7.62x39 improved

[meles meles]

Hmmm, perhaps a Yugoslav M48 Mauser? Readily available at a good price, and not so rare that changing it would be naughty. However, would it feed the short rounds easily ?

[dodgyrog]

Hmmm, perhaps a Yugoslav M48 Mauser? Readily available at a good price, and not so rare that changing it would be naughty. However, would it feed the short rounds easily ?

I'd go for an old Parker Hale, Midland or BSA that needs re-barreling - use one in 308 or 243 and hopefully the rounds will feed - I see no reason why they shouldn't.
PM me if you want to discuss terms

[meles meles]

We thought the rounds, being shorter than .308, might rattle around in the magazine and jam up...

[dodgyrog]

We thought the rounds, being shorter than .308, might rattle around in the magazine and jam up...

That's the point of a project - find the problems and fix 'em!

[Laurie]

want a 7.62X39mm improved? There are two already out there with reamers - 6.8mm Rem SPC and 308X1.5-inch. The former was developed to improve on the ballistics of 5.56X45mm with 77gn bullets in M4 or still shorter barrel AR based carbines used by US special forces, but also crucially that it should offer better ballistics, longer range and more retained energy than the 7.62X39 in military loadings. 6.8mm SPC II or 6.8X43mm chamber versions achieve both objectives comfortably. In a bolt-action though, there is a case-head dia. issue and you're back to the Cz527 Carbine in 7.62X39 chambering to get a bolt with a matching face.

.308X1.5 is a real performer and will easily knock the socks off the Soviet round. Very accurate, light recoil and uses the standard 308 etc 0.473-inch dia. rear-end so it's a rebarrel of any 243, 308 etc etc rifle. An alternative is .30 BR, again very accurate, light recoil etc and 0.473" case-head diameter.

[meles meles]

The objective is not to outperform the 7.62x39 in terms of range, et cetera, but to have a cartridge that can be used to launnch a heavy, sub sonic bullet / boolit with reasonable accuracy (minute of Farmer Giles) out to a maximum range of 300 mards.

[saddler]

want a 7.62X39mm improved? There are two already out there with reamers - 6.8mm Rem SPC and 308X1.5-inch. The former was developed to improve on the ballistics of 5.56X45mm with 77gn bullets in M4 or still shorter barrel AR based carbines used by US special forces, but also crucially that it should offer better ballistics, longer range and more retained energy than the 7.62X39 in military loadings. 6.8mm SPC II or 6.8X43mm chamber versions achieve both objectives comfortably. In a bolt-action though, there is a case-head dia. issue and you're back to the Cz527 Carbine in 7.62X39 chambering to get a bolt with a matching face.

I have the only Rem 700 Police LTR in the UK chambered for 6.8SPC
A very, very nice round. Accurate & hard hitting...modest/mild recoil, just a little more than 223.

The .277 bullet weights range from 77gr up to 200gr...more common weights being 85gr, 90gr, 115gr & 135gr. I tend to use the two latter in SMK form, plus the occasional Hornady match 110gr.

I also have a SPC II chamber reamer, but have not used it in the LTR as there has been no need up to now, as I'm not pushing the velocity/pressure envelope for max. loads just yet.

What case head dia. issue? Never run into this issue as yet.

The CZ527 is ONE possible route, another more common option in the USA esp. is the Savage bolt action. There are also versions of the Mini-14 in 6.8SPC.
The round is about to enter mainstream service with the Czech military...a nation that knows a thing or three about gun designs that work!!

Suggest anyone interested in the 6.8SPC looks up the archives on the 68forum - I'm on there with the same user name as on here.

[dodgyrog]

Why is everybody so keen on re-inventing the wheel??? There's nothing new, really. Just variations on a theme.

[Laurie]

6.8 SPC is maybe older than people think - in concept anyway, and it's not so much a reinventing the wheel rather resurrecting previous work and (maybe) correcting half-century old mistakes.

One of these things that not many people know (Michael Caine sonorous tone here!) is that we did a huge amount of theoretical and practical work on military cartridges immediately after WW2, the Army + Enfield Lock 'Ideal Calibre Panel' members coming up with 0.277" as the ideal calibre for a new generation of infantry rifles with 110-120gn bullets at around 2,800-3,000 fps.

