Paper Rings and "Short" Brass

[Woodtroll]

Folks,

To follow up on the thread I had going in the Blackpowder category, here is a summary of problems I'm having with one of my rifles:

I have a Shiloh Sharps in .45-2.10 (.45-70) that I am having a fit with, trying to get it to shoot paper-patch bullets.

It always leads a little just forward of the chamber when shooting grease groove bullets with black powder, regardless of alloy, bullet size, lube, or anything else I can think of to try. I wanted to try paper-patch in it for hunting, since I have had very good luck shooting paper-patch in several of my other rifles with smokeless powder. I thought that paper-patch would be a good means of eliminating leading, too, and possibly polish out the bore just a little, if there was a minor imperfection in the bore causing the leading.

When I got this rifle, I did a lead impact slug “casting” of the chamber, and found that it was a little long at 2.118”, with a diameter at the cartridge mouth of 0.482-3”. The transition from the end of the chamber at the cartridge mouth is an abrupt step, almost square, into a 0.460” diameter leade, the rifling starting about 0.050” further ahead.

As in my other rifles, I started with a bore-sized (0.451”) bullet patched up to just over groove size (0.459”). Loaded with a modest charge of SR-4759 that duplicates the velocity of my BP load, I fired ten test shots, and got paper rings on the end of the case and some leading, indicating patch stripping. Most of my cases are around 2.090” long, even though I have never trimmed them. I had always heard that the paper rings, and sometimes lead rings, were caused by cases that were too short for the chamber. After searching my inventory of .45-70 brass which includes WW (which I normally use for BP shooting), RP, Starline, and Federal, I found none that were even a full 2.10”. This left me with brass that, at 2.090”, was almost 0.030” too short in my chamber. Surely, I thought, longer brass would solve my problems.

Several folks offered help, and Montana Charlie pitched in with 20 RP cases that had been stretched to about 2.110”. I thought this would be close enough, and not wanting to go to my storage shed to dig my BP out, I used the same smokeless load of SR-4759. Even though these cases were longer, I still got the paper rings! They were not as thick, but they were still there on every shot. So, I ordered some .45-90 Starline brass, cut it down just until the breechblock scrubbed it in closing, and thought this would be the answer. The Starline brass is a little thicker at 0.011” at the new mouth where I cut it down, and makes a tight load in the chamber (0.459” bullet+0.022” brass walls= 0.481”) Nope, the paper rings were still there. Very small ones, to be sure, but still there! The brass “shrunk” only about 0.003” on firing, so it must have been pretty close to chamber diameter throughout its length already. I don’t see how the brass could be longer and still chamber, so I don’t think too-short brass is my problem.

Two different gentlemen sent me emails that said the rings would continue until I used some thicker brass (0.014-16” walls) and smaller bullets. At this point, it looks like they are right, at least for this rifle. However, I have used this same patched-to-groove-diameter technique, even the exact same bullets, in Marlin 1895s, Ruger #1s, and a Browning 78 with nary a problem or paper ring, and with good accuracy.

I am starting to think that the sharp “step” at the end of the chamber may be responsible for my leading with grease-groove bullets and the paper rings with PP bullets. It is only about a thousandth or so on each side of the chamber, but is still an almost-square, sharp edge. All of my other .45-70s mentioned above have a much more gradual transition into the leade and rifling. Does anyone know of any way to break or soften this edge without damaging any other part of the chamber or rifling? I am considering shooting a few firelapping rounds through this rifle, but really hate to do that to a Shiloh!

My next step is to use some 0.442” diameter bullets that Powderburner sent me, that patch up to 0.450” with the paper I am using. A Lyman neck sizing die sizes the Starline brass down just enough that it will hold the smaller bullets with a light slip fit. I will shoot these with black powder, but will probably try them with smokeless, too, just to see what happens.

If any of you have any further ideas on the paper rings, or how to change the sharp edge in the chamber, I sure would be glad to hear them!

Thanks,
Regan

[docone31]

It sounds like that is perfect rifleing for jacketeds.
However, with cast, or patched, you will need to soften the transition.
Were it me, and as a matter of fact I do this, I smear some valve compound. The fine stuff.
I smear it lightly. Since I only want to 'break' the entry of the rifleing.
That is my method. I use full tilt smokeless loads and it is with small caliber. .303 and less.
I might also try some grit on castings also. Again, not much.
Hang in there, others will provide more also. My information has worked with my smokeless loads. They were on barrels that I could swap out and I was suprised at how effective it was.

[Lead pot]

The rifle barrel is not your problem.
The Shiloh barrel is buttoned rifled and is smoother than any valve grinding compound.
Dont ruin a good barrel shooting that stuff through it.
The rings start right at the 45° chamber end. Thick walled cases will help your problem using PP bullets but you will still at times have a very thin ring but the thick walled brass will not let you chamber a GG bullet.
If your having a problem chambering a round because of the ring you will have to wipe the bore or deep seat the patched round so it has a short jump into the lead, but it will not do your accuracy any good if that ring interferes with the bullet..
There is one way you can fix your problem but I will not go there.


