Paper that DOESN'T work

[thirtythirty]

Hey everyone. Just been playing around with my Mosin and a new mold (lyman 301620) which measures out at about .301 or .3015. My Mosin slugs out at .3125. I had previously (last summer) tried paper patching a lee 309-170 gr boo lit up to about .3135-.314. I had issues with some pretty serious leading. I posted about it and someone suggested using thicker paper. Hence the smaller Boolit today. I pp'd it to .3135 again, obviously, with some thicker paper (loose leaf, about .0025"). I ran into the same issues as previously. I'm wondering if the loose leaf just doesn't have enough integrity to be used? Or is it more likely that there is something wrong (throat erosion????) with my gun.

Thanks in advance for all the input!

[Rcmaveric]

What is the throat diameter, diameter of the lands, and groove? For the .270 Win i size to the diameter of the lands (basically turning the entire bullet into a bore rider) and the patch up to my throat diameter. I also don't patch the entire bullet. Just past the first driving band, so as to not affect my seating depth. I went through a bunch of papers of various types. Haven't gotten my grubby paws on some green bar paper, but i did finally find some tracing paper that worked for me. Size your bullets to your bore then find a paper thickness that will take you up to throat diameter or .001 over groove. I haven't pushed the envelope of accuracy and speed yet. It gave me nice tight groups at 2050 fps over the same load that i normally use for greased bullets.

[OverMax]

There is a tutorial on the many patching papers available found in C/Bs library. Buckshot wrote it.
One die process many over look. i.e. little to no crimping involved and patching paper containing cotton not wood fibers is a suggested.

[Hardcast416taylor]

For my Mosin I cast an RCBS 30 - 180 FN and wrap unsized with wet copier paper. After drying over night I put a light JPW lube on the paper and run it thru my .315 push thru sizer I had made. I tried various papers, but stayed with copier white paper.Robert

[303Guy]

Bore or throat condition could be stripping the patch away. However, that can be fixed.

Before
https://s19.postimg.org/t8z1ww1z7/Rusted_303_bore_006.jpg (https://postimages.org/)

After
https://s19.postimg.org/y3sqv60ar/Pig_Gun_Bore_008.jpg (https://postimages.org/)

The bore is still rough but was handling full power loads delivering 2000 fps with a 194 gr boolit over 44 gr H4350 from a 14.6 inch barrel. I had to cut a bit off to get to 'usable' rifling (it was shortened already). That bore had a layer of scale from chamber to muzzle! And some in the chamber neck which doesn't affect it.

I firelapped it with a brass boolit that I made for the purpose followed by a firelapping cartridge as shown in the next pics.

https://s19.postimg.org/mf0a63jir/Fire-_Lapping_Pig_Gun_014.jpg (https://postimages.org/)https://s19.postimg.org/i5vk3xvoz/Fire-_Lapping_Pig_Gun_015.jpg (https://postimg.org/image/plutpqje7/)https://s19.postimg.org/plutprlz7/Fire-_Lapping_Pig_Gun_017.jpg (https://postimg.org/image/rdnsko5bz/)

There we have grits on top of wheat bran, then a card wad, then valve grinding paste. A patched boolit is then seated over the compound. That boolit needs to be short enough so as not to push back on chambering. The powder charge was H4227.

The paper that has worked is ordinary printer paper. The patched and loaded boolit does need to be lubed though.

https://s19.postimg.org/8e8gqgmir/TAILLESS_PATCH_005.jpg (https://postimages.org/)

[thirtythirty]

303guy

Thanks for that. The bore is definitely not perfect, there is some pitting. I haven't gotten a good look at the throat, but maybe what you're saying is the cause. I haven't noticed the paper "confetti-ing" after I shoot, and the leading is following the rifling (which I think indicates gas cutting?) so maybe that would make sense that the patch is getting stripped. Where did you get that brass bullet? Or would that not be necessary if I don't have scale in the barrel?

