duplex patching

[Black Prince]

Thanks to badgeredd for an e-mail asking me to report in on this thread.

Fellas, this isn't a big deal and it has been done since smokeless powder was invented. It is NOT anything new, nor is it dangerous to do or I would not do it.

Generally you can safely load up to 15 percent of your total powder charge with smokeless powder. I tend to stay at about 10 percent because all I want to do is make a clean burning load and 10 percent gives me that. You may have to experiment with your loads to see what works best for you. I suggest you START at about 6 or 7 percent.

What I am saying here is that if you have been shooting a straight black powder load of 60 grains, you can reduce that to 54 grains of black powder and 6 grains of smokeless for a total load of 60 grains that you had been loading with straight black powder, but now your load is a duplex one containing both smokeless and black. It should go without saying that you must make sure your load has at least some minor compression so that the smokeless powder does not migrate. We are NOT trying to mix the powder. We are trying to get the fire started quickly with the hot smokeless so the black powder will burn clean and you don't have to mess with stopping and cleaning your rifle while you are shooting.

I have used Bullseye, Unique and 4227 for the smokless powder under the black powder. I like 4227 best because it seems to make the load burn cleaner, but that is a subjective judgement, and you may get different results. I do not use the 15 percent maxium with Bullseye. I use a 10 percent maximum with it and my loads are 7 percent when I use it, which is not often, and only if I run out of 4227. Unique works very well, but I limit it to a 10 percent maximum also.

If you intend to shoot NRA matches, duplex loads are NOT ALLOWED and they do check your loads randomly.

But for general shooting of black powder without the hassle of blow tubing and wiping every 10 or so rounds, using duplex loads let's me shoot as many rounds as I want to without doing anything other than loading and shooting. I've shot 60 rounds without puting a cleaning rod in the barrel and the barrel was about as clean after those 60 rounds as it was after the very first one fired. I believe I could have shot 60 more and the results would have been the same. You will be simply AMAZED at how much cleaner your bore is using smokeless under your main charge of black in any brand or granulation size.

A word of caution here: Using small amounts of smokeless powder in duplex loads is a technique designed to make your loads burn cleaner. That is all. It is NOT to make them more powerful, so don't try to make your rifle a black powder magnum PLEASE. We like you boys and we want to see you stay around here and talk shooting stuff with us and you can't do that if you blow your rifle up in your face.

[catkiller45]

when you guys are duplexing your paper patch loads or
any load for that matter..Are you still compressing the
black powder or just letting it sit atop the wad..And are you using
any type of neck tension to hole the bullet in the case?

Been think of trying it with some 1 f goex I have here,but
wanted to get more of your imput on this..Thanks

[Black Prince]

catkiller

My answer is likely different from others, but I shoot 1.5 Swiss in my 40-65 and it does not need much, if any compression in that particular rifle using that particular load and bullet. I use only enough compression to keep the 4227 powder from migrating and just enough crimp to keep the bullet from being pushed back into the case when I push it hard into the lands. But I can do that because that rifle is a Browning BPCR which has a two tenths of an inch throat or leade in it, and I can seat the bullets out a long way which leaves enough room for the bullet without having to compress the powder.

My 38-55 was done up by Paul Shuttleworth on a 44 1/2 original Stevens action and it does not have that long throat like the Browning , so I have to compress the powder charge a full half inch to get my bullet and wad over the powder charge. I have to put a good crimp on my bullet or it'll migrate forward if left in a cartridge box and that Stevens action will cam it into the lands so hard, it'll shove the bullet back into the case.

For me anyway, the determining factor is how much powder I use (the powder column height) plus the wad plus the seating depth required to have the bullet engage the lands. I always jam the bullet into the lands so hard that if I have to open the breach after that, it is going to leave the bullet stuck in the barrel. Others may not find that to be the best way they get good accuracy, or that they don't like to chance having to knock a bullet out of the barrel with a cleaning rod after jaming it into the lands that hard.

