Blown out .308 cases / oversized chamber?

[kd5rjz]

I have a (new) rifle that must have a slightly large chamber. I'm skinning a bit of brass off the cases when I size them after firing, they aren't bulging per se, but just expanding a few thousandths overall - but very uniformly. Would I be better off just trimming for length and not sizing them? Factory rounds seem to have a nice solid fit in the chamber, but I've never seen a sizing die skin a case this much. Perhaps it's just the crappy RCBS sizing die?

 

[oneof79]

I wonder what would happen if you tried to resize a case with a 30-06 die. It wouldn't size the neck or push back the shoulder but should size the body down the same as a .308 die. Maybe it will help eliminate the possibility of the chamber being oversized.

 

[kd5rjz]

I wonder what would happen if you tried to resize a case with a 30-06 die. It wouldn't size the neck or push back the shoulder but should size the body down the same as a .308 die. Maybe it will help eliminate the possibility of the chamber being oversized.

I'll have to give it a try.

 

[DRC458]

I'll have to give it a try.

I would most definitely NOT do that. A .30-06 is actually a little smaller at the web than the .308, so you would be working the brass even harder. A little more information, please. You say it is 'skinning brass.' Where? You then talk about overall length. Is it a matter of length, or case diameter? With the info you give, I would first try only partial-length resizing. You don't necessarily need a neck-sizing die, just don't run the case all the way up into your full-length sizing die. Make sure your cases are under max length, then size only enough so they chamber 'easily.' Are you only loading for one rifle, and what is the use of that rifle? ... hunting, bench rest, or what? If it's for hunting, you want your cases to chamber more easily than what might be acceptable if shooting only from the bench or 'plinking.' A little more detail, and we can be more specific about what you might want to try!

 

[kd5rjz]

I would most definitely NOT do that. A .30-06 is actually a little smaller at the web than the .308, so you would be working the brass even harder. A little more information, please. You say it is 'skinning brass.' Where? You then talk about overall length. Is it a matter of length, or case diameter? With the info you give, I would first try only partial-length resizing. You don't necessarily need a neck-sizing die, just don't run the case all the way up into your full-length sizing die. Make sure your cases are under max length, then size only enough so they chamber 'easily.' Are you only loading for one rifle, and what is the use of that rifle? ... hunting, bench rest, or what? If it's for hunting, you want your cases to chamber more easily than what might be acceptable if shooting only from the bench or 'plinking.' A little more detail, and we can be more specific about what you might want to try!

The cases are under max length. The problem is they're not getting far enough into the sizing die to deprime.

 

[DRC458]

Oh, and I seriously doubt that it is the "crappy RCBS sizing die." I have had very good luck with RCBS dies.

 

[kd5rjz]

Oh, and I seriously doubt that it is the "crappy RCBS sizing die." I have had very good luck with RCBS dies.

I should clarify, it's a "crappy RCBS sizing die" because I got the die set for $10 at a pawn shop, the green box looked like it had been sitting in the back of a truck for a few years, but the dies were clean. It had a large hunk of masking tape identifying .308. lol

 

[DRC458]

The cases are under max length. The problem is they're not getting far enough into the sizing die to deprime.

O.K. A couple of questions. What lube are you using, and do you have the sizing die (I assume it's a full-length sizing die) adjusted so that the shell holder touches it when it reaches the top of its travel? If it is a full-length sizing die, and the shell holder is touching it at the top of its travel, and you are getting so much resistance as you approach the top of the travel that you are afraid of getting a case stuck and, thus, you back off before fully sizing the case, I have to wonder about two things. One, inadequate lubrication; and two, a really sloppy over-sized chamber. If it is inadequate lubrication, that doesn't necessarily mean it's your fault. All case lubes are NOT created equal. You might want to try something different, i.e. Imperial case sizing wax or the mixture of liquid lanolin and alcohol that has been discussed here before. If it is a really over-sized chamber and it really is a "NEW" rifle, I would be looking at letting the manufacturer replace it!

 

[DRC458]

I should clarify, it's a "crappy RCBS sizing die" because I got the die set for $10 at a pawn shop, the green box looked like it had been sitting in the back of a truck for a few years, but the dies were clean. It had a large hunk of masking tape identifying .308. lol

Oh, "crap." That could be another matter. The die bodies themselves should be etched. Are they, without any doubt, .308 Winchester reloading dies?

 

[DRC458]

As for decapping, it should be punching the primers out if the decapping pin is protruding roughly an eighth-of-an-inch ... give or take ... below the bottom of the die body.