Lp.

[leftiye]

I think the abrupt corner at the front of the neck is probly the problym. Chamfer the corner. I've polished leades, and chamber rims with 600 grit on a tapered dowell. I've also smeared grit (valve grit or diamond lap) on a chamber cast & turned it in the chamber for a similar effect. You could round the corner with the paper, and follow it with the lap. Turn the rifling out of the leade cone and forwards of there.

[montana_charlie]

I have a Shiloh Sharps in .45-2.10 (.45-70) that I am having a fit with, trying to get it to shoot paper-patch bullets.

I did a lead impact slug “casting” of the chamber, and found that it was a little long at 2.118”, with a diameter at the cartridge mouth of 0.482-3”. The transition from the end of the chamber at the cartridge mouth is an abrupt step, almost square, into a 0.460” diameter leade, the rifling starting about 0.050” further ahead.It sounds like that is perfect rifleing for jacketeds.
... Gasp! ...

[1874Sharps]

Woodtroll,

An interesting problem you raise, to be sure. You own a very fine rifle, indeed -- one whose price laughs at my income! Well, I am not an expert on this matter, but I am pretty sure the good folks at Shiloh made and designed your rifle for black powder shooting. That is not to say that smokeless will not shoot just fine in your rifle, but that the leade has probably been cut that way on purpose for BP. I think your problem may be solved if you go with a paper patched bullet that is well undersized such as one that patches up to around 0.451 to 0.454 inches. I have a mold that throws a tapered bullet of 0.448 to 0.442 inches. The patched diameter with 100% cotton 9 lb. onion skin paper is 0.008" more. This generous taper along with the smaller-than-bore size gets my patched bullet beyond the "shoulder" in the leade and I have had no patch stripping with it (with either BP or smokeless loads). To my surprise, this bullet shot well with smokeless powder, too. If your patched bullet is dimensioned thus so that the patch near the nose gets past the leade, I think that would solve your problem. Also, roll those patches really snug on the bullets.

[Woodtroll]

Thanks for the input, folks, I really do appreciate it!

I am going to try the 0.442" bare/ 0.450" patched bullets with BP the next chance I get, to see what happens, but they don't hold quite tight enough in my cases to make hunting rounds. I have not had good luck with crimping PP bullets in the past.

Leadpot, I agree that the bore is not the problem. It is indeed finished very nicely, which is why I am hesitant to even consider firelapping to break the sharp edge. Why mess up the bore to solve a more minor problem? I would be interested in hearing what your "one way to fix the problem" is- would you PM me, please, if you don't want to discuss it here?

I'm still puzzled, though, why this rifle won't shoot the same bullets that other rifles seem to do fine with. The only difference, looking at my chamber slug, is the sharp shoulder at the end of the chamber. I can't think of any reason why there should be a sharp edge there, that is smaller in diameter than the ID of the case when fired?

1974Sharps, I fully understand about the income! I was very fortunate to get this rifle at a great price at a time in my life when I had a little disposable income that I was able to "save up" over a long period of time, just like a schoolboy! Now, with my wife and daughter both in college, those days are gone for me, too!

Thanks, guys, y'all take care!
Regan

[Zeek]

Woodtroll:
The standard throating for the 45-70 consists of a single transition cone from the chamberneck to the bore diameter at 12 degres 45 minutes Basic angle (one-sided). That is the original design for the BP cartridge, as far as I am aware, so the throating in your rifle sounds like a nightmare. The 12+ degrees per side taper may be standard, but is still too steep for my taste. About half that cone steepness would be pretty good.

One solution that would not hurt anything would be to order a throating-only reamer with , say, a 6 degree Basic taper from perhaps 0.475 to below 0.450. That tapered section would then be ~0.12" long, measured parallel to the bore [= 0.025/(2 x Tan 6)]. You could turn that by hand ~~~> stick it into the chamber until it stops on the existing too-sharp throating, mark the reamer next to the rear of the barrel, then make another mark 0.12" further back . . . then keep turning the tool until that rear mark gets to where the first one was and STOP. The throater will not touch the chamber neck at all ~~~> the only place it can touch is the throating area.

That should do it for you. The cone will be gentle enough for paper patched boolits or regular cast boolits and you will be able to seat out your boolit to have a good jam-fit into that gentler leade cone. It will help, when you order your custom throating reamer, to give the maker your measured groove and bore diameters (or include the casting you made).
Regards, Zeek

[montana_charlie]

When I got this rifle, I did a lead impact slug “casting” of the chamber, and found that it was a little long at 2.118”, with a diameter at the cartridge mouth of 0.482-3”. The transition from the end of the chamber at the cartridge mouth is an abrupt step, almost square, into a 0.460” diameter leade, the rifling starting about 0.050” further ahead.

