Having been bitten by the wildcatting bug, I am looking at taking an existing 'cat and increasing the powder capacity by a calculated 15%. Is that enough to make a substantial difference? I know the rule of thumb: a 4% change in powder capacity gives a 1% rise in velocity, but is that true? If so, this isn't worth the trouble, and I would like to know that before I spring for a set of gauges and a new custom reamer.

What do you think, guys? Paul, you have done this for a long time. What am I looking at?

Thanks, fellas.

Darn good rule of thumb. What I normally found was on an 06 based case it was darn close (at equal pressure)to a 1 for 4 Something like the 7x57 case a touch better and magnum cases a touch less. The 308/ 243 etc were a touch less than 1 for 4.

In most cases you can find a factory magnum that will probably meet or beat your new wildcat. It will take more powder and won't be near as much fun.

For me I love to be different.

I truly believe that there is no longer any meaningful reason to create a wild cat except that you want to. That's not all bad. roger

yep.. its true -- unless you materially change the shape of the case, at the same pressure, 25% of your volume gain...

shush Roger -- people have been saying that since the 7x57 ...

actually, there are a number of good reasons for wildcatting.....performance isn't among them however.

An example: I built a 6 X 45 when I lived in Minnesota to get around the state law requiring a bullet of at least .23 caliber for deer hunting. The 6 X 45 did that and still allowed me to use my mini mauser for deer hunting.

In some antique guns, wildcatting just might be the easiest way to create ammo for them....especially the older rimfires.

One might discover that changing the shape of a particular case could solve feeding troubles.....

To wildcat for velocity gains are pretty much covered by a plethora of factory offerings.

BTW, I'm currently working on a wildcat to actually reduce powder capacity.....Makes no sense?....Yup...but there's no law that says we have to be entirely rational about it!

Vapor
Techcnally ALL but one of mine have reduced capacity of the parent case
257x300wsm. Necked 300 to 257 but accounted for neck thickness change to make no reaming
all of the accrel are shorted and improved from parent case and if you measure prior to changing the caliber the case is less capacity than entire parent case

The 550 express, which I have an assist with is reduce from 460 cum 550 mag

My biggest case the 550 flanged is actually larger than the parent case if we call the 500/577 the parent case. Some might not as if you go through the evolution 500 to 505 Gibbs to 577 NE then conceptually neck to .550 and improve. Well it becomes a snarl

Whatcha thinkin on...?

Rich, it is a 35 caliber wildcat originally done on a 7.62 X 39 case and run in an AR. It is called a 358 Gremlin, but feeding problems and sizer die troubles have me looking at something a bit longer. I am thinking of having a Model 85 Zastava re-bored to 35 and playing with this hare-brained idea of mine in it. But currently I am working out of state, so everything is on hold until I can get back home.

FYI. My .358x41mm =( 1.625")case length( 06 head dia. ) will put a 300gr. gas checked bullet out at a 30-06 energy level. Jacketed bullets can be driven at .35 Rem. velocities. I have the reamer if you are interested. roger

Roger, your offer is much appreciated. The issue is the .473" case head. The rifle I plan to use doesn't have that large a bolt face, and I am uncomfortable opening it up...

I think I have worked through all that, but if something comes up to bite me in the hindquarters I may contact you.

Many thanks for the offer. And I mean that.

I agree mostly that there is little need for any wildcat and today most are duplication or close enough for guvmint work!

My only wildcat is a 6x45 and I love that gun, had it for 30 or so years..but there are lots of 6mm as good and some probably better..

Want takes over and need falls by the wayside IMO..

quote:

Originally posted by vapodog:
actually, there are a number of good reasons for wildcatting.....performance isn't among them however.

An example: I built a 6 X 45 when I lived in Minnesota to get around the state law requiring a bullet of at least .23 caliber for deer hunting. The 6 X 45 did that and still allowed me to use my mini mauser for deer hunting.

I had a Savage 223/20 gauge rebored 6x45mm for similar reasons. I wanted a Wyoming-legal combination gun for antelope and sage grouse. A Krieghoff Ultra 20 was out-of-budget and Savage wasn't interested in making a 243/20 gauge. An accidental side benefit appeared when the rebored rifle barrel shot the same point of aim as the shotgun barrel. Sweet. I use nickel-plated cases so as not to mix them up with 223 for the Mini-14.

