i think that i've finally located a lefty ruger in 308 in fair condition,i want something bigger but not a 358.anyone ever heard of this cartridge(either AI or standard 20' shoulder).also what could i expect from a 220 gr.bullet?

Bart185,

I need to ask WHY? ...

Obviously you are planning to reload. If that is the case why not go with the 358 and download using 357 pistol bullets and load up with rifle when need to.

If you just want a 8mm-08 and you like the 8mm bore go for it, but you will not be saving an money or really gaining much over the 308. You will get a modest increase in velocity due to the larger base area of the bullet for a given bullet wieght.

In 30 cal you have bullets from 110 to 220 grains you can get over the counter.

In 8mm you have from 125 to 220 grains. At most I would be surprised if you gain 100fps for the same bullet wieght compared with the 308.

Why not the 8MM in its original form?? *8MM Mauser* It should fit in that action, and then you could shoot 200 grn part. at the same speed as 308 180s.

I've heard of this wildcat, can't remember where (maybe on this forum?), but have never seen it. I checked my 10th edition 'Cartridges of the World' reference book, but it doesn't list it. It must be very rare. However, that's what makes it coooool! I think it would be great to have a barrel stamped with 8mm-08 -- something unique.

I wouldn't do the 8mm thing myself. Tnhe .308 bore has a much better selection of bullets, MUCH better.

Then if I really had to open up a .308, the .338 bore would call me. .338 had a great selection of bullets from 160 - 300 grains.

I just don't see any advantage to an 8mm, unless that is just what turns your crank.

MM

I dont think that the 8mm mauser would not fit in a short action(3.25 overall length),the 308 is 2.80 and the 358 is 2.78.I am not really a bean counter but I think that this might work.Using H380 as a good reference,the8mm mauser uses 42gr.of powder to push a 220 gr hornady 2107fps. the 308 uses 45gr.in a compressed load to move a 200 gr.bullet 2440fps.the 358 win burns 54 gr.to get a 200gr.sp to 2375fps also a compressed load.(Lyman book).Is 2500 fps possible from this round in the Ackley version with the 225 gr hornady,or am I pissing in the wind?

It has already been done, about 100 years ago. It was known by its metric designation, the 8x51mm. Mauser chambered it in their Kurz (short) actions. Case dimensions were similar to the .300 Savage.

Using the slightly larger dimensions of the current 7.62x51 case should yield better performance than the original cartridge, which I believe was just a shortened 8x57 case.

The project would seem practical if you had an original Mauser Kurz in 8x51 and wanted to rechamber it to use a more common case.

Bart:

A 338-08 or 358 would deliver more velocity with equal bullet weights and the same pressure.

FWIW, my 21" 338-08 delivers about 180/2750 200/2690 225/2450

JimF

Bart,
Having nothing better to do today, so I did some figuring on the 8-08.It appears you will be able to get near 2500fps from the 200gr. bullets and you should be able to slightly exceed
the velocity of the 308 with 165gr. bullets with the 170 gr. 8mm bullets.My money is on the 200s at 2500 as real game getters.
Chuck

I guess that this idea is not as good as I first thought.I guess that I'll think about a 338-08 AI instead.Just dreaming any way.the ruger is right handed,so my LH dream is dead.Anyway thanks for the input.Bart