Neck Length - 7mm Mag H4831 139 gr SST

[gringle]

Thoughts... Using base Hornady dimensions from their manual, I notice that my neck length is too short by 0.015". The shoulder to head is correct it is just my neck length. This results in a shorter bullet seating which would allow the projectile to release quicker as the fired round builds pressure. For a slower burning powder like my 7 mm Mag with H4831 could this be anything other than an accuracy issue? If it shoots accurate is there a safety problem looming with this brass. Or do I scrap it. Thoughts please.

[ArizonaGunOwners.com]

[JesseL]

To sum up, your concern is with neck tension?

Brass that's over the max length can be a safety issue (due to the brass getting crammed into the throat and essentially giving it way too much crimp), but under max isn't a safety concern at all.

I'd trim them all to the length of the shortest one, load em up and fire them, then just neck size them and keep them trimmed under max for subsequent loadings.

[car-ram-rod]

your fine, just like jesse said as long as your brass isnt to long. after seating the bullet id check to make sure the brass has a good bite. thats it. your not changing your seating depth. so its gonna jump the lands just like before. hope that helps

[gringle]

Thank you everyone. Excellent feedback.

[steve2md]

I agree with the above. Trim them all to match the shortest one, then load as normal. just neck size. after 1 or 2 firings/sizings, you should make up that .015, then just trim to your usual standard

[ArizonaGunOwners.com]