bullets take a walk


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murf
March 3, 2012, 05:20 PM
thought i would share this experience i had today.

was shooting my 357 mag. blackhawk. the load was 125 xtps. the mv was about 1600 fps (very warm). anyway, i loaded five rounds but only shot two because the primer cup was flowing back into the firing pin hole and tying up the cylinder.

out of curiosity, i decided to measure the coal of the remaining three rounds in the cylinder. i figured that the bullets might have walked out a bit, due to the heavy recoil and the medium crimp applied to the rounds.

well, the original coal of the rounds (the ones still in the box) is 1.583". the coal of the three rounds i pulled from the cylinder are 1.589", 1.591" and 1.593".

that is quite a bit of walking! i'm going to re-crimp the rest of the rounds and see if that cures the problem. if not, i'll check the expander plug diameter on the sizing die.

anyway, i thought i'd pass this on for your enjoyment and amusement.

murf

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gamestalker
March 3, 2012, 05:44 PM
The amount of jump your experiencing, though worth addressing, is mild in comparison to what I've seen. I load exclusively with H110 and 296 for the magnum wheel guns, and I can tell you from experience that nothing less than a full roll crimp is the rule of thumb here. Over the years I've had a few that jumped completely out of the mouth, which locks the cylinder up real nice and tight. The reason for those intermitent moments of bullet jump, was the result of me thinking I could get by with just a taper crimp if done properly. Even though I managed the jump for the majority of rounds, I eventually got tired of having to watch my OAL's so I broke down and bought roll crimp dies.

Are the crimps still in the canelure?

murf
March 3, 2012, 05:54 PM
yup. they only jumped .010". the amazing thing, to me, was that i only fired two shots and the bullet only weighed 125 grains. this usually only happens to me with the heavy bullets. that's why i posted.

doesn't do much for accuracy when each round's coal is increasing .005" every shot!

murf

Josh45
March 3, 2012, 06:10 PM
I just bought some H110 with some 125 GR FP TMJ bullets I have. The only problem is they don't have a caanelure to set the roll crimp in. The area they used to be crimped in is heavy and if I did apply the crimp there, These rounds can and have before been set back from recoil.

After reading this, I am much more concerned about how to go about this. Shoot one at a time? or just crimp below the old crimp area as much as possible? But then that itself would dig into the bullet and would affect accuracy, Wouldn't it?

I'm asking this here because you mentioned H-110 already. Thank's for the tip about having to make sure it is a full crimp tho

murf
March 3, 2012, 07:23 PM
what weapon are you shooting these bullets out of?

do you have any other pistol powders available?

murf

Walkalong
March 3, 2012, 07:50 PM
Was the case mouth in the deepest part of the cannelure?

Josh45
March 3, 2012, 07:55 PM
The revolver I am going to be using is a Ruger GP-100 3 in
I have a few other powders available which I have already used but was interested in trying H-110.

gamestalker
March 3, 2012, 08:17 PM
Josh45,
It seems odd to me that you have bullets intended for the .357 mag. that don't have a canelure? What diameter are they? I'm just guessing, but I bet those FMJ's are for an auto loading cartridge / application. I can't imagine anyone manufacturing a bullet for a wheel gun, that doesn't have a canelure.

Be careful, bullets jumping out of the case can lead to mass detonation, which obviously leads to other bad stuff.

Walkalong
March 3, 2012, 08:30 PM
Josh45

Taper crimp the snot out of them, and see if it stops the backing out, as
and hope they can take that strong a taper crimp.

http://www.thehighroad.org/showpost.php?p=5942202&postcount=37

Josh45
March 3, 2012, 08:40 PM
Gamestalker,

these bullets are 125 GR TMJ by Speer. They was made for Lawman if I am not mistaken and they were bought from RMR last year. I think he still has some of them. I know it is odd to not have a cannelure for a bullet that goes to a wheel gun. I have shot them out of this gun before and have done fine.

The diameter of the bullet is .357

Walkalong,

That is what I was thinking. I have done a taper crimp on them before that nearly put a roll crimp into them. I have the 4 die set here and I believe that my FCD is roll crimp as is my seating/crimping die.

So I will just adjust just enough to get almost a roll crimp started.
Just like those pictures show is what i was thinking.

Walkalong
March 3, 2012, 08:47 PM
A roll crimp die will not do what the pic shows.

Josh45
March 3, 2012, 09:02 PM
Your right, It isn't a taper crimp die.
I just crimped another .357 a minute ago and it ended up doing a slight roll crimp.

BTW, Murf

I apologize for hijacking your thread. I did not mean to. I just thought it would be O.K to ask a quick question here seeing as it involved what i was going to use and what my concern was.

murf
March 3, 2012, 11:38 PM
no problem, josh. the op was intended to inform everyone of the risks of bullets walking out of the case and to invite anyone with this particular problem to voice their concern.

more power to ya!

murf

murf
March 4, 2012, 06:32 PM
update,

recrimped those 125xtps. loaded six, shot 5 and pulled the last round. did it twice.

measured the coal of the pulled rounds - 1.591" and 1.597" (unfired coal is 1.583").

even with the heaviest crimp i can apply, these rounds are walking out of the case. i guess i will have to measure the expander plug and see if it needs to be a bit smaller.

murf

yup, the expander plug measures .356". not enough to hold the .357" diameter of the xtp bullet. no wonder!

k9kev88
March 4, 2012, 06:42 PM
sorry, but I don't understand exactly what happened... I have been reloading for 9mm and just bought a GP-100 .357 that I intend to reload for soon. Sounds like a problem that I need to understand.

murf - are you saying that the recoil of the gun caused the other bullets to move in their casings (walking)? what makes this happen??