Because the action on the 38-55 is a Stevens 44 1/2, it cams the cartridge forward, so I can really jam that bullet up into the lands with it. I can't do that with the Browning because it is a high wall clone and that breach block comes straight up with little or no no camming of the cartridge. My thumb gets sore pushing those bullets up into the lands using the Browning, so I have to back off jaming them as far as I can with the Stevens. I do use a short starter to shove the cartridges into the lands with the Browning to keep from having the old sore thumb syndrome.

One of the things about this black powder cartridge rifle stuff is the almost infinite number of variables you can use. That can be frustrating when you are trying to work up a load, but as an old fart, I FINALLY learned a while ago to enjoy the journey and not be in a rush to get to the destination. If you could just follow a formula out of a loading manual and have good shooting loads, I don't think it would be nearly as much fun for me anyway. A lot of the enjoyment I get out of fooling with this stuff is trading information and experiencs with you fellas. I have learned so much from hanging out with you boys and also had some good giggles at some of the shall we say UNUSUAL things some of us have done trying to put bullet holes in a dang piece of paper. Anyone reading some of our stuff would think it was important. Heck, I go shoot with some of my buddies who are about as old as I am just to make noise and keep the old farts from falling asleep on the firing line. And don't that black powder smell grand once we start burning it?

All the best to you and let us know how your loads work out in your particular rifle. I just love range reports from you boys like those from Bigted. It's almost like I was there with you looking over your shoulder, smelling that smoke and calling the shot for you looking through the spotting scope while you shoot. I get a kick out of reading them, so keep'em comming all of you boys.

[bigted]

badger...guess i took it by mistake thinking that balck prince had passed on...LOL...glad this is NOT the case. i am really havin a ball with all this and so far the patch to groove has done me rite but i need to try the bore patched boolits as well to see if they will do as good. they should as there is enough blackpowder involved to obturate the boolits into the barrel.

i did try to lube the paper on some of my 420 lymans and it seemed to work well but didnt allow them to set around long so dont know how they would keep in the long run. i lubed them with rcbs case lube with my fingers before loading and wiped them down with a dry towel so they were kinda dry but enough still on em to be slippery when handled.

also i size the case necks just enough to be around .001 inch smaller then the patched boolits so they have a decent neck tension on em for good ignition and burn.

my favorite load by far so far in 45-70 is the 6 grains imr 3031 and 54 grains 2f goex black. this gives very clean burn and adds nothin to the power of the bp that i can see/feel. my patchs splinter into confetti rite at the barrel and the felt wads go around 30 feet where i find them on the ground being burned on 1 side and pristine and clean on the other with the edges in tact which tells me that there is no bypass of gas onto the boolit. any of them so far.

blackprince im glad to see and read from you again. didnt and havnt seen you here for awhile...hope you will stick around for awhile. thanks for the kind words and i also enjoy your posts as well so keep em coming bud.

[Black Prince]

I have not been sick, but I was sick of all the smart aleck remarks that were on this web site sometime back. Any time Brent Danelson comes to a web site, he always brings a bunch of his sycophants with him and they try to take over. I just leave because I KNOW what is going to happen next because he has done that on multiple shooting sites on the web. It is unforunate because Brent is an experienced shooter who knows a heck of a lot about shooting black powder and a lot about paper patching. He could be a great addition to any shooting oriented site but it never turns out that way. He can't help himself and he has just GOT to tell you that he knows everything there is to know about shooting black powder, that he is a PhD, and you should go sit in the corner and shut up. That doesn't sit well with some of us old farts and I am one of those.

Badger says most of the knuckleheads have either left or have been banned from Cast Bullets and all I can say is GREAT, and it's about time. This is supposed to be fun and when it isn't, I am outta here and gone to the shooting range. The good news is that most of the time everyone gets along around here and shares what we know about this stuff and everybody benefits from that. I sure get a kick out of hearing some of the things you boys do and I hope yawl get the same out of some of what I say. At this stage of life, if it ain't fun, I ain't doing it.

