sig 522 bulged cases

[aznanimekid]

have had a 522 for a couple years now and never noticed anything weird. was at appleseed over the weekend and one of the instructors noticed my brass was bulging in the rear. scrubbed out the chamber and it still happened so i retired it for the day. here are some pics of a casing i saved:







i noticed on examination that the bulge is directly under the firing pin strike, which would point to the feed ramp. since this uses the atchisson 22 type magazines, i did some research and it sounds like this might be a common problem with AR-type 22 kits with steep feed ramps. does this look like something i should be sending back to sig for? the rifle was shooting and grouping fine prior to being noticed and while i cant say i ever examined my 22 brass in detail, i dont think i've ever seen a rear bulge in my 6 years of ownership.

[GM4spd]

As long as it feeds,fires,ejects,and shoots the next round I wouldn't be
concerned. I've noticed the same thing in my 15/22 and STG 44/22 and
they are still running after thousands of rds. on all types of ammo including
all the usual suspects in bulk. Pete

[aznanimekid]

Federal 375 value pack 36grn high velocity

[aznanimekid]

i did try a random round of CCI blazer i had in the ammo box with the same result, but i didnt crack my minimags open. ill try that next trip. it does allow dry firing but as far as i can tell there is no burr. i dropped one into the chamber manually and it went in perfect as far as i can tell:





while we were testing on the line, we did check for chambering issues by pushing on the bolt/charging handle and as far as we could tell, the bolt was as it was supposed to be. i suppose i'll end up running it until i see some major issues.