Jumping the crimp

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Dsiwy

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I have been trying my hardest to crimp 44mag Campro's so they dont jump the crimp during recoil and nothing I do solves the problem. The 6th round moves about .030" during recoil, no matter what crimp I use.

I am using

new 44mag Starline brass
campro 44mag 240
RCBS dies seating and crimp in two steps
HS6 powder with Mag primers
Tried the Redding profile, Lee FCD, Lee collect and RCBS roll crimp

I had the same issue with my 357mag and manage to bring the jump down to .006"

At this point am thinking its ether the brass or the campro bullets


Thoughts?
 
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If it's only 0.030" after 5 rounds why are you even worried? Heavy crimps wear out brass faster. If you have already tried different crimps the only thing you can really do is use a heavier gun... FWIW I have found the crimp groove on some campro bullets pretty useless, such as their .45 Colt bullet. I have't used the .44 offering but I would imagine it's the same. Are you sizing the new brass?
 
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B said:
If it's only 0.030" after 5 rounds why are you even worried? Heavy crimps wear out brass faster. If you have already tried different crimps the only thing you can really do is use a heavier gun... FWIW I have found the crimp groove on some campro bullets pretty useless, such as their .45 Colt bullet. I have't used the .44 offering but I would imagine it's the same. Are you sizing the new brass?
Click to expand...


Only worried about effects on accuracy and I don't know what the allowable amount of jump normal is. I am sizing the new brass too.
 
Dsiwy said:
Only worried about effects on accuracy and I don't know what the allowable amount of jump normal is. I am sizing the new brass too.
Click to expand...

Fair enough. Like the other guy said you could try the Lee FCD if you haven't already. I use it for everything I can and the only thing that still pulls bullets is my .454.
 
I think your right about the crimp groove being sallow on the Campro's. Might be time to spend the big bucks on some hornady jacketed bullets for Mag loads and same the Campro for 44spl loads.
 
What is the diameter of the expander, if the cases are being over expanded this also effects bullet grip.

M-typical.jpg


"M"-Provements On Lyman's "M" Die
https://www.beartoothbullets.com/print.php?itemnumber=39&table=tech_notes&type=Tech%20Notes
 
Dsiwy said:
Only worried about effects on accuracy and I don't know what the allowable amount of jump normal is. I am sizing the new brass too.
Click to expand...

I'm up to 5/8 of a turn down from contact on my Lee FCD and no more bullet walk even with max H110 loads. I have tried as little as a 1/4 turn but that turned out to be not enough as the loads got hotter. I had a few batches that didn't have enough crimp and the bullets would walk to the point where the cylinder wouldn't rotate for the 6th round. Pushed the bullet back with my finger, took the round out and reseated the bullet by hand and shot it first. At 1.600" COAL and 1.400" brass the crimp grabs right on the back edge of the cannelure.
 
I've given up on the RCBS die crimp feature.
Anything need'in krimp'in I buy a Lee crimp die.
Something I can see with me own eyes and wtf is go'in awn.
 
I just ordered a Lee 357 .003 undersized sizing die, Maybe the increase neck tension will help. I was going to order the 44mag one one it's not on the market yet according to Lee.

I will play around with the FCD some more and it is the better holding crimp "even though it looks rough"
 
dirtybarry said:
I'm up to 5/8 of a turn down from contact on my Lee FCD and no more bullet walk even with max H110 loads. I have tried as little as a 1/4 turn but that turned out to be not enough as the loads got hotter. I had a few batches that didn't have enough crimp and the bullets would walk to the point where the cylinder wouldn't rotate for the 6th round. Pushed the bullet back with my finger, took the round out and reseated the bullet by hand and shot it first. At 1.600" COAL and 1.400" brass the crimp grabs right on the back edge of the cannelure.
Click to expand...

Are you using Starline brass and campro bullets?
 
I'm sold on the Lee FCD for the .357, .44, and the .45 Auto. I load 325 gr hardcast WFNs over 20 grs of H-110 in the .44, so my concern is a bullet jumping the crimp and tying up the gun at an unfortunate moment. Although I haven't measured rounds that have had been exposed to 5 or more firings, I have examined them and no bullet slip is apparent, when compared to rounds that have been recently loaded. From the photo on the Compro site, the cannelure appears to be a bit narrow, this could probably be tweaked with a Corbin cannelure tool, or just choose a bullet that has a wider/deeper crimping groove.
 
Dsiwy said:
I just ordered a Lee 357 .003 undersized sizing die, Maybe the increase neck tension will help. I was going to order the 44mag one one it's not on the market yet according to Lee.

I will play around with the FCD some more and it is the better holding crimp "even though it looks rough"
Click to expand...

Two things reloaders seldom do, trim their pistol brass and anneal pistol brass.

The Lee undersize dies compensate for work hardened cases that springs back more after sizing.

And the Lee factory crimp die with the carbide ring in is base is a "cheat" for people who do not trim their brass. The carbide ring sizes the longer cases that bulge below the crimp.

The Lee undersized dies work well with pistol cases that headspace on the case mouth and increase bullet grip. But with hot loads in .357 and .44 magnums I would trim the cases to get uniform crimps.

Below the upper left picture shows a bulged crimp on a long case and why reloaders use the Lee FCD.

PqmgVOa.jpg
 
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Tagging thread for future reference,
As I have just received my components, also will be using starline brass with 240 campro bullets Dsiwy , so this thread will be relevant to me.

To be sure of what's happening, your 6th shot is 30 thou shorter than your first?
So to check this I would shoot 5 shots, empty cylinder, and see how much the 6th has shrunk in OAL?

Myself will be using the Lee collet die, I can feedback soon enough with my own results.
I presume power factor will have an impact, the bigger the bang the more the next bullets will seat in if not properly crimped.
 
MartyK2500 said:
Tagging thread for future reference,
As I have just received my components, also will be using starline brass with 240 campro bullets Dsiwy , so this thread will be relevant to me.

To be sure of what's happening, your 6th shot is 30 thou shorter than your first?
So to check this I would shoot 5 shots, empty cylinder, and see how much the 6th has shrunk in OAL?

Myself will be using the Lee collet die, I can feedback soon enough with my own results.
I presume power factor will have an impact, the bigger the bang the more the next bullets will seat in if not properly crimped.
Click to expand...

I measure the 6th round and mark it with black marker, then fire five and remeasure the 6th for bullet jump. The 6th round is + .030" longer after the 5 rounds were fired. On my 357 I managed to get the bullet creep of the 6th round to only .006", which is acceptable in my mind.

I tried the lee collect crimp die and found it no better than any other crimp I used.
 
bigedp51 said:
Two things reloaders seldom do, trim their pistol brass and anneal pistol brass.

The Lee undersize dies compensate for work hardened cases that springs back more after sizing.

And the Lee factory crimp die with the carbide ring in is base is a "cheat" for people who do not trim their brass. The carbide ring sizes the longer cases that bulge below the crimp.

The Lee undersized dies work well with pistol cases that headspace on the case mouth and increase bullet grip. But with hot loads in .357 and .44 magnums I would trim the cases to get uniform crimps.

Below the upper left picture shows a bulged crimp on a long case and why reloaders use the Lee FCD.

PqmgVOa.jpg
Click to expand...

Trimming the brass makes sence for roll crimping and I think am going to try that too.

Thanks for the tip.
 
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