Bullets shaving on inner case / resistance when seating .308

[dirtbag]

Hi all, annoying this.
I was wondering if anyone can shed some light on a small issue I have please.

Every time I seat heavy bullets for .308 there is a lot of resistance when seating. They go in, but a small faint ring on the bullet tip, and sometime some copper shavings on the outer case mouth. However, assortment of shorter 147 - 150gr bullets seat fine with no issues. These few I am only testing short range for speed , but obviously long range I'd be better off throwing ammo over the fence.

I do not have this issue with any other of my rifles I handload for, just this caliber with expensive bullets !.
The brass is once fired and full length resized, I have tried the following brass :

Remington
GGG
Lapua

All trimmed, chamfered ,deburred, but with the same issue

Dies I have.
RCBS .308 small base
LEE RGB .308

Problem Bullets 175gr Sierra Matchkings

Thanks in advance

[Pete]

Are you tumbling the cases to clean them? I had this problem a while back. The tumbling (wet with steel pins) was peening the rim of the case over slightly, and the 45 degee de-burrer wasn't removing all of the burr. I got round it by annealing the cases after 4 or 5 firings and deburring the inside edge with one of these:

https://www.ebay.co.uk/itm/Taper-Reamer ... -enlarger/

Pete

[dirtbag]

Are you tumbling the cases to clean them? I had this problem a while back. The tumbling (wet with steel pins) was peening the rim of the case over slightly, and the 45 degee de-burrer wasn't removing all of the burr. I got round it by annealing the cases after 4 or 5 firings and deburring the inside edge with one of these:

https://www.ebay.co.uk/itm/Taper-Reamer ... -enlarger/

Pete

Hi Pete ,Yes I wet tumble with the Chicago rock tumbler and pins. The brass comes up like new.
So simply buy one of these and a few rotations inside ?

[dirtbag]

Hi Pete I have this tool, will this work ?

1/2" 12mm countersink deburring tool ?

[Ballistol]

Depending on the bullet you are seating, this can help greatly https://www.lymanproducts.com/brands/ly ... fer-reamer

[rox]

I've never had a problem from wet tumbling (and I never chamfer), but I do use a .307 carbide floating expander mandrel and (sometimes) something similar to an M die. Both of these might be an alternative way to solve the problem, and might lead to more consistent neck tension too.

[dirtbag]

Hi all I have purchased the cheaper reamer for now as I think that should solve the problem. Many thanks as I would of never of thought the tumbling would or could of caused this issue !

[Pete]

Sorry the first ebay link didn't work.......this is the reamer I bought.

https://www.ebay.co.uk/i/361894229840

The shooting specific types are intended to just remove the burr created when trimming the case.

Pete

[Alpha1]

They are probably no use at all. But it's your money.

[dirtbag]

They are probably no use at all. But it's your money.

What would you suggest then ?