One solution that would not hurt anything would be to order a throating-only reamer with , say, a 6 degree Basic taper from perhaps 0.475 to below 0.450. That tapered section would then be ~0.12" long, measured parallel to the bore [= 0.025/(2 x Tan 6)]. You could turn that by hand ~~~> stick it into the chamber until it stops on the existing too-sharp throating, mark the reamer next to the rear of the barrel, then make another mark 0.12" further back . . . then keep turning the tool until that rear mark gets to where the first one was and STOP. The throater will not touch the chamber neck at all ~~~> the only place it can touch is the throating area.

The procedure described by Zeek sounds like a workable one, but something about it is bothering me. I wish I had a good picture of the tool placed in that chamber to see how it would actually modify the topography.
Unfortunately, I don't have software that sophisticated, nor the skill to use it.

But, the cutter will contact the chamber step (which you say is almost vertical) at the point on the cutter which is .460" in diameter.
That point (on the cutter) will continue to remove metal until you stop going deeper.

Right now, your chamber step is 0.000" long (if it's truly vertical).
Zeek's plan is to move that .460" contact point 0.12" deeper into your chamber throat. That throat consists of a .050" cylindrical freebore and a leade tapered at (probably) 2.5 degrees Basic (5 degrees Included).

After going in 0.12" with that 6 degree cutter, the .460" contact point will be .07" beyond the far end of your current freebore. It will be well into your existing leade. The formerly cylindrical .460" freebore will now be a tapered freebore, with no dimension as small as .460" except at the extreme front end where it meets whatever is left of your original leade.
(groove diameter bullets are going to set ~.10" further out of the case to make land contact, and they will obturate to a diameter measureably larger than .460" to fill the new tapering freebore)

The new throat could not be called a duplicate of an original, as it is only half as steep. And, it would basically 'erase' all vestiges of your current throat, so you couldn't call it a 'modification' of that topography.

If you want a new throat, Zeek's plan might produce one that would do your job very nicely. I'm not saying it would...I'm not saying it wouldn't. It resembles some other discussions I have read lately, although it's a more extreme change (from modern throats) than those conversations describe.

But, if you just want to change the angle of your chamber step to a more gentle one...a cutter angle of somewhere between 45 and 20 (Basic) would probably get it done while leaving most of your current throat intact.

Zeek, if I have this figured wrong, you are welcome to educate me...

CM

[leftiye]

MC, I read it as he wants to put a 6 degree cone at the chamber neck rim without opening up the .462 throat any. I'd measure where the reamer was .462, and make a mark the length of the case head to neck mouth of the chamber (2.118") back from the .462 mark, and ream until that mark was flush with the rear of the barrel. Then maybe a chamber neck diameter (not to open up the chamber neck, just for centering) chucking reamer with a 45 degree entry angle and just break that sharp edge on the chamber neck, then polish. Fat city.

[Lead pot]

Zeek has it down!
Here is another read from the guy that makes these reamers and there are a few others that will grind reamers.
Before you recut your existing throat you must beside just exactly what you want. If you go with a cylinder throat like some of the early Black powder imports had like a Weatherby throat(free bore) or if you want a lead like the originals had that had a taper from the neck wall to the start of the land.
My rifle has a 5 degree tapered lead that is .128 long to the base of the land. This type of lead makes a very smooth transition into the bore and I feel is ideal for a patched bullet.
The chambers in the originals I have a cast for had a 3-1/2 degree tapered lead that is .380 long taper from the chamber wall to the base of the land.
Look down a .22 rimfire chamber you will see this kind of lead still used.

http://www.pacifictoolandgauge.com/pdf/unithroatinginstructions.pdf

This is the chamber reamer I had made for my rifle.
http://i22.photobucket.com/albums/b302/940Leadpot/Kurt44-90SBN.jpg

[Zeek]

The procedure described by Zeek sounds like a workable one, but something about it is bothering me. I wish I had a good picture of the tool placed in that chamber to see how it would actually modify the topography.
Unfortunately, I don't have software that sophisticated, nor the skill to use it.

But, the cutter will contact the chamber step (which you say is almost vertical) at the point on the cutter which is .460" in diameter.
That point (on the cutter) will continue to remove metal until you stop going deeper.

Right now, your chamber step is 0.000" long (if it's truly vertical).
Zeek's plan is to move that .460" contact point 0.12" deeper into your chamber throat. That throat consists of a .050" cylindrical freebore and a leade tapered at (probably) 2.5 degrees Basic (5 degrees Included).

