Anyone have experience with 8mm-338 Win Mag on Military Mauser

[mauser284]

I have 4 brand new 8mm barrels on hand. 2 are NOS military Mauser steeped profile barrels in 8x57 and 2 are Heavy 8x63/M32 Swedish machine gun barrels.

I also have at least 2 Mauser maybe 3 military Mauser actions just collecting dust none of them are rare or gems.


Seems like the 8mm-338 Win Mag would be a great way to make use of both a barrel and action.


Everything I have read makes it seem like a decent idea so long as you are not looking for unheard of performance. This is not about doing something not already done it is about making good use of parts on hand.

I have done some home work but home work and reading about something is not the same as having already done it!

I also considered doing an 8mm based off necking down the Ruger 375 but to be honest the case work for that would be a true Wildcat with lots of forming steps involved. It would represent a huge increase in performance. Brass price and availability of brass could be a problem in the future though not even counting Covid-19 brass shortage.

I like the idea of just running the custom sizing die over the 338 Win mag and none to very little case trimming involved. I also like the idea of knowing that the 338 Win brass is easy to get to feed while the 375 Ruger brass is kind of an unknown in my mind. I also like how many companies make 338 Win Brass.

This is a fun project not a serious target rifle or extreme long range hunting rifle. I thought about doing a 280 Express or dare I say it an AI version then I ran across this wildcat and it really caught my attention. I am leaning towards the Swedish 8x63 machine gun barrel.

I have 2 rifle stocks in various states of completeness already inlet for Mauser LR so something is getting built here soon on a LR surplus Mauser. I like the idea of doing something modern on NOS military surplus barrels and surplus military actions.

I understand no one would ever want to buy something like this should I get tired of it latter. I like that anyone could just rebarrel it to any other cartridge based on this style of magnum case and have a nice rifle latter on. If I build on the Ruger case and it get's discontinued I think the rifle would be a wall hanger.

Thanks guys for experience and other thoughts.

 

[Kurz]

Seems like the 8mm-338 Win Mag would be a great way to make use of both a barrel and action.

I also considered doing an 8mm based off necking down the Ruger 375

A couple of comments about these cartridges first.

You could consider the 8mm-300 Win. Mag. as well, skipping the .338 WM. You gain a little case capacity and it's a simple neck up operation.

In this same manner, skip the .375 and all the operation you mention and go with the .300 PRC which is the same case where you apply the necking up again. There is some excellent brass debuting in a few weeks so you have that to look forward to.

My thinking though runs to the 8x68 S as a classic modern pressure cartridge. There are Ackley Improved reamers available as well as the 8mm BooBoo which Dave Tooley did with the 7mm caliber from this basic brass, which is an improved form (30 degree shoulder) of the original case. Brass is available through Huntington's.



Nice article to read:

https://revivaler.com/the-8x68s/

The 8x68 S would be just cutting the chamber, headspace and crown. All the others require a new reamer to be made along with a headspace gauge although the belted versions all use the same common gauge.

If none of this stirs your thinking then by all means follow your own drummer.

Enjoy the process!

 

[ncageneral]

My brother has one , I'll ask that he chime in on this thread.

 

[Duckhunter39345]

I have done this very thing with a surplus Mauser. The 8mm-338 is a good cartridge and it shot well in my rechambered rifle. If you need load data I have quite a bit. P. O. Ackley list it as the "Poor Man's Magnum" and has load data in his books. I have some old Speer manuals that has load data plus other data that I have saved over time. I purchased a large number of 185 grain Remington core lock bullets years ago and use these for my 8mm-338. I have also used the 180 grain Noslers and several different 200 grain bullets in mine. This is a good reliable deer rifle with a powerful cartridge.

 

[rickiesrevenge]

I had a good buddy who used one for a long time. He killed 39 elk with his. He used a 220gr bullet. He loved that rifle.

 

[mauser284]

A couple of comments about these cartridges first.

You could consider the 8mm-300 Win. Mag. as well, skipping the .338 WM. You gain a little case capacity and it's a simple neck up operation.

In this same manner, skip the .375 and all the operation you mention and go with the .300 PRC which is the same case where you apply the necking up again. There is some excellent brass debuting in a few weeks so you have that to look forward to.

My thinking though runs to the 8x68 S as a classic modern pressure cartridge. There are Ackley Improved reamers available as well as the 8mm BooBoo which Dave Tooley did with the 7mm caliber from this basic brass, which is an improved form (30 degree shoulder) of the original case. Brass is available through Huntington's.

View attachment 1262162

Nice article to read:

https://revivaler.com/the-8x68s/

The 8x68 S would be just cutting the chamber, headspace and crown. All the others require a new reamer to be made along with a headspace gauge although the belted versions all use the same common gauge.

