Obturation on cast boolits. Trapdoor 45-70

[TheFlynn01]

Hey there folks, was curious about this and wanted to get my head wrapped around it. I recently have acquired a trapdoor 1884 Springfield. I want to do some good shooting with it, and I got the book by Wolf. There is a lot of info in there and I got a the Lee mold he recommended for the 500 Grain flat base bullet. the Lee90577 for those interested. He does recommend others but that one is the most economical to me at the moment.

Now I currently only have access to an indoor range, so I will have to make up smokeless loads to try this thing out. I got some good material made up for the 20-1 lead to tin as he suggests. I am curious to see if these will shoot well, or if the bullet will not obturate properly because it is smokless rather than black powder? Open to advice on how to get some well shooting rounds out of this old rifle.

Thanks for taking the time!

[Larry Gibson]

Spence was replicating 1873 sevice loads which did depend on obturation. However, better results can be had with TDs by not depending on Obturation. Have you read my posts in?

https://castboolits.gunloads.com/showthread.php?190999-My-Trapdoor-Loads-Technique-and-Equipment

[BLAHUT]

soft lead - over size bullets

[badwolf]

I like the 405 lee hollow base bullet and the carbine load in Spence's book

[Gtek]

May I suggest that finding your internal dimensions step one and moving on from there might get you to a success story a little faster. I must ask, you would not touch one BP load off at the indoor just for effect?

[steveu]

I have found.460-461” works best for me. 20-1 shot ok, now using isotope lead.

[Rockindaddy]

Hollow base Lee 45-70 mould sized to .461 soft lead 1-20 works in my 73 Trapdoor Cadet rifle and 1873 Trapdoor carbine. The Springfield 1873 Trapdoor barrels have very deep .462 groove diameters. 25grs of IMR4759 works well too! Also 25grs of 5744 shoots tight groups. I don't shoot black powder in my old metallic cartridge rifles. Hate scrubbing the fired cases and fouled bores.

[Green Frog]

If you're just starting out with reloading, you can disregard Rockindaddy's suggestion to use 4759, it's been discontinued for several years now and even if you could find a pound to experiment with, you'd use it up when you were starting to really do well with it and get frustrated trying to find more. Since similar amounts of 5744 do well for him, and it's still available (I think).

I say this as one who used 4759 in my 45-70 high walls, but that was 30 years ago and it was widely available back then. I loved this powder when it was being sold, but you'd be flogging a deceased equine to try to use it now!

Froggie

[Good Cheer]

Mine was dated 1889 and had a grossly oversized groove diameter.
You couldn't chamber a round loaded with a fat enough bullet.
Going off of memory the loads I used were #457125 of almost straight lead and Unique to fill the grooves.

[ascast]

Unique works OK, start at 8 grns and go up. 462" dia is also a good place to start. rad Larry G's peice.

[TheFlynn01]

Spence was replicating 1873 sevice loads which did depend on obturation. However, better results can be had with TDs by not depending on Obturation. Have you read my posts in?

https://castboolits.gunloads.com/showthread.php?190999-My-Trapdoor-Loads-Technique-and-Equipment

I have not, I am reading though it now. Alot of good info in here, thank you

[TheFlynn01]

If you're just starting out with reloading, you can disregard Rockindaddy's suggestion to use 4759, it's been discontinued for several years now and even if you could find a pound to experiment with, you'd use it up when you were starting to really do well with it and get frustrated trying to find more. Since similar amounts of 5744 do well for him, and it's still available (I think).

I say this as one who used 4759 in my 45-70 high walls, but that was 30 years ago and it was widely available back then. I loved this powder when it was being sold, but you'd be flogging a deceased equine to try to use it now!

Froggie

Well I do have some 5744 so I will start with that. I heard its good for BP cartages!

[Castaway]

steveu, I know what an isotope is and lead has four of them (stable). Which isotope? Exactly what do you mean?

