When you shoot BP in your Levergun do you clean after a couple of shots?

[Terryrm1-03]

I fired 20 rds of 35gr FF in my 38-40 73 Winchester today. 1st 3 Bullets hit where i was aiming, then the groups went 20" all over the place. Do you clean the bore with a wet patch after a few rounds? Or, why did my groups go to HECK?
Thanks TerryR

[Muddy Creek Sam]

Did you get a lube star at the end of the barrel? During SASS matches I routinely shoot 60 rounds through my 24" 357 Winchester 73. Probably need more lube.

Sam :D

[Muddy Creek Sam]

One other thing, What kind of gun oil are you using?

Sam :D

[missionary5155]

Good morning
Sounds like your Boolits are suffering from modern day design.. lack of lube. That is why custom boolit makers have a whole line of deep groove molds for us BP shooters.
Try smearing the noses of 10 boolits in your loaded cartriges with a real BP lube and shooting those. If acccuracy stays good you need a better BP boolit that carries enough lube. Or just get into the practice of smearing lube on noses..

[NickSS]

It is due to lack of lube or the wrong lube. You need to use a black powder lube not the hard stuff most commercial casters put on their bullets. you also meed large enough lube grooves to hold enough to get the bullet out of the barrel before the lube runs out. Most modern molds do not hold enough lube. If your mold has only one narrow lube groove you do not have enough. You can solve this by either getting another mold or placing a lube wad under the bullet. You do this by first installing a card wad and compressing the charge with a compression die, then press the case moth down on some black powder lube that you poured into a pan the about 1/8" deep. I then seat a news print wad over the lube then the bullet. You should be able to shoot at least one SASS scenario without wiping the bore.

[Terryrm1-03]

Sorry I should have posted about the bullet I'm using. The bullets I bought are Black Dawg 172gr. They have the large groove and are lubed with SPG. I'm going to try to slug the barrel, not sure if its .401. It an original 73 Winchester. Never expected to see 20" groups though. And I'm not joking!
I do suppose the lead is a 15BN. I don't know.
Terry

[Muddy Creek Sam]

Have you tried Balistol for oiling the gun, Regular gun oil will make a gummy mess in the barrel with BP.

Sam :D

[Maven]

Terry, There are several reasons for poor groups from your rifle, but I'm thinking poor bullet fit and a too hard alloy are the main ones. A rough bore, given that it's an original 1873, may also be part of the problem. I shoot a .45-70 Marlin #336 with Microgroove rifling and Graf's FFg and find I must damp swab the bbl. after ~8 - 10 shots if I wish to maintain target accuracy*, even when using a blow tube. The latter is something you may want to try and can easily be fashioned from a length of vinyl tubing. Btw, I tried not damp swabbing and while accuracy didn't exactly disappear, cleaning the bbl. was much more difficult than it was after more frequent swabbing.


*I was using BP lube.

[Terryrm1-03]

Cuts good rifling, bore measures .401 so am I needing a .402 bullet????
Thanks Terry

[SharpsShooter]

Better off with . 403-4" With B P leverguns, I like to shoot the largest diameter that will chamber without excessive force. I also use 40;1 alloy with NASA NP Lube and go 40-50 shots without a hitch.

SS

[Terryrm1-03]

Thanks very much. I was looking at a magma mold 160gr .403-.404. I don't get the star when shooting. the bullets are large groove, SPG. I wipe down the bore after cleaning with bore butter. I have used the blow tube shooting my Tradoor and it does work. I get 3" groups with it at 100yds. figured I'd be able to get this old rifle humming again! This is the FUN part, getting ER done!
Again, thanks for the tips, I'm gonna try to figure out how to slug the throat next, haven't ever done that!
TerryR

[w30wcf]

Terry,
I've had a bit of experience with shooting b.p. from repeating rifles. When everything is right, 30+ shots no problem.....no blowtubing or cleaning........good accuracy maintained.....

First a question......
Were you using real b.p. or a substitute?
If black powder, what brand?

w30wcf

[Terryrm1-03]

Goex FF

[KirkD]

You need to figure out if the deterioration was due to fowling or to leading. If you swab your barrel with a wet cloth and accuracy returns, then it is fowling. But if you swab your barrel with a wet cloth and accuracy is still terrible, then you may have leading happening. If your throat is .404 then I'd try either a softer cast bullet or a larger diameter bullet, but only after I had thoroughly cleaned the lead out of the bore.

