First venture in wildcatting and came up with this design. Wanted a cartridge designed for a Mauser 98, so I took the 375 Ruger and shortened it to 57mm and necked it down to 8mm. I wanted improved performance, but was hope for great functioning, since the 98 was designed for the 57mm case. I am in the process of forming cases and hope to fire form in the next few days. It has been a lot of fun, but forming cases has been more than I anticipated. A lot of thanks needs to go out to Dave Manson, Neil Jones, and James Anderson. I had never done this before and had a lot of simple and stupid questions. I'll try to get the reamer drawing and photos up. Went forward with a 9.3, 7mm, and a 6.5, but not sure I will get around to building those out, maybe?

375 Ruger, 8x57 magnum, 8x57

Cool project. Eager to hear how it performs.

Reamer Drawing

Right on, Dude...

I built a 9.3 x62 on an 8mm Mauser action...while I was futzing around with it I was also futzing with the Ruger, Rum, WSM and other "fat boy" cases in 9.3, 375 and 416 cals.

You could get case volumes between 85 and 100+ gr in the same COALs as the x57 - 92mm length and depending on the case neck length, shoulders angle and case taper. That's right up there close to the "Big boys"...any critter you prang isn't going to know the few fs difference between the full sized 375 Ruger and the "shorty".

I made up a few dummies and they seemed to feed alright but the rails and ramp could use a bit of work.

I didn't pursue it because of the cost of dies, reamers and CH4D was swamped, I already have more toys than I can possibly use, but I have a dummy of each cal sitting on my desk along with almost 100 other "messes" the keeps calling me...

I did cut a tool to turn the "Fat boy" case rim to .470" so I didn't have to muck about with the Mauser bolt face.

I'm guessing lots of others have the same ideas.

Let us know how it turns out.

Luck

Think My eyes played tricks on me...somehow 375 stuck in my mind...

I'm sure you already have some load data ready, Ozark Hunter, so this info is for anyone who's curiosity was peaked and for my own edification and nosiness.

I have a cartridge design program and Q.L. so this quick and easy to do.

8mm Magnum...2.25" case length...0.300" neck length...3.00" COAL...85 gr case volume...150 gr Speer SP...RL17...3400fs plus/3900 ft lbs...and as I said for the 375 cal version...right up there with the Big Boys....basically a 325 WSM tho'...

That WSM case works well for so many calibers as does the RUM.

I like that venturified radiused shoulder... gives a cool gnarly takincareofbusiness look to it.

Luck...

Preliminary feeding test in my prototype rifle(A Model 70 Classic 338 Win Mag. rebarreled and chambered) went well. Holds three down with enough room to depress the shells to close the bolt on an empty chamber. Fed and ejected great. Back to more case form work. Hope to start fire forming soon.

That Win Md 70 action gives you plenty of room to seat out and give you even more potential...already designed for a .532 Dia. case.

I think QL might have been a little overboard on the max velo compared to other 8mm's as it many times is, but that remains to be seen...depends on your case volume, barrel length, and all the other nebulous factors.

I'm curious to know the "WHY'S" of your design...much simpler to go with the 8mm Rem Mag or 325 WSW...every time I do a wildcat I usually have specific objectives in mind, although sometimes it's "just because". Your design is definitely reminiscent of the Roy Weatherby, Roy Gradle and Ralph Payne designs.

I only have one military Mauser 98 in 8mm now...I never could see any difference in game killing between the various calibers in that case volume arena, but 8mm bullets were scarcer than 7mm to 30 cal, were limited in weight (arguably), BC's/SD's were just some things to futz about within 300 yds and hardly worth the candles farther out if you just studied your ballistics.

Keep us posted...

Nonagonagin
The Why's are as follows. I felt that since Mauser designed the 98 around the 57mm length cartridge, that there were specific features that make that length important to the design. I thought by using a fatter case, but at the original length, function would remain close to the reliability of the original military round. I kept a similar body taper to the original, as well. Too much by modern standards, but again I was looking stay as true to the original design. This was my first ever attempt, and I knew ballistics would be nothing new. My venture was more about function. I don't know if it was smart, but I've had a lot of fun doing it. My planned rifle will be built on a 1935 Brazilian Oberndorf Mauser. Hopefully things will work out. Thanks for the interest.

I understand...That's a nice action to use...

Been doing wildcats for half a century...don't know about the smartness of many of my copies or creations, but they were ALL fun to build, develop loads for and shoot...AND schooled me constantly... Hahahahahahah

You got me poking about the 'net looking for something to muck about with...

I have something in every cal from 17 to 50 so it's hard finding that "something different", but I don't have anything on the WSM case and have been thinking of doing something on that case or a shortened RUM.

I designed several on the WSM (as did everyone else), the 2.25" shortened RUM and Ruger cases and did a 375 JDJ(9.53 x 62 or 375 x 2.25" whatever you want to call it)on a Savage Axis that could be taken out to the fatter case easy enough or give me the excuse to buy a WSM action.

So...I will be watching your progress with case forming, loading dies and load data with high interest.

Luck

That is a really cool idea. I'll bet it could become popular with Mauser fans.

