crimp for plinking loads

gotguns? · February 14, 2009, 10:51 AM

I have made some light plinking loads for .45 colt recently with 230 grain .45 acp fmj. I have been puting a light roll crimp on them as they dont have a canneleure, and I only have a roll crimp die. My question is: if it is even nessacery on light loads to crimp at all or just rely on the neck tension, or should i buy the taper die. Im shooting out of a blackhawk with 230 grain fmj over 5 grain of unique.

wncchester · February 14, 2009, 11:05 AM

No crimp needed.

mkl · February 14, 2009, 11:12 AM

Probably not.

You can check for sure by taking your caliper to the range.

Load six in your blackhawk measuring the OAL of #6 before you put it in the cylinder.

Shoot five shots.

Remove the #6 cartridge and measure the OAL again.

If it's the same as before, no crimp needed.

If it's longer, the bullet is trying to back out, and a crimp would help stop that.

**Unclenick** · February 14, 2009, 11:29 AM

Not usually needed with FMJ. Copper sticks to brass pretty well. For light loads with jacketed bullets you just need to go far enough to remove the expander die flare and get the case back to straight. Some lubricated lead bullets will need the crimp even in light loads, though. If the bullet is easy to push in with your thumb without the crimp, you need to crimp.

A roll crimp is the only kind to use in a revolver. In a semi-auto or a tubular rifle magazine you have to worry about bullets being pushed into the case. Taper crimps work for that in lead bullets by embossing them with a little step for the case mouth to hold them out against. In a revolver there is nothing to push a bullet in, but bullets can back out because recoil knocks the case back against the case rim, tugging the case off the bullet against the bullet's own inertia. It's an inertial bullet puller that creates its own blow. You need a crimp that hooks the bullets and hangs on to prevent that, and that is what the roll crimp does. If you don't prevent it, the bullets can back out enough to protrude from the chambers which will block the cylinder from turning. You then have to open the cylinder (or remove in an SA) and take the bullet out and home for re-seating.

amamnn · February 14, 2009, 07:31 PM

I don't crimp light target loads for that caliber.

kraigwy · February 14, 2009, 07:38 PM

The crimp isnt just to hold the bullet in the case. Its also holds the bullet allowing the powder to properly ignite, building the right ammount of pressure to add consistency.

Even if the bullet seems to be holding with little or no crimp, it could move (come out) under recoil jaming up your cylender.

Whats wrong with putting a standard crimp on all your loads, Something about consistency that just screams better shooting.

Consistency = accuracy, you cannot have any type of accuracy without consistency.

February 14, 2009, 10:51 AM	#1
gotguns? Senior Member Join Date: April 13, 2008 Location: Oakland City IN Posts: 136	crimp for plinking loads I have made some light plinking loads for .45 colt recently with 230 grain .45 acp fmj. I have been puting a light roll crimp on them as they dont have a canneleure, and I only have a roll crimp die. My question is: if it is even nessacery on light loads to crimp at all or just rely on the neck tension, or should i buy the taper die. Im shooting out of a blackhawk with 230 grain fmj over 5 grain of unique. __________________ "And what country can preserve its liberties, if its rulers are not warned from time to time, that this people preserve the spirit of resistance? Let them take arms. ... The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants." -Thomas Jefferson

February 14, 2009, 11:29 AM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,090	Not usually needed with FMJ. Copper sticks to brass pretty well. For light loads with jacketed bullets you just need to go far enough to remove the expander die flare and get the case back to straight. Some lubricated lead bullets will need the crimp even in light loads, though. If the bullet is easy to push in with your thumb without the crimp, you need to crimp. A roll crimp is the only kind to use in a revolver. In a semi-auto or a tubular rifle magazine you have to worry about bullets being pushed into the case. Taper crimps work for that in lead bullets by embossing them with a little step for the case mouth to hold them out against. In a revolver there is nothing to push a bullet in, but bullets can back out because recoil knocks the case back against the case rim, tugging the case off the bullet against the bullet's own inertia. It's an inertial bullet puller that creates its own blow. You need a crimp that hooks the bullets and hangs on to prevent that, and that is what the roll crimp does. If you don't prevent it, the bullets can back out enough to protrude from the chambers which will block the cylinder from turning. You then have to open the cylinder (or remove in an SA) and take the bullet out and home for re-seating. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 14, 2009, 07:31 PM	#5
amamnn Senior Member Join Date: May 13, 2006 Location: WA, the left armpit of the USA Posts: 1,323	I don't crimp light target loads for that caliber. __________________ "If the enemy is in range, so are you." - Infantry Journal

February 14, 2009, 11:05 AM	#2
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	No crimp needed.

February 14, 2009, 11:12 AM	#3
mkl Senior Member Join Date: April 25, 2008 Location: DFW area, Texas Posts: 494	Probably not. You can check for sure by taking your caliper to the range. Load six in your blackhawk measuring the OAL of #6 before you put it in the cylinder. Shoot five shots. Remove the #6 cartridge and measure the OAL again. If it's the same as before, no crimp needed. If it's longer, the bullet is trying to back out, and a crimp would help stop that.

February 14, 2009, 07:38 PM	#6
kraigwy Senior Member Join Date: June 16, 2008 Location: Wyoming Posts: 11,061	The crimp isnt just to hold the bullet in the case. Its also holds the bullet allowing the powder to properly ignite, building the right ammount of pressure to add consistency. Even if the bullet seems to be holding with little or no crimp, it could move (come out) under recoil jaming up your cylender. Whats wrong with putting a standard crimp on all your loads, Something about consistency that just screams better shooting. Consistency = accuracy, you cannot have any type of accuracy without consistency. __________________ Kraig Stuart CPT USAR Ret USAMU Sniper School Distinguished Rifle Badge 1071