Looking to Wildcat...

[jdgabbard]

Well boys, as few of you know, I have a soft spot in my heart for Soviet Block Cartridges. I know, a terrible thing for one to admit. At least I'm not a cold war vet.

The one that seems to have become my all time fave is the notorious "7.62x25 hand howitzer catridge." A couple of the surplus loads have been chrony'd at 1700 fps with a 85-90g boolit. Pretty good for a auto cartridge.

Now for some time I've had a nice commercial Martini Henry .303 of Belgium origin. The rifle is a bit beat up, but mechanically sound. These have been converted to quite a few different calibers. And are one of the stronger actions available for custom falling block rifles.

Now I have tossed around the idea of chambering this rifle with a new barrel to the 7.62x25 cartridge for use with cast boolits at about 15-1600 fps. However, I think the conversion is gonna be somewhat difficult considering this is a rimless cartridge. So, I've been doing some thinking about a solution. Use an existing rimmed cartridge with a body diameter of close to the same size and resize it in the 7.62x25 sizer die to neck it down. I'd have a 7.62x25r essentially.

Boy does this boggle me. At first I though of the .357 or .38spl case. Might work. Case diameter on the 7.62 is 0.387" while the .357 and .38 have a 0.379" diameter. However I'm fairly concerned about that 0.01". Think the cases will rupture?

A standard reamer could be used for the barrel since all I'm doing is essentially what was done with the .45 Rim cartridge. But this difference in case size is making me wonder.

What do you all think?

[Mohillbilly]

yup now all you need is the 9mm Federal cases, the 9mm equvilent of 45 arim.

[Firebird]

Checked my copy of Ken Howell's book, it recommends making 7.62x25 brass from 222 or 223 Remington, which are only .377" at the base. So I guess that .01" expansion of the body is ok.

[Jetwrench]

jdgabbard,
I have no 7.62x25 cartridge to measure, but in COTW 11th ed it list the 7.62x25 as rim .390, head .380, shoulder .370, neck .330, case .970, bullet .307, oal loaded 1.350.

The Handloader's Manual Of Cartridges Conversions says to use 38 special brass and trim/resize and turn the rim, but you want the rim. The case capicity is 1.04cc's, or 15.98gr's water.

Were it me I think I would go with a 30/357 Paxton. Use the full size 357 case, neck it down to 30 squair the case mouth and thats all there is to it. What you get is a case thats easy to come by cheap and a capicity of 1.54cc's, or 23.72gr's water. More muscle, But then thats just me, HHHMMMMM, 30/357MAX??? Jetwrench

[jdgabbard]

Jetwrench, I think those measurements were taken from a 7.63 Mauser. Another good round, that unfortunately is always said to be the same thing as the 7.62x25. They say the Soviets just changed the bore diameter to make it standard with the rest of the barrels they were making.

The truth is that this is incorrect. While many have used 7.63 dies to reload for the 7.62 there are enough differences to give you problems. Not to mention that the difference in pressure is there. If it would function I wouldn't have a problem shooting a 7.63 round in my CZ pistol. However, I WOULD NOT do it the other way around. Asking for disaster. The 7.63 shoots at about 1400 fps and the 7.62 about 1700 fps with the same boolit.

Firebird, you're correct. .223 rem is what I use to make my brass. Simply trim to about 1", resize, ream the neck and trim again. However, .223 is quite a bit thicker then the .38spl. Because the case is actually tapered the forend of the cast should not be an issue. Its the back end around the rim that worries me. Pretty thin, and too much or uneven stretching sure could wreak havoc on those cases. I'm not worried about the rifle blowing up. Just worried about putting that kind of money into a rifle, turn around and do it again because the cases couldn't handle it. Like to get it right the first time.

[Willbird]

I think if I was going to use 357 sized brass I would steer towards a rimmed 300 whisper.....you can chamber with a 300 whisper reamer and use 357 maximum brass to make your cases, then use 300 whisper dies. The 300 whisper is also called the 300x221 fireball.

I bought a 300x221 reamer for just these reasons, I have 310 martini that I want to setup for the rimmed 300x221.

Bill

[Jetwrench]

jdgabbard,
I rechecked and those measurments are for the7.62x25. I checked the 7.63 Mauser and all of the measurements are within .001, it also says some brands of the mauser ammo can be fired in the 7.62x25 guns. I don't think that would be a good idea or habit to get into. I dont have any pressure data close at hand, so I cant say anything about that. COTW list the 7.62x25 at 87fmj @ 1390 and the 7.63 Mauser 86fmj @ 1410. Don't misunderstand I am not saying you are wrong, you have the bullets all I have is some books. If the book I have is off on the measurments that would not be the first misprint I've ever seen. That being said I think I would check and see if the bullets were .308 or .307 dia., could that be some of the rather large fps difference? I did not include the 223 case because it said you would need to ream the neck I/D because of the donut, and you need a rim. Hope at least some of this is of some help. Jetwrench

[leftiye]

Use .222 rimmed brass.

