Can I form 300 Savage ffrom 7.62 NATO?

[wm]

It seems plausible to me.....just run the 7.62 NATO into a 300 Savage die and then trim to proper length.

Or am I missing something and about to screw up?

Wm

[Glenn]

Wm,
Yes you can. However I believe 7.62 brass is thicker and so your case capacity will be less than 300 Savage brass. Weigh a formed and trimmed case and compare to a 300 Sav. case. You'll need to start with starting loads and work up carefully.
Glenn

[Model 52B]

Not really.

First, 7.62 NATO cases are thicker than .308 Winchester cases as they are designed to be fired through full auto weapons that may have excessive headspace. The thicker walls reduce the chance of a head separation, but they also decrease the internal volume, making load development of your resulting .300 savage cases somewhat problematic.

Second, even if you use .308 Win cases, you'll find that while the case rim diameter is the same, the case dimension at the base of the case is .470", not .471" as it is in the .300 Savage. That's probably not a deal breaker, but it's less than ideal. Worse, the dimension at the base of the shoulder is .454" for the .308 compared to .446" for the .300 Savage. What that means is that when you try to reform a .308 into a .300 Savage, you have to increase the taper along the entire case, along with increasing the shoulder angle from 20 degrees to 30 degrees. Bring a pretty hefty compound press and a lot of lube if you really want to do that.

Third, once you've got them re-formed, you'll discover the necks of .308 brass are thicker than .300 Savage brass by about .002, so to prevent excessive neck tension and keep the diameter of the .300 Savage round down to the required .339" dimension (compared to .343" for the .308), and/or to prevent problems chambering the rounds, and/or excessive pressure in a tight chamber, you'll have to turn the full length of the neck as well as trim it to length.

(And numbers 2 and 3 are aggravated by using 7.62x51 NATO cases rather than .308 given their thicker case walls.)

In short, in a post apocalyptic scenario where I have lots of .308 brass and only a .300 Savage to shoot, I'd give it a go. But short of that, I'd just scrounge up some proper .300 Savage brass.

----

To put it differently, way back in the day I had access to a lot of .308 and 7.62x51 NATO brass and owned a .243 not a .308. That was in most respects a much more straight forward case forming operation in terms of starting and final dimensions, although you need to anneal and then neck down in stages (7mm, then 6mm) to reduce neck splits, but it was still not worth the trouble.

[wm]

Thanks guys.......I have a bunch of Lake City 7.62X51mm and I thought why order some 300 Savage if all I need do is invest a evenings worth of resizing and trimming effort.

I'll just order some Winchester brass and feel better about it because it is properly stamped.

Wm

[Retro]

FWIW my R-P 300 Savage brass was made with 308 tooling, the cases bulge just a little bit at the base.

[msmith1228]

I've done with 308 and it works fine, just trim and turn down the necks.

[Charles]

Yep, you can. To find out, I went to the shop and pulled out a LC 73 7.62 case and a Lyman Shell Resizer in 300 savage. The case came out with no increase in neck thickness (.015) and the base reduced .0005. Trim to length and you are good to go.

I have a collection of 40 of theses Lyman hand sizing dies in various calibers and they come in handy at times. You don't have to guess, you can get the answer by doing it.

[BAGTIC]

Don't worry about the head diameter. It will fit. A relative bought a M99 Savage in .308 back in the early 60's he came to me with some weird cases and asked what was wrong with his new gun. I told him "Nothing, you just loaded it with the wrong ammo. This is a .300 Savage case and your gun is a .308 Winchester." His answer was that no it isn't a Winchester it is a Savage it says so right on the barrel." The fired case stopped just short of the beginning of what should have been a neck.

[Ben_Rumson]

When the NRA staff wrung out the Savage 99 in 308 Winchester (which was about a month after it was introduced in the Win 88) Julian Hatcher deliberately fired 300 Sav rounds through the rifle to see what would happen... the old boy thought it was humorous that the rifle grouped better with those rounds than the308s it was intended for and described the cases much like you have...