If none of this stirs your thinking then by all means follow your own drummer.

Enjoy the process!

I too thought about the 8x68S but the brass issue worries me. I have never played around with much metric European cartridges. While I did practically grow up in Europe especialy Germany 1979-1991 and hunted often I was not an owner and reloader until I moved back to the USA. I was always hunting with borrowed gear in Europe. So all my reloading experience starts in 1995 while I was at University/College.

My first reloading rig was a Dillion 550B and the first cartridge I loaded was a 300 Win Mag.

I considered 8mm-300 Win Mag. I decided against it because I load for 300 Win Mag currently and did not want to scavenge components from 300 Win Mag to feed my just for fun project.

I still have bags of 300 Win Mag Brass that I bought new 50 count for $16 retail at Cabela's no less. When I sold my first 300 Win Mag rifle I held on to ammo, brass, powder and primers etc.....

While at university/college I would shoot 100 rounds of 22LR ammo, 40 rounds of 300 Win Mag and about 40 rounds of 44 Rem Mag 3 days a week minimum. Not counting what I shot leading up to Rifle Silhouette season and 22 Bullseye Pistol Season.

In the last 17 months I have not even been to the range!

 

[wboggs]

The biggest problem is obtaining good .323 bullets.
Once you have solved that, you have a good round.
Be careful, the light cup and core bullets will do poorly at the velocities you can obtain.

 

[DGP4]

I like the 8mm-300 Win. Mag. option mentioned by Kurz. Much easier to find cases for reloading.

 

[std7mag]

And the obvious question that no one has yet asked.

Do you have a magnum bolt face?

If not, that's a whole other can of worms.

 

[jasophil1]

The 8mm Mauser is a very good cal you could Ack it or 8mm 06 plenty brass around.

 

[Liven The Dream]

Back 35 years a very good Gun Smith from the Chicago Area Johnny Smith was a Mauser King.
His favorite was 8MM/06 with a 200 Gr RWS Blood Grove Bullets .
He loved going to BC Black Bear Hunting .

 

[David Milisock]

I have 4 brand new 8mm barrels on hand. 2 are NOS military Mauser steeped profile barrels in 8x57 and 2 are Heavy 8x63/M32 Swedish machine gun barrels.

I also have at least 2 Mauser maybe 3 military Mauser actions just collecting dust none of them are rare or gems.


Seems like the 8mm-338 Win Mag would be a great way to make use of both a barrel and action.


Everything I have read makes it seem like a decent idea so long as you are not looking for unheard of performance. This is not about doing something not already done it is about making good use of parts on hand.

I have done some home work but home work and reading about something is not the same as having already done it!

I also considered doing an 8mm based off necking down the Ruger 375 but to be honest the case work for that would be a true Wildcat with lots of forming steps involved. It would represent a huge increase in performance. Brass price and availability of brass could be a problem in the future though not even counting Covid-19 brass shortage.

I like the idea of just running the custom sizing die over the 338 Win mag and none to very little case trimming involved. I also like the idea of knowing that the 338 Win brass is easy to get to feed while the 375 Ruger brass is kind of an unknown in my mind. I also like how many companies make 338 Win Brass.

This is a fun project not a serious target rifle or extreme long range hunting rifle. I thought about doing a 280 Express or dare I say it an AI version then I ran across this wildcat and it really caught my attention. I am leaning towards the Swedish 8x63 machine gun barrel.

I have 2 rifle stocks in various states of completeness already inlet for Mauser LR so something is getting built here soon on a LR surplus Mauser. I like the idea of doing something modern on NOS military surplus barrels and surplus military actions.

I understand no one would ever want to buy something like this should I get tired of it latter. I like that anyone could just rebarrel it to any other cartridge based on this style of magnum case and have a nice rifle latter on. If I build on the Ruger case and it get's discontinued I think the rifle would be a wall hanger.

Thanks guys for experience and other thoughts.

I figured I'd post this before you started assembly. First I believe everyone should have an 8x57 Mauser or two, just because. They're cheap to shoot and so much fun I bought my son one too. I bought a couple thousand rounds really cheap and my son and I practice off hand techniques with them.

I was in a similar position in terms of parts laying around as you years ago but went a step up, I used the action but went 358 Norma Magnum, the increased expansion ratio of the 35 caliber barrel shoots several inches flatter and develops about 900 foot pounds more than a 338 Winchester with a nearly same case capacity with max pressures in both.

In short it shoots a 250 grain flatter and faster then a 338 does a 225 grain.

 

[cowboybart]

If you are not in a hurry, I will be selling an 8mm Hetzenauer chamber and die reamer soon. It is currently getting used on my 8mm project and upon completion both Manson reamers will be up for sale as a set. It is an 8x68 Improved, named after the WWII German sniper portrayed by Ed Harris in the movie Enemy At The Gates. I may have goofed up the spelling, but it is close.

