47-70 govt. loads for 1873 Trapdoor

[trap1873]

I am new to reloading and this forum. I look forward to learning from you all. I have 50, 45-70 cases primed and ready to charge. I have Trail Boss powder and 300 gn lead bullets. I'm questioning my choice of powder. Looks like there are much better choices out there. Pressures look high for the the velocity achieved.

I am interested in opinions. The weapon is in good shape. I want to keep it that way.

Thanks...

 

[joecil]

I like Trailboss behind a 405 gr cast bullet for plinking/target shooting. As for a Trapdoor it should be fine also as Trailboss is a smokeless powder with the intention of use in black powder cartridge guns. I just looked up a 300 gr lead bullet using trailboss is from 14.0 gr @ 1198 fps to 16.5 gr @ 1285 with 20900 PSI. That came from Lee's 2nd Edition book.

 

[ArchAngelCD]

Trail Boss is a very low pressure powder which was developed to mimic the velocities and pressures generated by Black Powder. Nothing wrong with Trail Boss from what I've read but I do like a 405gr lead bullet instead of the lighter bullets. If you don't like the results you get with TB give AA5744 or IMR/H4198 a try. Just don't load all those cases before you decide if you like the results TB delivers.

Welcome to the forum...

 

[JerryND]

Although I'm new to this forum I've been reloading for almost 50 years. I load for an 1876 trapdoor but only with Pyrodex. I'll have to try trail Boss. Just be sure your bullets are the proper Dia. Mine likes .460, .461 if I can find them. .458 Jacketed make a funny noise when the drop down the barrel.

 

[Cosmoline]

TB should be fine for a trapdoor in good condition. It is NOT designed to give high velocity so you just have to accept slow bullets if you use it. The only safety issues I know of with TD's are with certain reproduction guns that have blocks popping up. The originals are real workhorses and will do fine so long as they're not taxed with modern loads.

You can also use straight up Goex packed in there. That's really fun and you will get higher FPS than TB.

 

[au_prospector]

IMR website and please specify your rifle.

Call 913-362-9455 for more information. IMR customer service for load data.

IMR website for Trail Boss load data. http://www.imrpowder.com/trailboss.html
I would call because their load data pushes pressures up over 20,000 CUP which is a bit higher than LYMAN 49 calls for in trapdoors and repo trapdoors. The IMR data might be for lever action guns, it does not say.You should be good with their starting load on 300 weight lead bullets which is 14 grains of TB gives you about 1200 fps and 14,400 CUP.

Is your trapdoor original? I have an H&R Officers Model Repo and it is a lot of fun to shoot. Extremely accurate, it shoots lighter weight bullets better than heavier ones however.

 

[Stormin.40]

I have an original trapdoor as well and purchased TrailBoss and H4198 with the intention of reloading smokeless. In the end I decided to load black powder cartridges and am happy that I did. I used the TrailBoss in my .38 Special and still have the H4198. I might still load smokeless for the trapdoor but I really like the smoke of the real thing.The TrailBoss pressures seemed high to me compared to H4198, so any smokeless load I make will be with H4198.

 

[trap1873]

1873 Trapdoor

Thanks for the replies. Sounds like Trail Boss will work, but not optimal. I'll follow the advice and only load 20 rounds. The rifle is an original made in 1884 (it is a model 1873). It was first issued to the Minnesota Militia. It is in great shape and a nice shiny bore. I've shot Goex black powder through it. Works great, just did not want to load black powder. Maybe that will change after I figure out what I'm doing.

Stormin, I thought the pressures looked high on TrailBoss compared to the powder listed in the Lyman manual too....with less velocity.

Tim

 

[Curator]

Trail Boss has a very sharp pressure curve, and is OK for what it is intended for, Cowboy Action loads in handguns. There are several good smokeless powders that work well and won't stress your 130 year old rifle. SR4759 is always my first choice, after that IMR4198, and Reloder7. Use loads in Lyman or Lee handloading guides expressly for Trapdoor rifles. Keep pressures below 18,000 psi, use 405 grain lead bullets of at least .462 diameter and a good bullet lube and you will be amazed at how accurate they will shoot.

 

[.22-5-40]

1++ what Curator said! I too was fooled into thinking TB was low pressure..due to low velocities & case filling properties. Spoke with some experienced handloaders of old British double rifles..and was told guns had locked up using "safe" TB loadings.

 

[ArchAngelCD]

Just remember not to compress Trail Boss because that will cause pressure spikes that can be dangerous.

I bought a Trapdoor a few years ago and was shooting noting buy H4198 under a 405gr lead bullet until i tried AA5744. I usually don't easily change over from a time proven powder but in this case I really like the results i get with AA5744 under that same 405gr Cast bullet. I highly recommend IMR/H4198 and AA5744 for 45-70 Trapdoor loads and even for higher pressure loads meant for a levergun.

