Bullet setback in ar10

[jeremyschudmak]

Recently noticed my ar10 is having fliers. I've noticed that ammo in the mags are getting setback. Any info on how to help this would be appreciated.

 

[DangerClose3/5]

Just to clarify, the bullets are getting pushed back into the brass from the rifle cycling? Handloads or factory ammo?

 

[103M 95G]

Have you tried a different magazine?
Hand loads crimped?

 

[jeremyschudmak]

Factory ammo. The ammo seems to be getting setback while in the mags from firing.almost like the bullets are pushing against the mags

 

[Bigchillin83]

prob a bad crimp job from factory... that's why a lot of people tend to use mil spec m80 7.62 nato or the MSR (modular sporting rifle) ammo designed for semi auto to make sure there isn't any over pressure issues, be careful, a bullet seated to far could make a nice gun worthless and you hurt real fast

 

[Request Dust Off]

I have never had to crimp rifle rounds and never had set back
neck tension alone should hold the bullet very tight - But I am not dealing with an AR10 - Still though have not had it with M1 Garand and such.

is it just 1 kind of factory ammo or several types you get setback on.

 

[jeremyschudmak]

It's not setting back very far, but enough for me to notice. Not to the level of dangerous but affecting accuracy a bit

 

[Blue Diamond]

Try taking a round and push the point down against a table with your hand. If it sets back easily take them back to where you got them from or refrain from using them. It should take a LOT of force to manually set the bullet back. They are normally set in a press which puts a lot of pressure to seat and crimped. If set too deep the bullet has to jump quite a bit to contact the lands causing loss of accuracy and greater pressures from diminished case capacity.