Rifling twist rates

[Dick Hosmer]

Uhhh - not exactly.

The earliest trapdoor, the .58 cal "First Allin" M1865, kept the 1:72 twist of the parent musket.

The subsequent models of 1866 (a.k.a. "Second Allin"), 1868, and 1870, all in .50-70-450, used 1:42, in both lined (first) and unlined (later) versions. The trials carbine of 1870 was a .50-55-430, and used the same 1:42 twist.

The advent of the .45-70-405 round in 1873, brought a change to 1:22 (never 1:20)

The long range (.45-80, 2.4" case) testing of 1879-1881 saw experimentation with different bullet weights, up to 550gr., and twists of 1:18, 1:19.625 as well as the then-standard 1:22. This process turned out to be a failure so far as the original premise was concerned, but did show that optimum results could be obtained at .45-70-500 in 1:22. This load was then adopted as the service (rifle) standard until end of production in 1893. Carbines, beginning in 1873, were always .45-55-405, also in 1:22.

So, there is no reason why 500gr. bullets would have a problem with 1:22 - actually it's quite the opposite.

[Dick Hosmer]

Good luck! As you gain experience, and find the load your rifle likes, you should be able to cut those groups about in half on a good calm day.

Make sure the bullet fills the grooves of YOUR rifle, many barrels are oversize. Keep the alloy fairly soft, in the 1:16 to 1:20 area.

[Dick Hosmer]

You might want to try one of the snap-on spring steel sight covers of the period. They do a great job of shading the sight. De-burr the inside edge with fine emery cloth, and make sure to have a coat of oil on the barrel when taking it on and off = no scratches. Or, just leave it on. They are not expensive.

[Dick Hosmer]

Try the classifieds, and list of parts suppliers, at www.trapdoorcollector.com