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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

[This message has been edited by wildcat junkie (edited 01-18-2002).]

[This message has been edited by wildcat junkie (edited 01-18-2002).]

take the 8x68S as a base. It will fit standard Mauser actions as it was designed for them. Its a bigger case than the 9.3x64 case. There are more brass sources ( 2 manufacturers, not counting the very small garage outlets ).

If you go to 8 mmS ;-) it will be hard to improve much. Perhaps just an "improved" form. You could also neck it down to get real speed, e.g. to .264 ...

Of course, the possibilites are nedless.

Have fun! Hermann

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Good shooting! Hermann

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quote:

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Originally posted by Kimmo E:
Its already been made ~70 years ago. Its callef 8*64 and 7*64 Brenneke.
Two modern calibers are 6,5*64(brenneke?) and 6,5*65 (rws?)

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As aHunter pointed out, you are off track. These are .473" case head cartridges that are too long to function in the Intermediate length actions (of which I consider the M70 short action) Besides I already have an 8mm-06 Ackley Improved. I am looking for something to build on the two VZ500 M98 actions I got my grubby little hands on. These actions are 1/4" shorter than the "standard" M98, but are "large ring" in all other aspects. In my opinion the WSM is too short in the neck to be flexible with a wide range of bullet weights, and forming something with a longer neck (and slightly longer shoulder dimension to prevent acidental chambering in WSM chambers)from RUM brass would be a lot more complicated than necking down and fireforming this case. With the performance that Hornady is getting from this cartridge, it would seem that the forementioned 7mm and 8mm wildcats would be slightly better than the WSMs.

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

6,5 65 7g to 1000m/s (RWS)
im not sure that the base is.
6,5*68s 180gr 990ms(RWS) 6,5*68s
im not sure that the base is.
6,5*60s 12,1g 845ms
im not sure that the base is.

quote:

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Originally posted by Kimmo E:
I`ll think 8 64 and 7 64 are made on the same base as 9,3 64 all made be W Brenneke.
7*64 is loaded 10,5g to 880m/s(RWS)
8*64s 12,7g to 810m/s (sellier&bellot)

6,5 65 7g to 1000m/s (RWS)
im not sure that the base is.
6,5*68s 180gr 990ms(RWS) 6,5*68s
im not sure that the base is.
6,5*60s 12,1g 845ms
im not sure that the base is.

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The 6.5mm, 7mm and 8mmx64 Brenekes are .473" head cartridges. I checked the reamer specs @ Clymers website. All of the other cases have a larger head diameter, but are too long to form a case that would chamber in "intermediate" length (I consider the short M70 to be intermediate length @ 3.1") actions without several forming steps. I am looking for a case OAL of 2.3" and a COL of 3.065" to 3.180". The 376 Steyr as I spec'ed would only require a one or two stroke resizing followed by trimming and fireforming. If I am going to go to multiple stroke resizing, trimming, reaming, etc. etc., I would just as soon start with RUM brass and get an even greater increase in case capacity. Here are my criteria: One or two step resizing (to 8mm)followed by trimming and fire forming to a 40* shoulder. Case OAL of 2.3", base to shoulder length of approximately 1.850", .015" taper from base to shoulder, (this would yield .489" with the Steyr case) neck length minimum of .375",(for the 8mm version) COL of 3.180" max. I am looking for 3000fps (4000'#s of muzzle energy) with a 200gr 8mm bullet, 3300fps with a 140gr 7mm bullet. Does anyone have loading software that could calculate the potential of this configuration starting with the .504 base diameter of the 376 steyr case? If I am wrong in assuming that forming this length of case from 8x68S cases would require several passes through forming dies, reaming etc. please advise. I have talked to die makers about forming a shorter case from RUM brass, and that is the case there. Again, a simple three or four step case forming process is what I desire here.

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

[This message has been edited by wildcat junkie (edited 01-19-2002).]

[This message has been edited by wildcat junkie (edited 01-19-2002).]

[This message has been edited by wildcat junkie (edited 01-19-2002).]

[This message has been edited by wildcat junkie (edited 01-19-2002).]

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

I have been reading the thread, and fianlly got a fired .376 Steyr case and weighed it with and without water. I got 81.5 grains of water case capacity.