[dondiego]

steveu, I know what an isotope is and lead has four of them (stable). Which isotope? Exactly what do you mean?

I am thinking that he means the lead containers that medical isotopes come in.

[TD1886]

Spence was replicating 1873 sevice loads which did depend on obturation. However, better results can be had with TDs by not depending on Obturation. Have you read my posts in?

https://castboolits.gunloads.com/showthread.php?190999-My-Trapdoor-Loads-Technique-and-Equipment

I'm sure this has been done, but has anyone check their groove diameter and then see what is the fattest cast bullet they can load and chamber and perhaps it may be larger then the groove? I don't own a TD and wish I did, but I have an 1886 and that is what I had to do with my rifle.

[Sgt H]

You can get a pretty good idea of how fat a bullet you can load and still chamber the round. Measure the inside diameter of the neck from a case fired in your rifle. Cases usually contract about .001" after firing and this should give you the max diameter usable. In some cases this still may not be as large as the groove diameter on a trapdoor or so I have heard. That said you can still get soft boolits to obturate with faster smokeless powders. I would suggest nothing slower than 2400 or 5744.

[steveu]

I am thinking that he means the lead containers that medical isotopes come in.
That is correct! It has some antimony. Got some for 50 cents a pound before Covid. Has a bhn around 11.5.

[TheFlynn01]

You can get a pretty good idea of how fat a bullet you can load and still chamber the round. Measure the inside diameter of the neck from a case fired in your rifle. Cases usually contract about .001" after firing and this should give you the max diameter usable. In some cases this still may not be as large as the groove diameter on a trapdoor or so I have heard. That said you can still get soft boolits to obturate with faster smokeless powders. I would suggest nothing slower than 2400 or 5744.

So would that be better than slugging the bore? I heard that the trap doors can be weird for finding the right size because of the three groves.


Also curious on what molds you all might recommend. Reading through Larry's post... It seems some of those molds are hard to find. The Lee molds seem to drop them at around .459 but I am wondering if that is too small for the old trapdoors. Would any of the NOE molds serve well? Just wanting opinions to kick around.

[firefly1957]

My model 1884 was made in 1889 like someone stated above it has a large groove diameter . The groove depth of my gun is .461" I bought the Lee 405 grain .459" hollow base mold it casts at .461" and I pan lube it and shoot it as is . I use two loads in the old gun 55 grains of FG and a charge from a old Hercules booklet for RE-7 todays RE-7 is not the same powder so that information is no longer any good . Both loads should give me about 1150 f/s and the load of Reloader 7 has taken my largest buck yet .

The barrel of my gun was cut down somewhere over the years and does have some bad pits but shoots quite well enough at the lower speed .

[TheFlynn01]

My model 1884 was made in 1889 like someone stated above it has a large groove diameter . The groove depth of my gun is .461" I bought the Lee 405 grain .459" hollow base mold it casts at .461" and I pan lube it and shoot it as is . I use two loads in the old gun 55 grains of FG and a charge from a old Hercules booklet for RE-7 todays RE-7 is not the same powder so that information is no longer any good . Both loads should give me about 1150 f/s and the load of Reloader 7 has taken my largest buck yet .

The barrel of my gun was cut down somewhere over the years and does have some bad pits but shoots quite well enough at the lower speed .

Well thats good to know. I got the hollow point lee and the 500 grain flatbottom lee. So we will see how they drop, and then see how they shoot. I do wanna find a good round nose 500 grain mold. I like that classic look.

[firefly1957]

TheFlynn01 I like a flat point mostly because I hunt with my guns and it has a bit more impact on things. A hollow point is my second choice in cast bullets .

The very small dent that Lee calls a hollow base does not seem it would expand to me, as there is just to much metal around it . I bought the mold for the .459" diameter and was very happy it cast at .461" . I did powder coat some of those bullets and size them at .457" for my Marlin loaded over IMR-4198 at 1900 f/s they shoot under 2" at 100 yards . For that Marlin rifle I ended up going with the Lee 340 grain also powder coated I load them faster then I need here in Michigan but that is why I reload and the load is plenty safe in the gun.

