6.5 CM from 308

[bflee]

I know this topic has been on here over and over, but I was wondering if someone could lead me along the path to success!
I cut down a couple 308 cases to 260 length and ran them through my 6.5 new dimension dies just for curiosity. The result was a case that looked alot like my 6.5 CM cases. Overall length matched and side by side I could not tell a difference. I was really excited and loaded one to try and it just won't chamber. I think the shoulder is still a little high but thats a hard measurement to make! I am bottomed out on my die so I guess the next step is to buy another die and shave the bottom? Anybody have this particular problem? It is so close to chambering it makes me want to cry. I only ran two steps to get it here so I was hoping for cheap, easy 6.5 brass!

[bflee]

Not 260 length! 6.5 length. Sorry. Both on my mind!

[limige]

Keep us posted. I havent tried.

How'd you cut the cases down?

[bflee]

Lee case length trimmer and a drill. I do everything the hard way! If I can move the shoulder back just a hair I believe I can do it.

[BillPa]

Lee case length trimmer and a drill. I do everything the hard way! If I can move the shoulder back just a hair I believe I can do it.

You'll need a shorter shellholder. When I was playing around making 250 Imps from 243 brass I needed to use a .120" shellholder. I tweaked the FL die down a little at time until I got the amount of shoulder bump I needed.

You could also try putting a shim, maybe .002"-.003" between the floor of the holder and the casehead to allow the brass to enter the die a little further.

Bill

[yobuck]

You'll need a shorter shellholder. When I was playing around making 250 Imps from 243 brass I needed to use a .120" shellholder. I tweaked the FL die down a little at time until I got the amount of shoulder bump I needed.

You could also try putting a shim, maybe .002"-.003" between the floor of the holder and the casehead to allow the brass to enter the die a little further.

Bill

Wouldnt a set of the competetion shell holders work Bill? Just keep trying a different one till the bolt closes?

[bflee]

My shell holder has a little play so I may try to shim my brass up a hair. Thats a good idea. I will try that today and see if I can gain enough to push my shoulder back.

[BillPa]

Wouldnt a set of the competetion shell holders work Bill? Just keep trying a different one till the bolt closes?


Sure would.

Bill

[Arky 223]

Had the same problem making 300 savage out of 308 brass. When I sized down Rem. brass they chambered fine. When I used Federal brass they would not chamber. When I checked the outside dia. of each one the Federal brass was larger. The neck wall was thicker. Check neck thickness. Just a thought.

Arky 223

[bflee]

I checked that Arky 223. All of the measurements I have taken are within a couple thousanths. The inly thing I can figure is the shoulder height. It looks close but that doesnt count. I can almost shut the bilt but not quite. I aim to sharpie one and see if that is the case. It will show me the contact point so I can correct it.

[TC260]

Are you checking these with a bullet in them or just the bare case?

[bflee]

With the bullet.

[TC260]

With the bullet.

Ahhh. Check to see if there's a donut forming at the base of the neck. I've run into that before where the dimensions all seem right and pushing the shoulder back further doesn't help and it's little unseen bulge at the neck/shoulder junction hanging up the works.

[bflee]

Thanks. I see the problem now! What do I do about it, buy some more 6.5 brass?

[TC260]

If it's in fact a donut that's causing the problem then you have to neck turn (or ream but much prefer turning) to get rid of it. If using a bushing die with no expander ball you might be able to get away with not seating the bullet deep enough to push out the donut but that's more of a work-around than a fix.