Building an NRA High Power Match Rifle


PDA






Bart B.
June 7, 2009, 01:39 PM
Starting in 1903 with the .30-03 Springfield rifle, competition with high power rifles ramped up quite a bit. This set up was superior to the Krag's used and had much better accuracy. M1903 rifles were used by military and military and civilian competitors and did pretty good. Especially when a really good barrel (Pope?) was installed and decent sights (Lyman?) were installed.

Winchester introduced its Model 54 in the mid '20's based on the M1903 action and it was a success as an NRA match rifle (required by NRA for shooting standing slow fire and sitting rapid fire at 200, prone rapid fire at 300 and prone slow fire at 600 yards). Shorter lock time, better trigger and feeding in rapid fire was a bonus. In 1937, their Model 70 was introduced and was a good improvement over the 54. Some folks tried the M1917 Enfield action and its civilian counterpart, the Rem. 720, but neither was popular. The Remington 700 and 40X round ones worked well for bullets weighing less than 160 grains, but they didn’t hold bedding as well as rectangular bottom receivers. Rem’s also had extractor and short bolt handle problems as well as rapid fire feeding from their magazines. And the box magazine versions were only about 40% as stiff as the Win. 70's. All NRA match rifles had to use the .30-06 round for most matches; others could be used for 1000-yard prone slow fire matches in "any" rifle divisions.

Different techniques in 'smithing a Win. 70 were tried over the years. By the early 1960's, the best .30-06 rifles would shoot inside of 5 inches at 600 yards with good barrels and proper hand loads. Along came the .308 Win. in the late '50's but wasn't allowed in NRA match rifles until 1963. Its accuracy was phenomenal; near twice what the .30-06 produced.

Here's how the most accurate rifles were and still can be built. One could get a Tubb 2000 for several thousand bucks and it’ll shoot just as accurate but takes a bit longer to reload in rapid fire matches as one has to take the empty magazine out before inserting a full one.

First, strip the Model 70 receiver, thread a mandrel into it that sticks out the back end enough to clear the tang then mount it between centers on a lathe. Turn the lathe on and watch the back of the receiver. If it’s spinning off center at the bridge, then you’ve got one of those rare ones with the receiver threads aligned a bit off the bolt axis. About 1 in 100 may well be this way so just get another one and use that one for a hunting rifle. Turn the receiver face from the barrel tenon thread area out to receiver major diameter to square its face with the tenon’s thread axis.

Second, screw then lock a collet into the front threads that has a hole in it to hold an end mill the diameter of the bolt face. Put a stripped bolt in the receiver then close it completely. Adjust the end mill stop in increments to start facing the bolt just enough to clean it up. This makes the bolt face square with the receiver threads and eventually square with the chamber accuracy.

Third, for the cartridge of choice, get a barrel whose twist is correct for the bullet size and weights you will use as well as a few to several ten-thousandths of an inch smaller than bullet diameter. Land height should be at least 4/1000ths inch. It also has to be a couple inches longer than you want to end up with. The barrel must have a very uniform twist rate; no jumps, fast nor slow at any point.

Fourth, using the best machining practices known, make the barrel tenon to fit the receiver, face the muzzle to a flat 11 degree recessed crown then chamber it with a piloted reamer of SAAMI dimensions. Don’t use any “tight” match reamers. Set headspace to SAAMI GO minimum. Fit the trigger of your choice, or an Anschutz biathlon trigger with an adapter is wonderful.

Fifth, for the stock to be used, use one with an height adjustable cheekpiece that will clear the opened bolt. Inlet the receiver section about 1/8th inch larger than the receiver and the barrel channel 1/8 inch wider than the barrel diameter for ample clearance. If using a wood stock, epoxy a cross bolt through the stock between the magazine cut outs and recoil lug recess and another behind the magazine in the web next to the trigger cut out to prevent splitting. Pillar bedding isn’t needed; good wood or hard-core synthetics do well conventionally bedded with epoxy. No pad under the barrel’s chamber area as this tends to hurt accuracy more than it helps. Install a hand stop rail under the fore end and an adjustable butt plate at its back end.

Sixth, the critical part and I’ve left out a lot of detail. After filling the receiver holes and cutouts as well as those in the stock with modeling clay, smear a very thin coat of Simonize car wax on the receiver and barrel as a release agent. Mix then pour in the Devcon plastic steel epoxy, fit the barreled action in the stock, then put the stock screws in. Some people mix a bit of baking flour with the epoxy to make it thicker; works fine, too. Careful positioning is critical here. Scrape off the excess then let the epoxy cure for a day. Pop the barreled action out, clean up the overflow, clean out the barreled action then screw everything back together. Torque the stock screws to 60 inch-pounds for shooting, but loosen them when not.

Seventh, replace the factory 23-pound firing pin spring with one rated at 26 or 28 pounds. A titanium firing pin will make shooting offhand a bit easier with its shorter lock time, but won’t help in positions where you’re slung up and holding tighter. Put the front sight base on a barrel band then clamp it on the muzzle. Install a rear sight base on the receiver then mount a good aperture sight with no more than 1/16th MOA slop per click. Put an aperture front sight with spirit level on the front sight base and a level on the receiver sights windage arm. Level the rear sight then twist the front sight ‘till its level; tighten the band. Put a clip guide on the receiver bridge for charging the magazine with 5-round stripper clips in rapid fire matches.

That’s all, folks!

This thread will be followed by one titled: “Loading Ammo for NRA Match Rifles.”

