Crimping rifle bullets to increase accuracy?

[boisepaw]

I know crimping might be wise for a semi-auto like an M1 Garand. But for either a semi-auto or a bolt gun, will crimping help with accuracy because of more uniform and perhaps slightly greater neck tension?

 

[KRC]

No

 

[Harrys]

I know crimping might be wise for a semi-auto like an M1 Garand. But for either a semi-auto or a bolt gun, will crimping help with accuracy because of more uniform and perhaps slightly greater neck tension?

If you are truly trying to reload for accuracy , then crimping will do nothing but deforming the bullet you wish to be consistent. You can figure out what your neck tension you have by measuring , then measure your bullets pressure ring if it has one or the bearing surface. Then measure the inside of the neck and subtract the neck diameter from the bullet and you should end up with .003 to .004 thou neck tension which is more than adequate.

Benchrest shooters shoot EXTREEMLY small groups. Do they crimp? (NO)
High power shooters have stages of rapid fire. Do they crimp (NO)
F class shooters (some call belly bench rest) do they crimp? (NO)
Hunters? I doubt it
So who does?
Well the military uses crimped ammo, not for accuracy but to avoid ammo malfunctions in automatic weapons.
Factory ammo has a crimp, again not for accuracy, that ammo has to function in ALL rifles of a specific caliber.
Crimping may help a particular firearm but that is not the general rule. If it was believe me the bench rest guys would have been doing it a long time ago. Typically straight wall cartridges are crimped mainly used in lever action guns to prevent bullet compression.

 

[ohen cepel]

Consistent case prep and possibly annealing the brass if old or high pressure cartridge I think would be more useful.

 

[John from MD]

Crimping rifle bullets is not a good idea if you want the best accuracy.

 

[4g64loser]

Do not crimp if loading for accuracy.

Neck tension consistency is key to achieving minimal vertical (functionally, this translates to low ES) at distance. I neck turn most of my rifle brass, anneal it every firing, and use a bushing to size it without an expander. I'm about to process a bunch of lapua brass for a guy who does not neck turn and I will be setting final neck tension with a mandrel instead of an expander ball.

The only rifle ammo I crimp is for machine guns.