Jumping the crimp

[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