Crimping Bullets.

dgradinaru

dgradinaru

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So i reloaded for about 3 years now and am getting pretty good accuracy out of my bullets. I just bought some hornady bullets 195 grain .323 and would like to start crimping them. Some one told me it would give me better accuracy. How do i crimp for my 8MM Mauser.
 
You don't need a crimp die, if you have a set of dies, then you have a crimp die, just set it to crimp either while you seat bullet or crimp in a separate operation, unless I've misunderstood your current setup. I would be very surprised if you got better accuracy from crimping for ammo in a bolt gun. Changing case neck tension is a totally diff. story and could help with accuracy but it has nothing to do with crimping. IMHO
 
I'll just add a bit to Ben's comments.
There is no need for a "factory crimp die," as Ben points out, if you have standard dies you already have a crimp die, which I prefer to the Lee, so called factory crimp die.
I will guarantee that you and your 8mm Mauser will not be able to prove whether or not, crimping improves accuracy, or not.
 
H4831 said:
I'll just add a bit to Ben's comments.
There is no need for a "factory crimp die," as Ben points out, if you have standard dies you already have a crimp die, which I prefer to the Lee, so called factory crimp die.
I will guarantee that you and your 8mm Mauser will not be able to prove whether or not, crimping improves accuracy, or not.
Click to expand...

I agree with this wholeheartedly!
Eagleye.
 
i wouldn't bother crimping. those 195's shoot very good in my 8mag and 325. i'm looking forward to testing them on spring bear.
 
Do you guys crimp your rounds to keep the projectile from moving during recoil? How much effect does a strong crimp have on pressure?
Basicly, when/why do you crimp.
The reason I ask is I've noticed my 30-30 factory loads after loading and reloading the rifle ( Winchester M94 ) for bear hunting, the projectile on a few of the rounds are sinking deeper. I've seen this in my Glock 22 but that was with crappy old brass.
I've just loaded some test rounds for my 270 and I put a strong crimp on them to hold them in place during recoil and have yet to test them out.
 
Generally crimping is a must for ammo in tube fed magazines like .30/30 in a Winchester 94, heavy recoiling rounds in magazine fed guns like .458 Win Mag in a bolt action, and heavy recoiling revolver rounds 44mag 357, 500S&W etc This is to stop the bullet set back you have seen in your 30/30.

Some people feel it is needed in semi auto stuff as well, many do not and have great success.

With cases like .45 ACP a slight taper crimp can removed any flare/belling from the case mouth after seating a bullet.
 
If you use the roll crimp in your seating die, make sure you seat to a depth so that the crimp will enter the cannelure on the bullet. No cannelure, no roll crimp! haven't used the Lee "Factory Crimp" die, so I can't comment there. Prolly, the crimp won't do much to help accuracy, but hey, you won't know until YOU try. I would start with a pretty mild crimp, barely discernable, shoot some groups, crimp a bit more, shoot some groups, until you either see a trend, or don't.

One thing to remember about roll crimping is that your cases have to all be the same length, to get the same crimp. That generally means trimming a batch, and treating that batch as a lot - i.e. - fired the same number times, etc.
 
ykkid said:
If you use the roll crimp in your seating die, make sure you seat to a depth so that the crimp will enter the cannelure on the bullet. No cannelure, no roll crimp! haven't used the Lee "Factory Crimp" die, so I can't comment there. Prolly, the crimp won't do much to help accuracy, but hey, you won't know until YOU try. I would start with a pretty mild crimp, barely discernable, shoot some groups, crimp a bit more, shoot some groups, until you either see a trend, or don't.

One thing to remember about roll crimping is that your cases have to all be the same length, to get the same crimp. That generally means trimming a batch, and treating that batch as a lot - i.e. - fired the same number times, etc.
Click to expand...
One more reason not to crimp for best accuracy, slight differences in case length will mean uneven crimp amounts, causing inconsistency in pressure.
 
crimp

Listen to Ben, crimp will not improve your 8mm. Neck tension alone is more than adequate in a cartridge like this, unless you're trying to shoot "J" bullets from an "S" case and die.
Crimp never helpful in a cartridge under .375 H+H unless tube magazine.
Please note my comments apply solely to bottle neck rifle cartridges.
 
shakeyjake said:
Do you guys crimp your rounds to keep the projectile from moving during recoil? How much effect does a strong crimp have on pressure?
Basicly, when/why do you crimp.
The reason I ask is I've noticed my 30-30 factory loads after loading and reloading the rifle ( Winchester M94 ) for bear hunting, the projectile on a few of the rounds are sinking deeper. I've seen this in my Glock 22 but that was with crappy old brass.
I've just loaded some test rounds for my 270 and I put a strong crimp on them to hold them in place during recoil and have yet to test them out.
Click to expand...

