Ammo for Rossi RM308 (I think that's right)

Value priced adult & youth top break handguns, rifles, & shotguns chambered for centerfire & rimfire cartridges as well as shotshells. These arms are offered as single chamberings as well as a Matched Pair, Pick Four combinations, Trifecta, & the Wizard.
Post Reply
caljac51
Posts: 2
Joined: 28 Jun 2015 11:40
Location: Athens, GA

Ammo for Rossi RM308 (I think that's right)

Post by caljac51 »

I am new to this forum, and was glad to find it. I just bought a new Rossi .308 single shot and was wondering about the safety/advisability of using 7.62 x 51 NATO rounds. I have read differing views about this topic in general. The GUNSAMERICA seller listed the rifle as ".308 cal/7.62 NATO" but there is no engraving on the rifle or info in the owners manual even mentioning 7.62 NATO. And thanks to all members of this forum for providing an opportunity to draw on the combined wisdom and experience of the Rossi community.
User avatar
Ranch Dog
Site Admin
Site Admin
Posts: 9398
Joined: 23 Jan 2012 07:44
Location: Inez, TX
Has thanked: 1837 times
Been thanked: 2281 times

Re: Ammo for Rossi RM308 (I think that's right)

Post by Ranch Dog »

Welcome to the forum and it will be interesting to hear some reports concerning the Single Shot chambered in 308 Win. The Rossi's, both the Single Shot and Wizard, have always been roll stamped as "308 Win" and it is best to use that ammunition.

There is plenty of references on the web about the differences, here is one of the better ones: The Gun Zone
Michael
Image
caljac51
Posts: 2
Joined: 28 Jun 2015 11:40
Location: Athens, GA

Re: Ammo for Rossi RM308 (I think that's right)

Post by caljac51 »

Thanks, Ranch Dog. I have no reason (on this side of TEOTWAWKI) to use anything other than .308. But you know we gun folks are a curious lot.
Calvin
User avatar
Ranch Dog
Site Admin
Site Admin
Posts: 9398
Joined: 23 Jan 2012 07:44
Location: Inez, TX
Has thanked: 1837 times
Been thanked: 2281 times

Re: Ammo for Rossi RM308 (I think that's right)

Post by Ranch Dog »

caljac51 wrote:Thanks, Ranch Dog. I have no reason (on this side of TEOTWAWKI) to use anything other than .308. But you know we gun folks are a curious lot.
Calvin
Let us know how it shoots!
Michael
Image
Archer
2000 Shots
2000 Shots
Posts: 3942
Joined: 04 Feb 2014 05:30
Location: SoCal Loco
Has thanked: 137 times
Been thanked: 610 times

Re: Ammo for Rossi RM308 (I think that's right)

Post by Archer »

I had a nice reply all typed out and the forum ate it.
I'll come back later and have another go at it.

Ok, So let's try this again.
I typically use .308 and 7.62x51 (7.62 NATO) interchangeably.
BUT I do not, as a rule, load heavy hunting loads. I do NOT use .308 light magnum loads. Any such loads would be reserved for the .308 bolt action gun and no other IF I were to purchase or load them.
I generally reload ALL my .308 rounds based on data for the M1A/M14 Gas system.
I do NOT as a rule use foreign military surplus. When I have done so I have acquired it through CMP and reports/reviews on the condition and functionality of the ammo are pretty readily available.

My Springfield M1As are cut for a .308 chamber. At least one of them is more or less minimum head spaced or Match chambered. I do not own a weapon that is chambered for 7.62x51 but is also outside of .308 spec.

I had researched this before but with limited success. The Fultan Armory comments I had seen before. I had also seen comments in all the reloading manuals concerning the thickness of commercial vs. military brass. What I've seen in the past with .308 (and .30-06) is that brass from Lake City, Winchester and IMI has all weighed the same and appeared to have the same construction. Federal cases have been the same weight as the others but have had softer heads than the others. (This was some years ago and recent Winchester cases have not had as good reviews as the product did a decade or two ago.) Thus the thickness has generally been the same but commercial case heads tend to get ripped up more quickly in semi auto rifles.
http://www.thegunzone.com/30cal.html (The link from RD above)
http://www.cruffler.com/trivia-June01.html (Link from inside the above article)
http://zediker.com/downloads/14_loading.pdf (Reloading for the Match M14)

From the articles it appears that:
A) The pressure limits for .308 exceed by a fair margin the pressure limits for 7.62 NATO.
B) The chamber sizes for 7.62 NATO are larger than those for .308 Winchester although the cartridge size is exactly the same.
C) While 7.62 NATO ammunition IS standardized there are variations in the application of that standard both in terms of dimensions and pressures. Interchangeability and functionally the same are two different things. While we often see the NATO cross we rarely see the functionality clover.
D) There has been surplus ammunition which has been known to exhibit dangerous overpressures for ANY firearm system.