I'm trying to understand what the "walking" part is...

murf
March 4, 2012, 07:16 PM
another way of saying "coming out the end of the case due to recoil". usually happens with heavy recoiling loads shot in light weight revolvers. the last round fired in a revolver is subject to the recoil of the first five shots.

the cummulative effect of the recoils can pull the bullet out of the case. in the extreme case (no pun intended), the bullet will pull out far enough to stick out the end of the cylinder. this causes the cylinder to lock up when the exposed bullet hits the frame when the cylinder is rotated.

i'm having this problem and decided to share my "fix" of the problem. my fix is to call rcbs and see if they can sell me a .352" expander.

murf

k9kev88
March 4, 2012, 07:30 PM
another way of saying "coming out the end of the case due to recoil". usually happens with heavy recoiling loads shot in light weight revolvers. the last round fired in a revolver is subject to the recoil of the first five shots.

the cummulative effect of the recoils can pull the bullet out of the case. in the extreme case (no pun intended), the bullet will pull out far enough to stick out the end of the cylinder. this causes the cylinder to lock up when the exposed bullet hits the frame when the cylinder is rotated.

i'm having this problem and decided to share my "fix" of the problem. my fix is to call rcbs and see if they can sell me a .352" expander.

murf
thanks murf.

maybe I'll take a caliper with me when I go to shoot my first round of reloads!! :)

murf
March 4, 2012, 07:40 PM
couldn't hurt!

murf

beatledog7
March 4, 2012, 08:01 PM
Curious here. Read the thread and don't understand why walkalong was using a heavy taper crimp vice roll crimp in those pictures when the bullet has a cannelure.

murf
March 4, 2012, 08:21 PM
because josh45 bought some bullets without a canelure and wants to shoot them in a gp100. walkalong was just using that as an example of a taper crimp.

murf

Lost Sheep
March 4, 2012, 09:06 PM
yup. they only jumped .010". the amazing thing, to me, was that i only fired two shots and the bullet only weighed 125 grains. this usually only happens to me with the heavy bullets. that's why i posted.

doesn't do much for accuracy when each round's coal is increasing .005" every shot!

murf
How do you know the crimp jumping (or walking) is uniform? It is probable that the first impact of recoil causes greater movement than subsequent impacts. Typically, the first impact moves the bullet until the crimp groove seats into the crimp of the case. After that, it takes actual deformation of the case mouth metal (or the lead of the bullet) to get any more movement.

Invest in this experiment.

Make up or get 11 rounds (or 9 if you carry a 5-shot revolver) of what you will carry.

Mark one of the cartridges and put it in chamber #1.

Load the other chambers with the other cartridges.

Fire off all the other rounds, measuring the length of that #1 round after each discharge. Do not push the bullet back into the case at all.

At the end of the exercise, you have a round that has been subjected to 11 recoil impacts and a record of how much "walking" the bullet did against the crimp as the experiment continued.

If it hasn't jumped crimp by then, that round is OK. Probably all rounds from that manufacturer & load will be OK. If it advanced a little on the first discharge, and nothing in the 10 subsequent impacts, you are probably OK. If it advanced on every discharge and did not slow down toward the end, I would not carry that ammunition for defense, offense or competition.

Supposedly the crimp-jumping problem is worse with lighter guns and heavier bullets for the obvious reasons of Newtonian Physics. Your 125 grain slugs are a surprise to me as well.

Good luck and thanks for asking our advice

Lost Sheep

Walkalong
March 4, 2012, 09:16 PM
Read the thread and don't understand why walkalong was using a heavy taper crimp vice roll crimp in those pictures when the bullet has a cannelureThe bullet is a 125 Gr Powerbond. The "cannelure" is just roll marks with no real indention to crimp into. You could roll crimp into it, but it would damage the plating. The taper crimp will not. I have also played with a heavy taper crimp on jacketed bullets with a good cannelure, and it works, but I roll crimp with jacketed bullets with good cannelures.

walkalong was just using that as an example of a taper crimp.
Yep.

murf
March 4, 2012, 11:57 PM
lost sheep,

yes, i don't know the jump on each shot. but, i do know the jump after just two shots. i subsequently recrimped the rounds and subjected one round to five recoils (see post #14 above).

right now i'm not concerned about how much jump. i'm trying to find the cause so i can fix the problem. i think i found the answer (i. d. of sized case too big), but i will find out for sure after i get a smaller sizing plug for my die.

i'll post the results when i find out.

murf

Lost Sheep
March 5, 2012, 02:33 AM
lost sheep,

yes, i don't know the jump on each shot. but, i do know the jump after just two shots. i subsequently recrimped the rounds and subjected one round to five recoils (see post #14 above).

right now i'm not concerned about how much jump. i'm trying to find the cause so i can fix the problem. i think i found the answer (i. d. of sized case too big), but i will find out for sure after i get a smaller sizing plug for my die.

i'll post the results when i find out.

murf
Thanks, murf. I missed that detail in your post 14. .008" in 5 recoils and another .006" in the next 5. Progressing in the right direction, but still not a good sign. Something needs to be tighter. Your thought about a smaller expansion button is probably right on.

Lost Sheep

beatledog7
March 5, 2012, 11:59 AM
The bullet is a 125 Gr Powerbond. The "cannelure" is just roll marks with no real indention to crimp into. You could roll crimp into it, but it would damage the plating. The taper crimp will not.

Thanks. Your explanation makes sense, but it was not apparent (to me) from the photos.

ferges99
March 5, 2012, 01:27 PM
Why not just get the proper style bullet???

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