Best 7X57 Mold?

[1874Sharps]

Gentlemen:

I had the good fortune of trading for a vintage Mannlicher-Schoenauer rifle chambered in 7X57 Mauser. I had a whole bunch of 7mm j-word bullets on hand and found that it shot the 140 grain bullets and the 170 grain bullets equally well. In fact, I cannot seem to find a powder/bullet combo the rifle does not shoot well (the first time this has happened to me). I picked up some 7mm gas checks and will soon buy a 7mm boolit mold. The question is which mold to buy. I thought I would solicit advice from those of you who have cast and loaded cast boolits for this caliber, and especially for this rifle. Which boolits and molds have worked well for you? Thanks.

[Nobade]

I really like the SAECO truncated cone bore riding designs. The 160gr. version is a real shooter in everything I have tried it in. I also have the RCBS 145 SIL mould and don't like it a bit. Gaschecks don't fit, and the bore riding nose is too tight to allow cartridges to chamber.

Recently I have been shooting 270 boolits in my 7mm rifles, paper patched. That works even better, with factory level velocities and accuracy.

[405]

Well, may depend on your bore and groove diameters and the condition of the leade and the lands just in front of the leade. But, since you said it shoots well with what you tried I'd say that is a very good sign. I don't have a Mannlicher. I have a Chilean 95 in 7x57. It is one of the very few military rifles that took nearly no load or bullet tinkering to get excellent results.

I cast the Lyman 160 gr. 287641 GC, 12 BHN alloy, sized to .285", fairly soft lube, over 18 gr 5744 w/dacron filler. It is the easiest old milsurp I ever loaded for.

[atr]

I have shot both the 135 gr and the 160 gr (both gas checks) very successfully in my 7x57 Mauser. Between the two the 160Gr, which is a Lovern design, gives the best accuracy. My barrel is very close to design specification and I am sizing to 0.284. You should slug your barrel. My favorite powder for reduced loads is 4895

[Lefty SRH]

Eventually I'd like to try cast boolits in my Ruger No.1 7x57 RSI. Are theses rifle as succesful as the mil-surp Mausers?

[plainsman456]

I have shot the 135 version and was amazed it shot to the same point as my 140 grain jacketed loads.
So far with a 160 grain version I have only shot about 20 rounds or so and it has promise as well.

[runfiverun]

most of the 7's have a 1-9 or 1-91/2 twist rates.
it's the throat that will determine boolit shape for best accuracy potential.
my charles daley doted on the rcbs 145 silh boolit, the old tang safety ruger likes the 168 lyman, my ackley likes the 150 nei with the undersized nose the best [dunno know why, probably the longer bearing surface and the straight chamber to bbl]
and my i.c.l. chambered douglas bbl does fine with all three but has a difficult time chambering the lyman 168 and i can't unchamber a round or it'll pull the boolit.
so you gotta have a clue as to the throats shape and then determine which boolits shape will be a better fit.

[Lefty SRH]

most of the 7's have a 1-9 or 1-91/2 twist rates.
it's the throat that will determine boolit shape for best accuracy potential.
my charles daley doted on the rcbs 145 silh boolit, the old tang safety ruger likes the 168 lyman, my ackley likes the 150 nei with the undersized nose the best [dunno know why, probably the longer bearing surface and the straight chamber to bbl]
and my i.c.l. chambered douglas bbl does fine with all three but has a difficult time chambering the lyman 168 and i can't unchamber a round or it'll pull the boolit.
so you gotta have a clue as to the throats shape and then determine which boolits shape will be a better fit.

How do you check to see what shape chamber and throat the rifle has?

[atr]

YES the Ruger #1 shoots these well also,
the picture is of 10 shots at 75 yds
the Lovern mold will drop anywhere between 150 and 160 gr depending on my mix.
I was shooting a Ruger #1 with a scope


I have used 4350, I do like the powder but if my memory serves me correctly I did not get the same tight grouping...I might still have a picture of groups with 4350 if so I will post later....
I do use 4350 for full power loads with Jacket bullets.

[Lefty SRH]

Thats impressive. You used IMR 4895, can IMR 4350 be used?

[1874Sharps]

A word about the leade in the Mannlicher-Schoenauer: It has quite a long leade. It will shoot rounds loaded out to 0.060" over the maximum COL. I tried some accuracy tests seating the bullet out to 0.006" short of touching the lands and they shot well. I tried seating to maximum COL and they shot the same. That to me was odd. One would think that with such a difference of seating depth some difference would have been seen. I do not know what this means, only that I cannot seem to find a load it will not shoot well. HUBERTUS jokingly told me it must be a boring rifle since it has taken no load development to speak of. That is a good kind of boring! I have not yet slugged the bore but that is something I should probably do. The idea of paper patching a 270 boolit up to 284 is appealing, too, as NOBADE mentions.

What standard cast boolit design tends to lend itself well to accuracy in a rifle with a deep leade?

[405]

Who knows what your throat really looks like so a chamber cast would answer that question. I know that many of the military chambers in the 6.5-7MM range of the various cartridges were designed with long throats to handle the long round nose Jbullets. I imagine many of the older civilian chambers of that era would have followed that suite because that was the style of bullets/ammo available.