In regards to everyone else's comments, thanks. I'll check out that page of paper that works for pp'ing, thats helpful. I checked my Boolit and it is a complete bore rider-the mold is specifically designed for PPIng and therefore the entire Boolit is .301. I sized it correctly for my bore (.3135 for a .3125 bore) But I'll maybe try a tiny bit bigger just to experiment.

Thanks again everyone.

[303Guy]

I made the brass fire-lapping bullets. I measured the throat taper and bore and made the nose ride tight in the bore and the second ring engage the throat taper. The base shank holds a groove that is loaded with grit and seats within the neck so there is no exposed grit. I had a mishap with one - not enough powder charge to expel the bullet and it jammed in the throat. The pressure never did dissipate. When I eventually opened the bolt, the residual pressure tore off the case head. I never found that head but I still have the case body. So I'm very weary of that trick. But it cleaned the rust out of the the deepest crannies.

https://s19.postimg.org/c2jyjuzbn/MVC-565_F.jpg (https://postimages.org/) This one has more bands than necessary.

https://s19.postimg.org/tim9slqf7/20170902_163428.jpg (https://postimages.org/) Here you can see two deep pits that cleaned out just fine.

https://s19.postimg.org/5vrd3iq6b/MVC-445_F.jpg (https://postimages.org/)

I'll be cutting the muzzle back further in due course, to a point where the rifling is still reasonable. I have other rusty bores to play with still. :)

[303Guy]

Just one thing, when using a cast boolit to fire-lap, don't grit the portion being seated in the neck. [smilie=1:

https://s19.postimg.org/9ito10xs3/Fire-lap_round_-_No4_003_(2).jpg (https://postimages.org/)

[thirtythirty]

Ok, so I finally made it home today and was able to check out the throat of this gun. It doesn't look that bad-at least to my unpracticed eye. No rust or obvious pitting. The bore is a bit pitted, but nowhere near what yours looked like 303guy.

I was thinking, would the fact that my bore is counterbored have anything to do with my problem? I slugged my bore and got .3125, however if the last 3-4 inches is larger, wouldn't that allow gas cutting/leading/issues?

[303Guy]

My 'pig gun' gave me bad gas cutting. The bore kept on going rough, hence the grinding paste under the boolit. In your case it may be the boolit is not filling the throat. I size my patched boolits to seat snugly in an unsized neck. The nose portion of the boolit is sized to engage the throat taper as much as possible. This does mean that boolit base get distorted on swaging down into the bore, leaving trailing edges. To solve that I added a small rebate to the boolit bases.

The only factory mold I have is a Lee 180 gr .311 with gas check rebate. It patches up to fit several of my rifle throats but the nose shank is under bore diameter. I've never range tested it though.

Something I have found with one rifle is the boolits enter the bore off centre. Yesterday I fired a jacketed bullet and it was positively canted in the bore, yet the bore is tight and the throat good. I have found a boolit that enters the bore concentrically and I plan on testing this boolit. It's long and fat and contacts the throat/leade at seating depth. For now all I've done with this boolit is smeer it with AutoSol metal polish and fire it into my boolit catch. The bore does need polishing and the polish acts as a lubricant.

I would suggest slugging the muzzle end bore to check for reverse bore taper.

[thirtythirty]

Ok, I tried again with some copy paper that measured .0035". I patched the Boolit from .302 to about .315, which is as large as my gun will chamber. Despite the added thickness (and I think quality) in paper, I still got leading after 6 shots. I should mention that the bullets were seated pretty deeply into the case after chambering, so I guess .315 still might be a little fat. Nevertheless, something is compromising the patch on the way down the bore. I'm away from home again, but next time I'm back I'll try and take some pics of the Boolits and my bore.

[303Guy]

Are you lubing the patches?

[thirtythirty]

Are you lubing the patches?

I put on a little bit of vaseline after the patch had dried.

