OK guys let's see where this goes. I finally got the delivery of my Perdersoli percussion rifle which I refused because I wanted a flintlock.
Then I got to thinking (I know - major mistake): I have a T/C Hawken stock and lock laying around. Why not call Bob Hoyt and see if he has or can make me a .54 round ball shooter.
So after speaking to him today he can make me any length barrel I want, install and aftermarket under rib and ramrod barrels (2), sights, and a breech with hook for my T/C Hawken stock for half the price of the Pedersoli. He can put any twist rate in it I want. He recommended a 1:60 for the .54 but I was thinking more like 1:66 or 1:72. What rate do you think would give me the best accuracy?
Remember this will be strictly for PRB.
I may still order the Pedersoli with the 1:65 twist

wow, gotta love when that happens!

How many grains of powder you looking to shoot? Normally the 1:72 twist guns like heavy doses of powder where as with the 1:66 you can get away with 10-20 grains less.

You can't go wrong with either twists, but for a .54 I personally would choose the 1:66 twist.

I think I would go with the 1:66". Why? Because it sounds cool and that's what my gut tell me to choose.

My .54 Green Mountain barrel has a 1:70 twist. My .54 Great Plains has 1:60. The .54 barrel on the Swamp Dragon (made by either Douglas or Numrich) is 1:64". I doubt there's a nickel's worth of difference in accuracy among the three.

Maybe you should tell him to make it a 1:63.5" twist. Then when you tell people you had the barrel made special with that twist you will sound like The Great Round Ball Wizard.

My JBMR is a .50 and has a 1-60 twist. The same gun in .54 is 1-66.

Even 1-72 will be fine. The depth of the grooves is as important as the twist for a PRB.

The GM .54 Flint RB barrel I have is 1:70. The T/C "PA Hunter" .50 carbine I have is 1:66, although it probably wouldn't matter any if it was 1:60... that's the twist rate T/C made both the PA hunter rifle and carbine in.

BPS

My custom Colerain .54 caliber swamped barrel is a 1-56 twist. They feel that is the roundball twist for that caliber. Larger calibers they tend to go 1-66 twist. For instance if I go to a .62 caliber Colerain it will have a 1-66.

Now if I had gone with a Rice barrel it would have been made with a 1-66 twist. So its hard to say what twist you should go with. Only you can decide that.

I was thinking the 1:66 twist because its close to the Pedersoli (1:65) & GM (1:70), and same as Lyman GPR.
Bob Hoyt can put any twist in it and recommended the 1:60 for the .54. I did a couple searches for the optimum twist rate for shooting PRBs in a .54 but couldn't find a solid answer. If I go this route I may just take the expert's advice and go with the 1:60 unless someone can prove to me the 66 is better. Keep the comments coming.

Well for what its worth, the old Great Plains Rifles were 1-66 twist. Then for some reason they changed to 1-60 twist. My Great Plains Rifle is a 1-60 twist and it is a great shooter. When they made my rifle I talked to the gun maker. I discussed twists with him also. But finally decided to let him, the expert be the judge and told him .. make me a good shooter.

GPR is 1-60.

Just to add more confusion. The original Hawken was a deep groove 1-48 twist. It was made for the PRB.

I talked to GM a few years ago, and he told me they spent a lot of time coming up with the 1-70 twist as being ideal for a PRB. I believe it was used in all calibers.

So, is there a set answer? I don't think so, but all PRB barrels have one thing in common. They have deep rifling.

I would recommend the Colerain gain twist barrels which are 1:96 to 1:48. The gain twist will have less fowling and attain higher velocities. Accuracy for me is very well. Anyways just a thought.