• This community needs YOUR help today. We rely 100% on Supporting Memberships to fund our efforts. With the ever increasing fees of everything, we need help. We need more Supporting Members, today. Please invest back into this community. I will ship a few decals too in addition to all the account perks you get.



    Sign up here: https://www.muzzleloadingforum.com/account/upgrades
  • Friends, our 2nd Amendment rights are always under attack and the NRA has been a constant for decades in helping fight that fight.

    We have partnered with the NRA to offer you a discount on membership and Muzzleloading Forum gets a small percentage too of each membership, so you are supporting both the NRA and us.

    Use this link to sign up please; https://membership.nra.org/recruiters/join/XR045103

40 cal drop in barrel for GPR?

Muzzleloading Forum

Help Support Muzzleloading Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Jim C

45 Cal.
Joined
Feb 15, 2015
Messages
771
Reaction score
1
I would really like to get into target shooting but with something smaller in caliber than the 45 or 50. I'm wondering if there's someone that might offer a 40 cal drop in barrel for the right hand percussion GPR.
 
Oregon barrel (the Gun Works) will make you one to your twist/rifling depth/length specs but it will run you $350 plus shipping.

Stonewall Creek will provide the same service - they don't post their prices but suspect it would be about the same since they are sourcing their barrels and then charging for the extra's and the install (plug, rib, lugs etc).

Even if you did it yourself (if you felt confident), it would run you close to the $300 anyhow, so from one of the above is not a bad deal.

There is no "cheapie" drop in's anymore...
 
Thanks for the info galamb. Would have never found it w/o it. Really, that's not a bad price at all considering the cost of a fairly decent rifle nowadays. I figure not only will a 40 be much more comfy to shoot a lot, but it'll also make her good and muzzle heavy which imo is conducive to a good steady hold.
 
I have a hoyt .40 cal on my gpr. had it for 20 years won many matches with it.
 
Would anyone care to chime in with some recommendations concerning rifling twist rate, grove depth, and sight dovetail placement?
 
mtmanjim,
Mine is a fast twist target barrel from Ed Rayl. I had a lefty GPR shipped to him and he used the parts from the fifty barrel. I say target but in fact it's no different from shooting a 40-65 Winchester as far as "performance" goes. It'll kill anything I'll ever hunt. At rabbit and squirrel distances it shoots tight patched ball well enough for heads shots. But, being a fast twist it's cantankerous and persnickety about cleaning and loading.
Now, if I ever get another forty barrel it won't be fast twist or slow twist. It will have rifling suitable for patched round ball and to shoot .41 pistol molds cast from soft lead loaded as maxi's. As far as performance goes in more modern terms it'd be about half way between a 38-40 and a .41 magnum, plenty of available weight and velocity for penetration while still being easy to load patched round ball with good accuracy.
Any how, that's all I know forties unless I got started on what doesn't work.
 
My main reason for wanting it is for target/competition shooting. Although I do love to squirrel hunt, I don't care too much for any other type of hunting, so a prb is all I need. I'm just wondering what the perfect twist rate and groove depth would be for a 40 cal prb in a 28" barrel.
 
What's perfect for target work is a really good question. My Renegade with the GM barrel is 48" twist. Folks swear by them. Mine is 28" long like GM made them a long time ago. It's accurate but I never yet tried to work up the very, very most accurate load for it.
 
My 50 cal Lyman GPR is 1-66 I do believe, and it'll shoot one hole groups at 35 yards from a sandbagged rest. I use it to squirrel hunt with and hit them in the head many more times than not. I just can't imagine anything being very much more accurate than that.
 
My 40 and my 38 have 1:48 twists for shooting round ball.

The 40 has .012" round bottomed rifling (off the shelf Colerain barrel) and the 38 has .010" round bottomed (FCI custom).

Both work well with round balls.

If I wanted to shoot conicals, paper patched etc, I would go with shallow rifling (.004 probably) and a 1:32 or 1:28 twist (depending on the bullet length I wanted to shoot).

I am unaware of a 40 cal with a twist rate "slower" than 1:48 as a standard offering from the barrel makers - at least in the current market place and personally can't think of why I would want one slower than 1:48
 
Well, Oregon Barrel and Gun Works, where I'm planning on getting it only goes up to thirty for the GPR drop ins, and I figure that smaller bore diameter is gonna add plenty of extra weight as it is. I plan on target shooting with it mostly, but suspect that I will be hauling it around in the woods chasing squirrels too.
 
Back
Top