I have always wondered why the twist rate is not dsignated when a barrel is listed as "GAIN TWIST". To me the term "gain twist" means the twist rate is "0" at the start of the rifling and gradually increases toward the muzzle. Therefore, the bullet is spinning at a pre-determined rate when it leaves the muzzle and the barrel shoud have a designation such as (24"-gain twist-14).
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I have 2 rifles with gain twist both muzzle loaders. One is 1-72 the other Is 1-18. Don't know the starting point.
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Ross: That is the first I have seen the twist rate listed for a gain twist barrel. I find it interesting that a muzzle loaderd has gain twist since the bullet/ball is engraved when rammed down the bore. What is the make of your rifles? I would be interested in looking them up and see how they were listed.
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One is a flint hawken with a Bill Large barrel. The other is a slug Gun with un known maker. You can feel the twist when loading or cleaning.
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Cove: you shouldn't think of the beginning part of the rifle as "0". A Carcano is a common one that starts about 1:19 and ends at 1:8.5. So by the time the bullet spins out the bore it behaves as a 1:8.5. The slow start was meant to lower pressures and ease the bullet into a faster spin rate.
Scott Ingle
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.jpg?width=20 "JBinMN")
Scott: Good point, I made the mistake of assuming that the the initial twist was "0". With computerized machines the standard nowdays I am suprised gain twist isn't a common option for cast bullet barrels. Especially for revolvers shooting cast bullets. In my 38spl with a 1-10 twist barrel, recovered HBWCs show that there was quite a bit of skidding when the soft cast bullet engaged the rifling.
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many of us shot ARA 22 rf for several years ... pretty much open rules for accuracy improvements and nearly perfect rests. a lot of shooting ... and budgets busted ... from obsessive testers.
many tried gain twist barrels with no verified improvements in overall match results. Some shot well, but not necessarily better.
this of course was with slow, very soft, and very short bullets. perhaps longer or faster or harder bullets would benefit.
For what it is worth ...
ken
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Larry Gibson
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Tom Acheson
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Wm Cook
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Eutectic
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cove
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Lance Boyle
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Aaron
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andrewst35
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Gripmaker
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Glenn R. Latham
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