I have two right now, a 400 Whelen and a 6mmx222. The 400 Whelen fills a niche in my opinion. I'm still doing load development with the 6mmx222 and haven't made up my mind yet on it. I had a 375 Whelen for a while and while I consider it a useful wildcat, I already had the 400 and 35 Whelen so it was a bit redundant. If I had not had the 35 and 400, the 375 Whelen would be a very good option in my estimation though it does nothing the 9.3x62 will not.

I have one more of the little left handed Charles Daly mini Mauser actions and have not decided how it should be chambered. I am considering a 25 caliber on the 221 Fireball case. I know it would duplicate the 25-20 or 256 Winchester but would work in a bolt gun very well and brass could be easily formed from 223.

I know John Wooters was enamored of his 25/222 Copperhead and I have considered that one as well. I lean toward the 25/221 primarily because it would be very easy to mix up the 6mmx222 and 25/222 ammo. Of course it would also be an interesting project.

I've always been puzzled why the 6x45 and 6.5-06 have remained wildcats.

If a guy is willing to accept that he'll never financially get out of a wildcat rifle what he put into it, they can be useful and very enjoyable. I have enjoyed my 400 Whelen more than any rifle I've ever owned.

I guess I'd have to agree there is little ground that is not already plowed by the existing standard rounds. Some of us just want to be a little different.

Of course there is the fact that owning, shooting and hunting with a 400 Whelen elevates one in the world of riflemen, to the status of the most interesting man in the world.

Weeellllll...a 15% increase on an already wildcatted cartridge might be a bit of a stretch...

Buy QL and/or obtain a bunch of case capacities and breakout your calculator...only way to know if it can be done.

I've been 'catting my whole life but today I wouldn't recommend it except for something very specialized or as already suggested..."just for the 'helobit' because I wanna".

You only have to look at 6mmBR to see the proliferation of 6mm wildcats some years back to find the "PERFECT" 6mm case for specific target work...lots of very good products, each having a myriad of reasons it was "THE BEST" and all individually unique...magnificent work.

A day never goes by that I don't think about "what if...."...sometimes I build it, most of the time the COST of the custom reloading and/orforming dies and reamer end up being more than the cost of the rest of the rifle, something that most wildcat dreamers don't think about...limited income limits my playing but when I hit the Lotto...look out....I have at least two dozen just waiting to be built...

So...if you have that itch, scratch it and tell us all about your latest joytoy.

You can get 15% pretty easy in a 250 Savage, 257 Robts., and a 7x57 Mauser with a Ackley IMP..Even Ackley decided these were the best of his endeavor..

But there are lots of standard calibers that do the same thing such as a 284 Win, 280, 25-06 to mention a few...

quote:

Originally posted by Atkinson:
I agree mostly that there is little need for any wildcat and today most are duplication or close enough for guvmint work!

well, no, Ray

There was no bolt action 600 rimless
there was NO 55 caliber
there was NO 49 caliber

the 470 mbogo is utterly unique

there was NO true 30-06 length cases to match the full length HH cases --- you can't put a lott in a mexican mauser SAFELY

my accrel cases BEAT the capacity of the 416 rem, (itself based directly off george's case), the 458 lott (wildcat to factory) and 470 capstick .. all with no belts

the ONLY thing close to my 500 Accrel is the 495 a2 - with its legal/licensing issues - a TRUE 30-06 length 500 SMASHER, not just the largest that can be fitted into a standard mauser (highly gunsmithed) though i did pay homage by the shoulder angle being the same as the 500 jeffery

the 375 ruger - 30-06 length, no belt, beats 375 hh....

a $300 barrel on a 7rem gets one into a 470 pushing 500gr over 2400 fps - PROVEN .. as well as my pushed vels on 416, 458, 470, and 500 .. and 550 express ...

and my short action 257x300 wsm -- 308 length 257 weatherby ...

by your logic, we'd still be driving model T --

better isn't always newer -- but newer is usually smarter

Doubless,

many years ago, Jeff Cooper dabbled with the notion of a full-length 223 case necked up to create a cylinder profile 9mm.