[Grapeshot]

I fired 20 rds of 35gr FF in my 38-40 73 Winchester today. 1st 3 Bullets hit where i was aiming, then the groups went 20" all over the place. Do you clean the bore with a wet patch after a few rounds? Or, why did my groups go to HECK?
Thanks TerryR


I have to go with the use of soft Black Powder compatable lubricant and a bullet that is cast from at least 30 to one lead tin ratio.

The lube must keep the BP fouling soft and the bullet must be soft enough to opturate, that is fill the groves when the powder ignites, so you maintain accuracy.

Hard bullets allow gas to blow by the base and allow gas cuting of the lead which will lead to deposits of lead to coat the barrel, destroying accuracy.

Hard modern lubes don't soften the BP fouling and cause deformation of the lead bullet causing accuracy to fail.

When I started shooting BP in cartridge guns, as long as I got a wet lube star at the muzzle I did not worry to much about having to run a wet or damp patch through the bore.

[w30wcf]

Terry,
Under ideal conditions you should be able to get a minimum of 10 shots with Goex
before the accuracy starts to deteriorate. If the bullet carries an adequate amount of lube, many more shots can be fired before accuracy suffers.

I looked at the bullet you are using on Midway. It has a single wide lube groove so it appears that it has adequate lubrication.

I know that the maker claims that the bullet is softer alloy, but I had bought some of the same bullets in .44-40 a couple of years and I checked them for hardness and found they were close to 16 BHN.......definitely not soft as advertised. In addition, there were two distinct grooves down the side of the bullets that were apparently put there by a damaged sizing die.

The bullets were .001" over groove diameter and all in all did not shoot too terrible since they were also damaged......3"-4" groups @ 50 yards. By comparison, the 427098 bullet that I cast from a 12 b.h.n. alloy and are .001" over groove diameter will shoot into 1-1 1/2" @ 50 yards. The firearm used was a newer Marlin with a perfect bore.

Based on the above, I'm thinking that there is either a bullet issue or a firearm issue....(rough barrel / perhaps some erosion)....or both Here's what I would try......

Look the bullets over carefully...especially the bases. Set aside any that don't look well filled out. Load the cartridges with a reduced load of b.p.....say.....28-30grs.
Take some Corn Meal or PSB (Polyethylene Shot Buffer) and fill the case to within about 1/8" of the top then seat the bullet, compressing the filler and b.p.

The purpose of the filler is to act as a gas check that will keep the powder gases behind the bullet (wether too hard or undersized) and allow it to transcend the barrel (even if rough) undisturbed.

If that works, report back and we'll go from there......

w30wcf

[w30wcf]

Cuts good rifling, bore measures .401 so am I needing a .402 bullet????
Thanks Terry

Not with a soft bullet and b.p. since b.p. will bump up the bullet to fit. I would suggest getting a box of the bullets from Buffalo Arms illustrated in your other thread and giving them a try.

Good luck.

w30wcf

[405]

Fouling messing with accuracy? Common issue. You shouldn't have to clean that often if everything is working right. Soft BP fouling can be shot thru and will reach some kind of equilibrium as it affects accuracy. Leading is a different critter and does nothing but get worse once it starts. Might check for leading also.

Unstable bullets? Not uncommon when working up loads. But, 20" groups aren't good and indicate a large booboo. Sounds like wrong bullet diameter. Also, possibly too hard a bullet. May take some measuring and fiddling around with it but you might try the largest diameter bullet that, when seated in the case, yields reliable chambering. A fairly soft alloy like 20:1 is usually a good place to start with bullet hardness. And for bullet weight, try to stay down around 180 gr.

And, one last thing to try would be to put a .030" fiber card on top of powder (when using BP), then seat bullet. I know that using an overpowder card helped greatly in one of my old 38-55s that would occassionally go rogue and spew a bullet into the ozone now and then.

[Terryrm1-03]

I want to thank evryone for all your help and tips. I've documented everything, and getting a proper mold so I can adjust diameter and alloy, and will try the discs.
I really like this forum there's always great help here!
TerryR

[Springfield]

If you'd like to try some Big Lube 38-40 bullets I can ship a small batch in a small Flat rate box for 5 bucks. Worth a try, you won't find anything that holds more lube, and my bullet alloy is very soft. I have shot a 5 stage cowboy match, put the guns away without cleaning, shot another match 2 weeks later and never lost accuracy. Not something I like to do with regularity but it does happen. Some say you don't need this much lube, and they may be right, but I have found it is difficult to have TOO much lube with BP, most of the time.