After going in 0.12" with that 6 degree cutter, the .460" contact point will be .07" beyond the far end of your current freebore. It will be well into your existing leade. The formerly cylindrical .460" freebore will now be a tapered freebore, with no dimension as small as .460" except at the extreme front end where it meets whatever is left of your original leade.
(groove diameter bullets are going to set ~.10" further out of the case to make land contact, and they will obturate to a diameter measureably larger than .460" to fill the new tapering freebore)

The new throat could not be called a duplicate of an original, as it is only half as steep. And, it would basically 'erase' all vestiges of your current throat, so you couldn't call it a 'modification' of that topography.

If you want a new throat, Zeek's plan might produce one that would do your job very nicely. I'm not saying it would...I'm not saying it wouldn't. It resembles some other discussions I have read lately, although it's a more extreme change (from modern throats) than those conversations describe.

But, if you just want to change the angle of your chamber step to a more gentle one...a cutter angle of somewhere between 45 and 20 (Basic) would probably get it done while leaving most of your current throat intact.

Zeek, if I have this figured wrong, you are welcome to educate me...

CM
No. The 6 degree Basic throating reamer will contact the ~75 degree (damn near a sharp step, he said) at the BORE diameter of 0.450, and will then ream forward from there, replacing the sharp step with a more gentle 12 degree included angle leade cone.

I do not recall him saying ANYTHING about a freebore (i.e., a cylindrical section of the throating). Instead, he indicated (unless I got it wrong) that he has NO REAL THROATING AT ALL, just an abrupt step from the chamber neck to the bore diameter.

The new throat would have a barely discernable abrupt transition remaining (what is left of the current no-throating sharp step) from the chamberneck diameter to ~0.475" diameter, then would proceed forward on a single 6 degree basic leade cone right into the bore diameter (~0.450). In that way, any boolit or paper patch seated out to touch will contact only that relatively gentle cone. Likewise, because the reamer will not cut larger than 0.475, it cannot do ANY cutting in the chamberr itself ~~>> it can ONLY remove the current too-sharp-a-step throating.

Your last paragraph describes exactly what I am proposing, except using a 6 degree Basic taper rather than the far-more-abrupt standard one for the 45-70 (which, in turn, is much less abrupt than the one he has now).
Ed

[Woodtroll]

Gentlemen,

I work long shifts, and so am away from home a lot, and sometimes don't get to the computer every day, or even every other day. I apologize that I have to "catch up" in fits and spurts.

To clarify some of your discussion- my chamber has an abrupt "step" at the end of the cartridge mouth, which leads into a tapered section that measures 0.460" right at the cartridge mouth, and is of about 0.050" length (I guess you could consider this a small "freebore, although it is slightly tapered and short; I always considered freebore to be a long, cylindrical section but I may not have the concept down pat). This tapered section starts at 0.460" as stated, and tapers into bore diameter (0.458") at about 0.050" down the barrel. I wasn't clear, in my original post, that this section seems to be tapered slightly, and so I ended up confusing at least some of you, I think- my apologies! The rifling starts to show up at this 0.050" mark, and seems to finish at at smallest bore diameter of 0.450" about 0.100" further down the bore. This part, where the rifling reaches full height, is harder to measure, of course, because it is recessed in the "negative" chamber slug.

I am not sure how to measure or calculate the exact angle, but I would bet that this is one constant, gentle taper from the chamber mouth until it runs out into the full rifling. I think the "freebore" is smooth simply because the taper made it so, because it begins a couple thousandths larger than the groove diameter. So, what Zeek is proposing is, I think, exactly what I have, just not carried out quite far enough.

The shame of it is that I do have a .45 rifle reamer bought years ago from Brownell's, which is a gentle taper (the exact angle I have long since forgotten). The problem is that its major diameter, back at the chamber end, seems to be only 0.460", which is what I already have. If it had gone just a few thousandths bigger, I would have been in business!

I'm still pondering all this, trying to decide what is best to do. In the meantime, I have some 0.442" bullets patched to 0.450" loaded over black powder that I am going to shoot the next time my schedule allows.

Thanks again for all the thought and input, folks, I am learning a lot here! Y'all take care,
Regan

[montana_charlie]

This chamber diagram was downloaded from the Clymer site back when it was still active.
It depicts a 45/90 "Sharps" chamber, and a 45/90 "Winchester" chamber is different.
From your stated dimensions, this diagram seems to accurately represent your chamber in all details other than the 'abruptness' of your chamber step.

http://castboolits.gunloads.com/picture.php?albumid=88&pictureid=1325

The pink-shaded are (and corresponding dimension box) depict the .050" 'freebore' you describe. At the end of that pink area, you see the beginning of the ramp of the lands that rise to the full depth of your rifling.
The way you described it is, " The rifling starts to show up at this 0.050" mark, and seems to finish at at smallest bore diameter of 0.450" about 0.100" further down the bore."

Clyner calls that area the 'throat', I call it the 'leade'. You (meaning whoever is reading this) may call it anything you wish.

