GPR

[lineman79]

Hey everybody, sorry for the long post,I'm new to muzzle loading and have recently been handed down a GPR .50 from my dad. My dad is probably the absolute worst person I have ever seen when it comes to maintenance on anything. I knew he had a old gun in his safe and asked about using it for the upcoming season. Well to my surprise out comes the GPR and he told me to just keep it, he never cared for it and has an inline he likes better. Well I take it home and as I've learned to do with anything I get from him set about cleaning it. What I found was not very reassuring there was a lot of rust and pitting. After using a bronze brush and getting it back to as shiny as possible,I see that about the first 8in or so from the muzzle end is in pretty bad shape. I shot a bit with it and have found I could get about a 5in group at about 50yrds. So I'm thinking I need a barrel replacement. What are my options as far as replacements? Aftermarket?(if there is an aftermarket)Just order a new one from lyman? Thanks for any help anyone can possibly give.

 

[BrownBear]

Click here for one source. They're commonly listed by lots of others, but I've dealt with these folks with complete satisfaction.

 

[Philip63]

I would shoot it more with different loads before I ordered a new barrel. Try patched round balls and conicals with different powder levels behind them you may well find something it really likes.

 

[William O.]

Lyman makes drop in replacement barrels and you can often find them used in great shape. I would check out a .54 barrel as it will be a bit lighter and less nose heavy than your current .50. However, before you get another barrel I would try some more polishing and load development. I say this because sometimes a pitted barrel is capable of very good accuracy. It will however, always require more cleaning for the very fact that the pits collect fouling and it's just harder to get all that out as opposed to a smooth surface. Try some JB's bore paste and see if that helps things.

 

[bubba.50]

Midsouth Shooters Supply has 50 & 54 cal Great Plains barrels in stock for $210.00 apiece & Great Plains Hunter(fast twist) barrels for about 20 bucks more.

 

[Katahdin]

I took some valve polishing compound and a slug and lapped a barrel once that was in rough shape,someone has posted a tutorial on this or should..Might even take some Valve Grinding Compound then go to the Polishing compound.Try the compound on a brush and see if that improves it any!!
I have a GPR,(Mjolnir)and like it very much,heavy to carry but that keeps me in shape to drag out that 300 lb buck!!!!!!!!!!!!!

 

[Flash Pan Dan]

There is an alternative, have it bored out to 54. The advantages are pretty good. It is cheaper that buying a new barrel. You can have it rifled to a different twist rate and finally, you can have the patent breech chamber opened up and polished. Which will make a tremendous difference in ignition when dirty and in cleaning it.

 

[Roguedog]

I second the suggestion for a rebore. I had a .50 cal barrel that I ruined in my youth. I had a guy bore it out to .58 and now she is the bell of the ball. Like another guy said, don't give up on the existing barrel just yet. Try a few different loads, some different thicknesses of patches, etc. You just might find a load she likes.

Jeff

 

[lineman79]

Thanks for all the suggestions. I think for now I'll be trying to get some more range time in before buying a new barrel. As far as getting it rebored around here I wouldn't know where to begin getting that done. I think I'll just try a few more loads and maybe step up to .495 balls(all I've had were .490) see how that works out for me and go from there. I must say that I am impressed with this board already. Usually the others places I'm a member of(not muzzle loading) you hardly get a response or just a few that don't really answer anything.

 

[Roguedog]

If your bore is rusted and pitted, you may be better served trying a tighter fitting load, either larger ball size as you indicated or even tighter patches. This may help yield some usable groups.

Jeff

 

[bpd303]

Another thing to try for removing even more rust than the bronze brush alone. Try wrapping some Chore Boy copper kitchen scrubber around the brush and scrub with some good penetrating oil like Kroil or a 50/50 mix of acetone and trans. fluid. You will be surprised how much more rust comes out.

 

[lineman79]

For where I hunt the way it is shooting is fine for hunting but I'm the type that like get the best possible from my shooting. Next question would be what powder should I be using. I've been using goex FFFG a friend told me and from what I have been reading that I should be using FFG. Any recommendations?

 

[BrownBear]

...from what I have been reading that I should be using FFG. Any recommendations?

Yeah. Picture several elderly female spouses huddled in a circle swapping stories....

I.e., old wives tale.

Shoot what the gun likes. The 3f/2f stuff is worth testing, but each gun will give its own answers. Accepting such "wisdom" without testing is...well....joining the crowd of elderly female spouses. :wink:

 

[Roguedog]

The fact is, some guns like 2F and some do better with 3F. Two of my guns like the 3F, the other one likes 2F. When I say each gun likes what it likes, I mean that I can see a drastic improvement in accuracy when using that granulation. It is worth a try to see which one your gun may like. Now, if your on a budget, just buy one type and likely you will find a load that will work. But if your wanting to fine tune and wring out the best possible accuracy, it would pay to try different powder granulations.

Jeff

 

[Lonegun1894]

I use 3F in a .50 and a .54 GPR cause it was more accurate in both than 2F. As to the bore, I would either keep trying different loads, or rebore it. If you rebore it, at least you KNOW the bore is good so any inaccuracy is YOUR fault. You can always improve your shooting, but you can only improve a bad bore so much. If you're going to buy a new barrel instead of reboring your current one, I would send the current one out and have it rebored to a .54 smoothbore, that way you have a switch-barrel setup that'll let you hunt anything you want from squirrels on up to as big as you're willing to go after. I have 3 GPRs, a .50, a .54, and my last has a GM .54 smoothbore barrel on it. These aren't available anymore last time I checked, but your current one can be rebored to make one. The smoothbore does 4-5" for me at 50 yds, just as a reference to compare to your current groups, and also allows use with birdshot and buckshot, unlike a rifled bore. NO matter which way you go, stick with what you're doing and you will tighten up those groups.

Since no one has mentioned it yet, I would also order Dutch Schoultz's Blackpowder Rifle Accuracy System from his website. That $20 saved me a lot more than it cost, and would have saved me even more if I had known about it sooner.

 

[Black Jack]

Since no one has mentioned it yet, I would also order Dutch Schoultz's Blackpowder Rifle Accuracy System from his website. That $20 saved me a lot more than it cost, and would have saved me even more if I had known about it sooner.

Another vote for purchasing Dutch's system. The best $20 you'll ever spend. It works, and an interesting read to boot.

 

[Idaho Elk Hunter]

I keep both FF and FFF Goex BP on hand and I shoot two 50 caliber and three 54 caliber rifles and yes, you need to test each rifle as one will like FFG and the other may like FFFG. Just have to shoot them and take notes especially when you have several long guns to test.

 

[William O.]

The advice on getting your barrel bored out to a .54 is very good. Cheaper than a new barrel and you can also get it with a twist rate not available from Lyman.