All the best to all of you. QUIT sitting there in front of your confuser and get out and burn some powder. I'm headed to the range rat now so I'll catch up with yawl later.

[bigted]

black prince...i enjoy having you here and i understand the fun factor in life. im up in years as well but i refuse to allow the buggers to run me anywhere i dont want to go. thats why i stay and become a thorn in the flesh to the na-speakers. im having a ball with all aspects of cast bullet loading including this fairly new to me paperpatching. i do enjoy throwing out the duplex question on the other sites here and other places just for the small snippets of info i get from fellers that... without the urging to swim upstream... would otherwise keep a lid on their quality answers and findings. as well as those that would not...except for this oppertunity...ask their questions about something that does not happen to be anothers pot of beans so to speak or the mainstream of loading any particular style. folks fail to remember that the erra that the true buff hunters held was fairly short lived...kinda like the rocky mountain fur trade...lasted for what ...15 years maybe? but look at how many follow that erra as well. just has to be understanding with all persuits and if narrow minded folks need a spot to be elitists then i say develope your own spot that specifically allows only talk of like minded folks.

fortunately i find here as on other forums that the mainstream of folks that hang out there are good quality folks with a heart for sharing their findings as well as some of the dangers that maybe missed along the experimenting way. so here is a huge THANKYOU to all those regular shooters that contribute so much to the quality of fun to be found here and other places as well.

i also have a small problem with a few here and other places but they dont provide my oxegen nor do they feed me so i just let em beller and blow then we go on with life and fun and sharing info with each other whether we all agree with each other or not.

so i say this to the goobers that haunt those of us that are still human...beware that we will not allow you to drive us. nor will we set by quietly while you tear someone apart for going against your pre-concieved notions.

now like blackprince...i have a rondevou [spelling] with my loading bench and then the shooting range.

[catkiller45]

so if one is using a duplex load,can he still use the bore diameter
bullet or does he have to use a groove diameter bullet?

Will the duplex cause the black powder to create more bumping
of the bullet or will is stay pretty much the same?

I have heard that one has to use the 548-459 diameter bullet.

My intentions are a .442-.444 bullet....Any remarks about this?

[Black Prince]

so if one is using a duplex load,can he still use the bore diameter
bullet or does he have to use a groove diameter bullet?

CK45

You are trying to make this more difficult than it is. There is no definative answer because it depends on those almost infinite VARIBLES I mentioned earlier. If your bullets are soft enough, you can use bore diameter bullets and they MAY obturate and /or bump up to groove diameter and seal the barrel and they MAY not.

I like to use a bullet that has a nose section that is bore riding and whose base driving bands are one or two thousands above groove diameter. I jam the bullet into the lands so much that the driving bands are well engaged into the lands and the bullet nose section is being guided by the lands on which it is riding. Sometimes the nose section will get light land engraving on it but that is okay. That is the next best thing to a breech seated bullet and doing that gets it started off straight down the barrel. When I recover those bullets after having been shot, the land engravings are down the entire length of the bullet. That means the nose section bumped up at some point down the barrel BUT because it was started straight to begin with, it will shoot straight and mine do.

I have always gotten the best accuracy using that technique BUT I know shooters who don't do that and the rascals are tuff to beat on the firing line. The answer to your question will ultimately be which one of those approaches works best in YOUR rifle with it's particular chamber and the bullet design you are using and the alloy content and the caliber of the rifle and the load you are using and blah, blah. In other words, you are going to have to TRY those different methods to see which one works best in your rifle.

