Jumping the crimp

[TGS]

I own a S&W 642-1. I originally chose Remington's 158gr LHP due to their very soft lead giving reliable expansion at snub velocities along with it's good penetration.

Frankly, they're friggin painful as hell to shoot and I'm looking at a lower recoil option for 1) pain and 2) faster follow up shots and 3) better barrier performance, all the while accuracy and having a decent POA/POI relationship. I'm looking at the .38 110gr DPX, but now I'm reading something I'm not too familiar with.....crimp jumping.

I've read on the interwebz that it's only a problem with extremely light wheelguns, like the AirLite/Ti variety, and I've read stuff that it happens to Airweights as well. I've read that it only happens to lead bullets due to a light crimp so as to not deform the bullet, but also read about jacketed bullets suffering. Finally, I've read that it's only a problem with heavy bullets, but others have reported it being a problem with 110gr bullets.

So what's the deal!? Will the 110gr DPX be susceptible to crimp jump in my 642?

[Tamara]

I've never shot the 110gr DPX in an Airweight, but I have put a fair amount of various 125gr +P JHP loads through my old 442 and never experienced any problems with it jumping crimp.

[Wheeler]

I can't recommend any particular brand over another. On my reloads that I shoot through my LCR I have a very heavy crimp. I have not seen any bullet deformation as a result of the crimping process. I've never heard of crimp jumping in the .38 lite-weights, only in the .357 magnums. Where did you get that information, if you don't mind me asking?

Have you considered a different set of grips vs an ammo change?

Wheeler

[NGCSUGrad09]

I've had Remington 125 JHP +P rounds jump in a 442. It wasn't too the point of inducing a malfunction as there are only 5 shots to the gun, but it nonetheless happened. I can't remember the specifics but I didn't fire a full cylinder and ejected a round or two and noticed it. That being said, I haven't had any issues with Winchester 125 +Ps, Speer Gold Dot 135+Ps or any target loads.

It seems Remington ammunition in general is consitantly sub par to other brands (not just .38s) in my experience. Unless it's free, find something else that works. Corbon shouldn't have any issues, but until you try with YOUR gun you won't know.

[TGS]

Thanks for the responses, guys.


I can't recommend any particular brand over another. On my reloads that I shoot through my LCR I have a very heavy crimp. I have not seen any bullet deformation as a result of the crimping process. I've never heard of crimp jumping in the .38 lite-weights, only in the .357 magnums. Where did you get that information, if you don't mind me asking?

Have you considered a different set of grips vs an ammo change?

Wheeler

Wheeler,

The information is from googling. There's tons of reports of crimp jumping out there. I couldn't find anything definitive, so I figured I'd ask here.

Different set of grips.....I bought a set of hogue bantam boot grips, however I believe the back-strap is still exposed which I didn't realize when ordering them. I haven't shot the gun with the new hogues yet, nor do I think they're going to help too much with the gun feeling like a firecracker went off in my hand. If I could afford the nice crimson trace grips with the covered backstrap, I'd probably just buy an LCR instead. I can't find any other covered backstrap grips which are boot grips.

I got the 642 used for $280, but I'd never shot one before and didn't realize how painful they are. I had shot an LCR and liked it, but the price on the 642 got me. If I had shot a 642 before, I would have splurged on the LCR.

The first time I shot it, I fired 25 rounds of Remington 158gr +p's and 50 rounds of PMC 130gr plinking ammo. By the end of that, my hand was shaking, swollen red and white, numb, nor could I use my fingers dexterously(I couldn't even legibly sign my name on the receipt when I paid up at the range), so something needs to change.

Fortunately I only carry it on my trips to north Florida on days I'll be changing in and out of dive gear, and I'm not doing that trip until next fall/winter. Funny enough, I usually stay in Live Oak.....the same town Massad Ayoob now resides in.

[Wheeler]

Thanks for the responses, guys.



Wheeler,

The information is from googling. There's tons of reports of crimp jumping out there. I couldn't find anything definitive, so I figured I'd ask here.