That is interesting Oz H. Have you figured out how much case capacity you have gained with your cat? It kind of reminds me of my Bro-in laws 270 Ackley magnum in regards to shape and size of the case. I believe his falls somewhere in between the 7mm Mag case and an 06 case in regards to capacity. Which is not a bad place to be. Very efficient! I believe old Parker Ackley would like your design!

I had a FORMER "friend" that had a rifle with 270 Ackley Mag stamped on the barrel, used 300 H&H full length brass, on an 1917 Enfield action. Didn't come with dies!!! Never shot it...but it had the most beautiful maple stock, walnut forend and grip cap, walnut/ebony diamond inlays all over it, rollover, perfect skip-A-line checkering and engraving on the receiver etc.

He wouldn't sell/trade it to me or let me rebarrel it to something shootable and I never found anyone that would make dies because He was a cheap sucker worse than me...wouldn't pay the freight. Bawstid traded it for a 22 just for spite.


My sources show that cartridge had ~74 gr H20 capacity, so Yes, it would fall about half way between your selections depending on the brand of brass and be efficient. Ditto on Mr. A. I was very lucky to meet him once in S.L.C and listen to him talk for a few minutes, back in the early 80's, a few years before his passing. Probably what got me jumping into the deep end of 'cattin'.

All my design iterations for similar versions fell in the ~80-88 gr capacities so I'm looking forward to O.H. findings.

I can't say it enough...that venturified shoulder is "JUST SO COOL" ...Hurry up, Boss, I'm all wound up ready to turn...when the snow clears...Hahahahahaha

Luck

Wstrnhuntr

It is looking about right at 80 grains of H2O. That should put it right where you estimated. I have felt that it would provide plenty of power for a sporting round. Starting to fire form cases and continuing forward. Thanks and Happy New Year.

Nice! Looking forward to further updates.. Looks like it would make a fabulous Elk or plains game round. Ive always thought some 195 gn Hornady interlocks from an 8mm gibbs would be the cats meow. Maybe you could use some Gibbs data for your starting loads. ??

quote:

Originally posted by NONAGONAGIN:
I had a FORMER "friend" that had a rifle with 270 Ackley Mag stamped on the barrel, used 300 H&H full length brass, on an 1917 Enfield action. Didn't come with dies!!! Never shot it...but it had the most beautiful maple stock, walnut forend and grip cap, walnut/ebony diamond inlays all over it, rollover, perfect skip-A-line checkering and engraving on the receiver etc.

He wouldn't sell/trade it to me or let me rebarrel it to something shootable and I never found anyone that would make dies because He was a cheap sucker worse than me...wouldn't pay the freight. Bawstid traded it for a 22 just for spite.


My sources show that cartridge had ~74 gr H20 capacity, so Yes, it would fall about half way between your selections depending on the brand of brass and be efficient. Ditto on Mr. A. I was very lucky to meet him once in S.L.C and listen to him talk for a few minutes, back in the early 80's, a few years before his passing. Probably what got me jumping into the deep end of 'cattin'.

My Brother in law inherited one of his fathers Ackley rifles. He had a pair of them made back in the 70's and knew Parker. Ive shot the 270, it is pretty sweet! It's too bad your former acquaintance didnt get a set of dies, he would have liked it!

quote:

Originally posted by ozark hunter:
375 Ruger, 8x57 magnum, 8x57

Well done good sir!
I appreciate your effort. For me an afternoon spent on making cases, from another is more like therapy.
When I made 338rcm from 300rcm, some of the cases split the neck. I shall have to add proper annealing to my processes.

Cheers
Bruce

That is a very nicely designed case. I like that you incorporated a reasonable amount of body taper and kept the shoulder angle reasonable. Capacity must be similar to the 8mm Gibbs (blown out '06). I like it. Regards, Bill

80gr H2O? That could be a 264 Win Mag without a belt...and more efficient since it has a shorter, fatter powder column...or a 6.5x68 without having to buy RWS brass. Lots of possibilities for x57 Mausers.

That's a pretty cool idea.

Update. Have fire formed and reamed cases. getting ready to shoot some loads. I ordered a chronograph and want it to test velocities. This has been a lot of fun. Also, I necked up the case to 9.3. I am hopeful that it will be a 9.3x64 class round with a standardized case head. Will post more when I get the chrono and shoot it. Thanks for the interest.

quote:

Originally posted by LongDistanceOperator:
80gr H2O? That could be a 264 Win Mag without a belt...and more efficient since it has a shorter, fatter powder column...or a 6.5x68 without having to buy RWS brass. Lots of possibilities for x57 Mausers.

That's a pretty cool idea.

80gr of H20 is 4.3gr more than 8mm-06 Ackley Improved.

I saw that cartridge today and it is well done. OH put a lot of thought into wildcatting that cartridge and I think he did a heck of good job. He was kind enough to give me one for my.....assorted accumulation...of cartridges. I don't have an 8 X 57 but it looked about the same as the picture when placed alongside my 8 X 56 M/S.

Did you go home, load and shoot some today after we parted company? Dadgummit, had I known that I would have tagged along, uninvited or not...

