To Crimp or not!

[Robert Hood]

The discussion is probably on here, however I thought I'd share a reason to always crimp. Well, especially if you have calibers in bolt and semi auto. I picked this little up on the range. It was a malfunction, FTF. Fed through an AR and stubbed. Had this actually made it into the chamber, it would have provided a surprising outcome. Now it's a compressed load. The bullet is still in contact with neck, and the pressure upon firing would be great, (not in a good way)
The crimp isn't there to keep the bullet in, it's there to keep it from going in any further.
Obviously if one only has a bolt gun, neck tension would be adequate. But if you use the same ammo in both bolt and semi, better safe than have rapid disassembly of parts.

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[RVTECH]

Well, especially if you have calibers in bolt and semi auto.

Lever action and revolvers too!

 

[ROTORYWING]

I have found that I needed to crimp on light bolt guns that are Heavy magnum calibers due to recoil and the bullet shifting forward and breaking the ballistic tip off

 

[deadeye]

The discussion is probably on here, however I thought I'd share a reason to always crimp. Well, especially if you have calibers in bolt and semi auto. I picked this little up on the range. It was a malfunction, FTF. Fed through an AR and stubbed. Had this actually made it into the chamber, it would have provided a surprising outcome. Now it's a compressed load. The bullet is still in contact with neck, and the pressure upon firing would be great, (not in a good way)
The crimp isn't there to keep the bullet in, it's there to keep it from going in any further.
Obviously if one only has a bolt gun, neck tension would be adequate. But if you use the same ammo in both bolt and semi, better safe than have rapid disassembly of parts.

View attachment 1328066

I always crimp using the Lee factory crimp dies on rifle and rimless rounds, straight walls get roll crimp. Shooting rimless out of a revolver can also cause setback which is another reason to crimp. I also use a cartridge gauge when loading mainly for initial set up but especially when loading for semi auto to avoid a slam fire.

 

[HDR]

Neck tension is everything. Crimping has no additional benefit without proper neck tension.

 

[Nwcid]

How do you know it was not crimped? Was it taper crimped or roll crimped?

 

[Nwcid]

Double shot, please delete.

 

[DizzyJ]

1st off, crimp is NOT JUST to keep a bullet from going deeper into the case. It's also used to keep it from being "pulled" further out of the case as well. This is especially true for heavy recoiling revolvers.


Regarding semi-automatic rifles and bolt guns:
Over the years I've found that adequate neck tension is sufficient enough to hold a bullet in place. Problems arise when the feeding mechanism or the alignment of said components are off. Magazines, feed ramps, etc need to work in unison correctly to place the cartridge into the chamber.

A double feed can also cause what is shown in the picture where the bullet is forced back into the case due to hitting an object directly in front of it. I wouldn't blame this on a lack of crimp necessarily.

I've found .0025" to .003" neck tension to be sufficient enough to hold a bullet in place in a properly working semi-auto or bolt action rifle.

 

[Certaindeaf]

Looks like some dimwit forgot to properly size a case.
If I had a heavy kicking tube fed gun I'd probably crimp but I don't.

 

[MTpockets]

Used to call those turtles….

It would makes sense that @Certaindeaf doesn't crimp….I have heard that he likes turtles.

Spoiler: Don't Click This

 

[Pepe-lepew]

I won't roll crimp anything but revolver type cartridges and lever action cartridges. In bottle neck cartridges, most the bullets I use do not have crimp grooves. Without crimp grooves I will reduce neck tension or deform the bullet trying to crimp.

I doubt a bullet pushed the far back will cause a catastrophic failure or any damage. It will push out just like a really long 90 grain bullet that heavily crushes the powder but without the short jump and more mass to accelerate.

 

[ron]

I have been reloading rifle cartridges since 1980. Proper sizing will hold the bullet in place.
I never crimp rifle cartridges. No crimp on 223, 308 and 30/06 all fired in semi auto rifles with
no issues. Try the experiment of 2 identical loads one crimped and one no crimp. Every time
I have done this the no crimp is considerably tighter group.

 

[osprey]

After a lot of experimentation, i am slowly moving away from crimping in all my rifle rounds except 45-70. The round pictured probably would have done that crimped or not. When a properly feeding ar chambers a round it actually has more potential to have oal get longer not shorter. You have to have an over the top crimp to prevent this and accuracy will suffer. I am ok with rounds growing .0005 - .002" when chambered as long as it is consistent. Proper and consistent neck tension is what works for me rather than crimping. As always ymmv.

 

[Caveman Jim]

That settles it, Caveman going to do a test, may even get rid of all rifle crimp dies. I need all the accuracy I can get from my handloads…

 

[ron]

That settles it, Caveman going to do a test, may even get rid of all rifle crimp dies. I need all the accuracy I can get from my handloads…

My favorite 223 handload. Winchester brass, 53 or 52 SMK and 26 grain of W748. Winchester brass
will produce a smaller group than LC in my experience. Good for 300 yards at best but works in any
twist AR barrel. The 53 SMK is a flat bottom bullet and the 52 SMK is a boat tail. In some rifles but
not all the 53 SMK will group slightly better.

 

[Caveman Jim]

My favorite 223 handload. Winchester brass, 53 or 52 SMK and 26 grain of W748. Winchester brass
will produce a smaller group than LC in my experience. Good for 300 yards at best but works in any
twist AR barrel. The 53 SMK is a flat bottom bullet and the 52 SMK is a boat tail. In some rifles but
not all the 53 SMK will group slightly better.

I have been hearing a lot about the W748 powder for bullets 55g and under loads lately.

 

[Pepe-lepew]

W748 has a poor reputation. Every time I mention my success with it, someone poo poos it. Better for ron and me because it keeps the price lower and better availability. I am running a little over 26 grains for 55 fmj and 52 hpbt. The 52's are incredibly accurate.

 

[erslll]

I don't crimp rifle rounds. Never had any problem.


My 223 load is 26 grains of W748 and 55 grain VMAX.

 

[gmerkt]

Neck tension is everything. Crimping has no additional benefit without proper neck tension.

Over the years I've found that adequate neck tension is sufficient enough to hold a bullet in place.

Proper sizing will hold the bullet in place.

If you are using new brass, neck tension will be no problem. Once you get into resizing fired brass, adequate tension isn't guaranteed. Due to variations in sizing dies, expander buttons, original brass thickness. number of times fired. All of which can be remediated one way or another. A separate stage taper crimp into a cannelure is a form of insurance with AR shooting.

This is what sells the Lee rifle "Factory Crimp" die. It hides a multitude of sins by crushing the case into the sidewall of the bullet. A technique actually used on some factory ammo, but in that setting they are usually able to do it at a higher level of uniformity. And, they are not doing it out of a need to force bullet tension, rather to provide that "insurance factor" for feeding.

W748 has a poor reputation. Every time I mention my success with it, someone poo poos it.

I didn't know it had a poor rep. but I've been using it for years with satisfaction.

 

[Capn Jack]

I always crimp using the Lee factory crimp dies on rifle and rimless rounds, straight walls get roll crimp. Shooting rimless out of a revolver can also cause setback which is another reason to crimp. I also use a cartridge gauge when loading mainly for initial set up but especially when loading for semi auto to avoid a slam fire.

Double this in Spades! Especially in the semi-autos, where letting the action slam home can easily unseat a reloaded bullet. This is often a problem with cases fired in an AR15 (A notorious case stretcher) if you don't trim your cases.