Outside the box smiths...
Well two cals one barrel to be more specific. Was wondering the possibility and downsides to an idea. All help appreciated. Here is the idea. Think single shot say a Ruger #1 chambered in 30-30 the first 15" and the last 10" rebored in a muzzle loader or shotgun diameter. So you use a 30-30 blank as the primer and propellant for the front stuffer get up and go. This would make muzzle loading easier and quicker with the added function of the rear chambering. This could be done as a muzzle loader only option but I thought it could make a useful one gun option. 30-30 and 12 gauge in one gun and barrel. Any thoughts?

Interesting idea... You'd definitely give up some performance with the shorter barrel sections of each one.

My question is, (and I'm not a muzzle loader guy...) don't you have to tamp the ball down to compress the blackpowder charge somewhat? How might that work with a 30-30 chamber and 15" of .30 cal bore behind your muzzled loaded projectile?

Upside when shooting 30-30 is you'd have a heck of a crowning job to protect the rifling!

The only thing you would be stuffing is the projectile since the propellant would come from a 30-30 case. No black powder needed.

OK, I missed that in your first post. I was picturing using a primed empty case as the percussion cap only.

Can it be done? Yes, but I have no idea how well it would work.

Should it be done? Not a good idea due to the performance compromise plus the obvious safety issue of mistakenly chambering a loaded round with a 12 gauge slug in place.

P.S. I am not a professional gunsmith, but I would be surprised if anyone who calls themselves one would recommend trying this.

Until the day you load a live 30/30 in with the ball.

Your performance would be abysmal. The problem is that at the end of a few inches of 30-30 barrel, the pressure is down to nothing, even with a bullet. Plus, if you don't have a bullet in the .30-30, you can't get powder to burn with any appreciable pressure anyway. Even black powder won't do well. The smokeless will be blown out of the case by the primer, without even burning is my guess. Blackpowder will make a partially burned, heavily fouled mess in the barrel, and will not work particularly well.

What will happen is you will get a low pressure push that will roll the ball or shotgun charge out of the end of the barrel, and then a slow burn of powder in the air making a smoky fireball, if it burns at all. If the powder doesn't ignite, you'll get nothing except a small primer pop.

The problem will be made worse by the larger bore of the second barrel. The expansion ratio will go way up at the barrel transition, and the gas will have so much room to expand into, that it will further lower the pressure.

I don't even think that the idea is worth experimenting with, any knowledge of internal ballistics at all tells you it won't work.

dave

Think "chamber inserts" or "cartridge converter" instead. Unless you are thinking of a "ball or shot" gun?

SSDave, you make good points about why the larger ball round wouldn't work, but I can't follow the reasoning below:

quote:

The problem is that at the end of a few inches of 30-30 barrel, the pressure is down to nothing, even with a bullet.

If you are talking about shooting a 30-30, wouldn't the cartridge/barrel part be basically the same as if you had a 15" barreled rifle? Performance would suffer over a full length barrel, but I can't see the pressure drop you state until you get to the last 10". By then the bullet is essentially flying free, albiet through a 12 gauge tunnel...

Barrel pressure drops extremely fast. By the time the bullet is 1" down the barrel, more than 50% of the pressure has dropped. This is because the bullet moves down the barrel, giving expansion room for the hot gases to move into. The bullet moves faster down the barrel than the burning powder can produce gas. After 15 inches, my guess is you're down to 5000 psi or less. Less than shotgun pressure, and below muzzle loader pressure. Then, when you hit the larger bore barrel, the abrupt expansion will drop it even more, and you're probably down to 1000 psi or less. And, that is if you had a bullet in the 30-30 barrel to build pressure. Without a bullet, you won't have any appreciable pressure to start with. Maybe a few hundred psi. Powder just doesn't burn efficiently without resistance.

dave

Thanks, I follow you, I was just reading more into your first post. (5000 > nothing...)

Basically reaming the last 10" from .30 cal to 12 gauge would have the same performance effect as cutting it off.

In the example of a 30-30 you would lose about 150 fps depending on the length. I am not sure about the burn rate if used as a muzzle loader without a projectile in the propellant case.
A 30-30 rear .500" front end combo could be cool. 223 and 20 gauge?

Just curious, even if you could get the muzzleloading part to work, what possible advantages do you see in such a weapon?

You will have to use powder in the bore; a 30-30 won't hold enough powder for a muzzle loader, which will be at least 45 cal, I am assuming. I am not sure about doing that; expansion ratio and all. And with no air spaces. A long powder train like that won't burn well. And it won't be legal under ML laws as it can load from the breech with ammo. So, probably a bad idea; if nothing else, a 15 inch ML barrel will give you pretty low velocity. A 15 inch 30-30 is not bad....
Why not just go with 45-70, and muzzle load it if you want; that would work fine. Still not ML season legal.

Way easy method to do this is to reverse what you're proposing:

Get a 20 ga shotgun (or 12 ga) and make or have made a .30-30 insert barrel that will go into it.

.30-30 doesn't generate much pressure or breech thrust, should be fine in a shotgun action.

Or, buy a rifle, a muzzle loader, and a shotgun. Cost about the same as your project, and have way more resale value when you're tired of it!

dave

The combo could vary a lot but was just throwing out the 30-30 as an example. The idea was about versatility mostly. Perhaps pistol powders like Lil gun would be best. The idea of a high pressure smaller round and a lower pressure larger round is intriguing to me.

Why mess with that when you can use interchangeable tubes like used in 3 and 4 gauge skeet guns?

I'm struggling! So you want a Ruger No1 that you will insert a loaded (with primer ONLY) 30-30 case from the rear and then load from the front with loose powder and a ball.

OK.

This is to specifically produce a weapon that is classed as a "muzzle loader" for benefiting from the extended open season for "muzzle loading rifle" hunting?

I can see that. But surely:

1) If it can be loaded from the rear with a 30-30 case it can also be loaded from the rear with a 30-30 cartridge with primer, powder and bullet?

2) So you've already got BETTER performance than any muzzle loading conversion will give you and ONLY ONE OPERATION needed to have a second shot.

3) As 1) applies then, surely, in any case any Game warden would see the weapon as a breech loading cartridge weapon anyway (or able to be sued it that fashion regardless) and so not in fact as a "muzzle loader". SEE DPCD's POST.

I cannot see what such a conversion would achieve in either performance or in extending your hunting season as a "muzzle loader".

Surely the H & R Huntsman or similar concept is a better idea?

You would have to overcome the inertia of the ball some distance in front of the pressure wave produced by the burning powder from the cartridge case, which would probably introduce a pressure excursion at that point...

And I think you would need a larger capacity cartridge case to overcome the pressure reduction in the smaller bore's length.

Think of the 12 and 20 ga guns-from-hell concept with rifled bores and use brass cartridges will bullets in one application and a ball stuffed down the bore in the other...individually they work well but trying to make a twofer out of it might make for a rather ineffective combination.

All the other offerings have good points also...how WOULD the heat identify the object...think of the 45 cal/410 T/C dust-up.

Nice idea, Boomy, full of expectations and possibilities, but a little to much coffee/??? in there somewhere.