Thread: Who crimps?

Anyone bother to crimp reloads for bolt actions?all factory loads look crimped,does it help at all?

Nope, don’t crimp any of my reloads
If I was loading for use in a semi ( remember those ? ) then I would.
Bolt action, not needed.

I have heard crimping helps with consistent neck tension.

Comments from other people who have done lots of both?

I understand crimping does not help at all. A properly resized neck has all the hold you need.

"A guy on the range" once told me he crimps all his lead boolit loads, he told me that in connection with me having to pack up and go home as I had a lead boolit squib but no cleaning rod. I can see how a crimp into a lubrication groove might help prevent a boolit from being hammered back into the case during chambering.

The cause of my squib turned out to have had naught to do with lack of crimping - it was a bit more basic and embarrassing, like, no powder. )-:>

With BP loads and lead boolits I could see a case for just crimping and not bothering to neck size since the fast BP pressure build-up will obturate a bullet nicely no matter how loosely it's held.

I crimp for my tube mag lever action, and cast bullet loads for the bolt action (but I've been told I don't need to).
For bolt actions I wouldn't bother, to get a consistent crimp you need to trim all your cases to the exact same length, so chances are you will be introducing more variation rather than less.

Semi Auto Pistol loads I crimp as it stops the chance of the projectile being forced into the case when it hits the feed ramp.

I use to crimp all my semi Auto centre fire rifle ammo for the same reason.
They are all gone now so I don’t crimp them any more for the replacement bolt actions.

If I had a lever action I would crimp to stop the chance of the projectiles being forced deeper into the case due to recoil when they are in the tube mag.



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I've read too much crimp can mess up neck tension. Biting down too hard causes brass to bend back out further down.

Sometimes necessary for cals like 44mag to hold the bullet in place that fraction of a millisecond longer to help powder ignite when using "slow" stuff like H110.

But for traditional bottleneck cartridges, in a bolt gun, never.

You really dont have to crimp on bolt action ammo, except when you are loading to hunt dangerous game. (On larger calibres(dangerous game) you might want to crimp as the projectiles sometimes gets pushed deeper into the cases due to recoil.

On normal calibres crimpin really is not needed. Factory ammo is crimped because of the projectile movement issue and reputation and so.

If you take a look at the most accurate shooters around the world, you'll find that not one of them crimp.

Simon is spot on.

On the old .303, lots of people seem to find the lee crimp die (the collet one whatever its called) helps a lot with consistent grouping. Some rifles like it, some don't. Bit like reloading all round really.

Guess I'll have to change my whole approach for reloading .223 and .308 now I'm semi-less. Think the progressive press is going to be gathering a lot of dust in future too...

Gonna give it a try with cast Bullets in the.308,got an expanding die as well on advice from Robert the cast guru,might try crimping a few full power corlokt loads to see if anything improves,gun shoots Moa as it is though..

G'day Bomb mate I never used to crimp but when I got the 7mm rem mag I was fiddling one day and decided to lightly crimp 5 reloads that were grouping 1'' @ 100m when I fired them I was amazed to see they grouped even tighter to 5/8'' so I settled in getting the powder right at 69gr for 5/8'' ( 16mm) then lightly crimped 5 out of ten so 5 shot 5/8'' and 5 crimped shot 1/2'' (12mm) and more consistent group so then I repeated it and got the same so then I didn't crimp any and got 5/8'' then crimped all 10 and got a 12mm clover leaf so that was it for me with the 7mm so I decided to try the 22-250 it has had 3600 shots through it and is still shooting 3/4'' I have never changed the load I set up from new and so I crimped 5 loads fired 5 old loads then fired 5 crimped well there wasn't much difference in accuracy only i'd say down to 5/8'' not much at all but the consistency was quiet good they actually clustered rather than be random distances between shots I done this 2-3 times then decided to crimp the 22-250 as well I never crimped because most people said it didn't make any difference and it may not have for them but I've proved it to myself it works for me if you don't want a little extra from accuracy then I wouldn't worry about crimping but I strive for the best accuracy I can get for what I do and crimping does that for me my 7mm likes a bit of jump that may have something to do with it but the 22-250 sits just off the lands and it groups better with crimping so not sure what causes it but crimping for me is best others may have different outcomes different rifles different likes but I would say only lightly crimp just firm not squashing into the projectile another thing I do as well is anneal my brass more often like after every 3-4 firings I found both rifles settled down further doing that now it's a pleasure to go out on a job and know exactly how precise its happening from the pointy end of the barrel to the intended target

Yea I anneal every 4-5 loads in the .308 full power brass,don’t bother with the trail boss subsonics though,brass hardly moves firing those loads,think the crimp will help though.

I crimp my big boomers, don't want to have the projectiles being pushed back into the case due to recoil whilst in the magazine, especially the 45-70.