diff load. my friend and i can definitely tell the difference in recoil with the seven grain diff load. i also think the change in recoil with the seven grain diff load is not what the op felt. of course, only a chronograph can tell for sure!

murf

 

[murf]

finally got the second test done: ruger blackhawk new model 357 magnum, 158 gn lrnfp bullet, cci 500 primer, 1.590" col, no crimp except to take the bell out (there is no cannelure on this bullet), 15.7 grains of h4227, 8.4 grains of longshot, both loads chrony @ 1180 fps.

same blind test only this time the rounds were single loaded to prevent bullet pull (tested this later on and found no change in col). my friend said the h227 load rolled a bit more in ihis hand, but the recoil wasn't much more than the longshot load. i noticed a slight increase in felt recoil when i shot a couple rounds. note: we shoot heavy loads in handguns and that may skew our opinions. we like recoil!

conclusion: my friend and i can't tell a difference in recoil with the two grain diff load. my friend and i can definitely tell the difference in recoil with the seven grain diff load. i also think the change in recoil with the seven grain diff load is not what the op felt. of course, only a chronograph can tell for sure!

murf

update: i tested bullet pull on the longshot load with the 158 grain bullet w/o a cannelure. shot 5, pulled #6 and measured c.o.l.. result: .001" bullet pull. i can live with that and will be running another test using this load. thought you all might want to know that you can run bullets designed for autoloaders in a revolver and don't need a roll crimp. but check it first in your gun. all i did to this load was take the bell out.

murf

 

[buck460XVR]

Again, I asked what other factors if any could cause it, besides velocity. I wasn't looking for a definitive answer to what did cause it, only if other variables existed of which I was not aware. I'm struggling to understand why that is such a hard concept. Could it have been velocity? Sure. I never said it couldn't be the reason. But that's not the answer to my question, because my question specifically excluded velocity.

I'm struggling as to why you are so determined to exclude velocity even tho it is the obvious answer. As a reloader I am well aware that there is a myriad of reasons of why "felt" or "perceived" recoil can differ as well as "real" recoil. To many of us this is a relatively easy mystery to solve without grasping for straws. Ambient temps with temperature sensitive powders is one many folks disregard as is amount of crimp applied when using slow burning handgun powders. Same goes for low volume, position sensitive powders. But all of those contribute such a very small amount of change and most folks(especially those that would ask a question like this) would be hard pressed to notice. Same goes with the use of different powders. While flash and muzzle blast may contribute heavily to perceived recoil, it will add little to real recoil. While powder due to the charge weight can change real recoil, when one gets to upper end loads in small cases like .357, there is a very slight change in charge weights between those powders, that will give equal velocities. While companies like BB that produce boutique type ammo may use proprietary powders, recoil is not the reason......mainly it's velocity and cost. There are many variables of which you are not aware, mainly because you don't know the velocities of either load, nor do you know the type of powder used or the charge weight of the commercial ammo. Hard to give any good answer without knowing any of this....just WAGes.

 

[WrongHanded]

I'm struggling as to why you are so determined to exclude velocity even tho it is the obvious answer.

I don't have a chronograph. The reason I don't have a chronograph is because I have not had anywhere to use one (unless I spend a couple hours driving each time I want to use it). Therefore I cannot test velocities. But this does not mean that I have ruled velocity out as a possibility. All it means is that I asked those willing to reply to ignore velocity, exactly because it is the obvious answer. And I wanted to learn if/what other possibilities existed.

If I could have tested the loads, one of two possibilities would have come to be:

1. I would have found that my load was going faster (counter to the box and book data), which would explain the greater felt recoil. In which case I wouldn't have posted the OP.

2. I would have found the DT load was going faster, which lines up with the box and book data, but does not explain why my load had more felt recoil. In which case I would have posted the OP and included velocities. I suspects the only difference between this scenario and the current reality, is someone would be telling me the chronograph was faulty instead of saying it's velocity.

We can just let this thread die now, can't we?

 

[Rule3]

Send be a money order for the price of Double Tap .357 Mag 158gr "Bonded Defense" I will buy some and chronograph them for you. I will load what you loaded and submit the data collected.

 

[WrongHanded]

Send be a money order for the price of Double Tap .357 Mag 158gr "Bonded Defense" I will buy some and chronograph them for you. I will load what you loaded and submit the data collected.