[303Guy]

One rifle I have is leading with normal patches but seems to be Ok with a boolit lube mix I have. That mix has some carnauba in it plus STP, hard paraffin wax and an extreme grease. It is mouldable and sticky enough to smear a lump onto the boolit base with the idea of lubing the bore for the next shot. I haven't tested this with a string of shots but a with a single shot fired with a lubed bore, the patch survived, cut in strips and there was no leading for a change. With another shot at low velocity, the inner, forward layer of patch was almost whole.

https://s19.postimg.org/ragzog5hf/Sized_1917_5gr_AS30N.jpg (https://postimg.org/image/bozo4htj3/)

[thirtythirty]

Interesting. Where do you get carnauba wax? I'll maybe have to give that a shot. Sorry, dumb question, but what is STP. I looked it up and it looks like a whole line of fuel additives/lubes/etc.

[303Guy]

That would be STP Smoke Stopper engine oil additive. There are other brands of course. It's sticky and slippery stuff and is what I use as a case lube on my lube pad. The carnauba I found online (here in New Zealand).

[thirtythirty]

Ok, I've heard that there are a bunch of people out there using #16 copy paper. Out of curiosity, how thick is that? #20 seems to be about .0035 for me, so I'm assuming .003, or .0025?

[303Guy]

20# paper is .0038 or 0.97 mm. 16# paper is .0032 or 0.082 mm. I get lined notepad paper at 0.067 mm and I've found lined notepad paper, which is tougher at 0.1 mm. Printer paper (20#) is soft and porous while the notepad paper of the same thickness is denser and tougher (notepad paper id denser than printer paper).

I like printer paper because of its compressibility. This makes seating into an unsized neck great. The paper compresses without expanding the neck. To seat, I roll the patched boolit on the lube pad then seat immediately before the lube has time to soak away. It goes in easily (starting by finger then completing by press) and holds tight. I roll the loaded cartridge on the pad for more lube on the exposed patch and on the case - this prevents case elongation and head space separation.

Printer paper is also great for dry patching. It also absorbs more lube which could be a high was lube.

Here is a wax lubed patch that stayed on into the catch medium. It's a low pressure load of course.

https://s19.postimg.org/caudf595v/DSCF8751.jpg (https://postimages.org/)https://s19.postimg.org/gjz3hb4pf/DSCF8749.jpg (https://postimages.org/)

Something you might want to try is plain cast loads or subsonic even with paper patched. Increase the charge until the patch is coming off at the muzzle. In a worn bore, the patch is not cut by the rifling edges and also, the nose shank may be under bore size or not large enough to cut through as my photo shows, so more powder may be required.

[thirtythirty]

Ok, have access to my camera again, so I'll upload some pics. I doubt these will be super helpful, but they're better than nothing. I couldn't really get a good shot of the bore, but suffice it to say that there is leading in there. I think its clear enough to show that the bore isn't super pitted though.

[303Guy]

The bore looks good. Very difficult to get a good shot of the bore though.

I developed a load for a rifle with a well worn bore, starting from low velocity and working up until the patch was coming off the boolit. After a while the gun began to shoot badly so I fired a shot into the 'test tube' and found the patch was no longer disintegrating enough to come off properly. The bore had polished up. So I upped the powder charge.

Perhaps try a series of loads with at different velocities and range test them to see what happens. You might find that at some point leading begins. Also accuracy at different levels would be useful. One of my rifles was leading near the muzzle. I've done some bore polishing and now need to range test.

[303Guy]

The bore looks good. Very difficult to get a good shot of the bore though.

I developed a load for a rifle with a well worn bore, starting from low velocity and working up until the patch was coming off the boolit. After a while the gun began to shoot badly so I fired a shot into the 'test tube' and found the patch was no longer disintegrating enough to come off properly. The bore had polished up. So I upped the powder charge.