If you enjoyed reading about "Building an NRA High Power Match Rifle" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
SlamFire1
June 7, 2009, 09:00 PM
Bart; Very interesting, I am going to copy it and save it.

But in my neck of the woods, the "Classic" bolt gun you describe, is fading from the firing line. Long Range matches it is still holding on.

The "serious" crowd is using the Tubb rifles. There are a lot of Space Guns out there, and those are the most common match rifle for the expert/master class crowd.

I walked Vaile in 2005/2006 and found only two classic bolt guns on the line. Space guns outnumbered Tubb rifles by 6 to 1. (an estimate based on what I saw)

I missed 2008 Camp Perry, but after running a bolt gun, I decided to give the space gun a try. It is hard not to clean the rapids, offhand is the same, long range ain't my forte, so I actually shot the best ever with the thing. I play with the bolt guns on home terf.

Space guns are easy to build, just send an upper to Frank White of Compass Lake and he will install a Krieger barrel with a handguard cut for a handstop. Then attach your service rifle lower, and you are ready to go except for sights.

Space guns don't need bedding, don't need truing, factory two stage triggers are great, and they are extremely reliable on feed with good magazines.

Never had a clip misfeed due to stacking or autoejection.

ants
June 7, 2009, 11:16 PM
Many thanks, friend. Waiting for the next installment on ammo...

Hollywood Marine
June 8, 2009, 03:43 AM
These old eyes have changed some (not for the better) since I was shooting high power, and your thread interests me a great deal. I'm thinking of getting back into it, but in the long range any sight end. Guess I'll start looking for a good pre '64 M-70 action to build.
Thanks.

SlamFire1
June 8, 2009, 11:52 AM
Guess I'll start looking for a good pre '64 M-70 action to build.

Let me recommend you get right now one of thos “SBR” M70 actions made by FN. CDNN has them for $349.00 Get the one with the floor plate, it takes five rounds. The magazine version takes four in the mag and the stupid magazine is $50.00. The SBR/PBR rifles were the last M70’s assembled at New Haven, and the fit and finish is better built than any pre 64 I ever handled.

Mine has the old M70 trigger. I assume a Jewel two stage will drop in. I believe the trigger has been changed for later production M70's.

http://img.photobucket.com/albums/v479/SlamFire/M70%20pics/FNDSCN8747.jpg
http://img.photobucket.com/albums/v479/SlamFire/M70%20pics/FNfulllengthDSCN8751.jpg

Bart B.
June 8, 2009, 04:29 PM
SlamFire1 mentions:Never had a clip misfeed due to stacking or autoejection.Well, some folks have had stacking (two rounds next to each other, both on the same side of the box magazine and the 5th round from the clip wouldn't go in) when charging the pre-64 .308 Win. magazines. Seems the rib on the top-left part of their follower had its edge a bit too far to the right and somehow cause this problem. Filing a 45-degree flat on that ridge about 3/16ths inch wide fixed it. Had to do this with one of mine. Post-'64 versions didn't seem to have this problem.

My earlier comment about a few receivers barrel tenon thread axis: If it’s spinning off center at the bridge, then you’ve got one of those rare ones with the receiver threads aligned a bit off the bolt axis.In the 1970's one pre-'64 action was floating into and out of some of the west coast high power 'smith's shops. Seems nobody could get a rifle built on it to shoot well. Someone finally checked the tenon thread alignment on a mandrel then found the bolt hole in the receiver bridge was centered over 1/8th inch off the tenon axis. I think that receiver went to some hunter who really liked it.

krs
June 19, 2009, 09:52 PM
I've got an old trued Remington 700 that was once my Hunter benchrest rifle, and I've got an unused Jewell 1.5 oz. trigger, a Shilen barrel blank in .22 or a Hart 6mm blank, and three 36x scopes and I've been toying with the idea of making a Tube Gun for long distances or maybe F class. I'll have to look to see what other barrels I have left.

Tube gun: http://www.tubegun.net/

Do you see Tube guns at high power matches?

Howard Roark
June 19, 2009, 10:40 PM
krs, I've had a tube gun that i've shot MR and LR. Kevin makes a great product. The advantage is that there is no bedding to deal with. After you glue in your action, thats it. It is as stiff as a Rem can get.

The 36 power scope will be way too much for f-class. The mirage will be overpowering with that much scope. In GA the ability to dial down to under 14 power is paramount.

krs
June 20, 2009, 12:12 PM
Thanks Howard,

Yeah, the scopes were bought for 100 and 200 yd. benchrest where mirage is usually managable, one way or another, but I think I've still got two Weaver T36's that have never been used, as well as tow Leupolds and two more Weavers that I've shot but are good still. Trade fodder..

The Tube gun always did seem like a good idea and product to me but I never had occasion to buy one. I've got two Hart actions and a Nesika even still, but that old Rem 700 is burning a hole in my pocket and was always a good shooter. I think it'd make into a fine tube gun for long range with the rest of the stuff I have sitting around. I've got three sets of Redfield sights too, two Palma's and an Olympic I think (though I'd need to find and open up the box they're in) so there's lots of possibilities open. I might need to buy a reamer if I haven't got the caliber that works best for LR.

I just found that I've got two .30 cal. Shilen barrels as well. Would there be any interest in a switch barrel Tube gun that had barrels for a .30 cal cartridge, a 6mm/.243 cartridge, and maybe a 22BR or 22ppc cartridge? I could chamber them all up to use on the one action in any caliber that can share my .30 cal boltface.

If you enjoyed reading about "Building an NRA High Power Match Rifle" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!