My idea is to create a couple of cats designed to operate in an intermediate/mauser action.

My 1st idea was to basicaly neck down the 8X57 to .30 cal to accomodate the use of the plethora of .308 bullets without the need to alter the action. In essence a 7.62X57.

This is what I eventualy concieved.

Start with a .308 win bbl and using a .308 reamer, ream the chamber out until it will headspace using 7X57/8X57 go, no-go gages.

The cases could then be formed from either 7X57, 8X57 or 30-06 brass by setting up a .308 win die in a press with the expander button removed using the same 7X57 go gage in the press to accuratly set the dies up for full length sizing. The lock ring could then be set for repeat use. Seating could also be accomplished with .308 dies.

What you would theoretically end up with is similar to an 8X57 custom made for .308 caliber, but with less body taper. Or... A 308 Winchester lengthened by roughly 6mm.

Then I realized that I already have everything I need to do the same thing with the 6.5/260 win variation!!

The caviats I see at his point are only that the case overall length would have to be determined mathematicaly as the .308 has a slightly shorter neck than an 8X57 or a 7X57. Otherwise I am open to criticism or suggestions..

I decided to call them the .308 tomcat and the .264 tomcat respectivley.. The latter should come real close to matching the vaunted 6.5/284 in all respects with the ability to form brass from 30-06.

And please dont say "just make a 6.5-06 or a 30-06" etc. etc. If that were what I wanted I would build one. I am looking for advice or opinions as to why this would or would not work from gunsmiths or someone with wildcatting experience.

The only wildcat I have ever used at all is a 257 AI, so I would really appreciate some input..

You could also neck down the 7.65 x 53 Belgian (aka x54 Argentine) to .308 and then "Ackleyize" it.

When you run the 308 reamer in THAT deep, you'll also necessarily increase the diameter of the chamber at the base, perhaps more than you would wish.... IMO this needs a rethink.
Regards, Joe

The 6.5x57 has been around for 100+ years and if the action will take a slightly longer case, consider the .256 Newton. But then you wouldn't have the pleasure of owning 2 riles with ctgs. that you created.

I think your concept is sound, in the sense that you can create a wildcat that will fire and probably work reasonably well.

I'm somewhat with J.D. Steele here, a .308 reamer unmodified probably won't do it very neatly. I think it would work, but would make for a sloppy chamber that might stick brass. Some chamber polishing would make it work, but it would still be sloppy.

But, draw up a reamer print, and send it and about $200 to one of the Dave's that makes reamers, and in about 6 to 8 weeks you'll be ready to go, and it will definitely work. Or, if you don't want to go the correct reamer route, send in a .308 reamer to be resharpened, and have them relieve the back of the reamer slightly in the process, particularly turning it down past the normal cutting area to insure it's small enough. Probably about $100 bill there, but will do the same thing as a custom in a non-controlled kind of way at lower cost.

Personally, I think I would have to ask myself the question about 6.5-06 or .30-06 that you don't want asked. A wildcat really ought to have some purpose, or fill a niche not met by something else. I don't see either of your cartridges providing anything really unique in that way. It's really more a question of the mechanics, your question is can I chamber a rifle this way and load the cartridges this way and will it work. Yes it will, but you won't have anything purposeful when it's done. (The practical range of ballistics of your .30 cartridge could be duplicated by either the .308 or .30-06 with handloading techniques, and either cartridge can do it in the action you have.) To really make it work right would require both a custom reamer and custom dies, and then you might as well do an already standardized cartridge that serves the same end purpose, at better resale value and lower cost.

If you really want to invent a wildcat, find a purpose and need first, then design the cartridge to accomplish that. If you want a gunsmithing exercise, to do something interesting, your cartridges should fit that need well, and you should go for it.

dave

At one time in my life(about 1957)I started designing wildcats but 6 kids came along and I could not afford it until about 1966 when

I rechambered an Arasaka to a 6.5x.284. At the time I thought I was the first; probably not.

In 1968 Fred Barnes built my 6mm x.270 IMP.

In 1982 Elmer Spurger ( Grand Junction )built my 7mm x41, 7.62 x 41, .358 x 41, and .375 X41.

The .358 x .404 IMP, and the 8 mm X.404 X 2.5" were built in the 90s.