My intentions are a .442-.444 bullet....Any remarks about this

What caliber rifle are you going to shoot that in? What is the bore diameter of it? What is the groove diameter? Those are what SHOULD help you determine what the bullet diameter you will want to start off trying and experiment with bullet diameter by going up from there. If you are going to try shooting a .442 to .444 diameter bullet in say a 45-70 with a bore diameter of 453 or 454, you AIN'T gonna be shooting accurately I can tell you that much.

Will the duplex cause the black powder to create more bumping
of the bullet or will is stay pretty much the same?

I have observed no difference with the loads I shoot BUT some of these other guys who use softer bullets than I do or a hotter load MAY , and you may also using whatever load you shoot. The answer is it all depends.


Don't be afraid to try these different techniques because that is all part of the fun and enjoyment of shooting black powder. If you are the kind of shooter who wants to just load and shoot and expect good accuracy, you will want to shoot smokeless powder or buy your ammo at Wal-mart because IT JISS AIN'T that way shooting the Holy black stuff. It takes a lot more messing with and trying different things to find the right combination of those variables that will work in your rifle. If you are a reasonable loader, you are not going to damage your rifle or blow yourself up. About all you can do that is negative is to work up loads that don't shoot worth a hill of beans and if you have not done that, you AIN'T shot enough black powder yet cause if you work up and try enough loads, some of'em jiss ain't gonna shoot good.

Just don't get discouraged when that happens because it IS GOING to happen and for some of us, it is going to happen again, and some more, and two times twice even after we do it the first time. If it was easy to work up accurate black powder loads, everybody could do it and the very fact that everybody can't do it gives you some indication of the work you have to do in order to get good loads. But to those of us who are crazy enough to love the smell of the smoke from BP loads, we are also crazy enough to keep trying until we get it right.

Hang out here and ask these guys anything you need to and they will help you. Well, we will TRY to answer your questions anyway. Sometimes I think there is no good answer to some of these questions because it always comes down the the old IT DEPENDS thing and there isn't a lot any of us can do about that cause it just depends dang it.

[Nobade]

I have been playing with duplex loads in my 45-70 recently, with quite good results. Using a BACO 545gr. creedmoor boolit, and a Accurate 400gr. flatnose both sized to .442" and patched up to .449". I tried the duplexing, .5cc IMR 4227 under Diamondback FFg to clean up the fouling and it works quite well. The wad stack is a .030" card, a 1/8" lubed felt wad, and another .030" card. Bullet is in the case about .100". With duplexing I don't have to use the blow tube and can fire until the barrel gets too hot to see the sights. I was surprised at how well the small(er) boolit bumped up and shot, it worked just fine.

[Black Prince]

Well thar ya go CK 45. Nobade has worked it out. I knew somema these fellas would. They always do.

And I guess you know that in the discussion about bullet diameters above , I was talking about regular cast bullts using grease groove lube. It does NOT apply to paper patch bullets. Using PP bullets, the bullet diameters you suggested may work fine. I had a brain fart when I saw the big difference in the bullet diameters you were suggesting and the normal range of bore diameters in modern made 45 caliber rifles.

All the best to you and all of you fellas.

[bigted]

i guess the question of compression is just hanging so ill take a stab at it. i ALWAYS compress my bp...goex . i compress enough to adjust the stack for the boolit i wanna use and the grains of powder i plan to use. i have compressed as little as 1/8th inch and as much as .550 inch. the .550 inch compression made my felt wad ring the case where it stopped so i had to re-run em thru my size die to remove the bulg...yep loaded thru the size die! wont hurt anything but isnt something im all that fond of doing...just me!

i find that compression with all three powders i use is very usfull for ignition and dependability. i use goex in cartridge,,,2f,,,and 2f express. i also use a felt 1/8th overpowder wad between the powder and the boolit. this compression with my duplex loads ensures for sure that the duplex smokless dont move off the primer.