To the left of the 'freebore' is that sharp angle at the end of the actual chamber which transitions from chamber neck diameter, down to 'freebore' diameter -- .459" in this diagram -- and .460" in your actual chamber. The 0.050" dimensional length of the 'freebore' actually includes the length of that small angle. So, for those who don't like to use 'chamber step' as a discriptive term (and there are some) it's fine with me if you want to call that zone part of the freebore.

The diagram is not drawn to exact scale, so it doesn't look exactly like any chamber/freebore/leade configuration. By inserting correct numbers in the little dimension boxes, a machinist can use a single, unchanging, drawing to cut a wide variety of chambers.
But, it is kinda close to representing an actual Sharps chamber.

It certainly comes closer to depicting Woodtrolls Shiloh chamber than Lead pot's drawing comes to depicting the one he described.
You have to pay very close attention to the listed dimensions in Lead pot's to understand how his chamber must actually be shaped.

The area (in his drawing) called the 'lead' doesn't actually exist, at all, within his barrel...as evidenced by the numbers in the 'u' and 'v' dimension boxes.

But, this is the end of my string in this thread. Arguing over chamber shapes is simply too cumbersome when there are so many differences in the way people use the common terms that describe them.

Woodtroll knows what he believes his problem is, and he has an idea of what he would like to change about it.

I don't have any ideas that are 'better' than his.
CM

[Lead pot]

Here is a chamber cast of a chamber with a chamber end now mostly used except for that long cylinder free bore. It has a 45 degree step into the throat.
http://i22.photobucket.com/albums/b302/940Leadpot/SSFcast.jpg

And this is a cast from an original Sharps Cal. ,44-77 that has the chamber they used for the PP bullets and lead ball.
http://i22.photobucket.com/albums/b302/940Leadpot/Picture_150.jpg
There are no sharp transitions going into the throat to cut paper rings or lead rings.
And this is a cast from an original Sharps .44-2-5/8 ".44-90BN"
Notice the smooth entrance into the throat.
http://i22.photobucket.com/albums/b302/940Leadpot/IMG_0219-1-1.jpg
Seeing a visual makes it a lot easier to explain:):) you have to really look close to see the tapered lead in these pictures.

[leftiye]

Few of 'em are so gradual in their changes of size and direction. Gradual does help with lead boolits though.

[montana_charlie]

That photo of the .44/77 is so clear it even convinced me.

I opened MS Paint and drew a pretty accurate depiction of my chamber...then figured out what it would take to make 'my existing dimensions' work into something closely resembling Lead pot's 44/77 picture.

This is the whole chamber, with pink showing the metal that would need to be removed...without even digging to the existing leade.

http://castboolits.gunloads.com/picture.php?albumid=88&pictureid=1329

And, this is a 'close-up' of the modified area.

http://castboolits.gunloads.com/picture.php?albumid=88&pictureid=1330

The pictures make everything look so 'slick' I may even start looking for a reamer, myself.

CM

[Woodtroll]

An update on my progress and findings, folks. Between my 24-hour-shift job, my second job, and the rain, testing has taken me longer than expected.

I fired a batch of Powderburner’s 520 grain 20:1 Buffalo Arms bullets (0.442” bare, wrapped to 0.451”) with 74 grains of Goex FFg compressed so that about 0.2” of the bullet was in the case, and a 0.060” HDPE wad between. Even with the Starline brass sized down (neck only) in a .45 Colt resizing die, the bullet was a loose slip fit. No paper rings, but accuracy was mediocre, about 4x5” at 100 yards. The inner wrap of the patch remained mostly intact, with slits over the bottom 0.2” or so, but with the top and “tail” (portion tucked under the bullet) remaining intact. So, I thought that the part of the bullet in the case was bumping up to a diameter that allowed the paper to be sliced, but the forward section was not. Maybe, I thought, I needed thinner paper, or maybe a softer bullet, to slit the patches completely and hopefully improve accuracy?

So on the next batch, I used a thinner paper, and the same bullet. The slits got a little longer, but otherwise nothing else changed except that the bullet was REALLY loose in the case with the thinner paper. All right, I thought, I’ll use a softer bullet, that will allow more “bumping”, and hopefully THAT will slit the paper completely.

Luckily, Dean had been good enough to include a few 50:1 bullets with the batch he sent me, so I tried them with the thinnest paper I had, which is an 8-lb. tracing paper. The patches, if anything, were even MORE intact than they had been before, although accuracy got a little better with a group about 2-1/4x2-1/2”. Still no paper rings or leading, though. I chronographed this load, and was only getting an average of 1095 fps.

Just out of curiosity, I wrapped up some 0.451”, 30:1, 480-grain bullets in 9-lb onionskin, with a patched diameter of 0.459”. I placed these in the Starline cases over 63.5 grains of Goex FFg, which was about all I could get in under the bullet (which had to be seated much deeper in the case due to its greater diameter). Only one of these five produced a ring, accuracy was about 2x2-1/2”, and the load chrono’ed only 1040 fps.

