turning shikari into muzzleloader

[Jason F]

I have a model 155 shikari 45-70. 28" barrel I want to send to smokeless muzzleloading to get turned into a smokeless ml would the shikari frame be ok to use since it is now gonna have a breech plug instead off all the pressue being on receiver face and which sabots would I use since it is a 458 bore

[quickdtoo]

The frame will work fine. 

Tim

[PHATINJUN]

Your kind of in uncharted waters with the Shikari twist 1-18"? There is one other member here who has done your conversion maybe he will chim in. But Busta is working on a 1-20" 45/70 he has some information posted below. Also look at full bore slugs they should work well. Personally I would not do a Shikari...just because there aint to many left or easy to find . 45 Colts or 45/70's are easier to replace JMHO maybe you can research some White ML loads I think Busta has worked with several of those . Kurt

[Jason F]

I have 3. 45-70 rifles I figured this would be the best candidate because it has the cleaning rod that could be converted to a ram rod

[mcgiiver]

Tell me what's wrong with trying this. Take a 45-70 case and fill it with the charge of BP you intend to try. Trim the case length to the top of the powder charge, so a bullet loaded from the muzzle will just touch the end of the case, but not enter it. Load the cut off primed cases from the breech, pour powder down barrel, load bullet and away you go. Fire it and see what kind of leakage you get into the receiver, if any. This way you can see if the project is feasible with a minimum of expense, and revert to the .45-70 at any time. Yes prolonged firing like this might erode the chamber, making cartridge firing impossible. That would take many, many firings however.

[PHATINJUN]

Mcgiiver, that is pretty much what Blake had suggested to me when I was thinking of doing this very conversion. Please forgive my ignorance to the following as I really know very little about this subject and style of shooting. But there is a style that is ??  Schuetzen SP? or was used breech loading cartridge shooting?? I think it was for gents who were trying for amazing accuracy?? Special guns and bbl twists?? Long range?? I am not sure what Jason's reasons (not that you really need any to tinker) are but mine was to make it legal for ML only seasons it would need the breech plug. I got plenty of Huntsmans to fill that need and Shikari's are a little scarce around here. But the little 45/70 Shikari is a blast to plink both Trapdoor and BP cartridges with. Kurt

[mcgiiver]

I agree that I would not permanently alter a good Shikari.

[keith44]

Ok let me get this straight you want to take a Shikari, which is H&R's intrepretation of a trapdoor springfield, which is a muzzleloader decendent via the allens conversion, and turn it back into a muzzleloader, but with smokeless powders and higher pressures?? I don't like the direction this is going.  You are wanting to make a weak action hold pressures it has not been designed for.  Does not sound like a good idea to me.

[gcrank1]

The problem with trying to use the shortened case and muzzleloading a bullet  is this:
A 45-70 chamber is slightly tapered, you cut the case back as suggested above and the bulllet, once run down the bore and into the chamber will free fall loose. It is sitting there, not filling the chamber, and when the powder goes off the gas gets up past it in all kinds of uncontrollable ways. It will go off, and might even be short range 'usable' .
In a breech-seating specialized chamber there is no real 'ball seat' or common throat, as in a fixed ammo chamber. The throat is cut to only bullet (most likely barrel groove dia. or, say, .001 over) dia., not bullet plus 2 sides of brass case; ie, .458 + (2 x .010) = .478 . As you can see, if the throat is only .458-.459 and the chamber below it is cut for only the length of the brass case to fit behind the bullet, you can get a full case of powder to kick the bullet out with no gas leakage to cut the bullet base and bands. That is breech-seating, in a nutshell, and there is much more than this thread should have.
For muzzleloading:
If you do use a sporting chamber the bullet should only be loaded from the muzzle to stop while still in the rifling, a good ways from the top of that brass. Longer brass might work, say 45-90 cut to fill up to 1/32 - 1/16 of the bullet base. I say might work, this would solve the 'loose bullet' fit but gain you nothing for this poster as it is still a cartridge rifle.
This also brings up the question of starting a muzzle loaded projectile straight. A counterbored loading throat may be the best, at groove dia. again, otherwise you probably should use a soft lead bullet of bore dia., as the Long Range Muzzle Loading guys do, or even a Minie. This all is not new ground, but many here are probably not familiar with it.

[gcrank1]

Well, no.....the Shikari is not H&R's repro of the trapdoor Springfield, it is the typical H&R 'tip-up' or 'break barrel' action in 44M or 45-70 c/w a barrel band for the forestock and an extendable 'cleaning rod' beneath.

[keith44]

ahh, I have been mis-informed.  Thanks for the correction.  It does have the cast iron frame though doesn't it.

[gcrank1]

It is the pre SB-1/SB-2 designation, and that puts it into the 'low-pressure' end of things. The 'cast iron' thing is kind of a misnomer; it is maluable (sp?) cast iron (hammer 'real' cast iron and it will shatter, these actions dont). Somewhere I have a really good laymans explanation from an engineer of what this all means, but rest assured they do take quite a bit. No doubt someone has been using 'level II' 45-70 loads for years without trouble in one, but there is nothing wrong with the 'level I' trapdoor type loads (ask a lot of buffalo, Indians, or Spanish from 'San Juan Hill'). The 44Magnum is no pressure slouch either, and the Shikari has been fine.
A 'sleeved' Shikari chamber backed by a breechplug will make it a legal muzzleloader. This does preclude its use as a cartridge gun unless the breechplug is carefully designed to be replaced with another one bored to duplicate the rear of a 45-70 case. All doable. The sleeve should closely fit the chamber walls, use a fireformed case to get rough turning dimensions from, go wide, then fine fit to your chamber. It should have a bored powder chamber of sub caliber. This makes cleaning problematic if you are used to a 'plain breech', but if, say, .375 dia. a .375 Win type jag or better yet, mop, will clean it nicely. Being sub-cal. your powder will likely overfill it and the bullet can only go down just so far. Again, your bullet MUST be started straight. A separate turned 'loading starter' that fits snugly on the barrel OD and carries a short start rod will do this (see The Muzzleloading Caplock Rifle, Roberts).

[quickdtoo]

Older H&R frames were likely malleable cast iron(pre-1943),  SB1 frames are ductile cast iron, I have an email confirmation from H&R on the SB1 frame material. 

Tim


http://en.wikipedia.org/wiki/Ductile_iron

Ductile iron, also known as ductile cast iron, nodular cast iron, spheroidal graphite iron, spherulitic graphite cast iron[1] and SG iron, is a type of cast iron invented in 1943 by Keith Millis.[2] While most varieties of cast iron are brittle, ductile iron is much more flexible and elastic, due to its nodular graphite inclusions.