.308 to 6.5 CM.

[HABCAN]

Well, it'd sure be nice to be able to convert scrounged range pickup .308 brass to the shorter 6.5 Creedmoor! BUT, after trimming to length and resizing, the shoulder material of the .308 case making the new 6.5 CM neck........is too thick. The seated bullet expands the sized neck so that the outside diameter is too big by a few thou to chamber in my new Savage 10T-SR. Sixty-plus years of reloading and I don't know how to 'outside turn' the case necks. DUH! Can someone here please explain how to go about it? Is there a special small tool? I have a Lyman case trimmer, if that's any help. My pal has a great big lathe.

[RustyReel]

I'm a make it out of what you have guy as well, and I know nothing about neck turning. That being said, Midway currently has Federal brand 6.5 CM on sale for a very good price....about $19/50 and $91/250. I just took the easy way and ordered 100. YMMV

[GRUMPA]

Here's another option, and yes I've made those before.

When you size them leave the expander out of the die. Get the proper size reamer (math involved) and rream the neck. Remember your squeezing the case and the taper due to altering the neck is in the "INSIDE" of the new neck.

Once you ream the neck, simply resize with the expander in the die.

[Mr_Sheesh]

Inside neck reaming works very well, used that when forming up 243 from 308 in the past. (Reamed to 25 Souper then sized on down to 243, probably because 25 Souper was the reamer we could find, been "a while"...

Another option, for this one just don't way over turn the case necks (you don't want too thin a case neck!) is a "Case Neck Turner" (Pretty sure RCBS, Lyman, Lee, Forstner, etc. all make this for under $100 or so) - Usable for varminting or bench rest rounds as well, it lets you make your rounds all have the same neck thicknesses so the bullet tension will be pretty uniform through all of a loaded lot of rounds. It would also handle the excessive neck thickness from case forming. FL Size before turning, and do not cut into the shoulder very deeply at all, you want a nice uniform shoulder :) You will need a pilot to fit the inside of the cases' neck, and I found some necessity of polishing the pilots up and adding a little bit of lube for turning, so then you have to clean the cases, do NOT want lube in the necks in loaded rounds.

[dh2]

If you was to start with 7mm-08 or .243 Win. it would give you a thinner neck if it is easy to get

[nicholst55]

Here ya go: https://www.youtube.com/results?search_query=outside+turn+case+necks

[HABCAN]

Yessir nicholst55, that's exactly what I was hoping someone would show me. TYVM! And thank y'all.

[Moonie]

I turn the necks on all my 6.5 CM brass anyway so that is certainly my vote on the fix. I had the same issue with 300 BO using some (mainly pmc) brass, fixed by turning the necks. This is far more accurate than reaming. I use a K&M neck turning tool.

[Ianagos]

Question i want to neck turn some brass but how do you make sure the inside of the neck is perfectly round and concentric? i feel like its a waste to turn the outside if the inside is not perfectly round no?

[Mr_Sheesh]

Neck size it first, then turn the outside

[Happyguy]

Try 243 brass.

[Moonie]

Question i want to neck turn some brass but how do you make sure the inside of the neck is perfectly round and concentric? i feel like its a waste to turn the outside if the inside is not perfectly round no?

Outside neck turning uses a mandrel on the inside and pinches the brass between the cutter and the mandrel so it it cuts concentric.