Shooting a 1866 Trapdoor Springfield

[airforcemajor]

First post here, I have been lurking looking for information but now have taken the plunge and registered.

I have an 1866 Trapdoor Springfield in .50-70 Government that I want to shoot at the Single Action Shooting Society’s End of Trail match this June.

I have not shot this before and want to load black power cartridges, I ordered some cartridge cases and a Lyman mold (.515 diameter and 450gr).

I’ll be filling the case with enough powder (2Fg) to compress it about 1/16 to 1/8th of an inch, will use a wad, and will lube the bullet with SPG.

My question is: without spending lots of time on the range does anyone know what the original ballistics were? I know I won’t duplicate the round exactly as I won’t get a full 70 grains of powder in the case but I’m hoping knowing the original ballistics will be a good starting point in finding out where this thing shoots at various ranges.

If anyone knows what the modern ballistics with black powder and the Lyman bullet are that would be even better.

I may be able to chronograph the round; if I can do that does anyone know of software that models the Lyman bullet?

Thanks

[varsity07840]

With a 70 gr charge MV should be around 1260 fps and ME around 1480, if I remember correctly.
You might be better off with a Lee .515 mould. In my experience, newer Lyman moulds cast at around .512, while the Lee will give you .515 and a bit more. I cast mine in 20:1 and run them through a .517 sizing die. With a compression die, you should have no trouble getting 70 gr in a case. Also, if you have a gunsmith in your area who is familiar with original BPCRs, have him check for excessive headspace. The 1866 sometimes has issues with that.

[Washington1331]

I've several older trapdoors in 50/70. They're great guns to shoot, if they are in good condition. Remember the Model 1866 is actually a converted civil war musket. They sleeved the 58 caliber barrel down to 50 caliber, and milled the back of the barrel to accept a bolted on breech block. These are not known to be the strongest actions, but if they are in good shape you shouldn't have too many problems.

Common problems other than the excessive headspace as described by varsity include barrel liner separation, and loosening/separation of bolt on breech block support. You can check on the barrel liner by examining the braise holding the liner in the barrel. The bolt on part where the breech block attaches shouldn't have any wiggle. The breech block itself may wiggle a little, but you don't want too much play, especially if the action is closed. If you have questions, I would talk to a competent gunsmith. There's some great videos on Youtube by a gent with the handle of the Koba. He has a video on determining if your trapdoor is safe to shoot.

The original loadings were with what we would consider today to be FFg black powder. I actually shoot mine with Fg black powder. It has a slower rate of combustion and keeps pressure more on the lower end of the pressure scale. That's always a plus with the older and weaker actions. With the long barrels, you shouldn't see much variation in velocity. Also the larger grains allow you to get more case fill than with FFg powder. That means you can shoot lighter loads without the need for multiple filler wads.

The old Springfields are great guns to shoot. I wish you luck in your endeavor.

[StrawHat]

I shoot an 1866. I do not own a chronograph so can not give you more than a guess at velocity. The best way to determine where the rifle (carbine) will hit is to shoot it. No getting around that. Given the CAS events tend to have short ranges and generous targets, the 1866 will handle them easily.

Actually, the more I use the 50-70, the less use I have for the small bore 45-70.

Kevin

[bob208]

I have a sharps carbine and a army rolling block in.50-70. I get the best results with 1f goex loaded through a 24" drop tube . then a hard card wad then a grease cookie and the lyman bullet you have. I use spg lube. the drop tube settles the power much better then just pouring it in and crunching it down.

[Tom in Pittsburgh]

Anybody have trouble (and solutions?) with their 1866 2nd Allins shooting high? Mine shoots about 14" high at 100 yards.

TIA

Tom

[Washington1331]

Tom,

I plugged your 14 inches high at 100 yards into my ballistics calculator. Given the standard 50/70/450 cartridge with a muzzle velocity of 1250 fps, 14 inches high at 100 yards would correlate to a 200 yard zero.

Are you using a full 70 grain charge, or reduced loads?

I am unsure of the range graduation for leaf down on the rear sight of the 1866. I do know that with the sight leaf up, the lowest setting is 300 yards. So, unless someone bubba'd the sights or they are damaged, I would think that perhaps the rear sight is set for a 200 yard POI.

The other possibility, and I mean no offense with this suggestion, is that you're not leveling the front sight with the top of the deep "v" notch, and instead leveling the front sight with the extreme top of the rear sight. Doing this would explain why you're hitting high at 100 yards. I had an 1868 trapdoor that was printing high at 100 yards until a fellow trapdoor enthusiast mentioned that I was using the rear sight wrong. After I made the change to how I was aiming, my group moved closer to point of aim at 100 yards.

Just my two cents.

