Crimp for non-cannelure 77gr Nosler in semi auto?

[TheGerman]

I have boxes of 77gr Nosler's that I wanted to load for a 18" SPR semi auto and was curious if non-cannelured bullets needed to be. I've always been under the impression that magazine fed, semi auto rounds needed a crimp and therefore most have a cannelure, yet these do not.

Should I just not crimp? Get a Lee Factory roll crimp?

 

[rommel500]

I have never crimped any of my .223 or .308 semi auto loads. I use the 77gr noslers for all my .223 loads. Never had an issue.

 

[armorpl8chikn]

Only if your rifle does not feed properly. Yes a Lee factory crimp die will crimp a non-can bullet. It does not lend itself towards accuracy though as it buggers the jacket of the bullet.

 

[sinister]

Proper neck tension and seating the bullet true are critical for a precision bullet for precision groups.

Crimping can separate the core from the jacket and induce about-the-axis bullet wobble. In the big scope of things not by much, but in the world of precision shooting enough to enlarge your groups and give you off-call impacts (especially if the bullets have thinner jackets and the targets are at longer range).

Cannelures and crimping are for machineguns and weapons and ammunition that are seriously abused.

This bullet is dynamically imbalanced. Its CG is centered, but it's principal axis of inertia (Ip) is at an angle to the bullet's axis of symmetry.

Yaw refers to movement of the nose of the bullet away from the line of flight. Precession is a change in the orientation of the rotational axis of a rotating body. Nutation refers to small circular movement at the bullet tip.