The 22 jet rimles was built in 2010

The 6.5 R-Bar was built in 2011.
The point isn't that I'm a wonderful wildcater. As a younger person , in my own mind, all these were just great cartridges that the world was just waiting for.
Today I realize that the main reason these exist is because I wanted to do them and did.
Don't let obstructionists' reasoning deter you. That's your star! Follow it.OK let's here an AMEN roger

Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..

I wouldn't use tomcat in the name--it might get neutered.

Thanks for the replies guys. I got looking at my 260 reamer and came to the same realization about the continuing taper. I appreciate the heads up. I will have to try to figure out if it is negligible or not. Keep in mind that the base of many mauser cases are also slightly bigger than an 06 based case and yet those chambers have been reamed out and used with 06 brass for decades. But You guys might have a real good point.

As for it not serving any practical purpose, that is a matter of opinion. It is true that I could go with something like a 6.5X55 AI and have nearly the same thing as my 264 variation, but I do prefer the 20* shoulder for feeding purposes. And the plain vanilla 6.5X55 has much more taper which contributes to bolt thrust, so there is one practical purpose in itself. But there really is no other case like my .30 cal one that I am aware of.

I appreciate the input guys.. And thanks for the encouragement Roger.. As you know, I dont "need" either of them. It is all about trying something unique that suits my fancy, after all, isnt that what custom rifles are all about? Anybody can go down to Wal-mart and buy a .308 Winchester, thats not the point..

I will take my time before I start reaming any metal, I am in no hurry. It is just a consideration at this point. But a serious consideration none the less. I do like the idea of a .308X57 with minimal taper and a 20* shoulder. Kind of a .308 on steroids..

quote:

Originally posted by ssdave:
Personally, I think I would have to ask myself the question about 6.5-06 or .30-06 that you don't want asked. A wildcat really ought to have some purpose, or fill a niche not met by something else. I don't see either of your cartridges providing anything really unique in that way. It's really more a question of the mechanics, your question is can I chamber a rifle this way and load the cartridges this way and will it work. Yes it will, but you won't have anything purposeful when it's done. (The practical range of ballistics of your .30 cartridge could be duplicated by either the .308 or .30-06 with handloading techniques, and either cartridge can do it in the action you have.) To really make it work right would require both a custom reamer and custom dies, and then you might as well do an already standardized cartridge that serves the same end purpose, at better resale value and lower cost.

If you really want to invent a wildcat, find a purpose and need first, then design the cartridge to accomplish that. If you want a gunsmithing exercise, to do something interesting, your cartridges should fit that need well, and you should go for it.

dave

I didn't want to say anything because I hate to come across as a nay-sayer when somebody has an idea they want to try, but Dave captured my thoughts exactly. Go for it if you just want something a little different to call your own, but it seems like a lot of work for little gain. Good luck, have fun, and let us know how it shoots!

The 7X57 has a different taper and headspace than the 8X57.

The name will be a little confusing to some few of the old-timers. There has long been a Tomcat series of chambers, one of which I recall was based on the .25-35 case.

As to whether you can do it...sure you can. You can even use a tool post grinder in your lathe to grind a non-cutting relief (reduced diameter shaft) on a .308 reamer, right behind where the reamer cuts the maximum dimension you will want in your chamber. Not fancy, maybe not durable, but certainly adequate for a personal, not-for-sale rifle. Just cut the chamber with minimal feed, and keep backing the reamer out often to clear away chips.

Worse buckshee things are done every day somewhere in rifle-land.

6 MM Tomcat

.224 Weatherby - 30 degree shoulder - 6 MM neck

old Benchrest cartridge

Glenn

It was mentioned that the 6.5x57 has been around a long time.

The 7.7 Jap, 7.7x58 is very close to 7.62x57, still classified as 30 caliber.

http://en.wikipedia.org/wiki/7.7%C3%9758mm_Arisaka

I can appreciate enthusiasm for thinking up something different - a wildcat - been there done that. I've messed with several, and thought of several that didn't happen, another one Remington adopted as factory. Now, I have one wildcat and another nearly finished.

Now I'm thinking about it, searching for words to say how I really feel about it. I think my days of dreaming up a wildcat and spending the time and money to make one happen are over. So, my advice is that I think that it's something that should be given more thought than money.

