375 Cheytac down to 338

P3T3R

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Minuteman
Jul 16, 2011
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Kent, United Kingdom
Hi all, have never necked down a cartridge before, and I'm in the process of building a 338-375 Cheytac. So far I have the action, trigger and a barrel. My next purchase will be; Peterson brass, Berger 300gr OTM, Pacific tool and gauge reamer and probably Whidden dies.

I'm assuming running the 375 brass straight in to a 338 sizer is too much in one go, I was probably going to do 1 intermediate step using a bushing in the sizer so 375>355>338.

Anyone that has done this or has any experience necking down cartridges I'd appreciate any tips or guides or might have.
 
That should be a very intersting rifle. I'll bet you could get a few guys here to go in with you on the cost of the reamer if you wanted to share it. Alas, I will not be one of them as I blew the new gun budget early this year.
 
I run a 338 SnipeTac. I couldn't make a neck bushing die work. The lead on the bushing catches the case mouth and folds it over.

I made a forming die by running the chamber reamer into a die blank. If I chamfer the case mouth; I can neck down to chamber size and create a false shoulder in one operation. Then I size the case with a Whidden die.

The Petersen case is thick; so, I run an expander through the neck before seating the bullets.

Cheers,
 
If you have a lathe or a small arbor press, you can use multiple sizes of L.E. Wilson Neck Die Bushings. In a lathe, chuck up the bushing and run the brass in via the tailstock. I go in .010" increments because any more than that can lead to alignment problems, which will result in crushed/destroyed brass.

http://www.lewilsondirect.com/neckdiebushing.aspx

The bushings are $20.00, so cost can add up. But, if you buy one of their Neck Sizing Dies, the bushings are meant for that.

edit/correction; You can use loose bushings on a small arbor press, but you will have to work at getting the bushing off the neck of each piece of brass. Going the route of chucking the bushing in a lathe eliminates that problem.
 
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With a good custom FL die, you can go from 375 to 338 in one shot. As long as the brass is good and you use some imperial, you should be able to do it. I've worked with 338 Cheytac a bit. Peterson brass seems to be pretty good. After turning and annealing, it seems quite responsive.
 
That should be a very intersting rifle. I'll bet you could get a few guys here to go in with you on the cost of the reamer if you wanted to share it. Alas, I will not be one of them as I blew the new gun budget early this year.

I'm over in the UK otherwise I'd be more than happy to share, although if I was in the US I would probably be building a 375. Its hard enough to find a range over here to shoot 338 let alone anything bigger, there are some but none near me. I want something other than the lapua magnum though.
 
If you have a lathe or a small arbor press, you can use multiple sizes of L.E. Wilson Neck Die Bushings. In a lathe, chuck up the bushing and run the brass in via the tailstock. I go in .010" increments because any more than that can lead to alignment problems, which will result in crushed/destroyed brass.

http://www.lewilsondirect.com/neckdiebushing.aspx

The bushings are $20.00, so cost can add up. But, if you buy one of their Neck Sizing Dies, the bushings are meant for that.

edit/correction; You can use loose bushings on a small arbor press, but you will have to work at getting the bushing off the neck of each piece of brass. Going the route of chucking the bushing in a lathe eliminates that problem.

I've got a lathe so will most likely use that technique.