Hoyt GPR .54, 1:66 load recommendations

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Is a Hoyt .54 barrel going to be ballistically different than any other .54 calibre, 1:66” barrel?

Maybe. Mr. Hoyt, as a master barrel maker, can produce almost anything imaginable in terms of bore diameter, rate of twist, number of groves, groove width, groove depth, and groove shape (square bottom, round bottom, or flat bottom with slightly radiused inside corners). He can also make a tapered bore, .001" to .003" larger at the breech than the muzzle. That tapered bore was discussed by both Walter Cline and Ned Roberts in their respective books, and was routinely built into the handmade barrels of days gone by, and I believe barrels by Bill Large generally had tapered bores. Charles Burton and Robert Hoyt are the only currently practicing barrel makers I know of who are willing or able to make a tapered bore. This is not the same as progressive depth rifling, as used in Civil War rifle muskets. Dan Whitacre can make these.

We all know that individual barrels can also have unique preferences and "personalities," too.

Anyway, the OP has provided us the caliber and rate of twist for his new barrel. We don't know much beyond that, in terms of options Mr. Hoyt may have provided. However, I have no doubt that the usual rules of thumb, so ably described in the preceding posts, will provide the OP with a good place to start. From there, it will probably just require some judicious experimentation.

I hope no offense is taken from my response, as the question was actually a good one. I have a rifle and a pistol with custom Hoyt barrels, as well as an Italian "Richmond" rifle-musket barrel currently in his shop for a liner, and I was really surprised to learn the variety of options he can offer, especially with new barrels and re-bores. The man is a national treasure.

One thing is for certain... The OP will be happy with his rifle if he puts in the time for load development, and I'm sure he will.

Best regards,

Notchy Bob
 
Just received a .54, 1:66” GPR barrel re-bored by Bobby Hoyt (had been a .50). If you have had Mr. Hoyt do similar work for you, I am interested to know what hunting loads you have worked up in your Hoyt barrels?
Good luck with yours, they are a fine rifle. When I bought mine at Dixon's several years ago, I picked the .54 because the barrel will be a bit lighter, and I just thought it was a "cool" caliber. (I don't hunt).Anything done by Mr. Hoyt is going to be high quality; I have a friend who had a original 53 Enfield re-lined by him. I completely re-finished mine and did a lot of wood shaving, etc. Left-hand percussion, BTW.
 
Maybe. Mr. Hoyt, as a master barrel maker, can produce almost anything imaginable in terms of bore diameter, rate of twist, number of groves, groove width, groove depth, and groove shape (square bottom, round bottom, or flat bottom with slightly radiused inside corners). He can also make a tapered bore, .001" to .003" larger at the breech than the muzzle. That tapered bore was discussed by both Walter Cline and Ned Roberts in their respective books, and was routinely built into the handmade barrels of days gone by, and I believe barrels by Bill Large generally had tapered bores. Charles Burton and Robert Hoyt are the only currently practicing barrel makers I know of who are willing or able to make a tapered bore. This is not the same as progressive depth rifling, as used in Civil War rifle muskets. Dan Whitacre can make these.

We all know that individual barrels can also have unique preferences and "personalities," too.

Anyway, the OP has provided us the caliber and rate of twist for his new barrel. We don't know much beyond that, in terms of options Mr. Hoyt may have provided. However, I have no doubt that the usual rules of thumb, so ably described in the preceding posts, will provide the OP with a good place to start. From there, it will probably just require some judicious experimentation.

I hope no offense is taken from my response, as the question was actually a good one. I have a rifle and a pistol with custom Hoyt barrels, as well as an Italian "Richmond" rifle-musket barrel currently in his shop for a liner, and I was really surprised to learn the variety of options he can offer, especially with new barrels and re-bores. The man is a national treasure.

One thing is for certain... The OP will be happy with his rifle if he puts in the time for load development, and I'm sure he will.

Best regards,

Notchy Bob
If this hobby had designated living treasures, Mr. Hoyt would be in there, surely. He's not just a master machinist, but has to understand the shooting arts and usage of his products, too. I have not read about Mr. Burton but have no doubt he's in the same league. I'm happy to have read your comments.
 
IMG_0594.jpg

I have 4 Hoyt barrels 2-50s (1-56, 1-60 ) and 2 .54s with his gain twist all needed thick patching(all round bottom rifling) I use 10 oz denim with a tallow the 54s and the 1-60 like 70 grns swiss 3f (Hoyts suggested load 70 and add 10 grains for hunting load)the 1-56 is an odd ball it likes 60 grns 3f swiss
 
View attachment 145762
I have 4 Hoyt barrels 2-50s (1-56, 1-60 ) and 2 .54s with his gain twist all needed thick patching(all round bottom rifling) I use 10 oz denim with a tallow the 54s and the 1-60 like 70 grns swiss 3f (Hoyts suggested load 70 and add 10 grains for hunting load)the 1-56 is an odd ball it likes 60 grns 3f swiss
I’m old school…and I’m hearing a lot about GainTwist barrels…they allow you to shoot both RBs and Conicals with equal accuracy. Is that true…or even possible?
 