Continuing my experimentation, I loaded up some more groove-sized (0.459” wrapped) rounds to try over smokeless powder. I had had little luck with 4759, as even modest loads were leaving rings, stripping patches, and leading the bore, so I tried my old standby of 3031, and decided to use the Starline cases since they were just a little thicker. Due to case capacity with the bigger-diameter 480-grain bullet, I started off with 42 grains. Recoil was noticeable, even though this load is at the low end of most of the heavy-bullet charts. One case showed a little bit of paper ring, but no stripping or leading. The group was about 1” high by 2” wide. I tried a lighter load of 38 grains, with noticeably less recoil, but noted some unburned powder in the bore which had been pretty clean with the 42-grain load. Velocities were erratic with this load, ranging from 1187 to 1326 fps, although the group was decent at 2-1/2” high by 1-1/2” wide.

My conclusions so far are:

1. Even annealed, Starline brass is hard stuff, and left lots of soot on the outside of the case when fired with black powder loads. Although it was about 0.001” thicker in the walls, it seemed the thickness did little for accuracy, but made clean-up that much worse due to the sooting.
2. Relative length of chamber and case may cause paper rings, but they are not the only cause as some have asserted. How quickly the load bumps the bullet, in relation to its position in the bore, also seems to play a part, as a couple of you have suggested before. Cases that were exactly as long as the chamber before firing did not completely eliminate the paper rings.
3. Several folks believe that the paper must completely shred before best accuracy is achieved. I will not argue against this, but to date have been unable to shred the inner wrap of paper with bore-diameter (0.451” wrapped) bullets, even using thin paper and soft alloy. Maybe this is the reason my groups with these loads were mediocre (?).
4. The paper ringing, in general, has seemed to lessen considerably, even when I went back to smokeless powder and groove-diameter bullets. Maybe the sharp chamber edge is starting to wear off, or maybe there was a burr somewhere that is wearing down, even though nothing showed in the two chamber slugs I did.

Next steps are to try the 4759 load with groove-size bullets again, and see if that load still strips the patches as it had been doing. That should tell me if something has changed with the rifle. Also, I want to try some 0.446” bullets, patched with thin paper to 0.451”, and see if that improves patch slitting and group size. Eventually I will try some grease groove bullets again, and see if they still lead. Maybe I will eventually "touch up" that sharp chamber transition.

I’ll keep you posted! Y’all take care,
Regan

[powderburnerr]

pt sure sounds like your bp loads are not bumping up to seal ... hummmmmmm,,,,,,,,,,,Dean

[Woodtroll]

Dean, I don't doubt that you are right. That's why I thought the 50:1 would bump up more, but it didn't make much difference. But, I'm pretty much at the maximum charge I can compress before the case starts to bulge (my case size is VERY close to chamber size), so I'm not sure how to "bump" them any harder.

Thanks a lot, take care!
Regan

[powderburnerr]

it didnt look like you used a lube cookie... while you do not need it for lube necessarily it does act like a piston head and seal the charge helping to build pressure,, and use the paper that will fit the bore snugly . snug bullet sealed chamber =more pressure imho...Dean

[leftiye]

Take the HDPE overpowder wad out of the picture, it cushions the boolit. Or, use 3F (FFFg) black powder to hit it harder. 3f is all I ever use in my muzzleloaders, and I still have to use max loads when I use a 5/16" Feltan blue streak wad overpowder, (cut with a punch to appropriate size, and saturated with Natural Lube 1000) or accuracy suffers.

[Woodtroll]

Dean and Leftiye,

Good suggestions, and I appreciate it. Ironically, I use grease cookies in most of my BP loads, but left them out of these because I was wiping between shots as seems to be the most accepted way for a long string of accurate shots (one wet patch, one dry). Based on past experience, I felt I needed SOMETHING to protect the bullet base from the impact of the powder grains. I'll give this a try, and will go back to thicker paper, but it will be a few days before I can shoot again.

I really do appreciate your patient input!

Take care,
Regan

[Woodtroll]

Well, folks, it took me longer to get back here than I expected, but I have been tinkering away at my BP PP bore-size efforts. I'll try to summarize without getting into too much detail, but if you have questions about specifics, I'll be glad to try to answer. I've also posted a slightly longer version over on the Shiloh board, but am trying to keep this post pertinent to the bullets and load themselves...