Perhaps try a series of loads at different velocities and range test them to see what happens. You might find that at some point leading begins. Also accuracy at different levels would be useful. One of my rifles was leading near the muzzle. I've done some bore polishing and now need to range test.

[thirtythirty]

Thanks. I'm gearing up for another round, and I think I'll try that advice. I'll keep everyone posted! Oh, how did you polish the last couple inches of your bore? As far as I can tell, thats where my gun is leading as well.

[thirtythirty]

Made another round of five Boolits today. I had found that the nose section of the Boolit was actually a tiny bit bigger than bore diameter. I've heard that this is ok, however I've had problems with the 30-30 when this happens, so I choked them down a bit with my "sizer". Pretty much just drilled a hole in some mild steel (19/64, or about .296") and then opened it up with some emery cloth in a split dowel/drill to about .3005 or .301" and pounded the bullets through with a hammer. Then patched with #20 copy paper as previously, however I stayed well back of the ogive-the last time I patched the ogive and the Boolit was seated pretty deep by the action bc of the increased size. Anyways, patched them to .3135-.314. Shot them actually saw confetti! Haven't seen that before! Checked the bore after every shot and it stayed clean. Actually looks pretty shiny. Thanks so much for all your guys' help! Really appreciated it!

[thirtythirty]

Also, used 30 gr of 3031 instead of 10gr of Red dot.

[thirtythirty]

Ok, made up a batch of 40 rounds. 15 exactly as made previously (PP going up halfway from "lube grooves" to ogive, and sized to about .3005). 10 sized with the PP only going up to the "lube grooves". 5 unsized bullets with the PP just covering the "lube grooves", 5 unsized with the PP going up halfway from the "lube grooves" to the ogive. 5 with the lee 309-170 bullet sized to .3005. The results were interesting-I couldn't group any of the sized bullets-I was lucky to have any hit paper at 25 yds (I think 3 made it). the unsized bullets (about .3025) shot better (still not amazing, but 3" or so). The sized bullets with the PP only covering the grooves leaded the barrel slightly (either they got a bit wet, or there just wasn't enough patch I think?) Fortunately, they were the last ones I shot. I think the ones with the PP going up halfway to the ogive edged out the ones with the patch only covering the grooves. I think thats unfortunate, as they seat much deeper in the case bc of the longer patch, and these are already long bullets. I'm not sure how much powder I'm going to be able to put in there before pressure is a problem. I used 30gr of IMR 3031 for all loads.

[thirtythirty]

Am interested in why the unsized bullets worked today, but not previously. Maybe it was the use of a slower burning powder that made the difference, or maybe it was using a shorter patch (if that makes any sense)

[303Guy]

.... how did you polish the last couple inches of your bore? As far as I can tell, that's where my gun is leading as well.
Sorry to take so long to reply to your question. I had to go down and do it again to remember what I did.

Well, I did several things, the first was to fire a special fire-lapping bullet down the bore. That's the one that took out all the rust and scale, even from the deep pits. I'm scared of that that trick because of the stuck bullet in the throat once, under pressure! Ok, the next thing I did was to chamber a lead or PP round (bolt open) then smear a blob of grinding paste into the muzzle and push a small tuft of cotton wool down the bore, onto the boolit nose, so as to leave a layer of the paste all the way down the bore and fire it.

The other was the grinding paste in the meck supported by wheat bran under a card wad then a shorter boolit on top, the idea being that the wheat bran forms a fibrous wad under the grinding paste when fired. The last trick I did and which is what I did again yesterday was to roll a patch of scotch brite abrasive pad on a jag and polish the bore with it.

Yesterday I found I could cut the pad into discs, hold the disc over the chamber mouth and push a naked cleaning rod into the centre of that so that the disc folds back over the rod and fits the bore tightly and push it through. I'd turn the used disc the other way round and repeat then use a new disc.

I also used steel wool on a cleaning brush, winding it tightly and smearing it with grinding paste. That's messy, leaving grinding paste in the action - you don't want that. Pushing a ball of cotton wool down the chamber and out the bore gets rid of grit in the chamber and bore.