It's good that you are asking for feedback from others. That's something that I didn't have the benefit of. Fortunately, I didn't make many mistakes and get carried away with it. The first three, I just got rid of. After a while they just didn't make sense anymore. You should be aware that when messing with something like this, the good ideas may evaporate into something less interesting almost as fast as it comes together.

There are many ways to get satisfaction from messing with specialty aspects of the shooting sport, other than redesigning the wheel. But I do admit that the one wildcat I have now is as good as I thought it would be. I really enjoy shooting my 9.3mm on a necked up 338 WM case (9.3x338) It fills a niche, by duplicating the 9.3x64 Brenneke, with easier to find brass. That's the way I justify it, but it does perform well.

I suggest that you think about your project some more. If you want to be practical, you missed that boat. If you just want to be different - OK, you got it. If you want to design a wildcat that will do something better than what's already available, and you think the two you mentioned are it, you're kidding yourself.

I had a barrel made once for the Encore, chambered in 7.62x53R, which is the .308 version of the 7.62x54R. Lapua makes ammo for it using .308 bullets. I figured there would be some advantage in using .308 bullets rather than .311 - availability, etc. Now, I have another Encore barrel in 7.62x54R as well. Unless there is another reason to go specifically .308, for attaching a suppressor, for example, obtaining and handloading either .308 or .311 bullets makes no difference. IMO, that's especially true when dealing with a wildcat anyway.

If the use of certain caliber bullets is so important, supposedly because of availability, then it seems to me that readily available brass would also be important.

My suggestion is try feeding a plain old 308 Winchester in the Yugo action. If it feeds well, ........ well As a bonus, if you ever want to sell it, someone will want it.

If you go with the wildcat, only the action and perhaps the stock will be worth something. Even the dies and reamer are practically worthless on the market, and they cost plenty initially to have made. As said already, to do a project like this right, custom reamer and dies are necessary, IMO.

KB

Why not have a 8x57 reameer recut to a neck sized for .308 bullets+neck wall.

Keith

quote:

Originally posted by Hog Killer:
Why not

Good question.
1. It's a wildcat
2. Cost of special reamer, probably used only once.
3. Cost of custom dies
4. No factory ammo
5. No resale value for either the rifle, reamer or dies.
6. Nothing gained. And I mean literally nothing, and much is lost.
7. Wait time for everything to come together.
8. Probability of something going wrong, some spec out of tune, and it not working right, as a combo of dies, chamber, brass, etc.
9. The cartridges mentioned fill no (real) niche or void, compared to existing SAAMI or CIP cartridges.
10. No lab tested or published load data.

I have a proposal. Since I've been there, done that, I have a high dollar reamer that's been used only once. I'll describe it, and if he wants the use of it, I'll send it to the gunsmith of his choice for use on his one-time project. I will not send it to anyone who is not a qualified gunsmith.

The cartridge is the 7.65x53 Mauser, which will work perfectly in the Yugo action. My reamer is not CIP or SAAMI, which technically makes it a wildcat. However, factory ammo can be used in the chamber with no problems. Over the counter dies are correct for handloads. The only differences in this reamer/chamber and the old military chambers is the throat is not the long tapered CIP type throat, but more like that of the 308. The chamber is minimum specs, overall, which allows factory ammo, but the cases are not blown out, as seen on many old military chambers. The pilot is for .311 barrel.

That reamer design satisfied my wildcat itch, and solved several associated problems at the same time. That's an example of what I mean in saying that satisfaction from the shooting sport can be found without reinventing the wheel. No wildcat is necessary, but we do it for fun. IMO, it might as well fill some niche, however small, and the reamer did the trick for me, since I had wanted a rifle chambered in that cartridge for a long time, but I didn't want a sloppy mil-surp chamber.

You may find it interesting that in coming to the decision re the reamer described, I considered the 7.7x58, with a pilot in .308, and throat accordingly. That's basically what you described. But I abandoned that idea, in favor of the 7.65x53 as described, specifically to enable the use of factory ammo, and std RCBS dies.

BTW, the 8x57 is a great choice for the Yugo.

