converting a bolt action to an inline bolt black powder rifle

[MaxJon]

I have got an Omark 44 action, which I am considering building a .50cal inline black powder rifle or muzzleloader rifle?? A mate tells me I should build it using the bolt unmodified, and make a slip fit breechplug with an Oring on it that slips infront of the bolt head/lugs so that the breech plug extracts like a spent .308 case would have done. This way the rifle would be loaded from the receiver, not the muzzle. (easy cleaning too) I initially was thinking of simply threading the breechplug into the barrel, (like other inline bolt guns) tossing the bolt head, modifying the bolt to suit the No11 cap or 209 primer and threading the barrel to screw into the receiver. This would make it a muzzleloader/front stuffer, more traditional. I just want to shoot BIG bullets at paper targets, a BIG slug gun you might say! LOL If I was to thread the plug straight into the barrel to make a true front stuffer, how do I get it proof tested?? The bolt head rifle on the other hand would be fine as the pressure of the .308 far exceeds the .50 ML even at 150gn charges/loads. Any tips, advice would be great!! Thanks in advance!!!! BB033

[Nobade]

A lot of people have done this, and it seems the best way is to make a 2 piece breech plug that allows you to use something like a 10mm or 45 acp case (whatever fits your bolt face. if it's a 308 now a 45 acp will work) and set up so the plug headspaces on the inside web of the case. This way the pressure will allow the case to seal the "chamber" interior of the breech plug. It is important that you be able to load it without having a primed case in the chamber, for obvious reasons so a proper breech plug needs to be made. Another consideration is if you are going to shoot it with smokeless or black powder. If smokeless, you need some way to provide changeable orifices because they will erode very quickly. Many people who do this use tungsten carbide inserts or at least hardened steel ones. If you build it right and find the right sabots you can produce some amazing ballistics this way. If you use it with black powder it will be much easier to deal with and longer lasting, but of course won't be able to go as fast - not that that is a bad thing. The power the smokeless guys are getting out of these converted rifles would generate recoil enough to really damage your body.

-Nobade