Different set of grips.....I bought a set of hogue bantam boot grips, however I believe the back-strap is still exposed which I didn't realize when ordering them. I haven't shot the gun with the new hogues yet, nor do I think they're going to help too much with the gun feeling like a firecracker went off in my hand. If I could afford the nice crimson trace grips with the covered backstrap, I'd probably just buy an LCR instead. I can't find any other covered backstrap grips which are boot grips.

I got the 642 used for $280, but I'd never shot one before and didn't realize how painful they are. I had shot an LCR and liked it, but the price on the 642 got me. If I had shot a 642 before, I would have splurged on the LCR.

The first time I shot it, I fired 25 rounds of Remington 158gr +p's and 50 rounds of PMC 130gr plinking ammo. By the end of that, my hand was shaking, swollen red and white, numb, nor could I use my fingers dexterously(I couldn't even legibly sign my name on the receipt when I paid up at the range), so something needs to change.

Fortunately I only carry it on my trips to north Florida on days I'll be changing in and out of dive gear, and I'm not doing that trip until next fall/winter. Funny enough, I usually stay in Live Oak.....the same town Massad Ayoob now resides in.

I paid too much for my LCR. I've seen some used ones going for decent prices and I kick myself for spending as much as I did on impulse. You might be able to look for some local gun trading forums and post a trade offer, there are a lot of folks that constantly want to try something new and different.

My typical reload is a 125 grain JHP +P. My first 5 shots are match grade 147 grain wadcutters. To be honest, I can't tell a lot of difference in the recoil. I realize that isn't empirical data but there it is.

The reason I asked about the grip change was to determine if you had any attachment to the 158 grain ammo (accuracy, dependability, etc.). If not then you might want to do some research and find something that is managable for you, that maintains an acceptable level of accuracy. Shot placement is the important thing, followed by an ability to repeat as necessary.

I feel your pain with the hands being brutalized. At one time I thought I needed to carry a .357 pocket rocket. Of course what's the point of having a .357 pistol without .357's in it? When I developed a very noticable flinch on the third shot, I decided that .357's in a J frame sized pistol were for not for me.

Wheeler

[TGS]

I paid too much for my LCR. I've seen some used ones going for decent prices and I kick myself for spending as much as I did on impulse. You might be able to look for some local gun trading forums and post a trade offer, there are a lot of folks that constantly want to try something new and different.

My typical reload is a 125 grain JHP +P. My first 5 shots are match grade 147 grain wadcutters. To be honest, I can't tell a lot of difference in the recoil. I realize that isn't empirical data but there it is.

The reason I asked about the grip change was to determine if you had any attachment to the 158 grain ammo (accuracy, dependability, etc.). If not then you might want to do some research and find something that is managable for you, that maintains an acceptable level of accuracy. Shot placement is the important thing, followed by an ability to repeat as necessary.

I feel your pain with the hands being brutalized. At one time I thought I needed to carry a .357 pocket rocket. Of course what's the point of having a .357 pistol without .357's in it? When I developed a very noticable flinch on the third shot, I decided that .357's in a J frame sized pistol were for not for me.

Wheeler

So, first off, where is Jawja? I'll trade you my S&W 642-1 plus some cash for your LCR. Or how'bout a FNX9? I've tried my local thing, vaguntrader.com. No one with an LCR wants what I've got, the ones I've seen want LCP's in trade. Otherwise I would have gotten one long ago.....

I catch your drift on the grips. I'd like to try everything possible for it. In terms of ammo, I noticed a difference between the standard pressure 130gr and 158gr+p, so I'm confident the 110gr will give me what I'd like......or at least as close to it. If an LCR pops up, which I check for multiple times a day on vaguntrader, I'll probably swoop it up though.

[Wheeler]

So, first off, where is Jawja? I'll trade you my S&W 642-1 plus some cash for your LCR. Or how'bout a FNX9? I've tried my local thing, vaguntrader.com. No one with an LCR wants what I've got, the ones I've seen want LCP's in trade. Otherwise I would have gotten one long ago.....

I catch your drift on the grips. I'd like to try everything possible for it. In terms of ammo, I noticed a difference between the standard pressure 130gr and 158gr+p, so I'm confident the 110gr will give me what I'd like......or at least as close to it. If an LCR pops up, which I check for multiple times a day on vaguntrader, I'll probably swoop it up though.