I don't mean to rain on your wildcat dream, but you did ask for advice, and constructive ideas and criticism is what I'm attempting. I'm trying to be nice too , but not so nice as to avoid straightforward conversation.

http://forums.accuratereloadin...&forum_scope=9411043

http://forums.accuratereloadin...&forum_scope=9411043

I'll ask a simple question as a way of making my point. First consider the hundreds of thousands of dollars, perhaps millions in today's dollars, that went into the lab and design work on the following military cartridges. What makes you think, for a mere second, that you can in any way improve them?

Left to right - 7.65x53, 308, 6.5x55, 7x57, 8x57:



KB

Do it your way!. Too many cooks spoil the broth.Great learning experience! roger

quote:

Originally posted by Stonewall:
6 MM Tomcat

.224 Weatherby - 30 degree shoulder - 6 MM neck

old Benchrest cartridge

Glenn

Well that and the .35-35 Bases .25 Tomcat makes two different cases which have been used as a "Tomcat" series base. His proposed round would make a third. That wouldn't confuse any future inheritor of a gun, would it?

Thanks for all the input guys, even the critica input, really. I do realize that such a project would be for me, myself and I, and that resale is basicaly a not an option. Im not worried about that aspect. I have plenty other standard chamberings I can sale if needs be and if I do this it will be with a numrich or A&B bbl, something along the lines of a rather disposable bbl. I have several of them and they have served me well.

I also realize that what I am looking at is nothing that will gain any exceptional ballistic advantage. But what it is about for me is creating exactly what I want. Some folks like magnums, some like an 06 sized case, some favor a 308 case. I just happen to be a big fan of 57mm cases and it is no secret or mystery that the ones with much taper do benefit (sometimes considerably) from a more straight walled design. Again I dont expect magic, only precisley what "I" want.. That is the purpose, that is the niche.

It is interesting to know that there used to be an older series of "tomcat" wildcats. Im not too worried about little old me starting a brush fire with my wildcat idea though. The name isnt a big deal to me. .308X57 works just fine.

I also am well aware of the futility involved in building ANY wildcat and the fact that the factory offerings of today cover an awfull lot. But people, gun nuts like us, spend considerable amounts of $$ and effort to get precisley the rifle that they want every day. Why then should we "settle for" a chambering that doesnt also suit us to a "T"?

quote:

Originally posted by Alberta Canuck:
As to whether you can do it...sure you can. You can even use a tool post grinder in your lathe to grind a non-cutting relief (reduced diameter shaft) on a .308 reamer, right behind where the reamer cuts the maximum dimension you will want in your chamber.

That is just what I was thinking.. It seems like a very doable project to me and I already have .308 dies that could be set up the same way as the headspace is to be set.. With an 8X57 go gage.. I already have actions, and lots of brass I could use as well.

Full disclosure, I am in the process of building a 7X57 right now which is close as it gets to a factory round that fills the bill in reguards to what I am looking for. But I still think it might be fun and interesting to try my idea. Or maybe even a 260 rem version. Ive built three 260 rem's on m-48 actions. Sold the first two to friends and plan on shooting the other for the 1st time tomorrow. That one Ill keep if it shoots as well as the others have and I still have a bbl and action for one more.

Maybe I will decide that the 7X57 is close enough and let it go at that.

Maybe not..

I would stamp the barrel 7.62x57.

One way to look at it is:
With a properly made reamer, and correct dies, and quality barrel, and good gunsmithing on the package as a whole, it's almost a sure thing. That's because many, if not all, of the good aspects have been proven with similar SAAMI or CIP cartridges.

KB

quote:

Originally posted by Kabluewy:
I would stamp the barrel 7.62x57.

One way to look at it is:
With a properly made reamer, and correct dies, and quality barrel, and good gunsmithing on the package as a whole, it's almost a sure thing. That's because many, if not all, of the good aspects have been proven with similar SAAMI or CIP cartridges.

KB

All very true!! I kind of like the idea of stamping it .308X57 though, if nothing else then just for the sake of annoying the euro-eletists.. After all, it would indeed be a combination of both American and european design.