The case is the 9.3X64 shortened to 60 mm and necked up to .375/9.5mm. I have corresponded with the Steyr engineer who is the project manager, and they have considered a .416 version. I have a graphic he sent that pictures the two cases side by side. They had a ballistics lab run some calculations and decided that the muzzle velocity would be too low with the 400 grain bullet to market.

jim dodd

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"if you are to busy to
hunt, you are too busy."

quote:

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Originally posted by HunterJim:
I have corresponded with the Steyr engineer who is the project manager, and they have considered a .416 version. I have a graphic he sent that pictures the two cases side by side. They had a ballistics lab run some calculations and decided that the muzzle velocity would be too low with the 400 grain bullet to market.
jim dodd

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Jim... Can you post the graphic? Do you know, or can you find out, the speed they spoke of? What about the speed of a 350 grainer? Thanks. ~~~Suluuq

The 9.3x64 case is ~ H & H belted Magnum case sans belt. Arguably one can make cases this way.

The .376 Steyr is a shortened and necked up 9.3x64 case. The 8x68S case is BIGGER. ( Necked down to .264 its called 6.5x68. There is no "S". "S" is used only in 8 mm calibers, if appropriate.)

The next larger case commonly?? encountered ( on these forums its common to encounter it, IRL may be different :-)) is the .404 Jeff.

6.5x68 is overbore. 8x68S seems to be just fine. Open up to .375 should be just under the 404/375 somebody around this forum all the time talks about. If Steyr says a .416 on the 9.3x64 case is not practical, it might be on the x68 case.

Good shooting! Hermann

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What I have from Steyr is a private correspondence, and I am not comfortable sticking it up on the forum. If you email me, I can send you a copy of the drawing.

jim dodd

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"if you are to busy to
hunt, you are too busy."

quote:

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Originally posted by aHunter:
I repeat myself, but my answer seems to have fallen on barren ground.

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aHunter: AGAIN, I REPEAT MYSELF. THE 8X68 CASE IS TOO LONG TO CHAMBER IN AN "INTERMEDIATE" LENGTH ACTION! Yes you are correct, but the 8x68 case does not meet my criteria! Please read more carfully. If the 8x68 case case would not require EXTENSIVE CASE FORMING OPERATIONS, it would be a hands down winner! If I am going to go to that much trouble, (AGAIN) I would choose the RUM case and get more capacity than the 8x68 case offers! I AM LOOKING FOR A CASE O.A.L. OF 2.3" MAX. AND A C.O.L. OF 3.065" TO 3.180" Thank you very much for your input.

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

quote:

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Originally posted by dan belisle:
Kimmo, the 8 x 60 has a base of .470", .472 at the widest point on the case, 1.898' to the shoulder, which has a diameter of .431". Case length is 2.004".
wildcat- I say go for it. I think this would be a very interesting series of cartridges. - Dan

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I think the OAL of the 8x60 case would be closer to 2.400" (60mm?) Interestingly enough, there is also an 8X65 reamer listed on Clymer's site. From what I can tell, it is the same as the 8X68 reamer. Perhaps one simply dosen't go as deep? I doubt if this case is readily available or that might be a viable option as triming would be about 5mm as oposed to 8mm with the 8x68 case. I just about have myself talked into buying some brass and checking water capacity with the neck bushed down to 8mm. If memmory serves me correctly, my 8mm-06 Ackley Improved holds 73 grains of water. By the time the 376 case is "improved", it should hold quite a bit more. Any way, I can always rechamber for the 8mm on the shortened RUM case. 8mm ILM?(Intermediate Length Magnum)--------HunterJim: Can you get another fired case? I would sure like to have one or two to play with!

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

quote:

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Originally posted by wildcat junkie:
I think the OAL of the 8x60 case would be closer to 2.400" (60mm?) Interestingly enough, there is also an 8X65 reamer listed on Clymer's site

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Gentlemen,

in my gun rack there is a 8x60. I handload for it with shortened .30-06 cases. As Wildcat Junkie put it, the case length is 60 mm.

The 8x65 reamer is for the rimmed version of the 8x64. That case is basically a .30-06 case with rim. Most german calibers have a mauser version and a rimmed one.

As already said here, the 8x68S and the 9.3x64 have different cases measures compared to the standard ones.

