factory crimping question

Newton24b · December 12, 2012, 06:18 PM

i may not be the brightest at this time of day.

when i look at my factory winchester super x 150 grain hollow points for my 30-30, the crimp is heavy. the case mouth is crushed down to half the thickness and the bullets stay put nomatter how many times i run them through.

the remington ones arent crimped like that at all, and do get set back after a few dozen cycles.

so the question is, why doesnt someone use that heavy duty crimp on light weight pistol bullets and just alleviate the crimp jump associated with certain magnum loads in light alloy guns?

PA-Joe · December 12, 2012, 06:54 PM

Because you don't need such a heavy crimp. The manufacturers need it for liability protection.

243winxb · December 12, 2012, 07:02 PM

Quote:

the crimp jump associated with certain magnum loads in light alloy guns?

There is a warning not to use ammo with lead bullets loaded at +P levels, in the S&W 337PD. When lead is compressed .005" or more, it will not spring back as much as the brass case. This leaves a some what loose crimp when compared to a jacketed bullet.

CrustyFN · December 12, 2012, 07:46 PM

Just curious why you would cycle your ammo a few dozen times and not shoot it?

Tom Matiska · December 13, 2012, 01:54 AM

Quote:

Just curious why you would cycle your ammo a few dozen times and not shoot it?

Typical hunting scenerio... load for the walk in... unchamber to climb stand, cross fence, etc... rechamber.... use same rounds tomorrow.... few days into the season the rounds in coat pocket have loose bullets.. Multiple trips up the ramp and against the top of the chamber in my 94 is my only experience with crimp failures in a centerfire rifle.

Newton24b · December 13, 2012, 07:36 AM

i dont like to leave it around with a roudn in the chamber. dont need the cat to shoot me during lunch.

anyways, these are copper jacketed bullets. its a heavy crimp, why not do that on a revolver?

serf 'rett · December 13, 2012, 09:58 AM

Some folks do mash 'em.

drail · December 13, 2012, 10:00 AM

Because it is unneccessary if the case neck tension is sufficient.

mikld · December 13, 2012, 12:37 PM

They do. Look at any factory .44 Magnum ammo and you'll see a good roll crimp. Semi-auto ammo uses a taper crimp, but neck tension (on all cartridges) outweighs crimp for holding the bullet in place. Also, some crimps aren't as appearant as others; I can put a collet type crimp on my ammo and it's not as visible as a roll, taper, or profile crimp. If a cartridge needs a crimp, you can pretty much bet the factory stuff will have it...

CrustyFN · December 13, 2012, 07:51 PM

Quote:

Typical hunting scenerio... load for the walk in... unchamber to climb stand, cross fence, etc... rechamber.... use same rounds tomorrow.... few days into the season the rounds in coat pocket have loose bullets.. Multiple trips up the ramp and against the top of the chamber in my 94 is my only experience with crimp failures in a centerfire rifle.

Well I guess you can tell from my question that I'm not a hunter.

I'm more of a competition and target shooter. Every round that gets chambered comes out with an empty case. Thank's for the explanation.

Tom Matiska · December 14, 2012, 01:22 AM

Crusty.... worst I've witnessed was an 80+ old geezer with 32 Win who had some bullets fallling out of the brass. Seems he had been "hunting" (taking the gun for a walk) with the same ammo for last 20 years. Dunno how many cycles were on those rounds, but it was too many

CrustyFN · December 14, 2012, 08:40 PM

Quote:

Crusty.... worst I've witnessed was an 80+ old geezer with 32 Win who had some bullets fallling out of the brass. Seems he had been "hunting" (taking the gun for a walk) with the same ammo for last 20 years. Dunno how many cycles were on those rounds, but it was too many

Wow that's pretty bad.

December 12, 2012, 06:18 PM	#1
Newton24b Junior member Join Date: February 10, 2009 Posts: 974	factory crimping question i may not be the brightest at this time of day. when i look at my factory winchester super x 150 grain hollow points for my 30-30, the crimp is heavy. the case mouth is crushed down to half the thickness and the bullets stay put nomatter how many times i run them through. the remington ones arent crimped like that at all, and do get set back after a few dozen cycles. so the question is, why doesnt someone use that heavy duty crimp on light weight pistol bullets and just alleviate the crimp jump associated with certain magnum loads in light alloy guns?

December 12, 2012, 07:46 PM	#4
CrustyFN Senior Member Join Date: June 4, 2006 Location: West Virginia Posts: 2,258	Just curious why you would cycle your ammo a few dozen times and not shoot it? __________________ I don't ever remember being absent minded.

December 13, 2012, 09:58 AM	#7
serf 'rett Senior Member Join Date: June 25, 2009 Location: Stuttgart, AR Posts: 1,569	Some folks do mash 'em. __________________ A lack of planning on your part does not necessarily constitute an emergency on my part.

December 13, 2012, 12:37 PM	#9
mikld Senior Member Join Date: February 7, 2009 Location: Southern Oregon! Posts: 2,891	They do. Look at any factory .44 Magnum ammo and you'll see a good roll crimp. Semi-auto ammo uses a taper crimp, but neck tension (on all cartridges) outweighs crimp for holding the bullet in place. Also, some crimps aren't as appearant as others; I can put a collet type crimp on my ammo and it's not as visible as a roll, taper, or profile crimp. If a cartridge needs a crimp, you can pretty much bet the factory stuff will have it... __________________ My Anchor is holding fast! I've learned how to stand on my own two knees...

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December 12, 2012, 06:54 PM	#2
PA-Joe Senior Member Join Date: June 9, 2010 Location: NEPA Posts: 909	Because you don't need such a heavy crimp. The manufacturers need it for liability protection.

December 13, 2012, 07:36 AM	#6
Newton24b Junior member Join Date: February 10, 2009 Posts: 974	i dont like to leave it around with a roudn in the chamber. dont need the cat to shoot me during lunch. anyways, these are copper jacketed bullets. its a heavy crimp, why not do that on a revolver?

December 13, 2012, 10:00 AM	#8
drail Junior member Join Date: February 2, 2008 Posts: 3,150	Because it is unneccessary if the case neck tension is sufficient.

December 14, 2012, 01:22 AM	#11
Tom Matiska Senior Member Join Date: April 12, 2000 Location: Wilkes-Barre, Pa Posts: 1,029	Crusty.... worst I've witnessed was an 80+ old geezer with 32 Win who had some bullets fallling out of the brass. Seems he had been "hunting" (taking the gun for a walk) with the same ammo for last 20 years. Dunno how many cycles were on those rounds, but it was too many