Home Forums Hunting & Shooting Ask The Gunwriters Jack O'Connor wrote about the 7x57

Even if I never intended to shoot anything over 140 grain I would still go with a 1 in 9 twist. No down side to extra twist, unless the jacket is too weak and that’s not the case I a 7X57 with hunting Bullets at its top velocity.

Interesting stuff RinB.

At one time did put some effort and mostly dollars into the lighter weight M-70s--barrel, bottom metal and stock of course, being combinated for outcomes. But as John inferred, the fastest road to lighter is to change the action....

Am neither an evangelist nor claim any particular insight--just personal preferences...do like the M-70 for the 7mm RM and the small ring mausers for those 57mm cases.

Ken,

Interesting about the 1-11" twist. I had a custom 7x57 with a 1-11.5 twist, which was not my choice but the gunmaker's. He asked me what bullet I'd be mostly shooting, and I specified the 140 Partition--but didn't tell me about the twist, which turned out to be quite a surprise when I tried 140-grain Barnes X's. That's when I measured it.

The other interesting thing is that while the rifle shot 140 Partitions well, the 7x57 that shot them best (as in five, not three, in 1/2" to 3/4" at 100 yards) was one I stocked myself in New Zealand-grown Juglans regia, on a VZ24 action with a 21" Shilen barrel with a 1-9 twist.

All of which is just one of many examples of why I ceased trying to "match" the twist to the bullet many years ago.

John and Ken,

When you built your rifles did you consider throat dimensions?

Roundoak,no,I did not consider throat dimensions when building the 7x57. I have a CZ 550 that has a long throat and a Featherweight with a much shorter throat. Figure the one pictured will be closer to the Featherweight,but will find out this weekend. All I've done so far is get it on paper at 25 yards,will take it out to 100 this weekend sometime.

MD,I have two other 7x57's that will shoot 140-175 grain bullets,just wanted one that'll handle the 140 grain class bullets. No logic behind the decision,just wanting a 7x57 that'll shoot a 140 grain bullet.

Sounds like you have a nice 'selection' of 7x57s, Ken. If a guy was to look for one reasonably priced 7mm Mauser for use with 140-160gr bullets, what would you recommend?

You probably already know this you can get an idea of the throat length by inverting a flat base bullet into a case trimmed to 2.225" then insert into the rifle and close the bolt.

I did consider throat dimensions on my 7x57. It had a modern "short" throat, as does my present 7x57, made by what was then Serengeti Rifles and is now Kilimanjaro Rifles, with a Pacific Tool & Gauge with what I recall they term the "USA Match" reamer.

Thanks for info, John. I rescued a VZ-24 7x57 Mauser with a 24" McGowen barrel and Fajen stock a few years ago. Barrel and stock is in pretty bad shape so I am going to scrap them and build on the action.

Look for a used Interterms Mark X 7x57.

That's good advice. One of my 7x57s is a Zastava M98, basically the same thing as the Mark X, with a 1:220mm/1:866" twist. It handles long 175-grain bullets very, very well. You can also find some pretty good deals on older XTRs. As mentioned all over the 'fire, they are about the most underrated M70 there is.

I had mine built on a VZ24 action as well. It's a 1;10 twist for the 140gr bullet. I don't know what the throat measurements are however I havent found a 140gr bullet it doesn't like. I wish I could figure out how to post pics of it.

I bought a 7x57 on a mauser action from a Gent who speced a 1:10 twist, throated for a 139 Hornady to touch the lands when seated to the cannelure.

It has a bit more free-bore than specified, which is probably a reflection of the reamer the smith had on hand.

None the less, it is capable of touching holes in 4 shot groups, which is better than I am on the average day around here...

As I posted previously in this thread you can do a simple test to determine approximate throat length. Invert a flat base bullet in a 2.225 inch trimmed case, chamber it and close bolt. Some guns I have sampled for comparison.

.325 inches VZ24 action, McGowen barrel

.420 inches 1895 Chilean
.420 inches M98/08 Brazilian
.438 inches " "
.442 inches " "

Other measurements I have collected from gun writers. I do not know trimmed case lengths.

.250 inches Ruger MKII (circa mid 2000s) Dave Scovill
.289 inches Rem, BDL Classic Mike Venturino
.290 inches Winchester M70 Bob Hagel
.267 inches Rem. 700 Ken Waters

.Friends and 24HR Campfire member measurements. 2.225 inch trimmed case.

.275 inches Rem. 700 BDL
.290 inches Winchester M 70
.292 inches Win. M70 action, Buhmiller barrel
.305 inches Winchester M 70
.337 inches Ruger M77
.350 inches M98 (1935) SIG barrel
.353 inches Ruger M77
.395 inches Ruger M77

Just checked my 1982 M.70 FTW and it measures .277". The longest free bore I've seen is on my CZ-550 7x64 yet that hasn't hurt it at all in the accuracy department.

A long throat doesn't hurt accuracy (at least in benchrest terms) as long as it's close to bullet diameter--which prevents the bullet from tilting as it starts down the bore. But if the throat is considerably above bullet diameter, it sure can. The first Ruger No. 1A 7x57 owned, a red-pad obtained in a trade from a friend in the late 1980's, wouldn't shoot any bullet that wasn't seated very close to the lands, and no lead-core bullet under 160 grains would do that. It shot REALLY well with 160 Partitions and RL-22, but the case neck wasn't holding much of the bullet.

Ken,
Thanks. I will do that.

We have been blessed with a lot of great writers over the years and Jack O'Connor was one of the finest. I liked his style and thought he made a lot of sense. He worked in a competitive environment and had a very long and successful career but not without it's hardships.

I don't see him championing the .270 so much as defending it. It was probably his favorite cartridge but he used a lot of others as well. Eleanor's exploits with the 7mm prompted me to try it and I have owned several. It is a fine cartridge as is the 7-08.

We enjoy the benefits of good reamer manufacturers and barrel makers that Jack O'Connor never had. The scopes we have access to today are much more reliable and with better optical properties. Todays hunters enjoy many benefits earlier generations did not have but a lot of habitat has been lost. If success is your ambition then a good guide is truly beneficial. Some things never change.

Another good semi-traditional 7x57 to look for is a Ruger Mark II or Hawkeye. They shortened the throat in those considerably over the original Model 77 7x57's, and the hammer-forged barrels are usually really good as well. back when I tend to have several rifles chambered for the same cartridge, one of my 7x57's was a Mark II, and it shot very well, and was considerably lighter than the Mark X's I've owned.

I've turned back to working with a 700 Mtn Rifle, so chambered. It shoots Federal 175's and S+B 173's really well, but is cantankerous with other loads. I've gotten great accuracy with 154 Hornady SP's, but pitifully slow velocities. As of yesterday, 46.0 grains of H4350 would only get 'em to 2,425 fps. I'm tiptoeing upward to see if I can get 'em to the 2,700 fps range. The Gun Gack tome assures me this still oughta be safe territory in a strong "sucks" action.

Granted, a load with R15 that pushed this bullet to a scant 2,350 fps dropped a Dall ram quite neatly, but that was before I'd run 'em across a chronograph. It's a wonder he hasn't climbed out of the freezer to go resume his place on the mountain.

Perhaps he figured 'twas easier to just lay down, rather than face Ready's back-up shot...

FC