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Posted By: Ranchhand02 Should I crimp my bullets? - 10/07/09
I have a remington 7mm mag shooting a 162 a-max with 62.5 grains or RL-22. Should I use a lee factory crimp die and crimp my bullets? Will it help accuaracy?
Posted By: 1234567 Re: Should I crimp my bullets? - 10/07/09
You never know until you try it, but you should be aware that you cannot crimp a bullet unless the bullet has a crimping cannalure. I am not familiar with the 162 a-max, and whether or not it has a crimping cannalure.

In over 40 years of reloading, I have never crimped a rifle cartridge. I don't see a need for it, except possibly in a rifle with a tubeler magazine such as a 94 Win.
No it does not have a cannalure. Acording to the instructions on the die it said a cannalure was not required.
Originally Posted by 1234567
be aware that you cannot crimp a bullet unless the bullet has a crimping cannalure


Using the Lee Factory Crimp Die does allow you to crimp bullets without a crimping cannelure. If I am not mistaken, the only reason one would not be able to crimp without a cannelure is using a roll crimp--doing so could cause case collapse.
Can't come up with a good reason to crimp it.
+1
Originally Posted by Ranchhand02
Should I use a lee factory crimp die and crimp my bullets?


Other than some guys crimping 223 that is run through AR-15 type rigs (I don't even bother with that in mine), and guys running REAL big boomers worried about setback on recoil, I can't think of any reason that I'd want to crimp something else.

There is no need to crimp 7mm Rem. Mag. bullets. There is also no need for crimping 223 Rem. bullets even if they're to be run through an AR-15. I don't even crimp bullets of cartridges to be run through an M1A or M1 Garand.

There are several reasons to crimp:

1. Crimp for heavy recoiling cartridges to be fired in a gun with a magazine or cylinder. That would be stuff like a 458 Lott, 460 S&W Magnum, etc.

2. Crimping for some low pressure loads such as 45 Colt may help accuracy.

3. If in loading certain types of bullets (Barnes comes to mind), the bullets are a little loose, crimping with a Lee Factory Crimp Die will tighten them up.
In your situation, crimping would be to influence initial powder burn, not bullet set-back, and that does influence accuracy. As mentioned above, only experimentation will tell you if it will help you or not, not any of us. Any effect won't be massive, it's just a tweak.

There is a potential to damage the bullet with an excessive crimp exists, go easy. Ham fisted reloaders should NOT CRIMP!
I have gotten set back with my remington 700 XCR 300 ultra. But it is usually just the first shell pushed down when loading.The accubond tip will even be fairly beat up.
Originally Posted by Ranchhand02
I have a remington 7mm mag shooting a 162 a-max with 62.5 grains or RL-22. Should I use a lee factory crimp die and crimp my bullets? Will it help accuaracy?
..........No need to crimp a 7mm mag! Whether that affects accuracy or not, is best determined for your rifle by experimenting.

I`ve reloaded for my former 300 Win for 35 years, for nearly 3 years and currently a 300 WSM, and for the past year and a half and currently, a 375 Ruger. For either, I haven`t crimped a one yet! My more accurate reloads get moa and better.

The only things crimped in the past were revolver cartridges such as my former 44 mag and my current 500 S&W.

I really don`t see how crimping vs not crimping would offer any better accuracy. That`s not to say that crimping may offer a little better accuracy in some rifles.

Look at the study on AR about the effects of crimping with a Lee FCD. I use them on nearly all loads, even for my target rigs. Some folks crimp too much IMO, I use a light crimp.

Years ago I found it helped with SD and group size. Same thing that the AR test shows.

Is it needed? No. Can it help? Yes.

Shoot for groups both with and w/o to see what your results are. I have seen it help and I have seen it offer no help. It will not hurt.

Before you even tinker with crimping, you need to be sure your dies and loading practices are producing concentric ammo.

Good Luck

loder
Posted By: Bruce_A Re: Should I crimp my bullets? - 10/12/09
In shooting my 8mm Remington Mag I have had un-crimped 200 and 220 gr bullets move in the neck of the cartridges in the magazine from recoil. In one instance the bullet moved far enough to prevent the cartridge from feeding. This was with new sized brass with no neck turning. I use the "factory crimper" on all my loads: 30-06, 308, 8mm mag. Just a touch, barely discernible. Years ago I proved to myself that the crimp improved uniformity. Unexplainable fliers ceased happening when I added the crimp. The "factory crimp" works on bullets with or without cannelure. A roll crimp is used only on bullets with the cannelure.
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