P.S. I first noticed with my 50-3 1/4" sharps that a .509" bullet shoot fine with no leading in the .510" groove diameter barrel this is a 450 grain 50/70 bullet . My Marlin groove depth is .4575" and I had a very old .457" push though sizer on hand from a estate sale I used from the start with great results even at high speeds.

[TheFlynn01]

TheFlynn01 I like a flat point mostly because I hunt with my guns and it has a bit more impact on things. A hollow point is my second choice in cast bullets .

The very small dent that Lee calls a hollow base does not seem it would expand to me, as there is just to much metal around it . I bought the mold for the .459" diameter and was very happy it cast at .461" . I did powder coat some of those bullets and size them at .457" for my Marlin loaded over IMR-4198 at 1900 f/s they shoot under 2" at 100 yards . For that Marlin rifle I ended up going with the Lee 340 grain also powder coated I load them faster then I need here in Michigan but that is why I reload and the load is plenty safe in the gun.

P.S. I first noticed with my 50-3 1/4" sharps that a .509" bullet shoot fine with no leading in the .510" groove diameter barrel this is a 450 grain 50/70 bullet . My Marlin groove depth is .4575" and I had a very old .457" push though sizer on hand from a estate sale I used from the start with great results even at high speeds.


hmmm makes some sense to me. It would be neat to consider hunting as it is something on my bucket list.

I worked up some rounds just to see how things shoot. I am not sure if the results are from Me, the rifle, or my build up.

I shot 10 of each. one set up at 100 yards, the other set at 50.

10 were made up with 500 grain 20-1 over 25 grains of 5744

the other 10 were 405 grain hard cast also over 25 grains of 5744.

The target looks pretty sad, I think it could be me more than anything so I am open to proper shooting advice... but normally my groups are not this big with my 30-30 haha!

You will see there are plenty that didnt make it up onto the target at all! :( prolly me using the sights wrong as they shoot real high... but open to discussion!

316631

P.S. More info for those who might wanna know, I am using the buffington sight peep at the lowest setting. Its my first peep sight, my other rifles being a 94 30-30 and an Enfield no 3.

The double target was something i read about either in Spence's book or online. To aim for the lower one to compensate for the sights! Now, feel free to tease haha

[firefly1957]

Your left and right group looks a lot better then up& down Generally this would not be from a peep sight more of a open sight issue . It is quite possible it is the load I have never used 5744 I have seen others that did very good with it . As I said I used FG Black Powder and OLD Hercules Reloader 7 both loads should be at about 1150 f/s (Lee .459 HB mold) from my shortened barrel but I have never run either over the Chrony.

Does the gun hurt you after a few shots? That can cause such a group ... I did find this link with a internet search about the sight :
https://castboolits.gunloads.com/showthread.php?380702-Buffington-sights

Shortly after I got my 1884 I saw a Buffington carbine sight somewhere and ordered it I never added it because it was to fine to see . A tang sight is a better option if you want accuracy because the sight is closer to the eye.

Your bullets look like that are hitting nice and straight if you can try another powder , good powders are still hard to find in many areas . I have a 4 pound keg of SR 4759 I bought years ago I generally use in the large cases I am not sure why I had not used it in model 1884 . I use it in my 50-3 1/4 " Sharps under the 450 grain 50/70 bullet and get 2" 100 yard groups at 1725 f/s . That load is from a Lyman book

[Larry Gibson]

Try using a Dacron filler [3/4 - 1 gr] over that load of 5744.

[TheFlynn01]

Your left and right group looks a lot better then up& down Generally this would not be from a peep sight more of a open sight issue . It is quite possible it is the load I have never used 5744 I have seen others that did very good with it . As I said I used FG Black Powder and OLD Hercules Reloader 7 both loads should be at about 1150 f/s (Lee .459 HB mold) from my shortened barrel but I have never run either over the Chrony.

