H&A barrel twist

[stuffy25thia]

Does anyone know what the twist would be for a H&A underhammer rifle with a 20" barrel?
Thank you for your time.

 

[paulvallandigham]

It depends on the caliber, and what projectile the barrel is designed to fire. Want to give us a clue?

 

[stuffy25thia]

It's a .45 cal. I don't have it here with me, I'm thinking of buying it. But don't wnat one that has a fast twist. I know the shorter barrel won't have a slow twist, but still want one that will shoot roundballs.

 

[haroldpotter]

It’s a good bet that the rifle you are talking about has a 1 in 66” twist. When I bought my H&A (labeled “THE OFFHAND”) I read about it and found out that it had a 1 in 66“, twist. That was about 10 years ago and I don’t remember where it was written.
Blue Grouse (underhammers.com) list their 36, 45, and 50 cal. rifles as having that same rate of twist. I know my 45 cal. has a slow twist because when cleaning with a tight patch my rod makes about a half turn when pushed down the 32” barrel.
With all firearms I know about, the twist does not change because of the length of barrel and I think that would be true in this case.
Harold Potter

 

[faw3]

DAD HAS HAD OVER 20 H+A'S THE LAST !0 YEARS I KNOW OF AND FROM THE 36 TO 58 SIZE ALL HAVE BEEN 1 X 66 WITH BARRELS FROM 18" to 48" LONG (except) 2 THAT HAD BEEN MADE FOR A BULLET, ONE A 45 WITH A I THINK 1 x 25 AND I DONT REMEMBER THE OTHER, I just found his note on's the H+A's hes had > 32" long, 40 CAL, .0012 RIFLEING, 2 OTHER'S .400's 1 X 24 AND A 50 IN THE SAME. BLAINE

 

[CoyoteJoe]

Those old Numrich Arms barrels were very good round ball shooters. They had a different twist for each caliber, from 72" for a .58 caliber down to 40" for a .31 caliber. If I recall correctly the .45 caliber was 56", but it has been a while. :grin:

 

[paulvallandigham]

IF the barrel is actually one made by H&A for the gun, then everyone here is probably correct, and your ROT should be 1:66". If, however, the barrel is from another source, all bets are off.

It will shoot round ball., You are just limited in how fast you are going to be able to send it down range, even using Swiss 3F, probably the fastest BP on the market toda, by the short barrel length.