black prince...i loaded 5 unique for the duplex loads and 5 imr 4227 for the duplex loads to find out what burns cleanest and maintains the best accuracy...i also find for the imr 4227 powder for the smokless duplex portion of my loads in my 45-70. so clean that the cleanup was 1 ballistol patch brushed back n forth 3 times followed by a dry for taking out the ballistol then an oilly rem oil patch and done...what a treat...im always impressed with the cleanliness of these loads. i shot all 5 of these into a single hole with my browning bpcr with the browning soul sight rear and the spirit level and square post front globe...also a browning sight....this rifle is fast becoming my favorite 45-70 rifle. its pretty with very nice wood and the finish is flawless and the action is silky smooth with an extractor instead of the ejector...what a peach...best money i ever spent i think.

catkiller...like has been suggested...just jump in and find the nitch your rifle likes with the loading it prefers with the boolits it wants to shoot. some will like different things and different loads n such and the only way to dope it out is exactly like your doing...trying stuff out and asking a multitude of questions about your results. also i would admonish taking fairly detailed notes on everything you try as i didnt for the first 1 1/2 years of fooling with this blackpowder thing so i duplicated a bunch of stuff and when i get the same results my mind finally kicks in and i remember that i tryed that already...so now i take small notes on those little sticky pads and when i have a handfull i transcribe them to my shooters book for record and to help me remember where i am from time to time and what did and didnt work.

another thing that is invalueable is changing only 1 thing at a time. when you try two at once then things get muddled very fast... and at least i... will lose track of what im doing so those notes i mention come to my rescue and if ive tryed it then it is written down and if indeed i have a positively new idea it wont be in my notes so this tells me either i spaced the notes and im bound to repeat something with hard won boolits and patching as well as powder n primers that arent getting any cheaper or... it is indeed a new idea to try.

good luck on your persuit and as always i and others enjoy reading about your progress and findings. keep strokin bud

[catkiller45]

For the Black Prince My rifle is a Pedersoli Sharps model,30 inch barrel.I had to have the last 4 inch cut off in order to make it legal for the BPCR silly wet shoots...I have shot tons of cast bullets with black thru it and have had some superb accuracy using lbs of black powder.It is the only rifle I have shot in the past 7-8 years...I love the rifle..When shooting at the range I get lots of attention...My favorite bullets for it are the Lyman bif 500 gr round nose or the 535 grain Postell bullets..But these are all greaser grooved......

So now my quest is the 550 grain paper patch from Buffalo Arms...My bore is 450 and the groove is .4585.....These are pure lead bullets,swaged...That is why I said I was working with the .442-.444 inch dia. bullets...From what some have mentioned,maybe this rifle due to chamber design aint gonna shoot this bullet...I have no idea.

I am going to make a chamber cast,when the stuff gets here,maybe it will come today,you know how the pony express works...So when I do that maybe I will have a better idea of what is going on as far as trying to get it to shoot with any type of consistent accuracy...So far I have used basicly 1 or 2 f goex...One thing I did find out,and that is with the lube cookie I need to was a wax paper over the powder...If using a .022 veg.wad the lube getts wiped out of the bore..With the wax paper wad,I get a lot nice lube star on the end of the barrel...And I can wipe it out with one dry patch..

So this is what I have been doing..I was and am still thinking of trying the duplex load just to see if it makes things come together and better..May it will and maybe it wouldn't..I appreciate all the kind replies..And the ones NOT so kind as well.....John

[Black Prince]

CK45

I have several shooting frens who use those Pedersoli Sharps and the rascals shoot them dang good too. They beat me like a rented mule every chance they get. I had one and liked it. One of my shooting frens had a son-in-law who came out to shoot with us with an H&R break open 45-70. He drooled at our Sharps, but he is a welder with four kids and a sickly wife, so there was no way he could afford one. I remember the days when I couldn't afford things like that, so I packed mine up in the box it came in (It looked new) along with a set of sizing dies, 2000 cast and lubed bullets, wads, bullet moulds, bullet sizing dies, extra firing pins and one extra extractor and sent it to him by his father-in-law. I wish I could have been there when he opened it, but I missed that part. But now we have another shooter involved in the sport and that is a good thing.