Both the Loverin design and the various designs with bore riding noses with likely do well in that type throat and leade. The one caveat- sometimes to full take advantage of the bore riding nose, the longer and many times the best OAL can exceed the magazine max length. The key with that bullet design is to get a mold that will drop a bullet in the proper weight range that also has a nose that will lightly engrave into the leade and first part of the bore lands. Finding the mold to do that, especially with even a slightly worn leade and entry lands, can be frustrating. That is exactly the reason the 314299 mold works so well in various 30-06 milsurps that have slightly worn leades and entry lands.

[1874Sharps]

405,

That seems reasonable to me. The rifle in question was made in 1953 (it is a Model 1952). This rifle was likely chambered to shoot the larger round nose bullets and therefore has a long leade. The rotary magazine will hold over-max-length cartridges (this model of rifle was also chambered for the 30-06) easily, but I have not done so because seating the bullets way out did not improve the already great accuracy. That being said, maybe the way to go will be trying out a 160 grain or heavier mold.

[405]

Ya, that longer magazine is a good thing and will help with seating depth experimenting.

Those long bore rider nose designs do need to fit the bore correctly to work right. If that long nose just hangs out there unsupported when the round fires and all that upset/obturation is taking place, that loose fit may destroy any chance at accuracy.

As an FYI, the 160 gr. Lyman 287641 bore rider I shoot out of the Chilean M95 Mauser drops bullets with a consistent bore rider nose diameter of .276" with a medium soft alloy of about 12 BHN. It does lightly engrave on the lands when chambered.

[atr]

those old mausers originally used the 175 gr RN...so the throat was long to accomodate. With cast, depending on style, they really have to be seated way out before they begin to touch the lands. the magazine may not be long enough to accomodate when seated to just touch the lands. Not a problem with single shots such as a rolling block, or ruger #1

[ihmsakiwi]

I really like the SAECO truncated cone bore riding designs. The 160gr. version is a real shooter in everything I have tried it in. I also have the RCBS 145 SIL mould and don't like it a bit. Gaschecks don't fit, and the bore riding nose is too tight to allow cartridges to chamber.

Recently I have been shooting 270 boolits in my 7mm rifles, paper patched. That works even better, with factory level velocities and accuracy.

Hi Nobade, since you appear to have a 270 sizing die have you tried nose sizing the RCBS 7mm boolit to clean up the parting lines on the 7mm boolit? This is what I need to do to get the boolit to bore-ride in my F.A. Single shot 7mmBR. The same boolit has no problem fitting in my XP without this extra step. Peter.

[Nobade]

Hi Nobade, since you appear to have a 270 sizing die have you tried nose sizing the RCBS 7mm boolit to clean up the parting lines on the 7mm boolit? This is what I need to do to get the boolit to bore-ride in my F.A. Single shot 7mmBR. The same boolit has no problem fitting in my XP without this extra step. Peter.

I don't have a 270 sizer, I just use 270 boolits as cast and paper patch them. They come out just right for 7MM.

But I do know what you mean, I used to have to size the nose of the RCBS 165SIL 30 cal. boolit to fit in the bore of my Contender 32 H&R. It was just a hair big, would work in bolt actions but I couldn't close the Contender on it.

[adrians]

i'm following this post ,,, i have many mausers in most calibers but not a 7x57 amongst them.
:coffee:

[Larry Gibson]

If you run across the old original RCBS 28-168-FN you might snap it up. It is like a Lovern and shoots very, very well in my M95 7x57.

Larry Gibson

[runfiverun]

you will know the chambers shape by measuring a fired case.
the throat is done with either a cerosafe casting or by an impact done with soft lead.
basically the same as slugging a bbl, but when you do the throat you need to bump the lead up in that area to fill the throat.

[1874Sharps]

Gentlemen,

After considering all of your input and the long leade of my Steyr Mannlicher-Schoenauer 7X57 I bought an RCBS 168-SP mold and cast up a few. Finally the rain (and the mud) at the range let up enough to try out the cast boolit load of 14.0 grains of Bluedot. The results were very pleasantly surprising: a 7/8" three shot group at 100 yards. I tried an IMR 4227 load of 18.0 grains but only got a group of 1 1/4" due to vertical stringing. Below is a photo of the Bluedot group.

[.22-10-45]

Hello, 1874Sharps. Nice group with that 7X57. A few years ago, I purchased a pre-war..
(WW1) Mauser sporting rifle in 7X57. It has claw mounts with a very clear Zeiss 4X. Bore is bright & shiny. I had always wanted a 7X57, so had accumulated a few 7mm moulds.
Every one showed alot of daylight around when jammed up into throat.
Groove dia. is .2883"..Those Germans liked deep grooves for pressure relief.
I had Fred Leeth of Pioneer Products make up nose-pour copies of Lyman 311008 @ 150grs
& a copy of the early 1905 .30 @180grs. Both have flat meplats if I decide to use for hunting.
This rifle likes them fast..I am using H4895 & the more powder..the better the accuracy!
I tumble the gas-checked bullets in moly & use Lyman Super Moly lube. I am well up into the jacketed bullet starting loads..the only limiting factor is my shoulder..this little rifle is light! My groups look like yours at 100yds. with the 150 grainers.
I haven't yet tried the 180's...all loaded up though..perhaps when weather breaks. Best of luck!

[1874Sharps]

.22-10-45,

Very cool rifle you describe and great results, too. What charge of H4895 were you using and what velocity were they? Maybe I can crank up the velocity of my rounds a little. I am still on the bottom floor of experimentation. I have only owned a handful of German/Austrian firearms, so my sample group is not huge, but am very impressed with the quality of function, fit and finish on them -- even the military weapons.