proper speed for 8mm

[nekshot]

I want to get serious with my new barreled 8mm and I was wondering what is the suggested speed for the 1 in 9 and 1/4 inch twist with the 323470- 168 gr, Lee 8mm Max-240 gr boolits. Also wondered what the BC is of the maxi boolit? I have to wait for the groub buy to mature and then I will have a proper fit boolit. I beagled these and we are good to go but everytime I beagle I hold my breath fearing to take the mold out of round!

[Char-Gar]

I have some experience with 323470 and it has done very well for me in my 98/29 Persian BRNO Mauser from 1.3 to 1.9 K fps. I have not tried to go faster or slower so I can't comment on the upper and lower limits of the bullet. I have no experience with the 8mm Maximum.

[runfiverun]

huh I didn't know they were that fast.
I just treat mine like I treat every other 308 to 30-06 sized cartridge. [shrug]

[Ricochet]

I've shot the 8mm Maximum with good success at about 1700-1750 FPS out of various long barreled old warhorses.

[Ricochet]

You can gas check those bullets easily without sizing them, to better fill the loose throats those rifles often have. Mine cast about .328" IIRC. Use a Lee 8mm Factory Crimp Die and screw it in till it just touches the shell holder. Put the check on your boolit and hold it in the top of the FCD. Rest your fingers on the top of the die and watch to make sure the gas check is just in the top of the collet where the crimp is applied to the top edge of the gas check. Run the press ram up and see if it starts to crimp the check. When it starts crimping, measure the gas check diameter and the boolit diameter. Adjust the die till they're the same. Quick and easy, and it doesn't limit you to the standard sizing die diameters.

[Ricochet]

If you "Beagle" your molds to finagle larger boolits, now you can "Ricochet" your gas checks to go with them. :mrgreen:

[Char-Gar]

huh I didn't know they were that fast.
I just treat mine like I treat every other 308 to 30-06 sized cartridge. [shrug]

1.3 K = 1,300 fps and 1.9 K = 1,900 fps

[MBTcustom]

Yes, typical 8mm Mauser is a very fast twist barrel. That and they usually have bores like sewer pipes, so 1800 is pretty much where you need to be.
The good news is that you can drop most anything in North America with a 8mm 175 grain cast boolit at that speed. I've got a new Wideners barrel on my M48A and as soon as I clean up the headspace, I'm going to have some fun shooting it. Should be a walk in the park as the new barrel is of superb quality, and very straight, the rifle is heavy, and the loads are light.

[runfiverun]

I meant the twist rate Charles.

I push my 170 fngc boolit with 32 grs of imr 4895 and dacron, thats a bit over 2-k airc.
I gotta start paying attention to this twist rate stuff,, I'm doing everything wrong.

[nekshot]

ricochet, you are fortunate to get that size as cast. Mine was .324 and after beagling they give me .326. I am chicken to try get more diameter out of the mould. Glad to hear of 1700 with the max is doable. That boolit would go thru a locomotive if it was determined by looks! I thought I could get 1700 out of either boolit. I simply want to try get as good a load for hunting purposes with out going nuts. Thanks for all your input!

[nekshot]

Yes, typical 8mm Mauser is a very fast twist barrel. That and they usually have bores like sewer pipes, so 1800 is pretty much where you need to be.
The good news is that you can drop most anything in North America with a 8mm 175 grain cast boolit at that speed. I've got a new Wideners barrel on my M48A and as soon as I clean up the headspace, I'm going to have some fun shooting it. Should be a walk in the park as the new barrel is of superb quality, and very straight, the rifle is heavy, and the loads are light.

Tim, I got one of those 7.62x39 barrels from them for another carcano project should I stumble onto it. I was going to get their 8mm barrel but then I found those 30.00 dollar deals at Copes.

[Ricochet]

I was loading as I usually do with boolits in milsurps, with an appropriate Lee dipper of 7383. I can't recall which one I was using, but it was all that would fit under the Maximum with a little compression. No signs of high pressure, and it shoots reasonably well, about as well as I can shoot with those old things. I still have a few of those and use them in my 1888.

[nekshot]

Great, well I started out with the 168 gr Lyman on top of 21gr sr4759 and a win primer. I fouling shot and everything else stayed together very nice. Could not get these to chamber coming out of magazine so I pulled the barrel and ground and polished 3 times and still no good. I was sure the problem was the short stubby cartridge so I went to the maxium. With 16 gr 2400 it shot 1 inch off of the 168's and these fed well out of magazine and only slightly opened the groub. (we are talking 1 and1/4 inch groubs at 80 yards) I stopped as I am happy with everything so far. I am going to cut the maxi mold down to the length that allows the boolit and ck to stay in neck. I cut one by hand and it weighs 215 gr which is perfect for me.

[Ricochet]

Sounds like what you want is the Karabiner mould.

[Buckshot]

...........Many moons ago I commissioned a Lee group buy for a SC Lee mould of generous proportions. Fototime is currently down so I cannot post a picture but it was to drop a .326" diameter slug of ~235 grs. The design was a 'kinda' Loverin, but the drive bands were wider. For some reason I got the idea stuck in my noggin that I needed to get 2300 fps with it. I should have used a M38 Turk with it's 29" bbl, but instead us the M38/46 with it's 24" tube. I used the slow lot of surplus WC852, and GREX shot buffer to fill the case as I began.