If you've read the beginning of this thread, you remember that I first thought that my paper rings were caused by a long chamber and short brass. It turned out to be much more than that... Very generously, one of our board members here gave me a few stretched .45-70 cases to try out, to see if that would help the paper ring problems. It did to some extent, but not completely; the cases were still a little short, and some careful measuring also revealed that the cases, when fully expanded in the chamber at time of firing, had a larger ID than the sharp shoulder at the beginning of the throat, which started at 0.460” diameter. So, if the bullet bumped up completely inside the case, to about 0.462” or slightly more, it had to scrape across this sharp shoulder into that 0.460” leade. After a lot of discussion with folks here and on another site, I decided the most expedient thing to do would be to slightly break that sharp edge. I figured if I could take off just a couple thousandths, that would eliminate the sharp edge, making it “below” the edge of the case mouth and therefore leaving nothing to catch the bullet as it went by. So, I turned out a brass lap with a 45 degree shoulder, made pilots for the bore and chamber, and lapped out a little bit of that edge. Afraid to take off too much, I went very slowly and kept measuring, but ended up with the rear/“big” edge of the chamber/ leade transition at about 0.4635”. This improved things a little, as far as accuracy went, but did not help as much as I had hoped.

I next bought a few Starline .45-90 brass, cut them exactly to chamber length, annealed them, and tried them out. This eliminated the leading and gave me very good accuracy with the grease-groove bullets, partially due also to the thicker case walls, but I was still having some paper rings and mediocre accuracy with the bore-diameter (0.450” patched) bullets. Different alloys, charges, and wad combinations didn’t seem to help much. So, I bit the bullet and ordered 20 cases from Rocky Mountain Cartridge, with thicker walls to make the bore-diameter bullets a slip fit. It took some discussion and reworking of the brass; apparently my chamber is a little tighter at mouth and base, as well as a little longer than the average .45-70 Shiloh. Dave Casey was a little puzzled that his “normal” Shiloh dimensions didn’t quite fit, but he was great to work with, and was very interested in making things work out. I am happy though that my chamber is a little tight, diameter-wise, rather than overly large.

The RMC cases eliminated the paper rings, and improved accuracy somewhat (3-4” groups, mainly), but I still felt like I could do better. I would get a decent group going, and then the next couple shots would really widen the group out. I noticed that the first (inner) wrapping of my patch was usually cut only from the base of the bullet, up to about the mid-point of the shank, making me think that the bullet wasn’t bumping up as completely as it should. I felt I was sneaking up on a good load at this point, but something(s) still weren’t quite right. Acting on advice, I dropped the LDPE over-powder wad I was using, and went back to the grease cookies I had started out with, but that still didn’t seem to bump the bullet completely. Velocities didn’t seem to match what others were getting with similar loads, either. It wasn’t until I was reading a discussion over on the Shiloh board on primers for BPCR, and someone commented that “we really had to boot the old Goex with magnum primers to get the velocity out of it”, that I realized that I was still using “old” Goex FFg (April 1998) that is apparently considerably slower than what is available today. AHA! I thought (again).

So, I increased my load to 76 grains FFg fired with the same Federal 215 primer I had been using, compressed it heavily, put a grease cookie and a thin cork wad over the powder, and seated a 430-gr. 40:1 bullet over it (I had been using 30:1, which has been my standard hunting alloy for a long time). This bullet is from a Hoch adjustable mould I had made years ago, and has much more bearing surface and a more blunt nose that the current match-style PP bullets, so I wasn’t too worried about the nose slumping with the soft alloy. Bingo! The patches were uniformly shredded, no rings, no leading. But, my groups still seemed a little erratic. I found that it was easiest for me to use the blow tube a couple breaths, and then push one dry patch down the bore between shots; this seemed to be something I could do in the field if necessary, and seemed to work fine in my climate.

As I said before, I am a field person, not a bench shooter, and most of my load development consists of field rests or cobbled-up, improvised bench resting. I felt this rifle could do better than I was holding, so I sought advice about what I could do to improve my bench technique with the Sharps. I ended up building me some bench sticks, resting the “null point” of the barrel (which was right in front of the sling swivel on this particular rifle, making it easily repeatable) on the sticks, and firing six shots at 100 yards. The first was a little high, which was normal for this rifle. The next five grouped 1-1/8” high and 3/4” wide, measured center-to-center, with two pair almost in the same holes. AHA! (This time I really meant it- my load development was done!)

So, if you’ve made it this far without falling asleep, I want to say “THANKS!” to the folks who have sent me bullets, patching paper, and cartridge cases to try, and most of all for the patient advice that many have been willing to provide. I am not a new shooter, hunter, or rifle tinkerer by any means, but getting to this point with this particular rifle has been a trying path at times. Some of the questions I have asked here may seem foolish or repetitive to some, but they were an important part of my thought and development process, and I have certainly learned a lot from my experiences and from your advice. I’ve written all this out in hopes that it will save someone else some trouble if they face similar situations.

I still hope to make GROOVE-size PP bullets shoot with BP for field use (without wiping between shots), someday :?.

To each and every one on the board, I wish a most sincere “Merry Christmas”!

Thanks again, y’all take care!
Regan

[docone31]

I made it this far, and it is great information!
Thanks to you.
Keep us posted.

