So i bought a 7x57 prefit barrel

[Dimner]

7x57 prefit for my tikka T3x. Custom McGowan barrel in a heavy-ish sporter profile. Mcgowan #5 which is very similar to a bartlein #3b. 24" long. 1-8.5 twist. Stainless steel. Eventually I'll put a Bell and carlson sporter stock on it or maybe do a richards microfit frontier sportster

Currently the tikka has a 22.4" 270 winchester barrel that is rather flippy with the muzzle rise. Also the 270 barrels accuracy is just so-so. 1.5-2moa. I probably could do better than that with more load development, but i have wasted too many bullets/powder/primers already. I guess 2moa would be fine if this was a rifle I was planning on hunting under 250 yards with, but that's what my 308 tikka is for. So having those two faults, accuracy and muzzle flip, I figured let's put a 7x57 on the receiver. Much better cast bullet selection for the 7mms.

I already have the Noe 173 FN. Should be a good bullet for the barrel. I also have lyman 287346. However, that mold throws undersized bullets like crazy. I size them down to 284 and the gas checks still rotate/wiggle on the shanks. No idea why that's happening. Maybe I just dropped a bad batch of the bullets

I need to get some more brass and possibly an RCBS 7mm mold. Looking forward to this project...

8 weeks wait for the barrel, but that will go by way too fast with the holidays coming

 

[fiver]

those 90* butts can frustrate you with the muzzle climb.
you can usually fix that with a quarter,, by sliding it between the butt pad and the stock.

 

[Dimner]

those 90* butts can frustrate you with the muzzle climb.
you can usually fix that with a quarter,, by sliding it between the butt pad and the stock.

I'm not sure I'm following, but very interested on this method of reducing the climb. I have a limbsaver pad on the butt, if that matters.

 

[fiver]

it's called pitch.
it comes in negative and positive directions.
IOW the toe sticks out further than the heel and viceversa
what it does is help make the pad fit the slope of your shoulder better and align more of the squishy stuff against your body.

anyway.
loosen the top screw that holds your recoil pad on.
slip a quarter in the top and tighten the screw down and see if it helps.
if it helps a little slide another one in.
if worse put it on the bottom.
once you see, you can order a little piece of plastic for about 12 bucks that fits under the pad like a space, it's sloped from one end to the other.
magically you can get them about the thickness of one or two quarters up to about 4 quarters thick on one end.

 

[Tomme boy]

McGowan barrels are really nice. I have had a couple on different Savages I put together. With jacketed bullets they were extremely easy to work up loads.

Did you get a barrel nut or a shouldered barrel?

 

[Petrol & Powder]

Sounds like an outstanding project.

Tikka, AKA SAKO (now owned by Beretta) has a very nice receiver. I've always been impressed with the value of those Finnish rifles.
And the 7 x 57 is a great cartridge with an incredible history.
The 7 x 57 is a handloader's dream; lots of bullet molds and factory bullets available, extremely useful cartridge and versatile.

 

[Dimner]

I'll give the pitch adjustment a try for sure. Really appreciate the tip.

It's a shouldered prefit. I didn't want to have to deal with a barrel nut.

The history of the 7x57 was in the back of my mind when I was choosing this barrel. It's a gajillion year old cartridge that can do anything a non-magnum 7mm can do, but is constantly overlooked. Dozen other non-magnum 7mm have been introduced and the 7x57 still stands by like an old wise man saying "yep, I can do all the too".

 

[RBHarter]

It's because it doesn't save 4 oz for being in a short action and "wastes" that other 3/8" in a long action.....

 

[Petrol & Powder]

It's because it doesn't save 4 oz for being in a short action and "wastes" that other 3/8" in a long action.....

Well, actually the 7 x 57 is more of a medium action cartridge that gets built on a long action because it just will not quite fit in a short action.
When your only choices are short and long and short doesn't work; you only have one option left.

The 7mm-08 has just about killed off the 7mm Mauser in terms of new rifles chambered for it. This is a shame.
When properly loaded, the 7mm Mauser is a very capable cartridge.

 

[fiver]

it equals the 7-08 with 15-K less pressure.

i been digging for data for my 8 mauser the last few days, and of course since i'm there the 7 also.
i have found updated data for the 8 that goes to 50CUP, but nobody has ever done any for the 7mm that i'm aware of.

now i'm pretty positive my 7x57 ICL built on a winchester model 70 that was formerly a 270 is perfectly capable of holding just as much pressure as my 8Mauser built on a remington 700 action which just so happens to also be a long action capable of holding the 270 case.
or i guess maybe that Ruger i got can't handle it either.

it just makes me wonder what they are scared of, would the little efficient X57 case show up their other offerings?
i've found data for the 8mm version that'll push a 150gr bullet to around 2950 fps,,, the 8mm-06 can't do that with 5 more grains of powder.

makes you wonder don't it?

 

[RicinYakima]

I built two on 1903 actions that I like very well. For me, the advantage of the 7/8MM case in the '06 action is that it will feed any bullet from any position. The '03 action rails keep it under the extractor with a long bullet even upside down. Never having built up a rifle on a Mauser action, I don't know it they would do that or not.

