7.62 or .308

[25 Sharps]

When the NRA was forced to move to commercially supplied ammunition some years back, and sought bids / undertook range tests from prospective suppliers, key elements of the specification were 1) loaded with the original 155gn Sierra MK p/n 2155 which usually mikes out at 0.3083" diameter, and 2) must be loaded to be within CIP maximum pressure in the slightly 'tight' barrels normally used in 'Target Rifle' builds.

Many early TR rifles (ie from 1968 when 0.303" 'Service Rifle' was replaced by 7.62mm 'Target Rifle') were set up for really undersize bullets in military spec 7.62mm ball. Against the US SAAMI 308 calibre specs of 0.300 / 0.3080" (lands/groove diameters), some were reputedly as small as 0.296 / 0.306 or even smaller. When the UK MoD replaced the old 146gn 7.62mm 'Green Spot' sniper round with the 155gn FMJBT version in the 1980s following the Falklands War showing up how poor the L42A1 / 146gn ammo combination was, this bullet was larger diameter, but still I believe a bit smaller than Sierra and other match 30-cal bullets. Gunsmiths stuck with undersize barrels, but nothing like as much as earlier. IIRC current barrels are usually somewhere around 0.298" / 0.3075-0.3078" (across lands / grooves) subject to minor individual preferences. A CIP spec 308 Win round loaded up fully with the 0.308" SMK could be over-pressure in such a barrel and the NRA contract called for what in effect was a mild charge reduction to provide ~2,925 fps MV from a 30-inch barrel within allowable pressures. The initial NRA spec (RWS marque) ammo supplied by RUAG in the blue boxes performed very well for the first couple of years without any problems. One subsequent year (ie production lot as there was one run each year), I can't remember when, turned out to be over-pressure in some rifles, especially on hot summer days and was returned to RUAG as unsatisfactory. RUAG retested it in a standard SAAMI/CIP spec test barrel (ie 300/3080) and it was all within allowable pressures, so the comapny repackaged it as RWS 308 Win Match and put it on the commercial market for sale and .... you guessed it, at least some ended up back here. The NRA then had to put an advice that this 308 Win ammo could not be safely fired in 308 Win marked and proofed rifles made to TR specifications and banned it from Bisley.

I don't know the story of the GGG match ammo that gave problems a few years later, this company having now got the NRA contract, but I imagine that something similar applied.

That’s interesting, my .308 is a ‘70s proofed fultons built TR on a Mauser action with a scope added, excellent rifle and shoots the blue box RWS beautifully.

I have introduced a couple if new members to the club and as probationers have said they can use my .308, was hoping to use the GGG 155 gr as it’s a very good price but then read the following explanation. I have decided as it’s an older action and a TR barrel that the 155s are are probably best avoided.

Ammunition, Reloading Components and Accessories

 

[cjm1066]

I could resize 30/06 to fit a 308, would that be illegal?

The FAC application form says CalibreMetric/Imperial so for my 308" variation I can buy 308/30/06 300 mag of various types. Its the police who have work by at times specifying a specific caliber, they didn't like it when i insisted on a .22cf variation, but that is how the Home Office intend the law to be used.

 

[palmer_mike]

they didn't like it when i insisted on a .22cf variation, but that is how the Home Office intend the law to be used.

Really? There’s a lot of difference between a .22 hornet and a .22 swift.........

 

[Laurie]

That’s interesting, my .308 is a ‘70s proofed fultons built TR on a Mauser action with a scope added, excellent rifle and shoots the blue box RWS beautifully.

AFAIK, the 'super-tight' Enfield barrel was only fitted to No.4s. They came ready to screw onto the No4 as RSAF Enfield Lock made them specifically for this one type only - the factory apparently made far more than the forces armourers needed as so many ended up with Fultons who must have converted hundreds of 303 SR rifles for both rifle clubs and individuals - one of my clubs had four such back in the 60s, and I bought the last of them from the club for all of £40 in 1986 or 87 as my first TR rifle.

Many early Mauser '98 action TR rifles built in the UK (other than Parker-Hales who made their own barrels) had Schultz & Larsen chrome-moly barrels which was the premium match barrel of its day. This may well be what your rifle has if it's the original - they're very rare in this form now, most having been long shot out and either rebarrelled with a more modern stainless type or scrapped. I replaced my 7.62 Fulton Enfield with a private purchase of one such - I don't know the builder, but wouldn't be surprised if it was also Fultons. It had an enormous round count on its original barrel - almost exactly 20 years of regular shooting all with military 7.62 ball, either black or green spot - and a huge amount of throat erosion. I can't remember now if it had a 10 or 12 inch twist rate, but handled heavy bullet handloads handily. Norman Clark told me that these barrels had a reputation for superb performance if you got a really good one, but when they 'went', they really 'went', which is exactly what happened to mine after a further 18 months of regular use. It just stopped shooting mid match between shots.

