98 Mauser Blackpowder?

[nekshot]

I need some knowledgable input. Years ago I picked up this barrel thinking I could fit it to a mauser action and for a laugh take it to a public range and uncase this ungodly big holed gun and set some modified 378 weatherby cartridges cut to 2.3 inch in length, rim turned down to fit bolt face, a huge hunk of lead in them and proceed to shoot about 5 into a 3 inch black ring at 100 yards and put it back in its case and look at every body else with the "don't you have one of these" look. Ok that was vanity but I have shot this gun by inserting a 209 into the breech plug, turn the barrel in against bolt and pull the trigger. Works great but does anyone have ideas how I could use a cartridge of some type. I even thought of turning something out of round brass or copper. How important is headspace with black powder if I tried to head space off the cartridge mouth? Maybe this is totally stupid and over my head and I should get rid of it, then the problem is solved. It is 24 inches long with I think a 1 in 48 twist. Could we get enough powder in this to do more than punch paper? Lets hear from you!

[NickSS]

What caliber is it? I think you could probably start with a 50-90 Sharps (if it is 50 cal) and turn the rim down and make a rebated head to fit your bolt face. Then you could reload it using 50-90 dies and a 30-06 size shell holder. This would give you a 2.5 inch case that would fit your rifle. Now if it is a 54 cal you may be able to do the same thing with say a brass 24 gage shotgun shell made by Mill tech.

[richbug]

Are you going to rethread the shank? If not, you will be limited by how big the breech plug threads are. pictures look like 5/8" 18TPI, in which case the big WBY case is one of the few large enough to clean that up.

Need more info.

[nekshot]

Sorry about lack of info. It is a 50, and the breech plug measures .564 which will leave a little thread in barrel. This is what started to give me cold feet about trying to convert to a cartidge, but I never considered the old straight wall 50's.

[1874Sharps]

This is an interesting and most unusual project. I think I understand the questions and propositions, but am not entirely sure, so if I get off base please bear with me. I have a Pedersoli 1859 Sharps for which Pedersoli makes a brass cartridge case that can be loaded with powder and boolit (the 1859 was not designed as a metalic cartridge gun, but was designed to shoot loose powder and ball or nitrated paper cartridges). After it is fired the brass case must be removed by a rod down the muzzle as there is no other means of extraction. I see no reason why you could not shoot the rifle you have using a similar type of system. You could take an appropriate cartridge case, headspaced by the means of your choice (mouth, rim or shoulder) and screw on the properly chambered barrel and you are in business. You would not have to knock the spent case out with a rod, either, since you have a bolt gun with extractor. You could go with an off the shelf cartridge case, or even make up your own custom cartridge.

[nekshot]

1874 sharps, you got it right on. I simply want to be able to shoot the gun with a cartridge and extract it somehow. I don't want to pour powder down the barrel as I have those type guns. I got to looking again to the 378 weatherby and I believe this cartridge is fat enough to clean out thread grooves, almost. I also realised I can head space off the belt. My next questian is would this be more than a pop gun. Would I have enough energy to cleanly take a deer out to 100 yards, or will it simply be a paper shooter? I am starting to get excited about this project again! I wonder if I could get that action to feed or will it get too long overal to feed. That would be fine, I don't need a repeater but that would be neat.

[nekshot]

All of your input is helping me to get out of the fog and see this project more clearly. The threads will be gone when I rechamber. I still wonder how much capacity will be useable in the case?

[richbug]

378 wby should clean up a 5/8" thread. The examples I have here are .582" just ahead of the rim.

Pop gun? No

A 50-378 should be able to push a 450 grain bullet to 1800 FPS I would think. How tough are your deer? Or Elephants for that matter.

I think one could modify the bolt face to extract fine, but probably only as a push feed single shot.

I'll weigh a case full of BP when I get home.

[Boz330]

348 brass might be big enough to clean up the threads and come closer to fitting the extractor. With that 48 twist the boolit will have to be pretty short.

Bob

[nekshot]

Now I am really getting excited! (at my age thats impressive) I slugged the barrel and it is .505. I know I have to shoot to find the right load but I was hoping to move a 350 grain bullet at about 1500 fps. That is sounding like a can do deal. Next what input do you all have on molds? I like the looks of the rcbs 50-340-sws(paper patched) or the lyman plains 508656. Any advice on this or other favorites you have? What type of powder is recommended for something like this. I have alot of pyrodex P fffg. Bought it real cheap years ago. I was told this stuff is only good for a long fuse on fourth of july.

[Bullshop]

A 50x378 Weatherby is known as a 500 A-Square

[nekshot]

Bullshop, thanks for that info. I will look at that cartridge and make sure this one is different. Sure would not want an idiot to think of using smokeless here would we? I know the action is good but I don't know the barrel maker, or strength.

[1874Sharps]

That Mauser is plenty strong enough to take FFFG or the equivalent substitute. One word about subs like Pyrodex and 777: They have a shelf life and will lose their potency over the years. That is a very interesting project you have going!

[richbug]

level full I get 145 grains of 3F black in a 378 case. I think you could reasonably load at 130+ with a good amount of compression.

[richbug]

348 brass might be big enough to clean up the threads and come closer to fitting the extractor. With that 48 twist the boolit will have to be pretty short.

Bob

A 348 rim is just too big, you would have to virtually remove all the extractor hook.

[nekshot]

I got to looking at the 50-90. This is almost a perfect fit I think. All I have to do is turn the rim down enough as was noted earlier in a reply. What concerns me with the weatherby is I don't think I can get the taper correct from a reamer. I need to shorten from the base front not the other way. I believe the 50-90 is the correct length also with out shortening. I take it from your replies the twist is more for lighter boolits? That is fine for me.

[richbug]

I got to looking at the 50-90. This is almost a perfect fit I think. All I have to do is turn the rim down enough as was noted earlier in a reply. What concerns me with the weatherby is I don't think I can get the taper correct from a reamer. I need to shorten from the base front not the other way. I believe the 50-90 is the correct length also with out shortening. I take it from your replies the twist is more for lighter boolits? That is fine for me.

A 50-90 won't clean up those threads. It may be .560ish at the base, but it tapers to .528" at the neck.

The fired case would be permanently lodged in the chamber.

[nekshot]

Richbug this is the info I am looking for. A stuuupid thought went through my mind. I wonder if I would cut the 50-90 chamber and fill in the rough grooves with JB weld or try melt a low temp solder and polish it out , would this be ok. I am really grasping at straws for this project again.

[jh45gun]

Just a thought could you machine out the threads and have an INSERT Chamber made to fit for the cartridge of your choice?

[nekshot]

I laid out the 50-90 dimensions on paper and I realised I can solve my problem by back setting my barrel till I have a smooth chamber. I still would love to hear any wisdom of boolit molds with this 1-48 twist.