Best regards,

Fritz

quote:

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Originally posted by Martin BN:
Wildcat junkie,
I've the exact same idea with necking the .376 to 8mm. Should be a very effective cartrigde. I would hope to get around 2800 fps with a 220 gr bullet. My financial situation as a student hasn't made it posible to start the project but I will some day.....
My idea was to get an 8x57s (a lot of used ones in Europe) and just ream a new chamber if the quality of the barrel was ok. Do you know the price on a custom reamer + dies? I would really like to hear what you find out.
Regards
Martin

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Martin: A reamer from Pacific tool would run $146. I am going to go with it. I will be purchasing a 7mm version reamer that will permit "upsizing" with the apropriate pilot bushings. If you would be interested in an "improved" version (fire formed to minimul case taper & 40* shoulder) I would be willing to "rent" you the reamer, provided you could assure me of the competence of the "smith". I believe an "improved" version would be needed to get anywhere near the performance level you are seeking. The 376 Steyr gets 2900fps W/ 225gr bullets. I would estimate that a velocity drop of 200-300fps would result from necking down .043". This case has a lot of taper and a very shallow shoulder angle. it should respond very well to "improving" I had already priced dies, and the cheapest way to go is a "bushing type" forming die from Neil Jones. As this will probably take two steps to get too 8mm, I will probably get a .358 bushing, an 8mm bushing and a 7mm bushing. I am planning on a 7mm version anyway, and a 358 version would probably generate some interest. If I remember right the whole set up would run a little over $300. If you havn't done it, the fire forming is no big deal. One can use the fireforming loads for "plinking". Let me know if you are still interested. I will do the "ground breaking", and I am perfectly willing to pass on anything I learn. This will take a while,as I am on a somewhat restricted budget.(My wife and daughter are into horses, I have five of them) I siphon off the gun money when I get some extra overtime. I already have the actions. and I will probably pick up some of the "used in excellent condition" 98K barrels from Numrich. This will be a "budget" operation, but I think I can come up with a MOA "or perhaps slightly better" rifle that will produce 4000 ft lbs of muzzle energy. I have just come across a very reasonably priced gunsmith with a very good reputation that will turn a reaming job over in one week. He also believes in the accuracy potential of sound German barrels as do I.

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

quote:

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Originally posted by Martin BN:
Wildcat junkie,
I would be very interested in renting the reamer, but I don't think I can find the money the next couple of years. It is definetly the improved version that has my interest allthough my velocityidea is overrated; I'm use to metric terms. My goal was 800m/s~2600fps, not the 2800 I mentioned above. What would be the length of the emty fireformed case and loaded cartrigde?
Regards
Martin

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I think the potential is there for 2700-2800fps with the improved version based on the 376 Steyr case. an 8mm-06 Ackley improved would come close to 2600fps, perhaps that would be a cheaper alternative. I get just shy of 2800fps with 200gr Nosler Partitions in my 8mm-06 Imp. With a little more load development I think I could exceed that.(slightly) It would seem that 2600fps with 220gr bullets in an 8mm-06 Imp would be a realistic goal.

The finished case length for wildcats based on the 376 Steyr would be the same as the parent case, 2.362" (60mm) COL would be in the range of 3.065" to 3.200" depending on what action was used. I am shooting for 3.180" for use in "intermediate length" M98 large ring actions such as the 48 Yugos and Yugoslavian VZ500 comercial actions. A standard M98 would have room to spare as is. (The mag well will have to be lengthened to about 3.380" for 30-06 class cartridges such as the 8mm-06 Imp. No big deal)

I'm back! for more on the 8mm-06 improved: Go back to page 2 (last post 1-21-02) and read the "Yugo 48 - 8mm06" thread and go back to page 4 (last post 1-12-02) and read the "8mm-06, 338-06 or 280 Rem. Mauser" thread. There is a lot of info on these threads! You can get some idea as to cost.(page numbers are as of 9:42 EST on 1-24-02)
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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

[This message has been edited by wildcat junkie (edited 01-24-2002).]

[This message has been edited by wildcat junkie (edited 01-24-2002).]

8MM/376 STEYR IMPROVED (40degree)

Diameter @ base: .508"

Diameter @ shoulder: .486"

Diameter @ neck: .354"

Bolt face to shoulder: 1.920"

Bolt face to neck: 1.999"

Bolt face to mouth: 2.389

Nosler 200 gr Partition will reach < .015" into case body @ 3.200" COL

Sierra 220 gr Game king, boattail base will reach < .210" into case body @ 3.200 COL (the bearing surface will be confined to the neck area)

Next purchase (about 2 weeks) will be brass and I will be contacting National Arms Corp for availability of a semi inletted stock for Yugoslavian M48 actions. (same as VZ500 commercial actions) Supposedly they have these for $99.

