Burnt powder residue on case neck???

[mahbin]

Guys I have a question to ask please? I have a custom Mauser in 308 win, and I reload for it. The problem is the neck of the fired brass has burnt powder residue all around it. Am I doing some thing wrong here? Am I not seating the bullet out far enough or maybe full length resizing to much, and getting shoulder bump? The rounds do vary well for me out to 300 and 400yrs, but at those velocity's getting out any farther is pretty much a lob. I am a casual bench shooter and really have no need for any longer shots.
Any comments or suggestions will be appreciated!

Barrel is 24in" Shilen heavy bull, 1in10 twist, it likes long heavy bullets, can get 3 round bug holes at 100yrs

Bullet= 180gr SST

Powder=39grs of RL15 best load for groups, Hornady book says max for RL15 is 41.4gr at 2400fps out of 20in" Barrel.

At 40grs I start to get flat primers, at 41gr I start to get shinny's on case and heavy bolt.

Cases=Winchester new or once fired, full length resized and trimmed to 2.015

Primers=Winchester LR standard

COL.=2.750" book says 2.740" Should I go to say 2.800?

Vel. avg.= 2364fps chronographed at 10' from Barrel

Thanks Marvin

 

[Sniper Uncle]

Both of my bolt rifles have carbon on the case necks too. That is rather common, from what I have read. What could be a problem is if it were to go down onto the shoulder.
Have you tried annealing? That might help, as the necks would be a little more pliable and might seal a little better...but the sot is not really an issue.

 

[M_16_4_REAL]

Its normal for me to see some powder residue rings around the necks of my brass. As long as pretty much all the cases have the same rings its all good. I believe its caused by size of chamber be slightly larger diameter than loaded rounds. Its really nothing to worry about.

As far as shooting distance velocity isn't everything when it comes to accuracy. I'd take a slower moving more accurate load over a hot load that doesn't shoot as consistent. I've never really loaded hot other than work ups but I stick to mild loads as not to put excessive wear on cases and barrels. I've gotten as many as 8 reloads on FC brass and 10-12 on hornady before pockets loosen up. But that's not to say my loads are slow they just aren't even close to max.

 

[mahbin]

Thanks guys, pretty much what I thought. I have considered annealing, but must read more on it. Do you think I should seat the bullet out a little farther out. And will that bring the chamber pressures up too high?
Thanks Marvin

 

[Sniper Uncle]

Going farther out will lower pressure, unless you touch or jam the lands, then great pressure increases may be seen. You want to have measuring devices to see what the COAL is before you try touching or jamming in the lands. Threads about that here on the Hide.


Cheers,
Tim
The Right to Keep and Bear Arms Shall NOT be Infringed

 

[mahbin]

Thanks Tim will check it out!!!