SPR Loads....Crimp or no?

[nksmfamjp]

Should I use my Lee Factory crimp....collet type...for best accuracy?

Looking for SPR accuracy ....sub 1 MOA at 100 yds.

Build is WOA barrel, Geissele hi speed, 2-8x quality optic....

[jaholder]

Most precision loads don't require a crimp, bullet deformation may degrade accuracy.

With that said, I've got a Mk262 clone using TAC that I got better groups from my 16" carbine by crimping the Sierra 77's with the Lee FCD. My other AR's had no difference in accuracy between the crimped and uncrimped bullets, so I crimp.

I also crimp (with the FCD) my 55 grain Sierra HPBT but the Nosler 55 grain BT's get none.

[bp7178]

Sub MOA is sub MOA regardless of distance.

I applied a light taper crimp, but not to the point where it would deform the bullet. IMO, good neck tension is more important.

[gunnerblue]

I believe that neck tension is more important than crimping in a precision load. I control tension by using Redding Type-S sizing dies which use interchangeable bushings. Typically for an auto loader I will go for about 0.003” worth of tension. This is subtracted from the outside diameter of the neck of a loaded cartridge. I haven’t used the Lee product but a lot of people seem to like them.

[markm]

Buy the die and try it out. There's no correct answer since it depends on dozens of variables in your specific set up. I crimp everything.223. In my set up, I lose gobbs of accuracy without the crimp. I tested it once, and it was dramatic.

[Vegas]

markm, what is the amount you crimp?

Thanks.

[5.56 Bonded SP]

I apply a light taper crimp to all my loads. Some of them shoot submoa. I mainly do it because I feel safer doing so. YMMV

[HKGuns]

I use the Lee factory crimp for all of my 556 and 762 loads. They all shoot sub moa.

[markm]

markm, what is the amount you crimp?

Thanks.

I set the die so that I can just start to see crimp marks on the neck.

[Vegas]

Thanks. You had asked me in another thread a while back about whether I crimped. Think I am going to get motivated to order a LFCD and give it a try.