Then I started looking for a Browning BPC& R and wouldn't you know it, they stopped making them!!! JUST DANG!!! And that was before Winchester came out with theirs. So I scrounged around on the Internet and found one for sale out in Texas. I bought it sight unseen based on the description provided by the ole boy which proved to be exactly what he said it was. But it was a 40=65 instead of a 45-70 and I thought I would try it for awhile and then trade it on a 45=70 first chance I got. And Like Bigted says, those Brownings are NICE!! And because of the way Browning did the throats on the 40-65 models, I can actually shoot 80 grains of powder if I want to. And mine looks and feels and shoots so good, there is NO WAY I am going to trade it.

It sounds like you are on the right track and with all the black powder shooting experience you have, you actually know more about duplexing than you think you do. I was also a little ancy when I first tried duplex loads and if we are not , then maybe we outta take up golf because messing around with some of this stuff ain't for a klutz to be doing. But after I had shot a hunderd or so rounds with no problems and had those clean barrels and didn't have to mess with blow tubing or cleaning between shots, I was a CONVERT to duplex and I betcha you will like it too. Like Bigted and Nobade says, you get two patch cleaning and you are done, but you get all the accuracy, all the good smelling smoke, all the boom, and all the fun of shooting just like straight black powder. You don't notice any difference at all. At least, I don't.

So give it a try and let us know how it works for you but I wanna warn ya it's just like them dang Lays potato Chips. Once you try it, ya jiss can't quit doing it.

[catkiller45]

I appreciate you kind and thoughtful reply...But that aint helping with my
paper patch shootin...I was hopin you was gonna tell me about your
fern's shootin P P out of their Pedersoli rifles...Guess my chamber cast stuff
aint coming today...I want to make a casting and see what it looks like,maybe
I will be able to figuer it out then..

I have found that if I set the bollet deeper than what others claim I should it will shoot
a better group..And maybe with a duplex load it might perform even a tat better..
But first I gotta patch up some more boolets..

[bigted]

ck...bu deeper do you mean deeper in the case or deeper in the barrel? reasson i ask is that with my 458 ruger the throat is very long and when i load it with the 540's patched to .458 i have to seat them so far out that the boolit is barely in the case .125 inch. they are very tender like this so i have to single load em but that is what the rifle wants for accuracy.

i have a uberti long range express in 45-70 that probably has the same throat as yours but unfortunatly i havnt experimented with it yet...funny thing is that this rifle is the one ive had for the longest...but no paper patch thru it yet...gonna have to fix that i guess.

make a dummy case without primer and neck size it till your patched boolits are snug then start rediculasly long and keep seating in the case a little at a time till the fake loaded case chambers. this is the coal you will get the best results with im bettin....all my rifles respond well to this and i have a loaded dummy for each of the rifles and boolits i play with just so i can look at em before i start loading that particular boolit and powder charge.

[Nobade]

You guys need to be careful to not talk about two different things here at the same time. This is why the forum was split into two regarding paper patching. On one hand some are talking about fitting the throat with groove diameter boolits and on the other we're talking about fitting the bore with bore diameter boolits.

Personally, I don't see the point to groove diameter boolits and black powder. They have to be seated deep in the case and if I am going to do that I'll just shoot grease groove boolits or smokeless powder. But bore diameter boolits and black go together because now you are able to get a lot more powder in the case since the boolit is barely in the case, and you can't do that with smokeless since it won't bump up the boolit and work right. And if you are shooting bore diameter boolits who cares what the chamber looks like? Whatever you put in there is going to chamber if the boolit is the right size. It needs to be able to slide down the whole barrel without resistance. If you make a chamber cast you'll know what the throat looks like but it won't matter a bit since you are going to need to shoot whatever load is accurate in your rifle. Besides that, you can look into the breech of a rolling block and see what you need to know anyhow.