This wasn't for special forces' specialised weapons, but for a GP 1st gen assault rifle plus magazine and belt-fed squad support weapons, light and GP machine guns too, the intention being to have it adopted as the new NATO standard cartridge. As a result, and to meet long-range requirements, the calibre morphed up only slightly and we ended with the .280/30 British Experimental or 7X43mm, adopted as the 7mm Mk1z and which was very briefly the British forces' standard cartridge, nominally at any rate. It gave a German designed very streamlined 139gn FMJBT bullet that the Belgians dug out somewhere a nominal 2,530 fps from the EM whatever it was. Note the mention of Belgians who alongside the Canadians were very supportive and FN built its pre-production FAL rifle around this cartridge, the original prototypes using the WW2 German 7.92X33mm Kurz. That was when the FAL was what it said on the tin: F for Fusil (a rifle) that was A for Automatique (a true selective fire assault rifle that worked accurately and effectively in full-auto mode); and L for Legere (Light - which it was).

Not the over-length, heavy, semi-auto only FAL that we and 70 other odd countries adopted - all thanks to our US allies who vetoed anything smaller than .30 calibre and with less performance than the .30-06 M2 cartridge, hence 7.62X51mm NATO - a great bolt-action and GPMG number, but FAR too powerful and generating FAR too much barrel heat for a light selective fire individual weapon.

50 years on, other people (in the US forces ironically) came to a similar conclusion albeit by a different route and probably without any knowledge of and reference to the British work. Not that we were the first to get there anyway as John Pederson had come up with his .276 in 1923 to replace the .30-06 with his own design of semi-auto rifle to replace the M1903 Springfield, and that's also what John C. Garand intended to chamber in what later became the M1 rifle. The Pederson was pretty close to today's 7mm-08, but was rightly regarded as a very short, light, low recoiling design in the 1920s.

The issue is ALWAYS the same - how to get the external ballistics that meet all military needs in a single package that works in both individual rifles and crew served weapons while being small enough and producing a level of pressures, recoil energies, and heat that can be accomodated within a light hand-held rifle. 7.62X51mm has the ballistics and wounding / killing power but is too powerful for assault rifles, 5.56mm has the range and kills like nobody's business at short range, but lacks stopping power at medium and long ranges - as US forces have found in Iraq and Afghanistan. The Soviets, being a pretty pragmatic lot, simply accepted there isn't, probably never will be, a one-shop does everything cartridge and have kept three going despite the logistics issues - 7.62X39mm and later the 5.45X39mm for individual assault weapons, 7.62X54R for GPMG and vehicle anti-personnel MGs and 12.7mm for crew served vehicle and unit AA / anti-materiel automatic weapons.

Interestingly, noting that as Saddler says the Czechs and maybe some others are adopting 6.8 SPC as their standard rifle cartridge, I understand that the US has officially withdrawn it totally now, allegedly on logistic complexity issues, but one really has to wonder if it's a dog in the manger not-invented-by-a-Pentagon-committee-chaired-by-a-two star general issue, After all if we can have a couple of warrant officers, some armourers' and civilian shooting suppliers support produce something that works at a reputed intial cost of $5,000 in a matter of months, you might not need the Pentagon, general officers, vastly paid consultants and budgets of millions spent over 10 years. Can't have that!

So, some might say that the 6.8 reinvents the wheel - I'd say it resurrects the round version that was discarded in favour of the 'technically superior' threepenny bit shaped model in 1952!

Notably too, the late John Barnes devised the .308X1.5-inch in the early 1960s to provide a solution to the 7.62X51's indequacies which were by then all too apparent to anybody who knew anything about rifles, cartridges, and ballitics and was willing to criticise the emperor's new clothes.

Oh, on the case-head diameter / bolt-face issue. It's the matter of the 6.8's 0.422" dia. falling between the 222/223 family's 0.378" and Peter Paul Mauser's 0.473" still with us via umpteen generations of military and sporting cartridges, It's obviously not an issue for anybody building a rifle to suit the cartridge, but may well be (no, it IS) an issue for anybody looking to take a cheapo' P-H M1100, shot-out Remy 700 .243 etc and simply rebarrel it. As Saddler notes, he probably has the sole 6.8mm SPC LTR in the UK - so not a lot of help to the OP who wants a 7.62X39 PLUS.

[meles meles]

*Shoos everybody back on track, waves cattleprod as a reminder*

Interesting discussion, oomans, but we aren't looking for anything other than a useful carbine that can chuck a hefty lump of lead, accurately, to 300 mards, silently.

*glares*