Just tested my new 7.5 Swiss Match Rifle

[cprher]

A little over two years ago I built a match rifle to shoot 7.5X55 GP11 (Swiss Gov't Ball) ammo exclusively. Here are a few pictures. The action is a blueprinted Remington 700 with a one-piece oversized bolt (.704") from Pacific Machine. The action is reamed to .705" so the fit is very close and precise. The rail is from Nightforce and the trigger is an X-treme Model 22. The stock is a McMillan Baker Special with three way adjustable butt and thumbwheel adjustable cheekrest. The barrel is a Brux with a standard Palma contour and is 28" overall. The bore is .298"/.306" with a 10.5" twist in Chrom Moly. The scope is a Weaver CT-10 with a 1MOA dot and fine cross hairs. A little coarse for real precision shooting but works very well at 600 yards and out in marginal light.





Got out to the range this weekend to give my Swiss rifle project a full workout. Shot it on Sat and Sun and went through about 40 rounds. Here are the last three groups. The two side by side are one lot with a scope adjustment to separate the groups. The second target is the final sight in. All shooting was 5 shot groups done at 200 yards from sandbags over the back of my truck.





Based on my experience with this cartridge, reloading it with 168/175 Sierra Match Kings will cut the group size in half.

Keith

 

[Garrobo]

Why

Swiss?

 

[cprher]

Why?

The cost and availability of ammo. GP11 is high quality, packed to stay fresh and accurate, plus it sells for $.50 a round. I can cut the groups in half with careful handloading, but my handloading is focused on my 30'06 match rifle that is identical in layout. Gives me cheap practice with a much reduced amount of labor.

Keith

 

[Plastikosmd]

Beautiful

 

[barnbwt]

GP11 is also basically superior to 3006 on its own merits; it goes very nearly as heavy, and just as far, at significantly lower pressure.

TCB

 

[Mikee Loxxer]

My only concern would be the enhanced throat erosion associated with launching steel jacketed bullets, which is what GP11 is loaded with.

 

[cprher]

Throat erosion

Barrel wear was a concern of mine as well; however, K31s have a good reputation for maintaining their accuracy after thousands of rounds with proper care. But, due to the investment I had two extra barrels done up at the time of the build. When one wears out, I'll just spin on one of the extras.

Keith

 

[Edarnold]

My only concern would be the enhanced throat erosion associated with launching steel jacketed bullets, which is what GP11 is loaded with.

Since I've never seen a rusty bullet in GP11, I don't think the bullet jacket is bare steel. The fact that the bullets are magnetic means there is some iron involved: best guess is that it's tri-metal, which is steel with a thin layer of cupro-nickel on both sides. Widely used for military bullets, Norma used to supply many of their sporting cartridges with this material. Swiss rifles that were stored with the issue grease in the bore show a greenish color when the residue is cleaned, which would be typical for cupro-nickel.

This jacket material should be no harder on the bore than guilding metal. Earlier production GP11 also had a ring of wax lubricant applied over the bullet/case neck junction, which would help prevent erosion as well. Recent production ammo has discontinued this feature, but some Swiss shooters use a gadget that allows them to apply their own ring to current ammunition.

 

[barnbwt]

They're cupro-nickel (I read that somewhere a while back). At any rate, a properly greased K31 seems rated for tens of thousands of rounds, so who cares? As far as throat erosion, there's also that little bit I mentioned about significantly lower pressures (45k vs 60k for 30-06, IIRC) which equates to lower peak temperatures; this combats erosion to some degree as well.

"Based on my experience with this cartridge, reloading it with 168/175 Sierra Match Kings will cut the group size in half."
You really see that much improvement over factory GP11? For guns that happen to "like" the surplus load, it seems pretty tough to improve on in terms of consistency (that said, every gun seems to like Match Kings ). I would imagine the GP11 bullet might pull ahead at enough distance, though; those things are really long ogives, and I believe stay super sonic until very near 1000 meters (or was it yards?)

TCB

 

[farmerboy78]

Beautiful rifle...

 

[primalmu]

Wait, I'm confused. Okay, its a cool idea, and there's no doubt that GP11 is a cool ammo. But, if you're using it based solely on cost of using GP11 ammo as a cheap alternative to .30-06, then the economics just don't add up. Surely for the cost of building this rifle up you could have had several barrels for your .30-06 AND several thousand rounds of match grade .30-06.

 

[cprher]

You are absolutely correct

I could! But then I wouldn't have had the pleasure of building a truly cool and unique rifle. It was not entirely economic but since I shoot a lot of Swiss rifle with my K31, it just made sense.

Keith

 

[batex]

That's a great rifle and great idea. Thanks for sharing. I recently was bit by the K 31 bug and acquired three K31 rifles and have bought about five cases of GP 11. what a fun and accurate gun to shoot.