I don't know enough about these barrels to say how 'tight' they were made (and it's purely conjecture whether it's an S&L barrel on your rifle or not), but many people still use such early TR rifles with modern 308 Win factory loads or handloads and full-size 308 match bullets. Pressures are often modest to very low in high round count originals like my old example because of throat erosion producing far larger bullet jumps into the lands than normal. The '98 action is a very strong and safe one too, whilst the No.4 has no strength margin to cope with over-pressure ammunition. As you've used NRA 155 ammunition in the rifle how did it cope? This is the best guide to pressures being produced in your own rifle. ie was primary extraction easy, the bolt handle lifting without undue effort? If you reload the cases, are primer pockets still tight after the initial firing? Also, (and least reliable) fired primer condition. Finally, if you have access to a chronograph, what's the MV? MVs are directly related to pressure - if below spec, as often applies with elderly rifles because of throat erosion, then peak pressure will also be below normal.

 

[25 Sharps]

AFAIK, the 'super-tight' Enfield barrel was only fitted to No.4s. They came ready to screw onto the No4 as RSAF Enfield Lock made them specifically for this one type only - the factory apparently made far more than the forces armourers needed as so many ended up with Fultons who must have converted hundreds of 303 SR rifles for both rifle clubs and individuals - one of my clubs had four such back in the 60s, and I bought the last of them from the club for all of £40 in 1986 or 87 as my first TR rifle.

Many early Mauser '98 action TR rifles built in the UK (other than Parker-Hales who made their own barrels) had Schultz & Larsen chrome-moly barrels which was the premium match barrel of its day. This may well be what your rifle has if it's the original - they're very rare in this form now, most having been long shot out and either rebarrelled with a more modern stainless type or scrapped. I replaced my 7.62 Fulton Enfield with a private purchase of one such - I don't know the builder, but wouldn't be surprised if it was also Fultons. It had an enormous round count on its original barrel - almost exactly 20 years of regular shooting all with military 7.62 ball, either black or green spot - and a huge amount of throat erosion. I can't remember now if it had a 10 or 12 inch twist rate, but handled heavy bullet handloads handily. Norman Clark told me that these barrels had a reputation for superb performance if you got a really good one, but when they 'went', they really 'went', which is exactly what happened to mine after a further 18 months of regular use. It just stopped shooting mid match between shots.

I don't know enough about these barrels to say how 'tight' they were made (and it's purely conjecture whether it's an S&L barrel on your rifle or not), but many people still use such early TR rifles with modern 308 Win factory loads or handloads and full-size 308 match bullets. Pressures are often modest to very low in high round count originals like my old example because of throat erosion producing far larger bullet jumps into the lands than normal. The '98 action is a very strong and safe one too, whilst the No.4 has no strength margin to cope with over-pressure ammunition. As you've used NRA 155 ammunition in the rifle how did it cope? This is the best guide to pressures being produced in your own rifle. ie was primary extraction easy, the bolt handle lifting without undue effort? If you reload the cases, are primer pockets still tight after the initial firing? Also, (and least reliable) fired primer condition. Finally, if you have access to a chronograph, what's the MV? MVs are directly related to pressure - if below spec, as often applies with elderly rifles because of throat erosion, then peak pressure will also be below normal.

It is the original Fultons barrel as it still has the sticker on it, 30”, 1:14.

It shoots the RWS really well, no obvious sign of pressure on there than some of the firing pin strikes aren’t very deep, I don’t know if it’s possible for pressure to push the pin indent back out or if it’s light striking some rounds? I did replace the firing pin spring with a wolf spring when I first bought it as I was definitely getting light strikes then.

Reloaded RWS once fired had no obvious stretching of the pockets. I am reloading RWS brass now (have been for some time) with 2155s and the 168 gr SMK over 43.5 gr of n140 and kvb-7 primers, previously cci large rifle. This could be pushed harder but I’m getting 2880 with the 155 gr and 2850 with the 168s which is more than adequate for my informal target needs.

However with the new guys as they have signed up as probationers I would prefer they shot factory rather than eating up my stock of 2155s I got cheap as I only have 500 or so left plus there’s the whole liability thing if there’s an issue with my reloads (not that there should be!)

It’s a cracking rifle (bought off Ed Bewsher privately before he became Edinburgh Rifles) has a bit of pitting 6” or so down the barrel which it has when I bought it but it keeps up with the Tikkas and Sakos in the club!