[Tom in Pittsburgh]

These old 2nd Allins have a very basic rear sight -- similar to the rear sights on a Civil War rifled musket. Unlike the 1868, there is no sliding elevator when the sight is up. I was shooting mine with the leaf folded down. My guess is that these were sighted for something longer than 100 yards. Next time out I will pay more attention to my sight picture. You may be correct -- I may just need to take a "finer" sight.

I only fired four shots -- I wanted to fire-form a few cases to see how large of a bullet (diameter) I could load in them. Looks like the standard .515". I was shooting the "small" Lyman 515141 over a duplex load of 5.0 grains of 4759 under 35.0 grains (by volume) of 2F black powder, with the rest of the case filled with Cream of Rice. These loads shot OK in my own 1868, but not as good as the larger Lyman 515142 bullet over 22.0 grains of straight 4759 shot in that particular gun. 1866 load development still to come.

Thanks again -- will let you know how things develop, but it will likely be a while before I can get prepared and then get back down to the range. Work keeps getting in the way of the important stuff...

[Mark Daiute]

169151169152These photos show load development with WC872. I have both Lee molds, 450 and 500 grain. Groups have since tightened up. At 100 yards with the sight blade on the x ring the loads are hitting between the x ring and 6 O'Clock, all in the black and equally distributed between east and west. I know this is not BP but it is a case full of powder, no fillers. There are few kernels of powder with each shot that are not fully burned. When I open the breach I let the case bump up against my finger, extract the case by hand and dump out the unburned kernels lewaving the chamber clean. So far I am, having the best results with the 450 grain bullet.

[Tom in Pittsburgh]

Nice shooting. Whose cases are you using? I don't have any experience with WC872 - my smokeless loads have all been with 4759 or 5744, and these were with previous .50-70 rifles (a NYS Rolling Block and an 1868 Trapdoor - and I guess I could throw in a Swedish rolling block in the metric equivalent of a .50-70). My 1866 2nd Allin is "new," and I'm just beginning to work up loads using a variety of cases (some Dixie, some Bertram and some Garrett, which are cut-down .50 caliber basic cases). Looking forward to more range sessions - and to tweaking my sight picture so that I'm not shooting so high.

[Mark Daiute]

Nice shooting. Whose cases are you using? I don't have any experience with WC872 - my smokeless loads have all been with 4759 or 5744, and these were with previous .50-70 rifles (a NYS Rolling Block and an 1868 Trapdoor - and I guess I could throw in a Swedish rolling block in the metric equivalent of a .50-70). My 1866 2nd Allin is "new," and I'm just beginning to work up loads using a variety of cases (some Dixie, some Bertram and some Garrett, which are cut-down .50 caliber basic cases). Looking forward to more range sessions - and to tweaking my sight picture so that I'm not shooting so high.

I purchased one batch of 100 Starline cases. As I said, since these photos were taken the groups have tightened up quite a bit.

The cool thing with the 872, cost aside, is that I am using a full case of the stuff, can't get any more in and no signs of pressure.

[StrawHat]

I am sure most of the readers are aware but a reminder for the new folks who may have missed it. The 1866 Springfield, and the 1865 before it, are the source of the "weak Trapdoor" ideas. These two models were converted from muzzleloaders using the original barrels and milling the breech for the breechblock. The 1868 used a separate breech into which the barrel was screwed and is a stronger method.

Load the old rifles wisely and they will still give good performance. I like my 1866.

Kevin

[Bigslug]

I'd suggest you do a chamber slug / pound cast to find out if that .512 mold is really something you should spend a lot of time with. My dad's been playing with two .50-70's in his retirement (a trapdoor and a rolling block) and he custom-ordered (IIRC) a .518" for the one and a .524" for the other. IOW, quite a bit of variability to be found. The Accurate Molds 52-460L is pretty close to the regulation projectile shape, and can be ordered in any diameter you need.

[Freightman]

loaded up 10 rds of 50/70 with WC 860 62 gr or 4.0 CC and 10 rds of WC 872 58 gr or 4.0 cc with 450 gr .517 lee boolit powder coated. and after I got it regulated and sights set knocked the 10 ring out ( no camera ) but have witness at 100 yds. mild recoil clean barrel and no pressure. Thanks for the info.:drinks:

[John in PA]

Here's some load data. from the Lyman Cast Bullet Handbook, 3rd edition. http://img.photobucket.com/albums/v421/jwellsgnr/50-70%20data%20037_zpsn3x0ul20.jpg (http://smg.photobucket.com/user/jwellsgnr/media/50-70%20data%20037_zpsn3x0ul20.jpg.html)

And, here's a drawing from the Frankford Arsenal, showing the original cartridge and bullet design. Deep, square lube grooves, essentially identical to the Lyman 515141.

http://img.photobucket.com/albums/v421/jwellsgnr/50-70%20data2%20038_zpsbqzpyn1h.jpg (http://smg.photobucket.com/user/jwellsgnr/media/50-70%20data2%20038_zpsbqzpyn1h.jpg.html)