Hopefully 2 weeks after that I will be able to purchase reamer and pilots. Forming and loading dies will come from the "tax check"

About 6-8 weeks should see some loading developement and chronograph results. I am thinking RL 22, IMR 7828 and perhaps some cautious load work with IMR 4350. I was unable to get enough IMR 4350 into the 8mm-06 Improved case to get any pressure signs with the 200gr Partitions. I estimate case capacity to be 14% greater with the 8mm/376 Steyr Improved over the 8mm-06 Improved. Shorter, fatter case should give more effecientcy. A 5% increase in performance would give 2950fps or more with a 200gr bullet. 3000fps is what I am shooting for, this would yeild 4000 ft lbs of muzzle energy.

Any imput would be appreciated!

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

[This message has been edited by wildcat junkie (edited 01-26-2002).]

8MM/376 STEYR IMPROVED (40degree)

Diameter @ base: .508"

Diameter @ shoulder: .486"

Diameter @ neck: .354"

Bolt face to shoulder: 1.920"

Bolt face to neck: 1.999"

Bolt face to mouth: 2.389

I gave this same wildcat a lot of thought about a year ago. I even bought a box of brass.The brass I have measure's from .5012 to .5016 on the base. If you cut the base .508 you will have a bulge in your brass at the base. I was going to make my base .504 shoulder .494. Your neck diameter of .354 leaves a neck wall thickness of .0155. I measured my brass and the neck wall's measure up to .017. I was going to make my neck .359. I know Dave Kiff quite well.If you want ask dave to give Ron Morse a call and I will talk it over with him. He know's the number.
I ran this through quick-load. It show's a 200 Speer 2815 at 52000.Give me your e-mail address and I will e- mail the result's to you.
I hope this help's
Ron

One of the posters on this thread did some load models for the 8mm/Steyr Imp. It looks like 3000fps with a 200gr bullet will get into the "ragged edge" zone as far as pressure is concerned. 2900fps however should be attainable @ slightly more than 60000psi. Since this is the SAAMI spec. for 30-06 loadings (60000psi) I believe this would be a safe level to load to.

Although this level of performance is shy of what I had hoped, it is still "respectable", especially in a cartridge that will fit into an "intermediate length" M98 action. (COL 3.200") 2900fps with a 200gr Nosler Partition would be a flat shooter. The BC for that bullet is slightly better than the .308 165gr Partition bullet and the velocity is as good as most reload data for this bullet in 30-06, and better than factory loads. The 200gr 8mm Par will generate 3734ft #s of energy @ 2900fps as opposed to 3080ft #s for the 165gr .308. This load combination in the 8mm/Steyr Imp. should have a trajectory similar to my 8mm-06 Imp with 180gr Balistic Tips. Although the 200gr Partition would give up about 60fps in the 8mm/steyr Imp. the higher BC should make up for that. I would then have three rifle/cartridge combos with almost identical trajectories out to 400yds or so.

7nn-08 with 140gr Nosler BT (.474 BC) @ 2850fps. (2525ft#s muzzle energy)

8mm-06 Imp. with 180gr Nosler BT (.396 BC) @ 2960fps (3501ft #s muzzle energy)

8mm/Steyr Imp with 200gr Nosler Par (.424 BC)@ 2900fps (3734ft #s muzzle energy)

Although the 8mm/Steyr Imp is only besting the 8mm-06 Imp by 233ft#s of energy, I estimate that it is doing so @ lower pressure, in a shorter COL to boot. The higher BC of the 200gr Par. will result in higher energy differences @ longer yardages.

I have decided to "go for it", now all I need is money. Anyone want to rent the reamer to help me defer some cost on the reamer? I have a quote of $160 for the reamer. I would have it made in 7mm, allowing "bushing up" to larger calibers. Anyone out there with a Yugoslavian "intermediate length" large ring M98 action, (M48 milsurp or VZ500 commecial) here is an option!

Now, how about an 8X68S in a M98K action? 3000fps with a 200gr bullet in a 24" barrel? Hmmmmmmmm.

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Life is more exitin' when yer stickin' suppositories inta a wildcats behind!

[This message has been edited by wildcat junkie (edited 02-16-2002).]

[This message has been edited by wildcat junkie (edited 02-16-2002).]