AR bullet neck tension ?

[Gman]

What is common bullet neck tension for hand loading an AR15 @ max magazine length (2.260") ?

I am assuming since it is a magazine fed repeater, that more neck tension is required.

 

[jelenko]

I and many other competitors in High Power Rifle use 3 thousandths.
In Sierra's write up on reloading for gas guns, they recommend 2-3 thousandths less than bullet diameter.

 

[ronemus]

The elastic limit of most brass necks is ~0.002" - any more than that and you're using the bullet as an expander. You'll have to experiment to find what your rifle likes. I shoot moly-coated bullets in my AR spacegun, and the bullets don't move; I really have to work with a kinetic puller to get them out.

 

[Gman]

Thank You for that info !