rifling twist rate puzzlement

[Rifleman1776]

As long as I have been at this insane ml game, the one thing I have learned for sure is we never learn it all for sure.
For rifles, I have long been a fan of the 1:66" twist with deep rifling as pretty much the ideal for the popular calibers. e.g. .45" and up. But, I acknowledge the 1:48" might really be more versitile and won't argue someones choice of the 1:48. I regret having a 1:72" twist in my .54" cal. Jaeger. It require charges far above what I am comfortable shooting to get good accuracy. I know many pistol shooters use twists rifle guys would consider "too fast". Well. some of those pistol shooters will hit more 25 yard Xs than many a rifle guy can. So, whose to argue?
Which brings me to my current puzzlement, finally. :grin: A recent thread about Jaegers and the Schumway book 'Jaeger Rifles' stirred my interest so I started paging through my copy for the first time in several years. I noted a couple reviews that gave some startlingly fast twists for old original Jaegers. e.g.: a .55 cal. with 1:34" twist; a .58" cal. with 1:27" twist; a .56" cal. with 1:32" twist; and a .61" cal. with a 1:60 cm twist [23.6"]. Frankly I was very surprised to see these numbers. Even though the reviews do not so state, I presume the rifles were intended to shoot round balls. Now, in museums I recall seeing many American longrifles and the twists given are 99.99% of the time 1:48". Which brings me to the question(s): Where early European rifles all similarly fast twists? When/where/why did American rifles slow down the twists to the very popular 1:48" and slower? Plus, having never tried to shoot a prb from a rifle with twists faster than 1:48", are they as accurate? Will they handle heavier charges? Why don't we just give up this insanity and buy bolt actions? :surrender: :wink:
p.s. Unfortunately, Schumway did not document the twist for most the Jaeger rifles he reviewed. And, the way the book is compiled page number references cannot be given.

 

[BrownBear]

...having never tried to shoot a prb from a rifle with twists faster than 1:48", are they as accurate?

My experience is thin, but covering a fair number of rifles. All the "unmentionables" have fast twists and there are a lot of them in the hands of hunters. In my quest to get some of these guys shooting more, and coincidentally reoriented toward more traditional styles, I've helped them work up round ball loads for cheaper shooting.

Don't recall the models, but they're all characterized by really fast twists along with shallow rifling. If memory serves, twists ran as high as 1:20, but it could just as well have been 1:24.

To a gun they were rotten on first try with round balls except with small charges. But then we went to digging deeper. My guess was that the shallow rifling was the culprit, and we needed to play with tighter patch/ball combos for better "grip."

By going to mallet-tight combos, those guns (virtually all 50 cals) could be made to shoot round balls well with charges up into the 80-90 grain range. They also seemed to work better with spit patch than anything else. You just about had to swab between shots due to the really tight fit, but shoot well they did.

My guess on the shallow rifling was based on a 58 cal custom job I picked up used. For whatever reason the original owner had the barrel rifled 1:32, but with fairly deep rifling. Shoots like a house afire, fully the equal of slower twist 58 cal barrels out to 1:72. In fact, with charges less than about 90 grains of 2f, it consistently shoots better than the slow twists.

As an experiment I shot groups using a single 40 grain measure, with single scoops for one group, double scoop (80 grains) for another and triple scoops (120 grains) for yet another. It shot all of them well. Lots of us are familiar with old writings, in which the guys talk about adding extra scoops of powder for more range and power. Kinda makes sense if the guys were economizing on powder for general shooting and using relatively small charges unless they needed more. Sure wouldn't be doubling and tripling your charges in a slow twist barrel that demanded 80 or 90 grains of powder at a minimum for accurate shooting.

I'm limited to the guns I've had a chance to shoot, but I'm convinced the whole bash against fast twists has more to do with their typical shallow rifling than any facts against the faster twist speeds.

 

[Roy]

shorter barrel, regardless caliber, will require a faster twist to stabilize the ball.. or that is the theory.. I am about to build a .62 rifle with a 25.5" barrel and a 1-56 twist.. I will let you know how it does... :thumbsup:

 

[bpd303]

My 58 cal Jaeger with a 22 inch 1:24 twist shallow grove rifling is very accurate with both patched ball and HB Minie's and 70gr Goex FFG. It is an original German rifle that I resurrected. http://www.muzzleloadingforum.com/fusionbb/showtopic.php?tid/288590/post/1394956/hl//fromsearch/1/

 

[Loyalist Dave]

Unfortunately, Instructions for The Formation and Exercise of Volunteer Sharp-Shooters by Captain Barber (1804) is not available online in unedited form, and I cannot find my hard copy....

But (iirc) he documents that fast twists in long barreled rifles were known in Germany prior to the appearance of the American long rifle. He mentions that such fast twists gave "disagreeable recoil", by which I gathered he was referring to torque aka "cheek slap".

Barber mentions the slow twist of the Baker rifle of 1/4 turn for the length of its barrel (with a 30" barrel that would then have been 1:120). He also gives the reasons for the slow twist being large powder charges to allow for the rifle to hit man sized targets at 300 yards, and to allow two or three shots to be made before the bore needed swabbing...a combat requirement in his mind...

Considering at the time both in Germany and in the former English colonies in North America, shots on large game were likely to be at 100 yards or less, as well as German target shooting at the time had not hit huge popularity for long range shooting (more than 100 yards) so a fast twist wasn't rare, then a 1:48 twist in America was probably a good choice. Probably gave less cheek-slap than faster twists, and was easier on the rifling machine and the person working the machine.

LD

 

[Rifleman1776]

Probably gave less cheek-slap than faster twists, and was easier on the rifling machine and the person working the machine.

Ceratinly makes sense those factors could enter into the reasons for the change.