Modded muzzleloader

[JTknives]

I have just got into pcp and absolutely love it. But I started to wonder how difficult it would be to build a large bore gun. I am a machinist so I’m planning on making just about every part. My thought was to use a cva wolf 50cal muzzleloader. It’s a break action with a threaded breach plug that can be removed with just your fingers. My thought was to try and use the original hammer and have just enough air capacity for one shot. I had thought about leaving it as a muzzleloader and loading the Bullets from the muzzle but thy would also be loaded from the breach. I have 2 of these guns and only use one for hunting season so I thought it would be fun to see if I could convert one. I still don't know enough about the functionality of the big bores to start yet. But I’m hoping you guys could point me in the righ direction.

[Extreme]

   Hey Jarod, there are several guys here that have built and are in process of building big bores. I hope some will chime in to assist you.

Best of luck my Brother

[subscriber]

Jarod,

A muzzle loading barrel intended for ball would be perfect in twist rate for "waisted" airgun pellets, or short hollow base Minie ball.  If the twist rate is intended for heavier slugs, then you could shoot longer, solid, or hollow nose slugs without them lacking stability.

Do you know the twist rate of the barrel?  What weight and length of projectile shoots well using BP?  At what velocity?

The question is how much of the original parts you want to keep; modified or unmodified. 

It is possible that this thread would gain more traction in the Machine Shop Talk & AG Parts Machining section of this forum; or Bob and Lloyds Workshop.   Perhaps the mods will move it to either of those.

[BigBird]

I've actually thought about this alot but haven't made a muzzeloader.  I used to lurk on ebay and look at all the cheap 50 caliber barrels and 45s.

You can do it if you are a machinist and have access to a lathe with a big enough spindle through hole and bed.  When I was thinking about it I determined I would probably sacrifice a good useable barrel but it would be more fun, cost less to shoot and 50 caliber barrels are prevalent.  You probably have a 28 twist or 32 ish?  Those CVAs are good because they are made for conical bullets too.  They have a bullet starter in the muzzle.  I'd use lead and not the powerbelts, maybe sabots.  Minor: You may have to patch the ball which would be ok.  Or make a larger diameter ball. Just make sure you don't have it cocked when loading!  On the plus, you could put a pressure gauge on the muzzle end of the tube.

Some format considerations: Im my mind there is a problem of weight when you are using these barrels.  In a break barrel powder burner you have barrel and ramrod on the muzzle end and a stock on the other.  With a traditional PCP you have a barrel and an air tube underneath on the muzzle side with a stock on the other side.  So you'll have to turn down the barrel.  It was made for higher pressure and probably reducing the felt force of the shot.  I think even if you could make a rear bottle gun you would still want to turn down the barrel.

I wouldn't use the breech plug as it is too far away from your air source (wherever yours would be), I'd make another plug (usually standard thread like 5/8-18 for CVA) with a probe built in the front to stop your projectile from going all the way down to provide some space for air to go around it on its backside. 

You would turn down the barrel and breech (after using a dremel to take off the hardened lock lug underneath).  It comes right off after you cut through the welds. Actually if you can leave the breech a little bigger in diameter than the barrel it helps to free float the barrel.  Then put a transfer port hole straight through the bottom of the barrel right where the probe is. The air tube would go under your barrel and the valve would have to be directly under the transfer port.  Don't make your valve throat diameter too large or you will be stuck with a hammer spring that is too large for human strength.  The hammer portion isn't something I've though much about because if you have a traditional hammer coming off the air tube it will stick out too far to feasibly have a traditional stock.  I guess I'd implement a tube stock coming off the pressure tube with the hammer mechanism in there which could move more weight back to help with balance.

These are just thoughts not plans to implement without working out the details.

[MJP]

Well, thats an interesting concept. A friend of mine did do some pcp muzzle loaders some years back.

You need airtube, valve and hammer. If you intend to use the muzzle loader standard hammer you need to make a balanced valve.
Plenty of reading in the forum and some time with the pen&paperCAD and you'll get there.

Marko

[ezman604]

Moved this to the Machine Shop Engineering - R&D Gate.