Thus it appears that with the exception of D) above.
1) 7.62x51 loads are safe to fire in .308 weapon systems.
2) .308 high pressure ammunition may not be safe to fire in 7.62x51 NATO weapons when the NATO chambers exceed the .308 Spec as brass failure may result from the combination of a) stretching b) thinner/weaker brass c) additional pressure (over and above NATO spec.)
3) .308 high pressure ammunition can result in damage to a NATO weapon's gas system

The following happened at a range I've been to and the owner was a fellow I'd shot with at a few range events: http://www.thegunzone.com/m1akb.html
User avatar
Coop 45
Posts: 124
Joined: 25 Aug 2014 05:38
Location: Australia
Has thanked: 14 times
Been thanked: 37 times

Re: Ammo for Rossi RM308 (I think that's right)

Post by Coop 45 »

7.62 = Thicker case, lower possible max load, but is often loaded to near it's max.
.308= Thinner case, higher possible max load, but is almost always loaded lower than it's max.

7.62 chamber = higher dimensional tolerance (loose)
.308 chamber = lower dimensional tolerance (tight)

So yes, you can fire 7.62 in a 308 but not recommended for the other way around.

Having necked down ADI 7.62 brass and standard 308 brass to make 7-08 brass I can tell you that the military brass is significantly thicker.

Just for your information it is not the same for .223 and 5.56. The military spec round is loaded hotter (not by much ~ 5%, but this is enough to cause problems).
"Shoot straight you bastards, don't make a mess of it" Captain Harry "Breaker" Morant, last words to his firing squad.
92 45 Colt 20" stainless
Archer
2000 Shots
2000 Shots
Posts: 3942
Joined: 04 Feb 2014 05:30
Location: SoCal Loco
Has thanked: 137 times
Been thanked: 610 times

Re: Ammo for Rossi RM308 (I think that's right)

Post by Archer »

Coop 45 wrote:...

Just for your information it is not the same for .223 and 5.56. The military spec round is loaded hotter (not by much ~ 5%, but this is enough to cause problems).
I had intended to bring this up.
There are two problems.
The first is as you note 5.56x45 (5.56 NATO) tends to be loaded to a higher pressure.

The second is that as 5.56 NATO has continued being developed for the military there is more lead to allow heavier bullets to be used. This is the result of green tip ammo (62 grain steel core) penetration requirements (~3mm of steel at 600 yards) AND the use of heavier grain ammo for long range.

The combination of higher pressure and longer lead generally mean that 5.56 ammo in a .223 chamber is going to show even higher increased pressure as the bullet starts with at best less running room for the lands and at worse is already butted up against them or even hard engraved before being touched off.

The Wylde chamber is designed to shoot either but potentially get better accuracy than the GI chamber.

It's a case of knowing your firearm and the ammo you intend to shoot through it and it is even more important for the .223 vs. 5.56 NATO than it is for the .308 vs. 7.62 NATO IMO.
Archer
2000 Shots
2000 Shots
Posts: 3942
Joined: 04 Feb 2014 05:30
Location: SoCal Loco
Has thanked: 137 times
Been thanked: 610 times

Re: Ammo for Rossi RM308 (I think that's right)

Post by Archer »

I've not seen any Australian Defense Industries brass.

I did pick up some P.I. arsenal brass a couple years back both in .308 and .30-06 from a retiring match shooter.
In addition to the brands I listed above I've used brass from Remington, PMC, Prvi Partisan and MagTech.
Never been a particular fan of MagTech and Prvi Partisan is not my first choice.

One of these days I might have to pick up some Lapua brass and dedicate it to my top bolt guns but it doesn't make economic sense for plinking or for use out of the military semi auto actions.

There's been some Turkish 7.62x51 and 5.56x45 stuff showing up in the States the past year or two mostly sold through Walmart. Reports on the brass have been generally good with the ammo rated as decent plinking to a step or two better but possibly dirty compared to domestic production. I don't think they are NATO marked in any way whatsoever. When Walmart was selling it at $24 for 20 it was pretty ridiculous. They put it on sale last year for around $10/20 rounds and that made it tempting. Last I knew it was back up around $18 a box.
Post Reply