Crimping Die Question

bryceh12321 · December 13, 2009, 11:34 AM

Would you recommend using a crimping die for a 300 win mag, Ruger 77 (Bolt action)?
I've had a friend of mine tell me it is a good idea, as it insures the exact same amount of pressure on each load, but I had someone else tell me, it wouldn't do that, because you don't put the same amount of pressure on the press handle each time.

Which one would be a more accurate assertion?

80viking · December 13, 2009, 12:27 PM

I never use a crimp in a bolt action, except on my 458 win mag to prevent bullet pull from the heavy recoil, it makes your gun less finicky when trying to find your optimum load, but with a magnum load of a slow powder you could benefit from a crimp to increase pressure before the bullet gets released, if you do crimp make sure case length is uniform, that will eliminate the uneven press handle pressure, also check out a lee factory crimp die, its different and it works, bottom line is experiment, hope this helps

wncchester · December 13, 2009, 01:07 PM

"I've had a friend of mine tell me it is a good idea, as it insures the exact same amount of pressure on each load, but I had someone else tell me, it wouldn't do that, because you don't put the same amount of pressure on the press handle each time."

Both are correct. Case length plays a BIG part of crimping's effectiveness. IF you do it consistantly, a modest crimp can improve ignition and burn. Over done, it can damage the bullet. Done half-azzed, it may not help at all or it can actually hurt accuracy a tad. The practioners of each camp can be quite pursuasive and, depending on their method and experience, quite correct for themselves.

The Lee Factory Crimp Die is perhaps the best crimper available and is certainly the least critical of case length, but it's also the easiest to over-do.

gearheadpyro · December 13, 2009, 04:45 PM

+1 on the Lee Factory Crimp Die.

If your press has a positive stop at the end of the stroke and does not have any overswing then this die will give you the same results each time. Just press until the handle stops.

The Lee Factory Crimp Die shaved an average .1" off of my already .6" hunting load in my .308 win.

James R. Burke · December 13, 2009, 07:07 PM

I dont crimp for bolts or single shots. Does not make a differnce that I can tell. If you think the bullet is going to move below it in the mag crimp them, or if you have a really big cal that might move them like in the prior post.

wncchester · December 13, 2009, 08:38 PM

Those who adamently say it does or does not help have too little experience with crimping! The value of crimping varies greatly by the individual rifle and cartridge. Sometimes it helps, sometimes it makes no difference, somethings it makes things worse. No one can say which before properly trying it.

But, crimping can accomplish much more than simply holding the bullet in place during recoil. In some charges with some powders under some bullets and ignited with some primers, a crimp can retard bullet movement enough to help ignition and subsequent burn get up to proper pressure for better accuracy than otherwise.

December 13, 2009, 11:34 AM	#1
bryceh12321 Senior Member Join Date: December 9, 2008 Posts: 136	Crimping Die Question Would you recommend using a crimping die for a 300 win mag, Ruger 77 (Bolt action)? I've had a friend of mine tell me it is a good idea, as it insures the exact same amount of pressure on each load, but I had someone else tell me, it wouldn't do that, because you don't put the same amount of pressure on the press handle each time. Which one would be a more accurate assertion?

December 13, 2009, 04:45 PM	#4
gearheadpyro Senior Member Join Date: September 3, 2009 Location: Charleston, SC Posts: 169	+1 on the Lee Factory Crimp Die. If your press has a positive stop at the end of the stroke and does not have any overswing then this die will give you the same results each time. Just press until the handle stops. The Lee Factory Crimp Die shaved an average .1" off of my already .6" hunting load in my .308 win. __________________ www.southernmarksman.com Owner of & Chief Instructor for The Southern Marksman, LLC NRA Life Member, NRA CRSO, Multi-Discipline NRA Certified Instructor

December 13, 2009, 12:27 PM	#2
80viking Senior Member Join Date: December 8, 2009 Location: The Peoples Republic of Massac Posts: 333	I never use a crimp in a bolt action, except on my 458 win mag to prevent bullet pull from the heavy recoil, it makes your gun less finicky when trying to find your optimum load, but with a magnum load of a slow powder you could benefit from a crimp to increase pressure before the bullet gets released, if you do crimp make sure case length is uniform, that will eliminate the uneven press handle pressure, also check out a lee factory crimp die, its different and it works, bottom line is experiment, hope this helps

December 13, 2009, 01:07 PM	#3
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"I've had a friend of mine tell me it is a good idea, as it insures the exact same amount of pressure on each load, but I had someone else tell me, it wouldn't do that, because you don't put the same amount of pressure on the press handle each time." Both are correct. Case length plays a BIG part of crimping's effectiveness. IF you do it consistantly, a modest crimp can improve ignition and burn. Over done, it can damage the bullet. Done half-azzed, it may not help at all or it can actually hurt accuracy a tad. The practioners of each camp can be quite pursuasive and, depending on their method and experience, quite correct for themselves. The Lee Factory Crimp Die is perhaps the best crimper available and is certainly the least critical of case length, but it's also the easiest to over-do.

December 13, 2009, 07:07 PM	#5
James R. Burke Senior Member Join Date: January 3, 2009 Location: U.P. of Mich/Quinnesec Posts: 1,897	I dont crimp for bolts or single shots. Does not make a differnce that I can tell. If you think the bullet is going to move below it in the mag crimp them, or if you have a really big cal that might move them like in the prior post.

December 13, 2009, 08:38 PM	#6
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	Those who adamently say it does or does not help have too little experience with crimping! The value of crimping varies greatly by the individual rifle and cartridge. Sometimes it helps, sometimes it makes no difference, somethings it makes things worse. No one can say which before properly trying it. But, crimping can accomplish much more than simply holding the bullet in place during recoil. In some charges with some powders under some bullets and ignited with some primers, a crimp can retard bullet movement enough to help ignition and subsequent burn get up to proper pressure for better accuracy than otherwise.