7.62 No4 bedding

[tbonesmith]

Howdy all, I've just come by a brand new (old stock) 7.62, standard profile, No4 barrel. I have a brand spanking new Enfield 7.62 mag, and the extractor. I also have a No4 mk2 with a barrel that is just about knackered, and I'm going to convert this rifle before the start of next years shooting year, and if all works out well use it as my primary rifle for modified service rifle shooting.
What I'm after is expert advice on the bedding of these for competitive shooting. I know that with the L8's standard bedding was a dud, and I'm not sure if the Canadians were using heavy barrels in their conversions. We often see heavy's here but I havn't seen any standard profiles on the range.
I know it's a common topic here but can someone point me in the right direction please?

Information

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[Peter Laidler]

As I understand it from the L8 trials and the L8T trials, the 'problem' was all to do with the barrel length and weight ......, or lack of both! If anyone can elaborate on that.......

It's interesting that even for the heavy barrel L4 guns, the barrel length and weight was finely tuned before it could be used to the extent that many thousand unused .303" Mk3 gun barrel blanks couldn't be utilised in the programme

[Bearclaw]

Nice Score Tbone, I have just got lucky myself. I hope you can document this project again with your same detail.

Myles

[Badger]

How about this article in the MKL?

The Canadian Marksman (Bedding the 7.62mm No.4 Rifle) - 1965

... or, some of Peter Laidler's article or past post contributions?

Index of Peter Laidler's on-line series of articles

Regards,
Doug

[Thunderbox]

The No4 profile barrel is very sensitive to bedding/ammo combinations. I've had about 10x Charnwoods, Sterling conversions and DCRA-type rifles, and they all reacted differently to each other. In general, the barrel seems to benefit most from centre-bedding, but even then with some sensitivity to the position of the block. One or two rifles seem to do o.k. with standard military bedding.

My most accurate rifle is a DCRA-type prepared Long Branch where the barrel sits on a 1 1/2" wood block directly between the rear and centre lightening scoops in the forend.

Be aware that the Enfield magazine may require the receiver underside to be carefully relieved, in order for the ejector tab to be in the correct position - a farction low and the bolt will not pick up the round, a fraction high and the bolt will strip the tab off the magazine....

[tbonesmith]

Be aware that the Enfield magazine may require the receiver underside to be carefully relieved, in order for the ejector tab to be in the correct position - a farction low and the bolt will not pick up the round, a fraction high and the bolt will strip the tab off the magazine....

I'll hope for the best and be prepared to deal with the worst senario. I've noticed the drawing of the cutout in The Bible and my machinist mate has agreed to look over my shoulder while I mill it out if necessary.

[rgg_7]

Do you have a military profile barrel? If so bed it like you did for your No4T project plus centre bed at the mid point. The Canadaian 6 groove barrel can be made to shoot as well as the 303's. If you have the heavy Enfield profile barrel, bed at the knox and float the remainder. Of course a set up like this requires a target type stock.

If you use a Sterling mag there is no need for the relief cuts. However, if you use the Enfield 7.62 mag as produced for the L42, Enforcer, Envoy, etc you need the relieve receiver to fit the mag. This will give you enough in the action to engage the ejection system.

Keep us posted.

Ron

[Bruce_in_Oz]

This is a perennial issue.

Original No4s of all flavours were tuned to Mk7 ball.

7.62 NATO produces a completely different vibration and "whip" regime, even with an identically profiled barrel. All decent military rifles are tuned to the ammo, not the other way around.

So, if you manage to get your barrel to cut 2" groups at 100yds. with NATO spec ball, do NOT expect it to shoot one hole groups with MatchKings or VLDs. Most 7.62NATO spec barrels have a RH twist of 1:12". Long, super-slinky bullets will either NOT stabilize at all, or will precess wildly for the first few hundred yards whilst trying to settle down.

And all this assumes that the fore-end is seated perfectly on the draws and all the other normal Lee Enfield caveats. (See Mr Laidlers detailed instructions posted elsewhere on this site).

And don't forget headspace and locking lug bearing.

The L42 series perform astoundingly well with the ammo for which they were intended: Same action, different barrel and fore-end (complete with very nifty extra Plate, Seating (1005-99-963-1592) to spread the load from the front screw.