As tempting as that sounds, I'm not sure it would be an accurate test. I'd have to send you my loads, and the remainder of the DT box, to be sure we got solid results. But as I've recently been offered the opportunity to shoot at a local private area, belonging to a work-friend's family, I'll be getting a chronograph in the new year. He actually offered because if this very thread, so that's good news.

 

[buck460XVR]

We can just let this thread die now, can't we?

Iffin you wish.

Be interesting to see what the manual where you got your load recipe from shows for potential velocity. From my data base(Alliant Powder), I see 1620 fps with a charge of 15.3 of 2400 under a 158 LSWC. That tells me that 14.5 could well be capable of producing 1400 fps or even more than the "claimed" velocity on the D.T. box flap. Again, we don't know exactly what either produces. Newton's law says for every action there is an equal and opposite reaction. IOWs the recoil from a 158 gr bullet going 1400FPS should be the same regardless of what powder is used.....except for the difference in weight of that powder. Iffin there was 4 gr difference in the charge weight, it would be about equal to a difference of 4 gr difference in bullet weight(mass of the ejected gas will be equal to the original mass of the propellant). Again, in a small case like .357, it's hard to get a huge difference in powder charge weights when resulting in the same velocity. Are there differences in felt recoil that may seem greater? Sure, and may very well be a contributing factor in what you felt. But IMHO, the difference you felt is from difference in velocity. Did you start lower and work up to this final load? Did you use check weights to confirm your scale/powder thrower was giving you exactly 14.5?

Before I had a chrono, I generally always took along some familiar factory ammo when working on a new load. This told me how relative the accuracy was to the known ammo, and also crudely, how the velocity compared via recoil. Once I got a chrono, many of my previous opinions changed as I discovered "stated velocities" on box flaps were about as accurate as reading tea leaves. The fact that most times those stated velocities were well below my chronoed velocities has since made me a little skeptical of any stated velocity. One of the other things I noticed, is that sometimes it took a very little increase in powder charge to make a significant increase in velocity, especially in small cases like .357. Sometimes the little bit of error I made when adjusting the powder thrower made a significant difference. Sometimes a increase in powder charge, while adding a lot of recoil, did little or nuttin' to increase velocity. One reason I stuck to under published max loads until I got a chrono....just to be safe.

I'm not trying to be critical or condescending. It's just that I'm an ardent fan of the KISS system(Keep It Simple Stupid) and so I generally go for the most obvious and relevant answer first. Could there be another reason other than why my jeep won't turn over other than a dead battery? Sure, but I'd be a fool to think it was something else until I checked the battery. Iffin your loads are safe, and your stated powder charge correct, why are you concerned with the recoil iffin velocity is not important? Is it that you suspect you loads may be too hot and without a chrono are looking for another reason your ammo recoils more than a high velocity boutique round? I ain't trying to dis you, just trying to help. Without knowing where you are coming from is like walking in the woods at night without a compass and overcast skies.

 

[WrongHanded]

@buck460XVR

My load data origins: Lyman 50th has no load data for a 158gr LSWC. Neither the ring binder paper cover book for .357 (I can't remember the name of those complications) or the Lee Modern Reloading 2nd Edition seem to have any data using 2400 for such a projectile. So I looked at the Lyman book data for 155gr lead, which maxed at somewhere around 15.5gr (I think), and the 160gr lead maxed at 14.0gr (but with lower stated pressure than other powders, or other .357 data). Then I went online and looked around some too. So there was really no one place I found the data originally. For as popular as 2400 appears to be in magnum handgun cartridges, I'd expect Alliant to have more published data. But they don't. However the Lyman Cast Bullet Handbook 4th Edition (which I subsequently purchased) does have a 158gr lead projectile. Though I can't remember the max charge from that manual, I do not believe 14.5gr is over it (I checked specigically).

Both Lyman manuals state they are using 4" universal receivers for all their testing. And no matter the bullets weight or powder, I don't recall loads recorded much over 1,350fps with Max charges of 2400. I'd have to check to confirm that of course.

Conversely, the DT ammo is claimed to run at 1,400fps from a 4.2" GP100 (which happened to be what I was shooting. Now I do carefully check my scales including zeroing them before each batch, and I also check every 10th cartridge as I'm loading. I know mymy Auto-Drum runs + or - 0.1grs, or there abouts. Now it is possible that the DT ammo is not running close to 1,400fps, and it's also possible that my load is over pressure some how. If either happened to a significant degree; or both happened to a lesser degree; I could see the velocities flip flop from what the numbers suggest. It could have gone that way.