 

[buttrap]

I agree on the TB as the stuff has a very sharp pressure peak. Its about the last thing I would use in a trapdoor.

 

[trap1873]

Alright. I'm convinced. Trail Boss back in the jar. Now I have to go buy a Colt SA revolver! Would hate to waste the powder. I will look for the recommended powders around town and probably end up with what is available.

I would like to use the 300gr. lead I have. I do not see a recipe in the Lyman book for this weight. Would you just pick the 300gr. Jacketed recipe?

Appreciate all the feedback. I want this rifle to last a couple more generations.

 

[StrawHat]

I reload for several 45-70s including a Springfield Single Shot rifle. Blackpowder is the perfect powder for them. Predictable, and accurate, it has been the choice for just over a century.

Here is a book written by a fellow who took the time to duplicate the Arsenal loading for the Trapdoor.

http://www.4570book.info/

Another good book to read is "40 Years with the 45-70"by Paul Matthews.

The first book deals with blackpowder and the origianl 405 or 500 grain bullets (Wolf was the fellow responsible for Lee producing the 405 grain hollow based bullet mold). Matthews writes about a variety of bullets and powders.

While the Trapdoor is quite a bit stronger than most believe, blackpowder is still the best powder for it.

 

[boommer]

Trap The bore on the is on the .460 plus size, next the steel in barrel is softer and rifling is shallower, fire a .457 jacketed bullet would be shooting like a smooth bore. DON,T do that! The cast bullets 300gr are probably are a harder bullet AND WILL most likely not bump up and just strip on the shallow rifling lead up your barrel and also you NEED a bullet that carries enough lube to carry it down the bore. The bullets you should be looking at are black powder cartridge bullets they are of a softer alloy and more lube.

 

[boommer]

Trap the other thing is when your loading low volume powder loads to keep your loads under 18.000 psi you get into fillers with some powders. The thing you need to understand is you have old iron here and the margin for error is less here. I have a trapdoors and reload for many 1900 circa guns and you need to respect what you have and not try to re-event the wheel.

 

[ArchAngelCD]

I agree on the TB as the stuff has a very sharp pressure peak. Its about the last thing I would use in a trapdoor.

Not at all... TB is only dangerous if you break the "donuts" by compressing the powder. If loaded properly it's very safe and will duplicate the pressures generated by Black Powder and it's accurate too. It's actually one of the better powders if you're looking for a smokeless powder replacement for Black Powder considering that's what it was designed to do. I would use Trail boss over Black Powder substitutes any day.

 

[trap1873]

Trap the other thing is when your loading low volume powder loads to keep your loads under 18.000 psi you get into fillers with some powders. The thing you need to understand is you have old iron here and the margin for error is less here. I have a trapdoors and reload for many 1900 circa guns and you need to respect what you have and not try to re-event the wheel.

Boomer, I have read about using fillers but I don't see mention of using them in official publications. Are they necessary optional? I talked to a guy that uses Cream of Wheat.

I would not use jacketet bullets. It sounds like I got bad advice on the 300 gr. Lead and Trail Boss powder. Any suggestions on where to buy the proper cast bullets in 405 gr? Eventually, I would like to get to black powder and casting my own lead. Now is not the time.

 

[Stormin.40]

My trapdoor is also a 1873 model built in 1884. I went down the same road you are and settled on black powder. Black powder fillers (cream of wheat) are different than smokless fillers (light fluffy stuff). Black powder cases must be 100% full and generally better when compressed. Smokeless fillers take up case capacity in order to keep the powder back by the primer with such a large case like a 45-70, these are generally light and fluffy as to not interred with gas expansion.

I purchased my 405 and 500 grain bullets from Penn Bullets. They are sized to .460 and are 30:1 soft lead flat based bullets. You can get them unlubed and he will send you some SPG black powder lube for you to apply yourself or you can get them lubed for smokeless.

My trapdoor shoots 4" groups a 100yards, I used black powder though.

 

[boommer]

Lyman manual notes on filler loads in there Trapdoor loads. I would stay away from fillers you can use powders like Accurate 5744 or Alliant RX7.

www.Buffaloarms.com is a great company to find what you need for these older guns. Lubes like SPG or DGL for black powder also works well with smokeless.
The best advice I can give you on a bullet is a 405gr hollow base at .460 dia.maybe not the best but a good starting point.
Casting is the thing to get into because these big slugs get pricey.

 

[trap1873]

Great advice guys. Thanks. Im learning NOT to be in a hurry. Important to do it right with these old weapons.