I was just reloading my 243 for the first time and i couldnt tell if the crimp was tight enough. How can you tell? and what happens if you dont have a good enough crimp?

there's only two instances where crimping is necessary.....
1. on heavy recoiling revolvers
2. on lever action guns and other guns with tubular magazines.

If your .243 is not crimped at all there's nothing wrong.....if crimped poorly there's still nothing wrong.....unless you've buckled your case and the shells won't fit the chasmber.

I'd recommend just not crimping at all in the .243

Thanks a bunch Vapo, seems like im always asking ya for help!

You're actually probably better off not crimping your .243. If you're sizing die sizes your neck properly (which guarantee proper tension to hold the bullet) and true to the bore then your rifle will likely be more accurate than if you crimped your cartridges.

Like Vapodog said, (roll) crimping is critical on hard kicking revolvers shooting heavy bullets because the recoil and inertia are sufficient for the gun to literally act like a kinetic bullet puller. Guns with tubular magazines need to have their bullets crimped for obvious reasons.

I think that he left a couple reasons to crimp off his list though. If it were me I'd also crimp heavy bullets in hard kicking hunting rifles (for the same reason one would crimp a revolver bullet). I'd also crimp any round for use in a semi-auto firearm with whatever crimp was appropriate to that cartridge to prevent a bullet from being pushed back into the case during feeding, thus creating a dangerous high-pressure condition when fired.

But except for these reasons, neck tension is sufficient to provide an adequate grip on the bullet.

Mike

Roger that! Nor in any cartridge that you can find some other way of keeping the bullet from moving! (Like use of an undersized expander button!!) The more a bullet is deformed before it gets into the air, the less chance it has to be accurate!!

Eld, I have tried crimping my 300RUM a few times and was surprised at the accuracy improvement. This was with A-Frame bullets. Using the words, only, never, and always, really, is not good. There always exceptions to the rules.

You're absolutely right, of course! When if comes to guns and reloading, I often suspect there are more exceptions than rules sometimes......

Believe me, crimping is another process, I like to bypass. I think part of my success crimping A-frames has to do with the brass was fired three times. It was probably makeing up for neck tension. I haven't tried it again so I can't verify. Just surprised me that my groups went back to .75" with a crimp. Will I do it again? Maybe if I have time. I won't do it without a groove to crimp too however.

Agreed! When I first started reloading, I was using G.I. M2 bullets I got from the DCM, and despite the fact that they have crimping cannelures, I was never able to crimp them without bulging the shoulders to where the cartridge would not chamber. I have never really tried to crimp rifle cartridges since then, but of course crimp heavy revolver loads. I now crimp pistol ammo as a separate step, after seating the bullets. I back out the seating stem, and then screw the die down to touch the shell holder and apply as much crimp as the die will put on 'em. Generally this is with lead bullets, where buckling cases is not such a danger. But with jacketed bullets, I only apply as much crimp as the depth of the bullet's crimping groove will permit.

If you're not getting enough neck tension because of repeated firings, you can try annealing them- I found that its much more effort than what its worth especially when most flavors of brass are readily available.

The only crimps I use are for autoloaders- for the pistols I shot, a slight taper crimp is necessary to get them to chamber reliably- I just make up a dummy round with the case mouth at the correctly spec'd diameter and bullet seating depth to set up my seating dies.

For loading for my M1- I've gone both ways, but seeing that the bolt closes with alot of force, I've decided to put a very slight crimp on the case- I screw the dies down until it meets resistance with the case, then screw it down another 1/4 turn. The amount of crimp is very slight so as to not deforem the case or bullet, but enough to give an extra bit of neck tension.

I've used the Lee Factory crimp die for 8x57 and .308 and have gotten slightly better accuracy with each using it.