Early DCRA conversion face lift

I’ve collected numerous articles written by Maj E.G.B Reynolds on the work done by the UK NRA on development of the 7.62 Conversion rifles in the late 1950’s thru 1960’s which eventually became the Target Rifle (TR) Class.  Many experiments were conducted on forend bedding and also by brazing a reinforcing strap to the action body to add stiffness.   SQN LDR Dave Reynolds (RCAF), DCRA Armourer also wrote about this subject and collected shooting results data from various bedding methods from the DCRA team sent to Bisley.  

This work eventually resulted in the 4 lb heavy barrel allowed in the TR Class and installed on the L39, L42, Enforcer, etc.

My conclusion was that it was really the ammunition that was causing the problem, poor quality made in worn out WWII machinery. 

My own experiments with DA 59, 60, 61 and 62 ball ammunition that was used at the time confirms the problem was ammunition, particularly the poor control of charge weights which varied by as much as 4 grains between cartridges in the same lot.  This translated into significant vertical dispersion on the target.  Bullet quantity was surprising good as pulled bullets from this ammunition reloaded in re-metered charges and with my own match load with 40.0 gr Varget shot very good. 

My Dad shot in SR(b) matches in the 1960’s, prior to the new TR class being introduced, where both .303 and 7.62 conversions.  Reynolds also wrote about this, so I believe there was a transition where SR(b) matches were shot with .303 and 7.62 conversions with service length and service weight barrels and full length forends.  

The 28 inch long Kongsberg 4 lb heavy barrel appeared about at the time the new TR rules were adopted (late 1967) which now allowed a maximum rifle weight of 13.5 lbs w/o the sling.  Canada adopted essentially the same TR Rules in 1968, which was right after my Dad got out of DCRA competitive shooting.  This new TR rifle would not be eligible for SR(b) events for obvious reasons.  

Today we wonder why target shooters did not try handloads in the No. 4 7.62 conversions but at the time, ammunition was provided at the matches and handloads would have been prohibited. 

I know you know (and were involved) but I guess many here won't know anything about the arguments.

The 'revised' instructions / warnings ended up as :

NRA Safety Notice re No 4 7.62mm Conversions

This is the current stance of the NRA safety warning which first appeared in the Summer NRA Journal:

Safety Notice
Enfield No 4 Rifle Conversions to 7.62mm

A safety warning concerning the use of Enfield No 4 Rifle actions converted to 7.62mm was published in the Summer 2010 Journal.

After further consideration of all factors influencing safety of these conversions and consultation with the Birmingham Proof Master, the following advice must be adhered to in respect of the use of Enfield No 4 conversions:

• Owners of Enfield No 4 actioned rifles converted to 7.62mm currently proofed to 19 tons per square inch are strongly advised to have them re-proofed to the current CIP standard (requiring a minimum mean proof pressure of 5190 bar) which allows the use of CIP approved ammunition with a Maximum Average Working Pressure (MAWP) of 4150 Bar.

• Conversions retaining their original Enfield barrel or a replacement barrel as manufactured by RSAF Enfield are safe to use with commercial CIP approved ammunition, which complies with a MAWP of 4150 bar, loaded with any weight of bullet, providing they carry a valid proof mark, and are still in the same condition as when submitted for proof.

• Conversions fitted with any other make of barrel (such as Ferlach, Maddco, Krieger etc) should be checked by a competent gunsmith to determine the throat diameter of the chamber/barrel fitted before use.

• Conversions where the throat diameter is less than the CIP specification of 0.311” but not smaller than 0.3085” must not be used with ammunition which exceeds 3650 Bar MAWP when fired in a SAAMI/CIP pressure barrel.

• Conversions which have been checked and found to comply with Rule 150 may safely be used with any ammunition supplied by the NRA including the 155 grain Radway Green Cartridge, 155 grain RUAG Cartridge or any other commercial CIP Approved cartridges loaded with bullets of any weight provided that the ammunition pressure does not exceed 3650 Bar when measured in a CIP standard barrel.

• Owners of Enfield No 4 actioned rifles converted to 7.62mm who are uncertain as to the proof status of the rifle should have it checked by a competent gunsmith.

• Owners of Enfield No 4 actioned rifles in any calibre are strongly advised not to use them in wet weather or without removing all traces of oil from action and chamber prior to shooting.

• Enfield No 4 rifles which are fitted with a barrel which has a throat diameter less than 0.3085” must not be used on Bisley Ranges.

• Ammunition loaded with bullets of any weight which are of greater diameter than the throat diameter of the barrel must not under any circumstances be used on Bisley Ranges in any rifle or barrel of any manufacture.

 

***** The NRA seem to forget that the Lee Enfield spent many years of active use in varying conditions thru' Mud, Snow, Rain and Sand - but suddenly they can no longer be used in wet weather.

Mick, interesting discovery on Corporal Reynolds.  He published numerous articles in the American Rifleman (US NRA Journal) on the 7.62 conversions and development of the TR.  

Armourer, I agree with the comment about shooting in the rain, wet/oily chambers.  Although I do believe keeping it clean and free from oil is good practice to minimize bolt thrust loads.

This was after umpteen people had gone into the range office at Bisley demanding to know who had written the first draft that appeared in the NRA Journal.

We had our suspicions who was responsible, and we believe he didn't have the authority to write it in the first place!   

I don’t really have any worries over shooting my 7.62 conversions because I handload mild charges.  Now, having said that, I’ve loaded up some 155 and 175 Matchkings to moderately high .308 Win velocities (not max) in an attempt to get the electronic targets at 1000 yards to register hits (requires supersonic velocities) but this will be a very limited set of tests with less than 50 rounds, so not worried.