[jdgabbard]

Leftiye, that is wonderful idea. Only one problem, never heard of it or have any data on the cartridge. Gonna have to search for more brass now. Thanks bunchs partner.

Jetwrench, I think your information is misprint. What I have is Rim 0.392, Head 0.387, Shoulder 0.373, Neck 0.334, Case 0.985, with bullet diameters of 0.310 or 0.311. The 7.62 doesn't use the undersized 0.308 boolits. That is why most of the "American" made ammo makes such poor groups. The boolits are undersized. S&B makes some pretty good ammo for it, but it is made in the Eastern Block countries. And Wolf makes some decent ammo, but made in Russia.

I have check that data with my 5 varieties of 7.62x25 and they all fall right into the data listed above. I don't mean to beat a dead horse. But the US data publishers as well as the ammo producers are wrong. Those measurements are for the 7.63 mauser. I have the same problem with the data in my loading manuals. But I have measured catridges from various manufacturers as well as made chamber casts of several different firearms. The data is off.

[JeffinNZ]

JD: I have seen a number of Lee Enfields rechambered the the Soviet rocket also. Barrels removed, chambers lopped off, rethreaded and installed. I think a magazine conversion is done also and maybe a pistol mag laced into the original. If it can be done cheapish and you have access to milsurp ammo it's a great idea. Good small game rifle.

[jdgabbard]

JD: I have seen a number of Lee Enfields rechambered the the Soviet rocket also. Barrels removed, chambers lopped off, rethreaded and installed. I think a magazine conversion is done also and maybe a pistol mag laced into the original. If it can be done cheapish and you have access to milsurp ammo it's a great idea. Good small game rifle.

Exactly what I was thinking Jeff. Something to take small game with. As well as just a fun plinker to use with cheaper ammo. I'm thinking that 5g Bullseye would probably yield a load at about 1300. But of course I'd start low and work up.

I've seen some of those bolt guns converted to stuff like that. Mostly in .45 acp though. Besides the Tok and CZ mags chew up brass pretty bad. I think I would look for a different mag, or make one myself and just use the spring and follower from a Tok mag. You could make the bolt gun more slim doing it that way.

[Firebird]

5.6x50R is a longer version of the 222 Rimmed; case body diameter .376", again from Howell's book. RWS cases available at Huntingtons, but it's not cheap.

[jdgabbard]

Well did some reading up on the .222 rimmed. Same as the .222, which is a shoe in for 7.62 brass. And uses a .38spl's shell holder. Looks like I found what I was looking for. Now I only have to put up with the $1.50 a piece for the brass. I guess nobody ever said wildcattin' was cheap, did they

Thanks a bunch guys.

[sav300]

jdgabbard.u can make 222rimmed out of 357 maxi brass or buy brass from Bertrims brass in Aus.

[jdgabbard]

jdgabbard.u can make 222rimmed out of 357 maxi brass or buy brass from Bertrims brass in Aus.

If thats the case I might as well just go ahead and use .357mag brass as a base for the project. Heck for that matter .38spl brass would be long enough, and I have gobs of that.

[NoDakJak]

You might consider doing as I am and that is to run 303 Brith through a 7.62X39 die and then trim the case back and ream if neaded. The barrel can be chambered with a standard 7.62X39 reamer and then the rim recess cut seperately. This eliminated the cost of a special reamer and standard reloading dies can be used. This round is somewhat similar to Jeff's Pygmy but with a shorter neck. The new Remington single shot is chambered for 7.62X39 already and it should be simple to cut the rim recess. A restock job for mor pleasing looks and appearance and it should provide a fine Rook Rifle that is on steriods. This rifle should work fine in the original chambering but I like the positive aspects of the rim with light and ultralight loads. Neil

[Stove_Pipe]

What if you tried something like a C clip around the groove in the case? Kinda like a "single moon clip" ?

[Willbird]

What if you tried something like a C clip around the groove in the case? Kinda like a "single moon clip" ?

People have swaged rings in pace made from brass then machined rims from them. I'm thinking it will be a lot easier to start with rimmed cases

Bill

[Jetwrench]

jdgabbard,
Your not beating a dead horse, as I have now made notes in my books and at least I wont be giving out bad info on that cartridge again. Believe me that is the last thing I want to do. So thanks for posting the correct diminsions for the round. Jetwrench