Rifling twist rates

[JReed]

Was wondering what you all have come up with for twist rates in your original guns. I get 1: 22 1/4" in my 45-70 NYSM. Checked it 3 times and thats what I get. Odd since I have been shooting 500gr bullets in it with no signs of tumbling on paper at100 or 200. I just loaded a 30 rounds for load development so I will have to pay closer attention to groupings and what the holes look like. I would have thought since these were put together around 1880 that it would have the faster twist for the then new 45-500-70 loading of 1879. Or at least the 1:20 that the early trapdoor had.

[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.

[JReed]

Thanks for the great info. Did some more reading after I posted this. Its not the weight its that the 500 gov bullet wasnt overly long at 1.3" compared to alot of the modern competition bullets that are 1.4 plus. I will have to order up some of the original 500's and do some tests of my own. I have some of the 480gr Saeco semi-spitzers on the way as well and report what I find.

[JReed]

Did some paper punching at 100 with the Lee bullet. 20 rounds into a 7" circle with no sign of key holes. Tried a few at the 500 gong but I couldn't pull it off. For got my sight black and there was just to much glare off that military sight to get it lined up. Got in some of th Saeco 480's will try those out on the next range trip.

[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.

[JReed]

Suprisingly this rifle has a nice in spec bore with a grove diameter of .458. I have shot 20:1 and pure lead out of the Lee mold both shoot better then me with no leading issues.

This rifle shoots tight groups as long as I remember to bring the sight black to the range with me. If this wasnt an original gun I would have put a new front sight on it long ago. This rifle is always fun. It teaches me something new every time I take it to the range.

[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.

[JReed]

Cant say as I have ever seen one of those. Are like the hoods on the Win 94's and Marlins? Where might I find one. I dont consider myself old at 40 but the small front post coupled with glare makes it harder every year to get a good sight picture.

[Dick Hosmer]

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

[JReed]

Thanks for the link will put one of those on order.