crimp or no ?

[cranebird]

Is there an advantage to either way ? I never crimped until today I dug the die set out and full length resized some PMC brass, threw 3 loads together and crimped the bullet. That it was the first time I full length resized the brass, normally I only neck size and run them as is , trimming the brass as needed. They shot fine but that load does without the crimp. There is so much stuff that I should know but don't. Thanks in advance.

[bootsmcguire]

Crimping for a bolt gun is really only needed if the bullet is shifting during recoil, and normally that only happens when dealing with the larger stuff.

It can offer accuracy bonuses with certain loads. I had a 22-250 barrel that would not shoot a 45gr-HP without a crimp. Crimped it would do under 1/2 MOA, no crimp it would open up to just over MOA. Was the only one I have run into so far that was that way, but I have heard a couple of others having similar results.

Big down side I found was that it seemed to wear out the necks of the brass much quicker. I would get more cracked necks and they seemed to work harden quicker.

Just some of my observations.

[fgw_in_fla]

I have to agree with my esteemed colleague about case neck and mouth wear / damage from crimping too many times.

I tried crimping for a very short time and saw no real benefit. My crimp dies now resides in the "cabinet of lost souls" with other good ideas gone south.

[drybean]

If it shoots better with a crimp, then the uncrimped needs more neck tension

[darkker]

I'll disagree, but as to the *need* that is up to your situation.
What I found/find is that most people over-crimp, and do tend to muck-up the brass.
For my very long range loads in my 308(1,000+ yards) it helps noticeably.
Theory being that an even grip, or starting pressure will keep the bullet straighter, and in place until enough pressure forces it down the pipe.

Most long range shooters try to control this by constantly annealing the brass. I'm not interested in that, and find a VERY light squeeze with a Lee FCD will do the same thing. It also lowered my ES/SD. For regular hunting is irrelevant for my loads, but stretching way out, becomes important.

[bootsmcguire]

my esteemed colleague

I like that one.

[243LPR]

The only thing I crimp is pistol loads,don't even crimp 223's in the AR's. Never saw the need (KISS method).

[eddiesindian]

all my gas guns are crimp,d
all my bolt guns arent.
Im getting 1/4moa @ 100 with no crimp and they do fine out to 1K providing I read the wind correctly.
I agree with the other dudes.....its all about uniform/consistant neck tension.
Seeing as how youve already load up and shot those, Id load up some more and have a comparison so you can have a go at it yourself.

[Jetpig]

I'll disagree, but as to the *need* that is up to your situation.
What I found/find is that most people over-crimp, and do tend to muck-up the brass.
For my very long range loads in my 308(1,000+ yards) it helps noticeably.
Theory being that an even grip, or starting pressure will keep the bullet straighter, and in place until enough pressure forces it down the pipe.

Most long range shooters try to control this by constantly annealing the brass. I'm not interested in that, and find a VERY light squeeze with a Lee FCD will do the same thing. It also lowered my ES/SD. For regular hunting is irrelevant for my loads, but stretching way out, becomes important.

I will have to agree with this as far as over-crimping goes. It is normally way overdone.

[thermaler]

This is a question that almost borders on mystical philosophy and you'll get answers on both sides. I crimp ALL my hand-loads (but I'm weird)--there are different types of crimps and pressures so it depends on the situation and weapon. If you're doing "conventional" non-compressed loads simply follow the directions in the reload guide--most of the time you don't need a crimp for a conventional bolt rifle. As you reload more and more different bullets and cases you'll get a feel for what needs crimping and what doesn't. Unless you're starting out with pistol loads which have to have a healthy roll crimp--I agree with keep-it-simple and start with easy loads (308 being the easiest in MO).

[Frank V]

I'm with most, I don't crimp with a bolt gun or single shot gun.
I get very good accuracy with this method. I'd probably crimp something like a .375 H&H & up in a bolt gun.
I would probably also crimp in a tubular magazine rifle, but not a bolt or single shot.

[eddiesindian]

A little FYI about crimping.
I was given a box of factory Federal FGMM in 168gr SMK. I gave them a go in my Model 10 FCP-K. Low and behold,the consistancy of the nice and tight groupings made me want to have a look under the hood of those rds.
I took one apart to have a look at what type of propellant was used and what chrg weight. I used a hornady collet puller as to not mar the projectile. Upon inspection of the bullet, I was extremely suprised to see uneven deep crimping marks in the bullet, yet the consistancy and accuracy of the factory ammo is without a dought a head scratcher.
Just something to ponder on I guess...................

[thermaler]

A little FYI about crimping.
I was given a box of factory Federal FGMM in 168gr SMK. I gave them a go in my Model 10 FCP-K. Low and behold,the consistancy of the nice and tight groupings made me want to have a look under the hood of those rds.
I took one apart to have a look at what type of propellant was used and what chrg weight. I used a hornady collet puller as to not mar the projectile. Upon inspection of the bullet, I was extremely suprised to see uneven deep crimping marks in the bullet, yet the consistancy and accuracy of the factory ammo is without a dought a head scratcher.
Just something to ponder on I guess...................

Same deal with Atomic 168 nosler custom comp.

[eddiesindian]

Those things that make you say hmmmm??????

[LHitchcox]

The only time I crimp is for pistol rounds. Once upon a time I was having issues with an AR, but it turned out to be a mag issue instead.