 

[Ben]

They say not many respect the 8x57 except the guys that were on Utah and Omaha beaches. They had plenty of respect for the cartridge.

 

[fiver]

once that claw grabs the round it's trapped.
they'll feed upside, sideways, or whatever.
go in and out upside down too until you hit the ejector.

 

[Dimner]

It's because it doesn't save 4 oz for being in a short action and "wastes" that other 3/8" in a long action.....

Tikka centerfire receivers are all the same size regardless of cartridge. The only thing that changes is the bolt stop, magazine, and bolt if necessary. On top of that, these tikkas are super lightweight regardless of cartridge. I'm actually adding weight to this build. The 270 was just too light.

 

[Joshua]

but nobody has ever done any for the 7mm that i'm aware of.

The Lovex Manual has 7x57 data that is based on the Max. Pressure CIP: 3900 Bar.
That converts to 56564.7 PSI.

I know that cup to PSI is a bit tricky, but a commonly used conversion formula is PSI = -17,902 + 1.516 x CUP. Using this formula 50k CUP is something like 57,898 PSI, and 46k CUP is something like 51,834 PSI.

The European data for the 7x57 seems to get close to 50K CUP.

The 7mm-08 has just about killed off the 7mm Mauser in terms of new rifles chambered for it. This is a shame.

If there was a new $600 7x57 out there I would have bought one. There ain’t. A guy can buy a Savage Axis in 7-08 for $309 on sale! The only real draw back of the 7-08 is that it begins to struggle with 160 to 175 grain bullets. Out of my 20” barrel a 160 grain partition will run at about 2056 fps with 1502 pounds of energy at 300 yards. It’s also hitting 9.3” inches low at 300 yards (200 yard zero). Don’t get me wrong, I absolutely want a 7x57, I let a Ruger 77 slip through my hands at an auction a few years ago. But also, just to be clear the 7-08 isn’t an anemic cartridge.

 

[Dimner]

I'm not versed in how they detrime cartridge pressure... however, with a tikka action and a mcgowan barrel, what is the limiting factor for 7x57 pressure? Is it the chamber geometry?Perhaps the brass?

 

[RicinYakima]

I'm not versed in how they detrime cartridge pressure... however, with a tikka action and a mcgowan barrel, what is the limiting factor for 7x57 pressure? Is it the chamber geometry?Perhaps the brass?

There are two ways to look at this. One is blowing up the receiver by the case head failing. Second is at what level can you shoot it until the barrel is alligatored or worn out.

For my worth, if you can't load the case at least six times before the primer pocket is loose, you are using too much powder. For modern brass that is about 60,000 psi, or 52, 000 CUP in a proper bolt action. FWIW

 

[RBHarter]

Brass/primer failure , throat , leade , and neck clearance.

Speer manuals state that their data loads to 56kpsi , do not exceed start loads in 93' Mausers, RB etc .
When we step up to 1958 and forward actions we have actions designed on purpose to be fed 25,000 rounds of 60kpsi 208 175 loads .
There were many before that will handle that ,the German K98s , probably all of the 03's ,and most of the US commercial actions after 1935 , but they weren't designed and tested with that in mind really until the 308 and the Winchester Mags .
My theory anyway .

I was schooled that extra weight in a rifle should reside in it's barrel .
Later on I learned that if the barrel has enough substance to hold the pressure the bolt lugs are the next least likely fail point . They also play a role in case life and accuracy.
The receiver has to be able to support the lugs under load .
If all of this comes together and proofs at 90kpsi alls well . One only needs to look at the AR Stoner barrel extension and bolt and compare it to the K98 ,110 , or 700 , to see the alloy/temper vs billet/forge needs of holding 90kpsi .

Any action since 1960 should be capable of holding that .

Why the 284 Win isn't all the rage baffles me . It's a short , fat , high BC , short action , cartridge with a standard bolt head that with a special follower and floor plate will keep the 4+1 and as far as I ever read isn't a barrel eater , and it'll keep pace with the 280 . Which begs the question why is there no love for the 280 Rem ? Well probably because of the 270 ......

It's weird the 7mm is almost like the 25s it's either loved and followed almost cult like or completely unloved .

 

[Ben]

Makes me feel very fortunate to own my 7X57mm rifle.

 

[fiver]

it's definitely not the brass.
heck if your worried about that,,, just neck up some PLUS-P 257 Bob cases, or re-form some 270's, or re-size some 6mm rem's.
they are all pretty much the same and 'built' for the higher pressures... but so is 7mm brass [so nuthin gained except a little less case capacity with the P+ bob stuff]

the real problem we have is nobody wants to hook some pressure trace wires up to a 7 mauser test barrel and work some loads.
that's really all it would take.
i'd even be willing to make some powder suggestions.
heck i might could even be sweet talked into loaning them a short chambered barrel, a 98 mauser action, and loan of an Ackley reamer.