 

[Kurz]

Matthäus Hetzenauer - Wikipedia​

https://en.wikipedia.org/wiki/Matthäus_Hetzenauer
Matthäus Hetzenauer (German pronunciation: [maˈtɛːʊs ˈhɛtsənaʊ̯ɐ], 23 December 1924 - 3 October 2004) was an Austrian sniper in the Wehrmacht of Nazi Germany during World War II.He served in the 3rd Mountain Division on the Eastern Front of World War II, and was credited with 345 kills.His longest confirmed kill was reported at 1,100 meters (1,200 yards).

 

[mauser284]

And the obvious question that no one has yet asked.

Do you have a magnum bolt face?

If not, that's a whole other can of worms.

No but I have a gunsmith not more than an hour away! I am sure I have at least 3 mechanicaly sound Mausers just laying around waiting for to be machined.

 

[mauser284]

I figured I'd post this before you started assembly. First I believe everyone should have an 8x57 Mauser or two, just because. They're cheap to shoot and so much fun I bought my son one too. I bought a couple thousand rounds really cheap and my son and I practice off hand techniques with them.

I was in a similar position in terms of parts laying around as you years ago but went a step up, I used the action but went 358 Norma Magnum, the increased expansion ratio of the 35 caliber barrel shoots several inches flatter and develops about 900 foot pounds more than a 338 Winchester with a nearly same case capacity with max pressures in both.

In short it shoots a 250 grain flatter and faster then a 338 does a 225 grain.

I have one truck gun in 8mm Mauser and I have a hybrid 8x57 modern sniper rifle using M48A as the base and 8mm 8X63 Machine gun barel, custom stock, custom 30MOA scope base. I have plenty of VZ24 Mausers and at least 2 stepped NOS Yugo barrels in 8X57 and 1 more Swiss 8x63 machine gun barrel.

So I have the 8x57 covered. I agree it is a great cartridge. I consider the 8x57 easily the equal of 30-06 or 338-06 and maybe even the 338 Win mag inside of the 300 yards easily! It just depends on what bullet you use and what load you use!

This is just for giggles or just because. IF brass was not an issue I would build a 325WSM.

I have also considered 280AI or 7x57 mauser since I have an 7mm SS barrel just sitting around but it is an Ebay mystery barrel. To be honest I trust a NOS factory Mauser barrel from Sweden or Yugoslavia over random ebay 7mm barrel. The NOS Swedish barrels and NOS Yugo barrels are all really good barrels. Much better than ER Shaw or Green Mountain but not as good as a Lothar Walther, Brux or Hart etc.....

I have no idea if the feed ranps and magazine box would accept 325WSM. I have not run across anyone that has built a Winchester Short Magnum on a Mauser 98 action. It is not a pressure issue to me rather will it feed from the magazine reliably?

I also considered a 35 Whelan but I have so many barrels on hand that I hate the idea of not using what I have on hand first before buying more barrels. I have a SS 338 barrel blank but it is like 29 inches at least long and 1.35 in straight cylinder 1:9.5 twist. Finding a gunsmith that will contour that beast down to a hunting weight barrel or even a varmint weight is mission impossible.

 

[cowboybart]

The 8x68 is the easy button. BTW I have sold the 8 Hetz reamers since I posted the above post 4 years ago. If you need a magnum bolt I have 2 that I want to part with. I have seen 98s chambered in WSM cases on the used rack in stores - have to wonder if they feed or not.

 

[Tommie]

I’ll throw an idea out…
8mm-284 would have the standard bolt face covered. Case length essentially the same as the Mauser. Almost an easy conversion while still being somewhat exotic.

 

[std7mag]

^^^
Now that is an interesting idea!!!

I've heard of people doing the 30-284, but not a lot of larger diameter bullets.

And as mentioned, the length would work.

 

[Fire Dog]

Back in my days of youth, {Ah, sweet bird of youth where hast thou flown?} 8mm Mauser’s were selling in the $30 - $45=brand new, range, the standard conversion was to run a chamber reamer in and convert it to a 30-06-8mm. The local gunsmith would do the conversion for about $25-$35 if I remember correctly.
Got around the problem of the only ammo available for the 8mm Mauser was surplus German WWII corrosive ball.
The reamer cleaned up the original chamber without any extra work and the barrel screwed right back in for a head space check.
A 30-06 case is an easy button to neck up and load with 8mm bullets, especially now that a greater range of projectiles are available.
Plenty of “Horse Power” without going into exotic chamberings and needing a magnum bolt… Perhaps even an “Ackley-used” 40* shoulder…??