Accuracy was darn good up to about 2200 fps, and I DID reach the 2300 fps mark. However in addition to that I also ended up with a crack in the wrist of the stock due to the action trying to walk backwards! At that time I was using the good old Beeswax/Alox mix lube but it may have been tiring out at about 2100 fps as that was when I noticed how gray the bore appeared at the muzzle.

.............Buckshot

[UBER7MM]

Yes, typical 8mm Mauser is a very fast twist barrel. That and they usually have bores like sewer pipes, so 1800 is pretty much where you need to be.
The good news is that you can drop most anything in North America with a 8mm 175 grain cast boolit at that speed. I've got a new Wideners barrel on my M48A and as soon as I clean up the headspace, I'm going to have some fun shooting it. Should be a walk in the park as the new barrel is of superb quality, and very straight, the rifle is heavy, and the loads are light.


Glad to hear you're in the 8x57 game. What's the twist on your new barrel?

[MBTcustom]

I was about to answer but remembered that I had not actually measured the twist yet, so rather than talk out my butt, I elxclaimed "Quick robbin! To the bat scope!" LOL!
I got out my borescope and measured the twist rate.
They must have been feeling really ambitious when they cut this one! Twist was exactly 1-9 3/8".

To everything - turn, turn, turn
There is a season - turn, turn, turn
And a time for every purpose under heaven

A time to be born, a time to die
A time to plant, a time to reap
A time to kill, a time to heal
A time to laugh, a time to weep

A time to cut a barrel like a dad gum corkscrew!!!!!!
LOL!


Told ya they were fast.[smilie=2:

[UBER7MM]

1:9.375" sounds like "vanity and vexation of the spirit....."

Is there profit under the sun?

[Char-Gar]

I have excellent results with cast bullets in the 8MM Mauser. The twist may be a mite fast, but the rifling is deep and grabs the lead very well. I have never pushed on faster than 1,900 fps.

Not all 8mms are shot out relics of the past. I built a Sporter on an excellent BRNO Persian 98/29. I shorted the barrel to 24" and stocked in as a classic American sporter. In the safe in another Persian 98/29 in full factory dress, mint and unfired since it was made. Someday I will cure that.

[MBTcustom]

That's awesome Charles.
And I agree with you that there are some good ones out there. However, out of 100 that come through the shop, maybe one or two have decent bores, and I've never seen one that I would call "really nice". However, these NOS Yugo barrels are impressive no matter who you are, and can really breath new life into an old mil-surp!

[Char-Gar]

Tim, when SAMCO brought in the Persian 98/29s from Iran about 20 years ago, they had been in storage since before WWII, many had never been issued. There were of the finest made under Mauser license by CZ at Brno. Finish was equal to the finest commercial rifles of that day. They were delivered to Persia in 1931 and 1932. They were sold in several grades. The top grade came with the issue bayonet and the test target from CZ. The next grade down was unissued and unfired, but without the bayonet and target and that is the one I bought. The price was $200.00 plus shipping.

These folks also had some barreled actions for sale that came from rifles with broken stocks. After receiving my rifle I was so impressed with it, that I bought a barreled action for $125.00. It had a little blue wear on a few edges but otherwise was mint inside and out. I set it aside to build the rifle pictured above.

I had laying about the shop an old Fajen semi-finished AA grade American walnut stock that I got from Fajen in 1959 for $25.00. To say it was dry, is an understatement. It would split if I was not careful in the final inletting and finish. Luckily it did not do so in any place was not taken off in the final shaping or was on the inside. I did a tight metal to wood fit and then glass bedded any place that would take recoil in respect for the dry wood.

Having long been a fan of Bob Owens stocks, I keep that mental image in my mind except for the forend tip which I shaped like the "pig nose" favored by Al Linden. I am left handed and I made the stock to fit me and nobody else. It has the proper cast and shape. When fired from the right shoulder it feels like a fence post, but when fired from the left, it is like holding your favorite gal. They will probably have to bury it with me as it won't be a good fit for anybody on earth but me. When I made it, I decided to heck with anybody else, I would build just one rifle in my life that was for me and only me. I am well pleased with the results. I finished the rifle in 2007.

It will deliver 2 MOA accuracy with euro military surplus ammo and 1 1/4 MOA with good handloads either condom or cast. The sight is a NOS Redfield that I traded somebody out of in the far distance past. I don't remember who or when.

An interesting factoid is the serial numbers on these rifle are in Farsi which looks like chicken scratching. SAMCO put the SN in our numbers on the receiver in front of the bolt. I covered that with tape and told the man who blued it not to polish there. This SN is neatly covered by the rear sight base, should I ever need it.

[nekshot]

that is a nice piece for sure. I bought a bunch of vz24's about the same time and one swede that was perfect.

[Char-Gar]

that is a nice piece for sure. I bought a bunch of vz24's about the same time and one swede that was perfect.

A bunch of good Swede rifles came into this country in the late 70's and early 80's. I bought two primo ones for for $75.00 each. I gave one to my son and still have the other. They are spooky accurate with good ammo.