More Springfield Trapdoor Action and a "cold bore" question

[ckpj99]

So many of you may have been following my adventures with my new-to-me Springfield Model 1884 trapdoor rifle.

I got some decent groups with it with Ultramax ammo (about 1.5" at 50 yards) during my first outing. I finally got some time to go test my first batch of reloads.

First, concerning my velocity and POI question ( http://thefiringline.com/forums/show...41#post5942541 ). It appears that at 50 yards with a 45-70 out of a 32" barrel a round traveling at 1200 fps will print HIGHER than a round traveling at 1050 fps. We had concluded that because of the slow velocity and the long barrel that the recoil would throw the slower round higher, however, this is not the case. The faster rounds printed higher.

So my reload for 45-70 ended up being a 405gr hard cast bullet with a flat base made by Oregon Trail (they're called "laser cast," but I don't know what that means). I loaded that bullet over some IMR 3031. I tested 37.5, 38.5 and 39.5 grains with the following results.



37.5 grains - almost 3.5", but notice the low shot (which was the first shot) followed by the two higher shots grouped closer together.



38.5 grains - just about 1.5", again the first shot was low, the second and third shots higher.



39.5 grains - just over 1", sort of the same pattern I've been noticing with other loads.

So now for a few questions:

1) I waited 5-10 minutes between groups (and I did shoot a group of factory Ultramax loads before I started my testing). Would letting the bore cool between shots lead to the first shot being consistently lower than the other shots? Do I need to figure out what's happening with "cold bore" shots and compensate for it?

2) The more I read about reloading for this rifle, the more I think I need to be using soft lead, hollow base bullets to get proper expansion of the bullet in the barrel. However, how much more accuracy could I possibly squeeze out of this rifle? 1" at 50 yards (taking into account that there's some human error there) means this is a 2 MOA rifle with these hard cast loads. Would switching to soft lead and all that help enough for me to notice?

3) Related to the first question, could someone explain how heat affects the typical Springfield 1873/1884 rifle? Does they shoot best warm? Should I expect the accuracy to start degrading after a certain number of shots in a row? I notice the barrel stay A LOT cooler than my 30-30, which was drastically affected by temperature.

Thanks! This old girl is a shooter. I can't wait to get her back out again.

[ckpj99]

One final question - which 3031 load do you think I should test more? 38.5 grains or 39.5 grains?

[ckpj99]

Nobody?

[Clark]

I may shoot trapdoor loads, but I do not own a trapdoor.
My brother does.
He is accurizing it.
The book on accurizing loads for a trapdoor is:
http://www.4570book.info/

That is THE book on the topic, but if it were handed in as a jr high english term paper, it would get a D+.

My brother could not read it and set it aside.
Years later he asked on the internet how to accurize, and posters who read the terrible book gave him the answers.
He went back, held his nose, and the answers where there.

And my brother could read the copy of Kuehnhausen Mausers that I could not read. That Mauser book is junk.

And I could read "The Black Arrow" when I was 14.

What does it all mean?
Wolf's book on accurate reloading for the trapdoor is hard to read, so find a synopsis on line.

[44 AMP]

means this is a 2 MOA rifle with these hard cast loads.

Yes, and ..no. All it really means is that your rifle and those loads is 2MOA in your hands.

Now, that might be the best that rifle and ammo will do, in anyone's hands, or it might not be.

"Softer" bullets might help, or they might not. Each individual rifle seems to have a load that it prefers over others (meaning one combination of bullet & powder will group better than the rest), but what that combination is can only be learned by trial and error in your gun. And the load you gun likes "best" may be a lot smaller group that usual, or it may only be a tiny bit smaller (on average) than other ammo. Again, each gun is different in this, and only shooting will tell.

Another thing to consider is that your old trapdoor wasn't a match rifle when new, and its a LONG way from new. 2MOA from an original blackpowder rifle isn't a BAD thing.

A 2 MOA rifle was always good enough for deer hunting, until the Internet came along....back in those dark days, we worked hard to find rifles and loads that did better than that, and a rifle/ammo combination that shot MOA was a joy, and a fairly rare thing and one that shot less than MOA was a pearl of great price, and not something one got rid of.

Today, reading the Internet, seems like anything that doesn't shoot less than MOA is junk. That's not true, of course, but its the impression I get from what a lot of (un and under-informed) people say.

I shoot those Oregon Trail bullets, they work very well in my guns. (No, I don't know if they actually use a laser to melt the alloy or if its just a trade name).

What I'm trying to say is that your old Trapdoor was built to a different standard than what is expected today, AND it wasn't a target rifle to begin with, and then there is what it has gone through during its life, all of which add together, along with how well the shooter can use the sights, and the trigger pull to make up the "accuracy" of the piece.

Serious black powder shooters will tell you how the alloy of the bullet, and bullet lube play a big part, as well as the powder, case & primer. They go to great lengths to replicate the original ammo. What you (and I) are shooting approximates the original ammo. There is a difference.

As to the loads you tested, either of the last two is worth testing further. A single 3 shot group isn't enough to be sure what the load is capable of.

It is very common for the first shot to be in a slightly different place than following shots. If the first shot is from a clean (oiled), cold bore, the difference can be drastic. That's another thing that will vary from gun to gun.

[Barnacle Brad]

Here is another resource for loading the trapdoor with smokeless powder:

Larry Gibson

The writer met with Spence Wolf and discussed both Spence's work and his own. They were on separate paths - Wolf seeking to replicate the original arsenal loads, and Gibson seeking to glean as much accuracy out of the rifle with smokeless powder.

It appears you are finding success with your handloads. Good job!