To crimp or not to crimp?

Hey guys,
I will be handloading for an AR-15 soon and I am just curious if you guys crimp your handloads or no? On a side note does anyone load subsonic .223 at all? Or is it more of a waste of time?
Thanks guys!

@thefamousgrouse

My .223 is not crimped

I got a friend that is very into black rifles…He says subsonic ammo he uses will not cycle his semi auto. “Kinda defeats the purpose, huh?”

Forgot to add that he is using a suppressor also.

Thanks guys! on a side note any idea on loads for a 1:7 twist rate? i usually use sierra bullets so maybe match kings or game kings. Any thoughts on weight?

I use simple Hornady 55 grain FMJ for my 1:7 twist AR Carbine. “Cheap and Effective”.

I read many years ago,that crimping was done to keep the bullet from walking out of the case on heavy recoil guns.I crimp the 44, and 357, and also have a 7mm tcu,and crimp those. 22.250, I never crimp.seems sometimes my groups open up with crimps on the 250.

I don’t crimp any .223. For the AR platform specifically, I’m trying to max out how far I’m seating the bullets within the limits of the mags I use, so the cannelure (on bullets that have it) is too far forward to be of use.

The only ammo I crimp are rounds destined for big revolvers or tube-fed repeaters like a lever action. If I had to load heavy magnum safari calibers, I would also crimp those.

Grouse

Guaranteed that the very best shooters firing in the National Match Course will NEVER crimp ammo for the AR-15. It has a tendency to alter ballistics to a high degree for a long string of shots. Even when cycling from the magazine into the rifle, bullet-setback is not an issue.