Shoulder crumpling when seating bullet

[JDB]

On occasion when seating the bullet on my 204 the shoulder gives way causing the case to bulge. I had 3 rounds do that so far. One was Hornady brass two were on Winchester Brass.
OAL with 39gr Sierra BlitzKings is 2.258 to 2.261.

Any help would be appreciated.

JDB

[jo191145]

Most likely your using a standard seating die with a roll crimp feature built in.
Back your seater out of the press another half a turn and try again.

[JDB]

Thanks Jo

Using the Lee Dies, I will give this a shot.

Also on seating depth, When I test loaded a bullet to check the rifling marks. Odd thing is seating depth done in this matter is exactly 2.260. Does my Rifle just happen to match the Max OAL. Or did I do the measurments wrong?


Thanks.

[JDB]

Disregard the OAL question. I mulled it over in my head about 30 times wondering what I was doing wrong and it hit me. I will do the measurment again. Most Likely with Much different results.