Another trick I used is a fat two diameter smooth side boolit, knurled and smeared with AutoSol metal polish. This gets the base shank smeared then seated (a slightly loose fit in the unsized neck) then the long exposed portion of the boolit gets a thick smearing of the polish. Chamber and fire. I sometimes pushed a small cotton wool ball thick with the stuff down the bore first. The metal polish paste 'lubes' the boolit. With this stuff it doesn't matter if it gets into the chamber (in fact, I smear the case with it). All that happens is the fired case comes out polished! Hopefully, the chamber gets a bit of polishing too.

The abrasive pad trick is the one I prefer, polishing as well as removing rust and crud and presumably rounding sharp edges on rust pits. I could feel the resistance lessening as it got shinier. Most of my damaged bores are rough toward the muzzle where leading occurs.

I took photos but for some reason Postimage can't be reached so I'm not able to post those pics.

[303Guy]

Am interested in why the unsized bullets worked today, but not previously. Maybe it was the use of a slower burning powder that made the difference, or maybe it was using a shorter patch (if that makes any sense)

Probably both. Also, the bore might be polishing up a little.

Does that 3031 leave the bore dirty, as in sooty? I use clays for subsonic load testing and it is so sooty. It might be lubing the bore.

There is a trick you might try and that is to put a wad of lube under the boolit, the idea being to lube the bore. It works for jacketed bullets. I get zero copper fouling.

[303Guy]

Photos of the abrasive pads.

https://s19.postimg.cc/dfzu1lrb7/20180414_160617_(2).jpg (https://postimg.cc/image/q7e084133/)
https://s19.postimg.cc/n0jgoj6df/20180414_160635.jpg (https://postimg.cc/image/llhvzt5a7/)
https://s19.postimg.cc/ugiqaeu3n/20180414_160805.jpg (https://postimages.org/)
https://s19.postimg.cc/sbyd9b5bn/20180414_160837.jpg (https://postimages.org/)

[thirtythirty]

Yeah, I think the 3031 is a bit sooty. At least, there was a big black streak on the snow after I finished shooting a couple days ago. Interesting method with the abrasive pads. I've been using brass wool to remove any leading that accumulates in the barrel, so I wonder if that is accomplishing the same thing?

[303Guy]

The brass wool would not polish the steel. My bores are mostly rust roughened, hense my attempt to polish them up. I plan on loading up and taking an interesting gun, a martini 303 carbine on a MkI action with a lightweight sporter stock.

[303Guy]

I've now found that oiling the abrasive pad patches works better. I used ATF which has a detergent in it, for better or worse.

I gave my pig gun the treatment as this was leading with every shot, even low pressure loads. Now it doesn't. The bore even has a shine to it, in a rough sort of way.

[thirtythirty]

I've now found that oiling the abrasive pad patches works better. I used ATF which has a detergent in it, for better or worse.

I gave my pig gun the treatment as this was leading with every shot, even low pressure loads. Now it doesn't. The bore even has a shine to it, in a rough sort of way.

Huh, interesting. I guess there is just a threshold you need to get past then.

Hey, I am preparing to make another batch of cartridges. The last go round showed that bullets that had a larger/longer patch (and therefore were seated deeper by the action) functioned better than ones which had less patching. These bullets are pretty long, and as far as I can tell the base is about equal to the base of the case shoulder. I am using pretty minimal powder loads right now, however am I right in saying this could be a pressure problem if I increase powder charges?

[303Guy]

I did some developments for my ancient carbine which was a Martini 303 carbine barrel on an 1896 Lee Enfield action. Now this barrel is worn like the rifling is rounded and the bore quite large and remember that in those days the bores were cut to tight tolerances. Anyway, I worked up a load by firing into my 'test tube' as I call it, until the patch was coming off at the muzzle. I then took that load out and tested it at 100 meters and I got a pretty decent grouping. With open sights it was something like 1.5 MOA. After a while, accuracy seemed to drop off and I found that the bore had smoothed up and the patch was no longer coming off properly so I increased the powder charge.