For the most part, @Rock Home Isle, shooting round ball or conical bullets, the main consideration is depth of grooves. Round ball accuracy seems to be improved by deeper grooves. Conical bullets shoot more accurately with shallower grooves and the conical is more critical of the fit of the bullet to the barrel. A gain twist rifling allows for more acceleration on start up and filling the grooves. At the muzzle the faster spin provides some more stabilization.

Accuracy with a round ball or conical bullet is achieved through load development not with some exotic form of rifling.
 
Maybe. Mr. Hoyt, as a master barrel maker, can produce almost anything imaginable in terms of bore diameter, rate of twist, number of groves, groove width, groove depth, and groove shape (square bottom, round bottom, or flat bottom with slightly radiused inside corners). He can also make a tapered bore, .001" to .003" larger at the breech than the muzzle. That tapered bore was discussed by both Walter Cline and Ned Roberts in their respective books, and was routinely built into the handmade barrels of days gone by, and I believe barrels by Bill Large generally had tapered bores. Charles Burton and Robert Hoyt are the only currently practicing barrel makers I know of who are willing or able to make a tapered bore. This is not the same as progressive depth rifling, as used in Civil War rifle muskets. Dan Whitacre can make these.

We all know that individual barrels can also have unique preferences and "personalities," too.

Anyway, the OP has provided us the caliber and rate of twist for his new barrel. We don't know much beyond that, in terms of options Mr. Hoyt may have provided. However, I have no doubt that the usual rules of thumb, so ably described in the preceding posts, will provide the OP with a good place to start. From there, it will probably just require some judicious experimentation.

I hope no offense is taken from my response, as the question was actually a good one. I have a rifle and a pistol with custom Hoyt barrels, as well as an Italian "Richmond" rifle-musket barrel currently in his shop for a liner, and I was really surprised to learn the variety of options he can offer, especially with new barrels and re-bores. The man is a national treasure.

One thing is for certain... The OP will be happy with his rifle if he puts in the time for load development, and I'm sure he will.

Best regards,

Notchy Bob
These fellows should adopt small orphans from the Birmingham docks, and train them in the magical arts so that the art and science can continue on! :)
 
If you have a land-to-land bore diameter of 0.500" and a groove depth of 0.012", you may want to select a ball of 0.490" with a patch that compresses to 0.017" (0.012+0.005) or 0.495" ball and a patch that compresses to 0.015" (0.012+0.003). I have found that using a patch that compresses to the groove depth + half the difference between the ball and the bore provides the best on target accuracy. Patches less than the groove depth will shred which isn't best for accuracy.

05 patch is way too thick. I always use 0.018 thich cotton tearing or ticking that's been washed before cutting into 2 inch wide strips.
 
For the most part, @Rock Home Isle, shooting round ball or conical bullets, the main consideration is depth of grooves. Round ball accuracy seems to be improved by deeper grooves. Conical bullets shoot more accurately with shallower grooves and the conical is more critical of the fit of the bullet to the barrel. A gain twist rifling allows for more acceleration on start up and filling the grooves. At the muzzle the faster spin provides some more stabilization.

Accuracy with a round ball or conical bullet is achieved through load development not with some exotic form of rifling.
I had to read this twice…great information.
 
I’m old school…and I’m hearing a lot about GainTwist barrels…they allow you to shoot both RBs and Conicals with equal accuracy. Is that true…or even possible?
Velocity and accuracy are the reasons I would consider gain twist. Bobby says he gets much higher velocity per grain of powder with gain twist. It’s also unlikely that the ball will strip the lands at higher velocity.
 
I have a 50 and I have had 2 58 calibers that Bobby redid for me. They all shot very well. The 50 likes either a 490 or a 495 round ball. I have always used an .018 patch with all of them and about 70 grains of 2F Old E.
 
Hello all,
I had Bobby Hoyt rebore two TC flintlock barrels to 54 cal. 1/60. They do well with 80 gr. 2F., .535 ball and .015 patch. Bobby does excellent work !
 
Just received a .54, 1:66” GPR barrel re-bored by Bobby Hoyt (had been a .50). If you have had Mr. Hoyt do similar work for you, I am interested to know what hunting loads you have worked up in your Hoyt barrels?
Ask Bob ,he knows what works ,he doesn't just build them !/Ed
 
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