So, let's all agree what type of boolits Catkiller wants to shoot with what powder and then some useful advise can be given. Until then we will spend too much time comparing apples and oranges and it all gets very confusing and not very useful.

My 2 cents for the morning before coffee...

[catkiller45]

Nobade,

FWIW Maybe it's all bull ****..I have been told on here and other forums,unless I am mistaken,that bore diameter bullets may not shot if the chamber is such and such..I can see this point to a certain extent..Like with the bullet way out of the case and the pressure gas's might have a tendency to go around the bullet since it is almost out of the case anyway..Does this make since to you?

It is a very corn fuseing thing to me anyway..Kind of like I have an 243 that will NOT shoot a boat tail worth a damn...Why,I have no fracking idea..

And,I am finding that IF I seat the bore diameter bullet deeper into The case it does seem to shoot better..And the lube cookie HAS to used if I want any accuracy at all..

I can shoot the grease groove bullets with no problem and they are damn accurate as well.BUT,now I am playing with these bore size bullets and it is giving me real fits..Maybe I need to add a thicker wad or wads..Time and bowder will tell...

So maybe I will not post anymore questions about it as it is driving some of you more nuts that it is me tring to make the damn thing work..I think it is sometimes because some of you have no idea what the hell is going on..Any more than I know...

Some people don't even shoot...All they do is read about it and then place a bunch of post,pretending they know something when that don't....

[Nobade]

Sounds like you are in the same boat I was a few months ago! I am shooting a C. Sharps rifle that has about 1/2 inch of freebore in front of the chamber. I also was convinced that bore diameter PP boolits wouldn't work, and had the results to prove it. But then I started using a 1/4 inch stack of lubricated felt wads between two card wads and all of a sudden it would shoot! I tried it again with Wonder Wads, and they were useless. So I went back to homemade, punched to .460" and lubed with Gatofeo #1 lube, and the darn thing shoots great with either the 400gr. Accurate boolits or the BACO 545gr. creedmoor ones. Both sized to .442" and patched back up to .448". It just took a combination of the right wads to seal the throat so the boolit didn't get torn up on launch and enough powder to get the pressure up there where it would bump the boolit properly. (80 gr. KIK FFg or 5gr. IMR4227+75gr. KIK)

I still need to try a grease cookie and see what that does. Mulhern on the BP room says he's using a 3/8 inch grease cookie so I guess sometimes it takes a lot to get it to work.

So, keep at it and find the magic formula and I bet you'll get your rifle to work too.

[XTR]

You guys are confusing me with the .442/.448 demins. The bore on most 45-70s is about .452 give or take .002, and the grooves are about .458 again give or take .002, so you are patching up to .004 less than bore and .010 less than groove to shoot PP over BP and letting the obturation seal the bore?

Sorry if I'm missing something here.

[catkiller45]

No you aint missing nothing,you got it right...The thought is that with smokeless it will not bump the bullet up as much as black powder does....
My bore is .450 inch.So I am experimenting with a smooth sided bullet of .444 when patched it measures at .4505 a snug fit in the bore...

A lot of these guys are shooting them with the bullet seated way out so they can get more powder in the case..But with my rifle I am finding it works just the oppisit..I have to have it seated in the case deeper,there for not allowing as much black powder.That is why I am experimenting with the duplex load...I have a 80 yard range out back the house so I can load a few and go out and test them..I just put 6 into 2 1/2 inch this time..I need the lube cookie or it wouldn't shoot worth ****..And I am also finding out it is a lot more accurate with the 1 F goex than the 2F goex...So much to learn about it...I have also read where the brand of paper used can make a big difference..This I am not sure of.....
I have tried using news paper and also dress patteren paper which is only about .0015 and they both seem to be alright...So if your gonna try it be prepared to have fun..