I would say that pressure and velocity are closely linked in that both translate into stress between the boolit and bore.

That pig gun I mentioned, I was shooting a 194 gr boolit over 44 grs of H4350 to produce 2040 fps from a 14.6 inch barrel! Pressure was right up there and yet no leading (accuracy not so great though). But once the bore got rough again with fresh corrosion, the patch would fail even with light loads. Same with the carbine even though it was only a light rust in the bore. I wonder about certain primers being corrosive?

[thirtythirty]

I did some developments for my ancient carbine which was a Martini 303 carbine barrel on an 1896 Lee Enfield action. Now this barrel is worn like the rifling is rounded and the bore quite large and remember that in those days the bores were cut to tight tolerances. Anyway, I worked up a load by firing into my 'test tube' as I call it, until the patch was coming off at the muzzle. I then took that load out and tested it at 100 meters and I got a pretty decent grouping. With open sights it was something like 1.5 MOA. After a while, accuracy seemed to drop off and I found that the bore had smoothed up and the patch was no longer coming off properly so I increased the powder charge.

I would say that pressure and velocity are closely linked in that both translate into stress between the boolit and bore.

That pig gun I mentioned, I was shooting a 194 gr boolit over 44 grs of H4350 to produce 2040 fps from a 14.6 inch barrel! Pressure was right up there and yet no leading (accuracy not so great though). But once the bore got rough again with fresh corrosion, the patch would fail even with light loads. Same with the carbine even though it was only a light rust in the bore. I wonder about certain primers being corrosive?

Thats interesting-you were obviously using modern primers, right? Correct me if I'm wrong, but in the past I think it was the mercuric primers that were corrosive, because they formed some kind of salt in the barrel. The modern lead styphnate primers (hopefully?) shouldn't do that. But maybe there are different kinds of lead styphnate? Other ingredients? Was the barrel oiled during storage?

I'm just curious, how deep do you seat your bullets? What is a good rule of thumb (i.e, for seating something too far?).

[303Guy]

The barrels were oiled, yes and modern primers. I've only noticed this rusting with a certain primer. I'm not sure so I don't want to mention brands. One barrel had been oiled and stored for a few years then one shot fired, bore cleaned and oiled the same old way. A few weeks later the bore was rusty! I didn't use bore solvent, just cleaned the bore out with ATF. I checked other bores cleaned a few years ago the same way and they are still fine.

I seat my boolits to no deeper than the internal shoulder junction. I have seated deeper and noticed signs of boolit base riveting. That was with a soft alloy though and with a filler that would compact into a wad so there wouldn't have been equalizing pressure on the side of the exposed boolit. I don't use that filler anymore although it did give good results.

[thirtythirty]

ok, sorry for the stupid question, but is the internal shoulder the upper part of the shoulder where it transitions into the neck?

[303Guy]

The shoulder/neck junction. It's a little further back on the inside but I suppose that's really splitting hairs.

[Old Coot]

303 Guy; The primers you are referring to are the old
"Chlorate" primers found in a lot of surplus ammo (WW2 and earlier for US made, I don't know about British made ammo). They were made with mercuric chloride, and the resulting salts deposited in the barrel are not removed by oil or mineral solvents. The salts are water soluble and can be removed with either old GI bore cleaners or hot water and soap. Follow with drying and oiling the barrel to protect it.
The chlorate salts absorb and hold atmospheric water against the barrel causing the steel to rust. Oiling over the deposits does no good because the oil will not penetrate the water. Older bore cleaners contained water soluble oils which allowed them to flush the salts from the bore. Brodie

[303Guy]

These were brand new primers purchased four years ago. I had bought a 100 pack of them a few years earlier and it was after that I noticed rusting and thought it was something else. Surely modern primers should not be corrosive?