Does the gun hurt you after a few shots? That can cause such a group ... I did find this link with a internet search about the sight :
https://castboolits.gunloads.com/showthread.php?380702-Buffington-sights

Shortly after I got my 1884 I saw a Buffington carbine sight somewhere and ordered it I never added it because it was to fine to see . A tang sight is a better option if you want accuracy because the sight is closer to the eye.

Your bullets look like that are hitting nice and straight if you can try another powder , good powders are still hard to find in many areas . I have a 4 pound keg of SR 4759 I bought years ago I generally use in the large cases I am not sure why I had not used it in model 1884 . I use it in my 50-3 1/4 " Sharps under the 450 grain 50/70 bullet and get 2" 100 yard groups at 1725 f/s . That load is from a Lyman book

Well the only other powder I own is 4198. So I could try that. I am just hoping to get a closer grouping if I can. At this point I feel like its a bit of a shotgun spread. Wanna work it into at least Minute of Deer haha


Try using a Dacron filler [3/4 - 1 gr] over that load of 5744.

I saw you mentioned using Dacron in your thread, been reading that over a lot. So i have ordered some and I will do that!

[Carrier]

Well the only other powder I own is 4198. So I could try that. I am just hoping to get a closer grouping if I can. At this point I feel like its a bit of a shotgun spread. Wanna work it into at least Minute of Deer haha



I saw you mentioned using Dacron in your thread, been reading that over a lot. So i have ordered some and I will do that!

I don’t shoot smokeless in my 1873 trapdoor much but when I have I use 27 grains of H4198 under a powder coated 405Lee HB and every shot hits a 12 inch gong at a 100 yards.

[TheFlynn01]

I don’t shoot smokeless in my 1873 trapdoor much but when I have I use 27 grains of H4198 under a powder coated 405Lee HB and every shot hits a 12 inch gong at a 100 yards.

That is pretty cool! I guess I need to learn what to expect from this rifle at 100 yards. What would be a good size target to practice with?

[Carrier]

That is pretty cool! I guess I need to learn what to expect from this rifle at 100 yards. What would be a good size target to practice with?

With my 65 year old eyes it’s getting harder and harder to see that little front sight. I have to aim at just below the bottom of the plate. I also cast the Lee 500 grain pointy one and it does about the same as the 405 HB but passed 200 yards it’s not so good. But then again it is probably me. It’s been in the family since before 1900 so I don’t abuse it much and mostly only shoot black powder in it.
I picked H4198 as it has the lowest pressure of any of the smokeless powders I have but still only rarely use smokeless.
I would use a steel plate 12 X 12 or a little bigger (or whatever size you want) as I like that better than paper as I get immediate feedback and can see where on the steel it’s hitting.

[firefly1957]

I have had good luck with IMR-4198 in lower loads I am a bit confused if H-4198 is currently the same . My can of IMR-4198 is steel and probably from the 1980's at one time I had all the Dupont powders on the shelf to see how they worked in my guns . Some of them I found very useful others were used in Niche loads in soft hell pistol or rifle . IMR - 4198 is just a tad slower then RE-7 if I remember correctly and there is plenty of data for your gun for it .
Hodgdon only has 405 grain cast data: *
Hodgdon H4198 OUT OF STOCK 0.458" 2.540" 27.0 1,251 14,200 CUP 31.0 1,459 17,100 CUP
IMR IMR 4198 BUY NOW 0.458" 2.540" 30.0 1,370 17,000 CUP 32.0 1,462 19,000 CUP

