Another 7.62 NATO thread, but I really DID search/read!

[emmagee1917]

Yes , inserts have been known to come out with the last case fired once in a while. Least wise , you hope it was the last case fired , otherwise you'll have some rimless 45-70 looking brass at best.
Chris

[browningautorifle]

But on the upside Chris, at least there's no danger of blowing something up. It will function normally and you won't even notice. I have a Kreiger barrel myself, but I HAVE run an insert for thousands without incident. The rifle in question here is probably going to be fine...try it and see.

[emmagee1917]

That's good to know . I know that when a .308 is chambered in a 30-06 , the case sides wedge in and gives a false "headspace " allowing the front to just blow out while sealing the chamber. I was not sure if the boring and adding of the chamber insert caused this to change if the insert came out , but I had not heard of a major problem.
Chris

[Redleg]

.308 Garand history. - Page 2 - M14 Forum

The above link has info by Gus Fisher at #22, regarding his experience with the Navy conversions.

[JamesB]

.308 ---------------------------------- 7.62
GO 1.630
1.631
1.632
1.633
NO GO 1.634
1.635 --------------------------------1.635 GO
1.636 --------------------------------1.636
1.637 --------------------------------1.637
FIELD 1.638-------------------------1.638
---------------------------------------1.639
---------------------------------------1.640
---------------------------------------1.641
---------------------------------------1.642
---------------------------------------1.643
-------------------------------------- 1.645 FIELD REJECT


http://www.thegunzone.com/30cal.html

Let's address the oft-posed question "Are the .308 Winchester and 7.62x51 NATO one and the same?" The simple answer is no. There are differences in chamber specs and maximum pressures. The SAMMI/CIP maximum pressure for the .308 Win cartridge is 62,000 psi, while the 7.62x51 max is 50,000 psi. Also, the headspace is slightly different. The .308 Win "Go Gauge" is 1.630" vs. 1.635" for the 7.62x51. The .308's "No-Go" dimension is 1.634" vs. 1.6405" for a 7.62x51 "No Go" gauge. That said, it is normally fine to shoot quality 7.62x51 NATO ammo in a gun chambered for the .308 Winchester (though not all NATO ammo is identical). Clint McKee of Fulton Armory notes: "[N]obody makes 7.62mm (NATO) ammo that isn't to the .308 'headspace' dimension spec. So 7.62mm ammo fits nicely into .308 chambers, as a rule." You CAN encounter problems going the other way, however. A commercial .308 Win round can exceed the max rated pressure for the 7.62x51. So, you should avoid putting full-power .308 Win rounds into military surplus rifles that have been designed for 50,000

Actually the pressures for both 308 and 7.62x51 are closer than this indicates. the NATO ammo was originally measures via CUP (copper crusher measurement), SAAMI uses transducers. Most ballistics experts (or internal ballistic calculators) show very little difference.

[browningautorifle]

very little difference.

That's sort of what I figured. It's amazing what can be "Shown" with a bit of manipulation of facts and figures...

[bczrx]

Thanks for the info everyone!

I finally got out to the range and put about 6 clips through it without problems. I was actually quite surprised at how smooth it felt. I was expecting a harsher recoil, as it has a steel buttplate.

My experiences with Mosin-Nagant and Mauser K98 with steel buttplate traumatized me.

I was happy to find it felt no worse than my short-barreled [16.5"? 18"? Completely legal and factory original, but forget] Saiga .308/7.62x51. Yes, I understand they are different calibers/cartridges. The Saiga is labeled with BOTH on the receiver. Saiga is unconverted, so it has a sporter hunting rifle stock [wooden] with a rubber buttplate: not the 'traditional' AK look.

Steel feels as comfortable as rubber butt pad. NICE!!!

I was happy with the accuracy, but was primarily testing for function, with half of the rounds brass reloads my dad made up [168gr, etc, etc. Specs are in the ammo box as to powder and grains] and half Wolf polyperformance 7.62x51 150/145/149grain [one of the three]. I made the metal plate gong about as well as I had hoped at 200 yards with open sites.

A LOT of fun.

Now I have to read up on the design before a create a new redundant thread, to figure out why it ejects to 5 o'clock, instead of 1-3 o'clock. My preliminary research seems to show it is linked to the shorter case.

Gun completely cleaned and lubed with the lubri-plate, or whatever the original g.i. spec lube was.

Barrel has NO conversion marks from the project, but IS labeled 7.62 NATO. The closest thing to a date on it is early 1950s.

Fun!!!

I like it. Now to clean up the stocks.

[browningautorifle]

Thanks for the come back on that...

[Bob Womack]

The reason for the soft recoil is that the semi-auto action absorbs a good chunk of the recoil so it feels like a shove rather than a whack.

Bob