Recoil very rarely is the reason a bullet moves in the case.
Your 30-30 after repeated loading & unloading procedures will occsionally get loose due to your pushing the nose in & out of the loading gate & against the spring pressure in the tube mag.
You see it far more often in pistol type rounds where the brass length holding the bullet has far less surface area.
I personally don't crimp anything, including my lever gun loads, but then I rarely would have more than 4-5 rounds in the tube when hunting.
 
I crimp the rifle ammo I load with cannelured bullets, and I believe this practice makes my ammo just a bit better. One reason the practice results in slightly better ammo is that the bullet pull weight is uniformed from cartridge to cartridge, providing a similar advantage as seating a bullet into the lands has for the match rifle shooter, but allowing you to seat your bullets short enough that the rounds will cycle easily from your magazine. The technique for achieving uniform results is not difficult with either standard RCBS or Redding style seating dies, although best results are attained when crimping is done as a separate step. The bullet should be seated so that the case mouth comes even with the forward edge of the cannelure or crimping groove, depending on your style of bullet, and this should be done even if it results in small differences in OAL.

For best results, unscrew the bullet seating stem out far enough that it will not touch the bullet, and back the die out of the press a couple of turns to ensure it will not contact the longest case neck. Now place a loaded cartridge in the shell holder and run the ram to the top of its travel. Screw the die downwards until you are unable to move it further with strength of your thumb and two fingers only, do not attempt to grip the die with the entire hand, and repeat for each cartridge. Crimped in this fashion, the results will be very uniform and can be completed quickly. The number of rounds you can do at a single sitting depends on how sore your fingers get from the rough textured die body. If your case necks are very uniform, you might prefer to lock the die in place after you've crimped the first cartridge, and while you can do that, uniformity might suffer slightly.
 
H4831 said:
I'll just add a bit to Ben's comments.
There is no need for a "factory crimp die," as Ben points out, if you have standard dies you already have a crimp die, which I prefer to the Lee, so called factory crimp die.
I will guarantee that you and your 8mm Mauser will not be able to prove whether or not, crimping improves accuracy, or not.
Click to expand...

x2! Your dies, once set up properly, will do just fine.
 
Boomer said:
I crimp the rifle ammo I load with cannelured bullets, and I believe this practice makes my ammo just a bit better. One reason the practice results in slightly better ammo is that the bullet pull weight is uniformed from cartridge to cartridge, providing a similar advantage as seating a bullet into the lands has for the match rifle shooter, but allowing you to seat your bullets short enough that the rounds will cycle easily from your magazine. The technique for achieving uniform results is not difficult with either standard RCBS or Redding style seating dies, although best results are attained when crimping is done as a separate step. The bullet should be seated so that the case mouth comes even with the forward edge of the cannelure or crimping groove, depending on your style of bullet, and this should be done even if it results in small differences in OAL.

For best results, unscrew the bullet seating stem out far enough that it will not touch the bullet, and back the die out of the press a couple of turns to ensure it will not contact the longest case neck. Now place a loaded cartridge in the shell holder and run the ram to the top of its travel. Screw the die downwards until you are unable to move it further with strength of your thumb and two fingers only, do not attempt to grip the die with the entire hand, and repeat for each cartridge. Crimped in this fashion, the results will be very uniform and can be completed quickly. The number of rounds you can do at a single sitting depends on how sore your fingers get from the rough textured die body. If your case necks are very uniform, you might prefer to lock the die in place after you've crimped the first cartridge, and while you can do that, uniformity might suffer slightly.
Click to expand...

The 270 test rounds I've got are all trimmed to the same length, so should be all crimped the same. Thanks for the info on crimping slightly different case lenghts.
When I was loading this brass years ago for a coyote load I only started trimming after the 2nd or 3rd loading. That method should work for new unprimed brass with different case lenghts eh?
 
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