If you want to borrow my Pact chrono until yours gets here you're welcome to it.

Sharps4590
Did not. Sat up there all day with Co2 install.
I will certainly give you a call when I get to the range. Really nice visit this morning. Always enjoy your company

It was a nice visit, I could do that all day....and probably would but for obligation!!! Looking at the cartridges side by side I can more readily see why the several steps in necking down, especially once the new neck gets into the case body. I do have a question and, I expect we talked about this but my memory for details...uh-huh...did you anneal the cases and did you lose any?

I did not anneal the cases. Forming wise every thing went well, yet tedious. I did lose quite a few cases of Hornady 375 basic brass due primer pockets being very shallow. Hopefully I will get the chrono by the weekend and can shoot some loads.

9.3x64, 9.3x57 Mag, 9.3x62

I did the 9.3 version last night, the bullet is seated just to the base of the neck. It has the same length as the other two rounds. Usable capacity should be right with the 9.3x64. Looking for a donor action on Gunbroker. Wildcatting is costly a habit.

Wow...never saw a bullet with a threaded shank. Do they screw into the case?......

Seriously, I have never seen that, what is it? I also think the case looks even better in 9.3!

North Fork 9.3 286 grain

quote:

Originally posted by ozark hunter:

9.3x64, 9.3x57 Mag, 9.3x62

Looking for a donor action on Gunbroker. Wildcatting is costly a habit.

An intermediate length L98R like a M48 Yugo or the commercial version VZ500 would be made to order if the COAL is kept to 3.20".

9.3x57 Mag, 8x57 Mag, 6.5x57 Mag

This should be a good battery of wildcats. I think I'm done. Now I just have to get rifles made. Chronograph came in, so I hope to start load testing for the 8x57 Mag soon.

quote:

Originally posted by ozark hunter:

9.3x57 Mag, 8x57 Mag, 6.5x57 Mag

This should be a good battery of wildcats. I think I'm done. Now I just have to get rifles made. Chronograph came in, so I hope to start load testing for the 8x57 Mag soon.

I got good results with Norma MRP in my 8mm-06 Ackley Improved. (2900 fps @ < 60K with a 200gr Speer Hotcore) It should work even better in yoiur 8X57 Mag.

Looks like the perfect battery!! Well done OH!! BTW, do you have an extra 9.3 to spare...

quote:

Wanted a cartridge designed for a Mauser 98, so I took the 375 Ruger and shortened it to 57mm and necked it down to 8mm. I wanted improved performance, but was hope for great functioning, since the 98 was designed for the 57mm case. I am in the process of forming cases and hope to fire form in the next few days.

It'll also work well with a 60mm case..I've owned and used 8x60s rifles, with a 62mm case in 9.3x62, with a 63mm case in 8mm-06 and 64mm in 8x64 (now almost long forgotten) and 9.3x64.

But it also works well with a 68mm case. And there's the nub of it.

I respect the effort you've made but doubt it offers anything, I sorry to say, that the 8x68S doesn't do equally well in the standard Mauser 98 action.

Got out to the range with the chronograph today. I used Hornady 338-06 data for a starting point, as they had loads for IMR 4895, of which I have plenty of. The bullet was a 200 grain Woodleigh PP. I was pretty happy with the results and the data is for three shot averages with each charge.

52 grain IMR 4895 avg. fps 2643
54 grain IMR 4895 avg. fps 2706
56 grain IMR 4895 avg. fps 2746
57 grain IMR 4895 avg. fps 2809
58 grain IMR 4895 avg. fps 2886

I felt that I am close to Max loads and am happy with the velocity. So far so good.

My home brewed 8mm X 2.5"-404 IMP. developed 3200 ft.lbs. of energy. Just a little better than a hot loaded 06. It originally was a 8mmX 2.5"-.425 WR.

When the .375 UM came out I lapped the 404 chamber out to fit the Ultra Mag case.

I still have 45 once fired 8mm X 2.5"- 404 WR cases which I will give away , no charge. You will have to pay shipping. roger

Thank you Bartsche, but I don't think they would work for me. Mine is based on the 375 Ruger. Thank you for the offer though.

Nicely done- I did not see a mention of whether or not your new creation would clean up an 8x57 chamber, or whether a barrel set back is needed.

358ELK
I think that is a bit above my pay grade. I would contact Dave Manson(Dave Manson Precision Reamers at 810-953-0732) to be sure. I didn't consider that when I designed the round. Things are progressing though. Feeding is really great in the unaltered Model 70 Classic. And a big thanks to Sharps4590 for range help today. Hope to get the bugs out and have more load data soon.

OH, thank you but don't be too profuse in your thanks to a fella who couldn't get it through his thick skull that 2.236 was shorter than 2.240 and couldn't remember why he had a fired case in his shirt pocket....lol!!! What a day of brain cramps!!

If what I saw in regards to accuracy at 50 yards extrapolates to 100 yards that particular rifle in that cartridge is going to be a shooter once it all comes together. There's just a few little bugs to work out, none of much significance.

Looks interesting.
You need to dig up some of Charles Askins writings. He did a lot of work with 8mm's based on the .404 case.
C.G.B.