I took a course at the old Gunsite, when he owned it.

We discussed the options for an AR-based rifle with a bit more thump. It would have headspaced on the mouth, which made it complicated to build. These days, with the CNC tolerances available, it might be a real fun gun.

Rich

Rich, funny you would say that... my "cohort in crime" with this Gremlin jaunt and I were talking about that very thing right at a year ago. The trick is magazines and feeding, as is the case with most wildcats on the AR platform. But I think Calvin told me there is a guy playing with that 'cat now.

This brain child of mine will go in a bolt action rifle if I ever get back to Texas, and I believe it will work. Just have to get the time to do it. Dave Manson has told me to send him the mockup round and he will do the rest. Just gotta get some time, and with the cancer working on me, I don't know just how much time I have left, to be truthful.

Back on the subject of the AR 15 platform, the problem with anything using a .473" case head is finding bolts. They are out there, but typically they come with an "upper kit" that supplies barrel, BCG, etc. I don't want all that, and I refuse to lock up that much cash for something that will just become a tomato stake. If you are willing to go to the AR-10, it is not a problem, but I don't want to lug that much more rifle around!

.35x6,8spc? .35x30rem

Nordic, no, but close. And actually, since the 6.8 is a derivative of the 30 Remington, what you list are really the same, it is just that one is the 6.8 necked up, the other is the 30 Remington necked up, I believe...

What is the trim length of the 6.8 case? What I am thinking about might be nothing more than what you proposed...

What I am playing with is designed to feed from the Model 85 Zastava magazine, so it has to have a COL of no more than 2.19". Of course, that lends itself well to the AR platform as well, since mag length is 2.260 for the 5.56. The trick is opening up the extension so the larger ogive bullet feeds as it should.

Doubless,

You can get a very similar cartridge on the cheap by running a 35 Remington reamer in short. Just stop the reamer at the depth that corresponds to the case length of the 7.62x39mm. When cut this way, the chamber is a good fit at the base of the 7.62x39mm case. You can cut down a set of 35 Remington reloading dies. No expensive custom reamer or dies. There are old discussions with more details about this here:
http://forums.accuratereloadin...=306103117#306103117
and here:
http://forums.accuratereloadin...=342103567#342103567

The Zastava M85 was also available in 22/250 and should have a longer mag available in that chambering. If so, it might be feasible to simply use a stock 35 Rem chamber reamer as LOA is very close to that of a 22/250.

I lengthened my Mini Mauser magazine to 2.470 and run my Grendel-Max with its COAL of 2.405

quote:

Originally posted by Doubless:

...

Back on the subject of the AR 15 platform, the problem with anything using a .473" case head is finding bolts. They are out there, but typically they come with an "upper kit" that supplies barrel, BCG, etc. I don't want all that, and I refuse to lock up that much cash for something that will just become a tomato stake. If you are willing to go to the AR-10, it is not a problem, but I don't want to lug that much more rifle around!

Off the top of my head, both Tromix and Southern Ballistic Research offer individual AR 15 .473" bolts in the $100 range.

quote:

Originally posted by Doubless:
Having been bitten by the wildcatting bug, I am looking at taking an existing 'cat and increasing the powder capacity by a calculated 15%. Is that enough to make a substantial difference? I know the rule of thumb: a 4% change in powder capacity gives a 1% rise in velocity, but is that true? If so, this isn't worth the trouble, and I would like to know that before I spring for a set of gauges and a new custom reamer.

What do you think, guys? Paul, you have done this for a long time. What am I looking at?

Thanks, fellas.

An exception will happen depending on powder suitability/availability. Probably the best known example would be the 375 H&H Vs the 375 Wby or 375 AI with 300 grain spitzers and 4350 burn rate powder.

In this case the 4350s are too slow for the 375 H&H and the 4064/Varget burn rate a bit fast. The net result is the Improved 375s add quite a bit of velocity and simply because they can get up more pressure with the 4350s.

Jeffe,
I got your point in the first sentence, the rest was repetitious to the extreme, based on that long winded reply to a simple question tends to make me believe you suffer from a delusion or adequacy!