Author Topic: 8mm Mauser: 2,700 fps with 220 grain bullet? (Read 2074 times)

lgm270 · « **on:** February 13, 2005, 03:15:49 PM »

I was reading a thread about the use of muzzle brakes on 8mm mauser mil-surp rifles, and one poster claimed to get 2,700 fps with 220 grain Sierra Bullets (!).

Most loading data shows 2,400 fps as about max. This is consisent with ballistics from such similar sized cartridges as the .308 and .30-06.

Is it possible to get 2,700 fps with the 220 grain bullet from the 8x57? This seems hard to believe.

Graybeard · « **Reply #1 on:** February 13, 2005, 03:43:55 PM »

Sure it's probably "possible". Safe or sane? No way. I have no clue what pressures it would take to get there but they'd be way above SAAMI maximum and likely well above the safety limit of an old military rifle.

RaySendero · « **Reply #2 on:** February 13, 2005, 04:35:32 PM »

I've read claims of 2,550 tops with the 220 SGK out of an 8x57, but never anything close to 2,700!

Only thing I can think of is maybe with dulpex powders like Hornady loads in their "light magnums"? Just a guess if claim is real.

PS: Remember some Mauser have 29.5" barrels

jh45gun · « **Reply #3 on:** February 13, 2005, 07:36:00 PM »

I load my old war horses on the moderate side. A bullet going 2400 fps or slower is good enough for me. Even with my 308 Encore Pistol I will in the future load more moderate even though it is a strong action. I loaded up some faster ones that were still below max and they about hit me in the forhead every time I shot it. Recoil was more than factory (which I can handle well) and I developed such a bad flinch I missed a large wall mounter buck with the load. I then switched to some mild cast loads to get rid of the flinch which they did.

kombi1976 · « **Reply #4 on:** February 14, 2005, 01:07:38 AM »

Well, you can either put a 40" barrel on the baby or hammer as much powder into that case as you can.
The first is ridiculous and unwieldy and the second is, how can I put it......

NUTS!!!!! :shock:

Even the European pressure limits don't allow those sort of loads.
SAAMI pressures for the 8x57 are lower because they take into account the fact that bozos who don't know the difference may try high power loads firing .323 bullets in 88 Mausers with .318 bores but 2700fps is crazy.
I mean if you want to test the gas ports on your 98 and feel you are immortal................ :?

1911crazy · « **Reply #5 on:** February 14, 2005, 03:14:50 AM »

First velocity "speed" is not the key to accuracy the hotter the load the more the accuracy falls off. Go to www.turkmauser.com/ lots of ammo info there surplus and reloading info read everything you can there about ammo its a great site for 8mm info. BigBill

Robert · « **Reply #6 on:** February 14, 2005, 05:28:06 AM »

Gas Ports? Where are the gas ports on my Mauser. I haven't heard of that. About 2450 looks like the max for a .323 bore with 220's. Give the 8mm-06 another 100 fps on average...2700-2800 is fine with a BIG BELTED MAGNUM CASE..the 8mm Remington Magnum.

S.S. · « **Reply #7 on:** February 14, 2005, 06:40:09 AM »

The 2700 fps with a 220 grain bullet claim was actually made by DWM
before WWII. These ballistics were figured by formulas
and not by an actual chronograph (Didn't exist)
I have seen a 198 gr fmj reach that velocity, but never a 220.
I have found that some loads were listed for Aircraft machine
guns that were pretty stout too. Some of the FN49s or Hakims
have adjustable gas systems so the rifles would probably
function at that pressure. But you would probably damage
the system pretty quickly. My personal opinion is don't
push the old 8mm that far. It really isn't necessary.

S.S. · « **Reply #8 on:** February 14, 2005, 06:44:29 AM »

Forgot something.
I think what was meant by gas port on a 98
was the relief port in the receiver that is intended to bleed
off pressure out the sides in case of a ruptured shell.
Some rifles had it some didn't.

1911crazy · « **Reply #9 on:** February 14, 2005, 07:51:23 AM »

The Hakim or FN49 won't take those kind of hot loads heck I heard the gas exhaust on the FN49 is all the way open on some of the surplus stuff like the turk 8mm ammo. And one must be really careful with the Hakim with the higher pressure rounds it can cycle too soon like before the bullet leaves the barrel causing the shooter to get the breech pressure in the face. I'm very careful how the gas systems are adjusted and to what rounds i send down the pipe too in the semi auto's. So that leaves the higher pressure rounds for the bolt actions only. Thats is pushing on the edge of disaster for sure the breech pressure is much higher and stays higher time wise due to the heavier slow bullet. The lighter bullet moves much quicker out of the barrel.

BigBill

I wonder what the breech pressure actually is on a load like that?? It has to be way over 50k i would think your hitting 55k and maybe higher. I know your reloading it but the same principal applies to reloading too. If we look at the surplus turkish 8mm 155gr bullet runs on average 3,000FPS and moving that fast time wise the breech pressure is much less. The yugo ball ammo ruins around 2,500 FPS for 199gr bullet. To me if i undersand it correctly there are two things that influence the breech pressure its the bullet weight and the powder charge and "time" the actual time it takes to get the bullet moving down the barrel which is caused by the powder burn rate too. The heavier bullet takes more time to get it going.

We also have the what if factor too just how much use and abuse have these guns seen in battle and how much more can they take. I'm hoping the headspace is a good check for reciever stretch, like how much the bolt lugs can wear or be pushed back into it. Or chamber wear but with higher pressures it would be the bolt first to see the wear.

Lets talk about shooting the hotter machine gun ammo out of your surplus gun too. I looked at buying it for my french 49/56 7,5 caliber but i didn't want to put the gun thru the abuse of the higher pressures. Most of the 7,5 french ammo that is now available is or was linked machine gun ammo.