[Lead pot]

This is a before and after photo of one of my chambers and it has solved my problems with paper rings and lead rings caused by that .45 degree chamber end.
This particular throat is a 5 degree taper with a compound cut. at the case mouth it is a 5 degree and the very front is a 2 degree that shapes the lands or keeps them at the original taper that the rifle came with.
The original 1878 Sharps Creedmoor I had a cast made of had a lead that was a little flatter than I wanted, it had a 3.5 degree tapered lead that was longer than I wanted but would have made a very good throat for a guy wanting to shoot a PP bullet at groove diameter.
The 5 degree taper bottom cast is .128" long.
I have a reamer for the .40-70SS with a 4 degree, that has a taper .243" long.
If you guys are thinking about re throating your fine rifle think very hard on what you want to end up with because once you re cut that throat you cant put metal back on.
The chamber you new have will work very good as is but you will at times have to get a problem worked out.
The .45 degree step is ok for a grooved bullet but a PP it raises hell but again it will shoot them very good also.
So is it worth the effort that choice is yours.


http://i704.photobucket.com/albums/ww43/Kurtalt/IMG_0254.jpg

Here is a photo of a PP bullet shot with 5744 smokeless powder in a 45-90 74 Pedersoli Sharps.
I just dug these bullets out a few days ago to see for my curiosity to see what a bullet looks like using smokeless powder with a PP bullet that was patched @ bore diameter with a card wad over the powder 1/8" lube wad and a card under the bullet and the alloy was 1/18.
You people wondering why you are getting a lead mine in your bore using smokeless. That 45 degree chamber end is not all of the fault.
Just look at all of the gas cuts on this bullet shank.
If you want to take a really close look hold down CTRL and hit the + and enlarge it to about 500 or 600.

Kurt

http://i704.photobucket.com/albums/ww43/Kurtalt/IMG_0293.jpg


I just caught an error I forgot to add.
Before somebody jumps on me for using wads with the smokeless load. I used cotton stretched out to make sure the card and lube did not work down below the bullet base.
Bad error that I forgot about the filler.
Sorry.

Kurt

[Woodtroll]

Hello Kurt,

Thanks for the post. I had wondered what a compound angle in the leade and throat would do. If the lapping had not worked well for me (just to break the edge), I was going to cut a 5 degree angle or so at the rear of my 3-degree throat, just to open up the diameter right ahead of the case. Now I won't have too, though, but thanks for assuring me that that would have worked.

I mentioned early in this thread that I had fired ONE bore-sized PP bullet with smokeless, just to see what happened, and that I would NOT do that again! Your pictures prove why. I am perfectly happy with the groove-size PP bullets on the rare occasions I still shoot smokeless PP.

I really applaud you, and Montana Charlie, and some of the others that can dig these bullets out of snowdrifts, and take the time to show us what happens with them. I don't have that option (the best I can do is a clay bank that always expands the front half or more of the soft alloys I shoot). I have really learned a lot from y'all's posts and pictures, and my results are a direct testimony to what y'all have taught us!

Take care,
Regan

[windrider919]

Very interesting thread as I used to have a ring problem too as discussed on a previous thread over a year ago. I had my barrel shortened one thread and re-chambered with a tapered leade but that ended up .463 dia. I should mention that I shoot .458 WinMag and 95% of the time I shoot using smokeless / PP. I went to the WinMag because I wanted a bolt action big bore. I shoot at reduced loads keeping the velocity around 1600 to 1800 FPS. The .458 case is 2.5" Max OAL, the 45-70 = 2.1”, 45-90 = 2.4”, 45-100 = 2.6 so I load to the 90 specs. I use a 460 gr 30:1 bullet with 60gr H4895. ( This load is safe in my rifle but proper load development should be done in any other rifle. I'm not responsible for what you do.) Anyway, before I re-chambered I used to get rings 3 out of 5 shots, after re-chambering the problem went away, even with brass trimmed to 2.490.

What was interesting was leftiye's comment on not using the PE wad. In my rifle, with smokeless, a wad tightens my groups about 1/2"! To show the difference between BP and smokeless, I found nothing worked to get accuracy with bore size bullets and smokeless. But after lots of experimentation I found that sizing my PP bullet/paper to fit in the THROAT dimension of .463 reduced groups considerably. The bullet is .454 with a double wrap of 100% cotton rag paper to .462. I also use a 1/4 strength solution of water soluble Rooster lube to wet the patches for rolling. Cases are neck sized to an ID of .459 so the case neck tension does not 'crush/size' the bullet. Seating depth is 0.200. I use a taper crimp die to take out the case mouth flare to just straight, no crimp as it destroyed accuracy.

From the bench (rifle in the sled/sandbags, I'm only touching the trigger) I get groups of 1 1/4" all day and if I do everything right I have gotten 5 shot groups of 3/4". The point is that only when I upped the bullet diameter to fit the chamber throat did I go from 3" or 4" groups to 1" groups. Note that pressure is still less with PP bullets at .462 than a 450gr, .459 GG bullet using the same powder n load.