Minute of deer is generally considered a 8" circle at what ever range you can keep your shots in that should be the maximum range to hunt deer at . Shot placement on deer is a issue also I like to hit the upper shoulder rather then the heart lower down the shock to the spine knocks them down right there with these big bullets . Of coarse a deer is a dynamic target in three dimensions so you may not get the classic broadside shot at all . For instance with the modern load I use in my Marlin I had a deer come out facing away from me at 90 yards. There is no way I wanted to damage so much meat as a raking shot would cause . As I held the scope on the deer it turned giving me a neck shot and I took it ,even though I have never trusted a neck shot. The 354 grain soft cast powder coated bullet averaging 2168 f/s (lever action load not trapdoor) dropped the deer right there. On butchering the deer I found the bullet made a larger entrance then exit and passed cleanly between the windpipe and spine it was only the hydraulic shock that separated the vertebrae causing a sudden death .
I followed the bullet path after the deer though two small trees then lost it I would like to have recovered the bullet.


*If you have a Lyman or Lee book check them I have them if you want me to look . They have separate but similar data for H or IMR 4198 on what I pasted from Hodgdon.

[Sgt H]

Flynn if your trapdoor is unmodified and hitting about a foot high at 100 yards is normal. This was the battle zero and enabled the soldier to be minute of man out to a bit over 200 yards at the lowest setting. Many have replaced the front blade with a taller one to be able to zero at 100.

[TheFlynn01]

I have had good luck with IMR-4198 in lower loads I am a bit confused if H-4198 is currently the same . My can of IMR-4198 is steel and probably from the 1980's at one time I had all the Dupont powders on the shelf to see how they worked in my guns . Some of them I found very useful others were used in Niche loads in soft hell pistol or rifle . IMR - 4198 is just a tad slower then RE-7 if I remember correctly and there is plenty of data for your gun for it .
Hodgdon only has 405 grain cast data: *
Hodgdon H4198 OUT OF STOCK 0.458" 2.540" 27.0 1,251 14,200 CUP 31.0 1,459 17,100 CUP
IMR IMR 4198 BUY NOW 0.458" 2.540" 30.0 1,370 17,000 CUP 32.0 1,462 19,000 CUP

Minute of deer is generally considered a 8" circle at what ever range you can keep your shots in that should be the maximum range to hunt deer at . Shot placement on deer is a issue also I like to hit the upper shoulder rather then the heart lower down the shock to the spine knocks them down right there with these big bullets . Of coarse a deer is a dynamic target in three dimensions so you may not get the classic broadside shot at all . For instance with the modern load I use in my Marlin I had a deer come out facing away from me at 90 yards. There is no way I wanted to damage so much meat as a raking shot would cause . As I held the scope on the deer it turned giving me a neck shot and I took it ,even though I have never trusted a neck shot. The 354 grain soft cast powder coated bullet averaging 2168 f/s (lever action load not trapdoor) dropped the deer right there. On butchering the deer I found the bullet made a larger entrance then exit and passed cleanly between the windpipe and spine it was only the hydraulic shock that separated the vertebrae causing a sudden death .
I followed the bullet path after the deer though two small trees then lost it I would like to have recovered the bullet.


*If you have a Lyman or Lee book check them I have them if you want me to look . They have separate but similar data for H or IMR 4198 on what I pasted from Hodgdon.

interesting, I wonder how different the H to IMR 4198 is. 8 inches is a good target size, so I will hope to get a decent group with that. At least at 100 yards. It will give me something to go on. I have hard folks talk about the surprising accuracy with these rifles, so I hope I can get a fraction of that. I want to at least get to the point where I know it is ME and not the boolit or the rifle.

[TheFlynn01]

Flynn if your trapdoor is unmodified and hitting about a foot high at 100 yards is normal. This was the battle zero and enabled the soldier to be minute of man out to a bit over 200 yards at the lowest setting. Many have replaced the front blade with a taller one to be able to zero at 100.

It is unmodified as far as I can tell! Seems to be in standard spec. So I will need to learn where to hold to get it where I want it.

[waksupi]

It is unmodified as far as I can tell! Seems to be in standard spec. So I will need to learn where to hold to get it where I want it.

If you put on a taller front sight blade, and zero at 100 yards, you will find it answers to the sight setting well out to long range.