7.62x51 Chambered REM Short Action Rifle

[Homerange]

One must remember military cartridge vs chamber dimensions will be wider for one reason, the reliability to feed and load in the field where as hunters/paper punchers we wouldn't dream of chambering a dirty round.

That it's only 6 thou surprises me.

 

[troupe]

A difference of .006 will not cause a rupture. Just ask the Ackley Improved guys or tons of others that fireform cases.

Josh, can I come over for popcorn later. The drive will be a tough one, but sounds like fun.

 

[Laurie]

Few in the UK would ask about this in past times, although that might change now. UK 'Target Rifle' (prone, sling, iron-sights) the largest formal shooting discipline until a generation ago and equivalent to US Fullbore/Palma used organiser issued arsenal 7.62X51mm ammunition from the switchover from 0.303 'Service Rifle' in 1968 until fairly early this century when commercially loaded 308 Win replaced it. You'd find the same pattern in Australia, New Zealand, South Africa, and Canada. Likewise the British (and other countries') armed forces had 7.62 rebuilds of Enfield service rifles for various purposes including sniping and target shooting. In the UK, the British Home Office ministry which is responsible for police forces and the courts commissioned ca. 1,000 Enfield No.4 rifle based 7.62mm 'Enfield Enforcer' marksman rifles from RSAF Enfield Lock for distribution to the UK's police forces.

Owners, both original and the large numbers of secondary/tertiary civilian purchasers of the 7.62mm chambered military/police rifles and 'TR' rifles as and when they were superseded used 308 in these rifles all the time, both commercial and handloaded. The only thing needed to be taken into account that could cause problems is the combination of the relatively weak rear-locking Lee-Enfield action and the very internally undersized heavy barrels produced by RSAF Enfield Lock and used in all 60/70s military/police rifle conversions and many 1st generation civilian 'TR' match rifles. These barrels produce excessive pressures with commercial 308 Win ammunition which poses considerable risk thanks to the the weak action. (This is still an issue even now over a half-century on - the UK NRA warns against the use of the commercial 308 it procures in these old No.4 based rifles.)

I myself have owned and shot four such 7.62 TR single-shot prone rifles (two Enfields; a Swedish M96 Mauser commercial conversion; an M98 Mauser rebuild by the Norwegian Kongsberg arsenal) and on top a former police 7.62mm Enfield Enforcer. None saw a single round of 7.62 used in my years of ownership - all handloads in 308 Win commercial brass.

On top of that is the much more modern Accuracy International series of 7.62 sniper/police marksmen rifles sold around the western world and very popular with UK civilian competitors in some 'tactical' disciplines. Again, they are chambered and proofed for 7.62X51mm, and again used all the time with 308 Win ammunition. Yes, the headspace is marginally greater but cases cope easily with this. An old shooting partner produced astonishingly good results from a 7.62mm AI rifle in the early days of UK F-Class with 308 Win handloads. He always maintained it wouldn't shoot well on its first firing of new Lapua 308 brass, but was transformed by fireforming then subsequent resizing with the die set to only marginally bump the shoulders. He never lost a case through separation, although as he always loaded really 'HOT' he only got a few firings before the primer pockets came loose!