Jawja=Georgia :) I'm originally from Va. When I moved down here everyone I met sounded like that. I have partially assimilated with the folks down here so now I sould like a SW Va hillbilly with a pronounced drawl.

I appreciate the offer for a trade, and if I had an acceptable alternative for EDC I would give it serious consideration. Money is something that has become hard to come by these days so getting a replacement LCR would be tough. Keep watching the tradering forums. I see trends down here, everyone buys and sells Glocks for awhile, then S&W revolvers, then M&P's LCR's LCP's etc. I swear these guys buy/sell/trade just so they can say they owned one at one time.

[JFK]

Crimp Jumping -

I do not think I have heard this term. Can someone please explain....

Thanks

[TGS]

Crimp Jumping -

I do not think I have heard this term. Can someone please explain....

Thanks

The recoil of each shot causes the bullet to dislodge slightly from the casing, which can lead to the cylinder locking up as the front of a bullet will bind against the forcing cone. Supposedly it affects lightweight revolvers with loads 110gr or less being most susceptible according to S&W manuals, though people have reported it happening to everything up to 158gr as well.

[JFK]

The recoil of each shot causes the bullet to dislodge slightly from the casing, which can lead to the cylinder locking up as the front of a bullet will bind against the forcing cone. Supposedly it affects lightweight revolvers with loads 110gr or less being most susceptible according to S&W manuals, though people have reported it happening to everything up to 158gr as well.

Got it thanks.

[Al T.]

First time I had it happen to me was with a Bulldog .44 Special. The Remington factory ammo had too light a crimp. Ammo plays a big part in the mechanics of the malfunction.

FWIW, my S&W 340PD (Scandium) has not had an issue for about 2.5k rounds.

[JodyH]

I shoot the 110gr. DPX in my S&W 360 Scandium and haven't had any bullets jumping crimp.

[TGS]

I shoot the 110gr. DPX in my S&W 360 Scandium and haven't had any bullets jumping crimp.

How is the POI in relation to POA?

Thanks guys

[JodyH]

I use ct laser grips and a big dot front sight, so mine hits dead on the laser ;)

double-Tapatalk

[Chuck Haggard]

No issues with my 642s and DPX ammo.

I have had other bullets jump the crimp, but I atribute that to QC issues with that particular lot of ammo.

[Isaac]

Quick question: I've never owned a .357, but if you were to put .38s in a .357, would they be less likely to jump the crimp? (vs a purely .38 gun)

[SLG]

I'll buy your 642 off you, and then you can put the 280 into an LCR, if you prefer.

Alternatively (not my first choice, see above), you could put the LG-405 laser grips on the gun and shoot 148 wadcutters through it for practice. Then test and carry the CCI 135g NYPD load. I can comfortably shoot 50 rds of either load through my 442/642's.



*edited, but still stand by the above.

[Tamara]

The recoil of each shot causes the bullet to dislodge slightly from the casing, which can lead to the cylinder locking up as the front of a bullet will bind against the forcing cone. Supposedly it affects lightweight revolvers with loads 110gr or less being most susceptible according to S&W manuals, though people have reported it happening to everything up to 158gr as well.

The crimp-jumpingest revolvers I've ever seen were the .45ACP 325PDs. Titanium-cylinder flyweight snubbies shooting budget 230gr FMJ with a half-hearted taper crimp seems to be a recipe for tying a gun up.

[RevolverRob]

My biggest crimp-jumping offenders have been CCI Blazer (aluminum case) 158-grain LRNs. I've never made it through a full cylinder in an aluminum framed snub without crimp jump. But I've never had an issue with quality defensive ammo jumping crimp. That includes stuff from Speer, Remington, Winchester, Corbon, and Buffalo Bore. No issues in a 642, Colt Agent, or Colt Cobra.

-Rob

[Tamara]

The heavier the bullet, the more likely to jump crimp, since it has more inertia. Jumping crimp being caused by the bullet holding still while the rest of the gun and the cartridge case all start recoiling rearward.