Problem forming 308 brass to 260

[Brians356]

I would try sizing it with a standard Fl die. NOT a bushing die. at least the 1st
time. a bushing die don't size all the way to the shoulder.
hh

I agree, a Fl die is better for forming down cases. The bushing die obviously works, but a good FL die really does form the neck/shoulder junction properly.

 

[Brians356]

My first attempt with this process was done with a FL 260 die, but even that never sized the neck the whole way to the shoulder.

If you engaged the FL die all the way to the shell holder, and overcammed it slightly to boot, yet it did not fully form the neck/shoulder junction, something's amiss.

Was the 308 brass fired in a standard 308 Win chamber?

 

[CKshooter]

42.8 gr H4350 & 139 Scenars. Same load I've been shooting from my 260 brass. Ran both over the chrono and the 308 brass was about 20 fps faster (2830 vs 2810) than the 260.

I don't have a book in front of me. Is 42.8 close or over max charge for your rifle? Brass can vary in thickness. If your reformed 260 brass is thicker, and there's not as much room in the case it could be a pressure issue.

 

[jr600yd]

I’m following this. I’ve got a 260 and ammo cans of once fired
308 brass.

Never had good luck with H-4350 in the 260. Try H-4831sc start at 42grs and work up

Good luck Jim

 

[sbhooper]

I re-barreled a rifle to .260, strictly because I have a lot of Hornady, .308 brass. I now have two, .260s. I pass the brass through a standard Lee die and then turn the necks a bit. I have not had any issue with it so far and the rifle shoots better than I can aim. I would definitely start lower on the powder, just to see if that is an issue and then go from there.

 

[dstoenner]

I’m following this. I’ve got a 260 and ammo cans of once fired
308 brass.

Never had good luck with H-4350 in the 260. Try H-4831sc start at 42grs and work up

Good luck Jim

Funny, I couldn’t get my 260 to shoot till i found h4350. I had tried Varget and h4831 with no real success. Then a guy at the range said the standard load for 260 is any 42 gns of any 4350 powder with a 140. With 42.5 loaded long i was shooting better at a 1000 than i ever had. The second 260 barrel liked all of the loads the first liked

David

 

[riflewoman]

Not the case body. I have a custom Whidden FL die, and I measured the base on both cases. They were identical.

Maybe I should clarify what I'm calling heavy bolt lift. 90% of the bolt rotation is fine, but that last 10% is VERY sticky, and extraction can be tough.

What you’re experiencing is stiff primary extraction. This is usually body issues not neck and shoulder. I’d suggest a SB die.

 

[ballison]

Thanks guys, but this is a 4-year old post. 260 has been gone for almost 3 years.

 

[Dgd6mm]

Thanks guys, but this is a 4-year old post. 260 has been gone for almost 3 years.

LOL