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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

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

Pete wrote: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 ?

Hi Pete I have this tool, will this work ?

1/2" 12mm countersink deburring tool ?

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

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.

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 !

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

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

Alpha1 wrote:They are probably no use at all. But it's your money.

What would you suggest then ?