Would bore cleaners like Hoppe's and Sweet's remove the salts? I know that hot water and dishwasher liquid removes rust so maybe that would be a good way to go.

[Old Coot]

Any petroleum based solvent mixture will not remove chlorate salts. Use hot soapy water, and rinse with hot water followed by oiling the cleaned barrel.
To test your primers to see if they leave rust producing salts: Take a 3" putty knife, remove all oil and or grease, polish the blade to a bright shine with fine abrasive paper, fire a primed cartridge into the blade from about one to 3 inches, place the blade overnight in a humid atmosphere (a wet rag at the bottom of a seal able container {ie. tupperware} over night. The next day the blade will show a close shotgun like pattern of rust where the priming compound hit it. The rest of the blade may show some rusting, but if the primer is the cause it will be very apparent.
Good luck , Brodie

[303Guy]

Thanks, I'll try that. My pig gun has a problem in that the suppressor is not removable so the hot soapy water is a problem. Maybe swabbing would get it out. I don't have to use the suspect primers in that gun though.

[thirtythirty]

Ok, so I put together another bunch of cartridges after cleaning my gun from the small bit of leading after the last go-round in the hopes of finding an accurate load, now that I found a system that works. I used the unsized bullets and ran three down the gun with the 30gr of IMR 3031 again just to make sure it still worked. And guess what? It didn't. There was no confetti and the barrel leaded up. I was so confused. I cleaned the barrel again and then sized the bullets down (like .001") and ran 3 through and I got no leading and confetti again, so that was a relief. I then ran 3 unsized bullets through, and then functioned well with confetti. Then I ran 3 through with 34 gr of IMR 3031 and unsized bullets. The first shot confettied, however the second and third did not. And there was a thin and uniform patch of leading all the way around the barrel for what appeared to be the last 7". So, I guess my patch is just failing? I'm only patching 3/4 of the way to the ogive because if I patch further the bullet gets pushed way back into the case when I chamber it. So maybe thats a part of the reason? Any suggestions?

[thirtythirty]

Ok, took some more bullets out today after cleaning the Mosin once again. After firing a couple shots (about 6, with confetti) it started looking like soot coming out instead. There appeared to be some sort of buildup in the barrel, I couldn't tell if it was heavy carbon deposits or light uniform leading. After shooting about 20 more (with increasingly miserable accuracy. Began with shooting at a sheet of paper and by the end wasn't hitting a 2x2' board at 10 yds) I checked the barrel and there was most definitely leading. My question is, is it possible that my load is producing an unusual amount of carbon, which is decreasing the bore size, and thereby shredding the patch as I progress shooting? Is that even possible?

[303Guy]

I don't think so. One of my rough bore rifles leads with just one shot. It's just a fine grey wash, visible by shining a light into the muzzle. Looking down the bore it appears as a matt appearance on the lands near the muzzle. Patches disintegrate with very low charges too. Anyway, that Scotch Brite patch trick pulls out flakes of lead. Now I'm talking about one or two shots.

[thirtythirty]

Hmm, k, thanks. Thats helpful.

[gidgaf]

Interesting. Where do you get carnauba wax? I'll maybe have to give that a shot. Sorry, dumb question, but what is STP. I looked it up and it looks like a whole line of fuel additives/lubes/etc.
For carnauba wax (and other stuff) see "thesage";
wax: https://tinyurl.com/y8gn4a2c
The "OLD" STP mix had a lot of zinc, etc to help keep metal-to-metal contact in a rotating engine minimal. Especially for older engines. Which made it a good bullet lube component. BUT the byproducts of combusting these additives had a tendency to plug up cat converters. Especially for older engines. BTW, if you have a housemate with feminine qualities, "thesage" can afflict you with a ridiculously cute and slightly costly hobbyist. Tho a drop or three of peppermint oil goes a long way in your bullet lube.