Home Forums Hunting & Shooting Hunting Rifles 7x57 - Not Supposed to Do This

I posted some of this on another thread, but yesterday got my digital caliper out in order to get some precise measurements (old eyes and dial caliper just doesn't cut it anymore). Here's the back-story.

A couple of years ago I bought a M1909 Argentine Mauser that had been bedded into a B&C Carbelite stock. I bought it because I wanted something I could use in the wet weather that we have during our rainy season. The rifle shot ok, but the barrel was a pretty heavy profile, so I sent it off to have a few things done to it: check for lug set-back (there was none), have the action hardened, and then turn down the barrel. The 'smith used an old Rigby profile on the barrel, including the step, and finished it at .540 inches at the muzzle (24 inches). It took almost a pound off the entire rifle, bringing it to 7lbs, 2oz on the scale. I put an old 3-9 VXII on it, mounted in old-fashioned Weaver tip-off rings and Weaver base. Now the entire outfit comes in right at 8lbs. Not bad for an old, heavy military action.

Since this rifle will spend most of its life chasing pigs, I loaded up some 175-gr Hornady Round Nose Interlocks that I got a while back from Rocky Mountain Reloading. I loaded six three-shot groups, starting at 41.0 grains of IMR4350 and worked up to 43.5 in half-grain increments. Brass was Prvi, primers were WLR, and the CBTO was 2.635 inches, .010 off the lands. I didn't chronograph any of the loads, but using the data in Nosler's manual, I adjusted for a 24 vs. the 22 inch barrel they used in developing their data. I came up with about 2400 fps for the 41.0 grain load, and about 2500 fps for 43.5.

Here's where things get interesting.The first 100 yard three-shot group measured 1.607 inches CTC. Each subsequent group tightened up just a bit until I got to groups 5 and 6. Group 5 tightened up considerably to .661 inches CTC, and group 6 went .387 inches CTC. .387 inches! I suppose I could tweak the powder charge and seating depth to maybe even improve on that, but I'm not consistent enough off the bench to make it happen. Considering the fact that I was going to be content if this rifle shot around 1.5 MOA, I think I'm going to stop right there. Just about everything I shoot is inside of 125 yards or so, generally much closer to inside 75, this load will do.

I never dreamed that this old cobbled-together Military Mauser would be capable of anything even close to this, especially with that particular bullet. I guess I'm not all that interested in a 7-08 anymore.

Sorry for the crappy smartphone pictures. I ought to learn to use my wife's camera.

175-grain Hornady Interlock Round Nose


Turned down barrel with step


Finished rough weather Mauser


Three shots into .387 inches. That load is a keeper.

No need to tweak anything with that load!

Go forth and slay porky pig!

I agree with elkhunternm. Don't mess with it any more.

Well done. Who was your smith?


Okie John

Tom Jackson, out in Davenport, Iowa. He posts quite a bit on AR.

The 7x57 and the 175 gr. RN are like bread and butter...meant to go together.

Pretty much.

I like either the 140's or 160's in my 7x57's.

But I am a heretic according to one person here.

Yeah, but he's now shooting 150-grain Ballistic Tips, so....

Yeah...but I'm shooting them in a .275 Rigby...made for lighter bullets and Red Deer....

Made for 140-grain Rigby HV...which were lead tipped. You can't rationalize away this one.

I saw on FB that you're using Hunter behind those bullets. Are you using a standard or magnum primer?

That's right!

You tell him Rev!

You'll have something if it repeats even close to that performance.

Wow.................flash back.
I used to have a classic English styled 7X57 I made for myself, but my brother-in-law beat me out of it.

I also used a fairly warm load of 4350 with the same Hornady 175 gr round nose bullet and got clover leaf groups from it too. The barrel was an original from a 1908 Brazilian Mauser I cut to 22" and turned the steps out of it. One of those "old surplus rifle barrels" that so many want to replace. If the bores are shiny you'd do well to give those old barrels a chance before you decide to replace them.

My current 8X57 is another one. It's so accurate with 170 gr Hornady SSTs that it is unbelievable. It was 29 inches long and I just cut it off to 19 and turned a nice taper to it.
I never took pictures of the best groups I shot with it, but I do have this picture of the target shot with the worst ones. These were shot with 200 grain Speer bullets and the 170 SSTs shoots[u] groups 1/2 this size .

That's groups too, not just one group. I've done it several times. So it's not just a lucky happenstance.
This old barrel really is that accurate.
PC070001 by .com/photos/156296479N08/]Steve Zihn, on [bleep]

Not bad for old surplus military junk .

Not a 7, but I have a 6.5 Swede still packing the 114 year old military barrel that is just over a 1/2 minute shooter. Was supposed to be a truck gun, but it lives in the safe with the fine guns now.

Exactly - you do NOT fix what ain't broke...

I still remember the ass chewing you gave me over Ballistic Tips in the 7x57

120gr NBTs are looking promising in my 275. I had a match 7x57 reamer in my rifle and now the throat is too short for 175gr RNs.