I would not use the 8x57 gauge but would chmber to the proper length for the 57mm case ("trim to" length plus .010"). Use the 308 gauge to determine the actual headspace measurement. I have done this before and it works fine. The 308 reamer I use is on the tight side so the taper wasn't a problem. Regards. Bill

While it can be done, the idea of grinding a clearance on the 308 reamer and reaming deeper is fraught with danger. Basically, the last .2" of the chamber will be perfectly straight. If the reamer wobbles the tiniest bit, you will have a "bulb" in the chamber, and every case will stick. You will also have brass that is unsized at the base, and eventually get hard to use over time, if you short size. OK for targets, but not a good idea for a hunting rifle.

I did some checking, and found at least three cartridges that are a form of what you are doing. One, the .30 Special, is mentioned here on AR in the reloading pages:
http://www.accuratereloading.com/30-06s.html
Maybe they can point you toward some info on it.

Ackley and the Handbook of Cartridge Conversions have a couple of others.

The .300 ICL Tornado is a 257 Roberts necked to 30 and improved to about the same shoulder diameter as the 308 Win. It appears to have been relatively popular back in the day.

The .30 Improved Arch is a similar cartridge based on the 6.5x55.

I would recommend you seriously look at a cartridge called the .30 Dunlap. The info I found sounds exactly like what you are doing, with one exception. Instead of long chambering with a 308 reamer, you short chamber with a 30-06 reamer. You simply use a 30-06 reamer and run it in to 7x57 headspace. Your die problems are then solved, since you simply grind the equivalent length (about 0.2") off a 30-06 die, and there you go. Instead of the abortion chamber you would get with a 308 die, you get a smooth chamber taper. I calced the new base diameter, and it is only about .003" less than the standard 06, which is less than most chamber tolerances. The revised die would easily size it down, if necessary, but I have never measured an 06 sized cartridge head which is not smaller than this when new.

Any of these would give you what you are after, which is in essence a .308/7x57 Improved. The Dunlap route, however, does it with no custom reamer and no custom dies, and they will work perfectly and not be cobbled. It appears to have been around a long time, and several references to it can be found on the web.

If it was something I really wanted to do, I think I'd have a reamer made in 224 or 6mm X 8 Mauser with a removable pilot so that you could chamber any barrel that bore size or larger you wanted, and them neck and throat for whatever larger cal. barrel you are using afterwords.

quote:

Originally posted by Art S.:
While it can be done, the idea of grinding a clearance on the 308 reamer and reaming deeper is fraught with danger. Basically, the last .2" of the chamber will be perfectly straight. If the reamer wobbles the tiniest bit, you will have a "bulb" in the chamber, and every case will stick. You will also have brass that is unsized at the base, and eventually get hard to use over time, if you short size. OK for targets, but not a good idea for a hunting rifle.

I did some checking, and found at least three cartridges that are a form of what you are doing. One, the .30 Special, is mentioned here on AR in the reloading pages:
http://www.accuratereloading.com/30-06s.html
Maybe they can point you toward some info on it.

Ackley and the Handbook of Cartridge Conversions have a couple of others.

The .300 ICL Tornado is a 257 Roberts necked to 30 and improved to about the same shoulder diameter as the 308 Win. It appears to have been relatively popular back in the day.

The .30 Improved Arch is a similar cartridge based on the 6.5x55.

I would recommend you seriously look at a cartridge called the .30 Dunlap. The info I found sounds exactly like what you are doing, with one exception. Instead of long chambering with a 308 reamer, you short chamber with a 30-06 reamer. You simply use a 30-06 reamer and run it in to 7x57 headspace. Your die problems are then solved, since you simply grind the equivalent length (about 0.2") off a 30-06 die, and there you go. Instead of the abortion chamber you would get with a 308 die, you get a smooth chamber taper. I calced the new base diameter, and it is only about .003" less than the standard 06, which is less than most chamber tolerances. The revised die would easily size it down, if necessary, but I have never measured an 06 sized cartridge head which is not smaller than this when new.

Any of these would give you what you are after, which is in essence a .308/7x57 Improved. The Dunlap route, however, does it with no custom reamer and no custom dies, and they will work perfectly and not be cobbled. It appears to have been around a long time, and several references to it can be found on the web.

Art,

Thank you for a very informative post. I will research the .30 dunlap, what you said makes a lot of sense.. I appreciate your help.