So why am I concerned about the recoil? The original intent of my load was to somewhat simulate shooting ammo that I would carry, but without the cost of shooting that expensive ammo. I hadn't expected to work up a safe load that would give as much recoil as the boutique companies, and I'm not sure I see a point is dealing with more recoil for practice than I'd be subjected to if I need to use the gun and carry ammo in a defensive situation.

But then I thought, well perhaps the DT ammo is just going much slower than advertised. That's not good and not worth the money. Or what if load data aside, my load is somehow horribly overpressured. And then I started wondering if either of those things were really that likely, or if maybe I was missing some other factor.

I suppose the easiest thing to do is as you say, buy some other factory ammo and do a comparison.

Edited to add: I have no check weights for my scale. I did work the load up from 13.Xgrs.

 

[buck460XVR]

Many manuals limit the velocity of lead bullets due to leading issues at higher velocities. Because of limited space for recipes, many manuals limit those recipes to the ones that work the best, or ones they feel will be used by most folks. I'm a firm believer that iffin you can't find info for a particular bullet/powder combo from reputable sources....there's a reason. As for the credibility of DTs velocity claims, I see from their website that they claim 1750FPS from a 6" barrel. That's 350fps more from just 2 extra inches. I have a hard time getting 1750fps with my 20" carbine in .357. I also saw on their website that the bullet they are using in that load is indeed a 158 Speer GoldDot. Except they don;t call them GoldDots anymore, but DeepCurls, as to differentiate them as hunting bullets and not SD bullets like their other GoldDots. So IMHO, not only is their claim to velocity a tad misleading, but also is using a hunting bullet designed for deep penetration in medium to large game for SD ammo. So I agree with your conclusion that the ammo really is not worth the price of a buck a pop. Lot of other options out there that perform much better on two legged threats.

 

[WrongHanded]

I'm just going to say this in bold, so it won't be missed:

I was wrong!

No, I haven't checked velocities. But I just got home and decided to pull a bullet on one of these DT cartridges. It has ball power, and it weighed 15.7gr. Which means the excess recoil cannot be from the weight difference of powders. Therefore it seems very likely it is from velocity.

Then I double checked my Lyman 50th and Cast Bullet Handbook. I got that data I listed in my previous post a little mixed up, and I can't leave it out there without correcting myself.

The 160gr lead bullet with 2400 powder, has a max charge of 15.5gr. C.U.P. pressure is at 39,700, and the velocity from a 4" barrel is 1,344fps.

The 155gr lead bullet, has a max charge of only 14.0gr. The pressure is at 41,900 CUPs, with a velocity in a 4" barrel of 1,299fps.

So I swapped the charge weights of those two from the manual.

But here's what really surprised me. This Cast Bullet manual is new, so my load had already been worked up using other available data online (some of which was found on this forum). The 158gr lead bullet has a max charge of 13.5gr (which I misremember and claimed was over 14.5gr). A pressure of 40,800 CUPs, and a velocity of 1,275fps from a 4" barrel. The particular cast for this 158gr bullet is Lyman #358665. But that is not the same bullet as I am loading, purely from a visual inspection.

So could my load be overpressured and be running at a much higher velocity than I thought? It certainly seems possible.

 

[buck460XVR]

But here's what really surprised me. This Cast Bullet manual is new, so my load had already been worked up using other available data online (some of which was found on this forum).

The last part in bold, is a statement that scares me every time I read it. While these online forums are a great place to glean information and get advice, using recipes given by random posters without being able to verify it from a tested and published source is one way your last statement could be true......

So could my load be overpressured and be running at a much higher velocity than I thought? It certainly seems possible.

 

[WrongHanded]

The last part in bold, is a statement that scares me every time I read it. While these online forums are a great place to glean information and get advice, using recipes given by random posters without being able to verify it from a tested and published source is one way your last statement could be true......

I don't disagree. However, after 3 reloading manuals yielded no data for a 158gr LSWC with 2400, I resorted to asking for help (along with browsing the internet). I did receive some information with the appropriate "use at your own risk" cautioning. For such a popular powder and bullet weight, I was and still am amazed that data for this load is so difficult to find.

Anyhow, when I get a chance (and my chronograph), I'll test both loads and get some velocity data.