Home Forums Hunting & Shooting BPCR Chamber pressures in BPCR cartridges

Aye, but I referred to nekkid bullets, not those with undies. I do put the card underwear under my PP though. No hard cast in my life. A friend with a mentioned Marlin CB gun in .45-70 does not use the wad however, his groups better than mine. Might be the Vernier Sight. Or his with cupped bases, something mine will not shoot. Therein may lay an undeciphered clue, suspecting pressure the culprit, mine more than his.

Don't think you missed a boat though, only sabot worth having takes an Abrams to tote it around. Plastic is as plastic does.

This Black Science is simpler and more confusing that Le Smoke, the latter a passing fad no doubt. Sulphurous residue is quite hard and abrasive I hear. The USN got about 100KPSI out of Black once, did that yield a curve or an event horizon?

I am skeptical both ways about leading. If I fold a poor patch or crimp incorrectly, I get leading, yet I'm quite certain that there is no gas blowby based on paper shred/pieces inspection. This would be a looooong smear down the bore. Paper is stout enough that subsequent shot(s) remove it. It has not the character of leading I've seen where bare lead gets torched, seeming to be a random distribution of some sort. Proper sizing of hard alloys has a positive effect though I don't diddle with the Peeestol anymore, having matured somewhat, even if not gracefully at times. Sometimes very soft alloys don't leave evidence for CSI. A .25-20 load I use, albeit with gas check, has trotted upwards of 1500 fps by my reckoning, 1:30 alloy, Lyman 70 grain FN, no smear, no runs, no errors. 5 under a silver dollar at 50. With my eyes.... <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> I've been told by the Master Moulder of these pills they will do near 2000 fps w/o leaving trace, lubed with liquid allox thinned with angel sweat or some such. I shoot them to regulate to 120 year old sights, he has a newer gun, not a century old yet. Or so I understand.

A question just occurred. If low pressure obturates soft lead, it stands that but a few milliseconds on the way the pressure will of course drop below the 'O' threshold. Given lube failure(mebbe) and/or bore dimension variance(quite common) would not a wild conflagaration begin? Bullet smear, gas seal lost, blow by, an almost neverending spiral that leads to dominance of the DNC in American Politics? All the more reason to paper patch I think, to avoid bad leading after good obturation.

Dan <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />

crossfireoops,

Well here we go, son. this time it looks like shooter vs crank. I must preface this post with this observation: The following are my "Observations" those observations come from my own considerable shooting time, they are mine and mine alone no theory or computer programs EXPERIANCE'S. However I do feel that any shooter willing to spend the time on the mat will come to the same "Basic" observations and thus conclusion. I simple have seen this happen too many times.

This wad thing is "Really" a subject that is going to debated forever. i am not trying to convince anyone of anything. I do know however what works at least for me and I am a firm believer that it will work and be the same for everyone.

I use 4 wads in each and every loaded shell. The first wad and this is the first one in the case, is an under powder wad or some call it an over primer wad. This wad is common newsprint and is .003 thick. This for me is one of the best wads I use. this wad lowered my ES by a consistant 10 fps. That is my regular Swiss load without this underpowder wad had an ES of 14fps with this wad my ES is 4 fps. Now does that make any difference what so ever on the target? My thoughts are it damn sure don't hurt! Then after dropping the powder i put on top of the powder another .003 newsprint wad that I color red with a marks a lot. The reason for the color I will explan later. Then I use a .060 LDPE plastic wad. Next is another wad cut from common wax paper found in most kitchens, thinking here is to keep all of those damn wads from taking a trip to the target. Now with the wads in my loads known I will say I could with a little time recover most of the wads after fireing. i have in fact recovered hundreds of them, they don't even go very far down range on average feet and not yds but all could be recovered within at least 30 feet or so. The LDPE wads are absolutly undamged and I defy most shooters to be able to tell a fired wad from an unfired one. I have a few of these I have fired dozens of times just to see if they change in anyway at all. I have cut notches in them, marked them with a lead pencil and in each and every case they are exactly the same fired as unfired. The paper wads are also very easy to find as they don't go as far as the plastic wads. You can even many times see them fluttering down range. I mark the one on top of the powder red so that I can find and identfy them. They are not burned or damaged 99 % of the time. the under powder wad is the only ones I have never found, so I assume they are burned up on igntion.

The only conclusion "I THINK" can be drawn from these "Observations" is the wads sure as hell are not getting molton. On the recovered wads I have never seen any evidence of gas cutting on these wads, but then again I very rarely have any leading at all.

Leading is damn sure being caused by something. i don't know what is causing it but I feel that the wad is not the culprit. So what is?

Gunny

Gunny said:............Well here we go, son. this time it looks like shooter vs crank.

I don't really feal much like I versus much of anybody, ....well, OK.....child molesters, meth people, some political stripes.....but in shooting sport....dialogue with knowledgeable folk......nah.

Can say i've never put a plastic wad down a barrel yet....but you've sure got me thinking....I know that some of the regional bunch are having success with'em.

The wad isn't causing leading.....................no, but wad failure will.

Wad failure = " gas cutting"............and the lead blown off the diameter of a projectile, or plastic sabot, WILL decelerate faster,against atmospheric pressure, than an accelerating projo.........this from Sandia labs, and the skunk works........and that's the "Ironed on" sorta leading.

In that ramble, and I was just rambling.............."I think it was SPG who figured that this stuff was molten, in it's transit down the tube".........................

I have no idea, as to whether the stuff is molten, lukewarm, or popsickle cold................

I run .060 veggie fiber, Walters.........Chip's " Arizona lizard Blood" lube ( A "Dago Red "variation / concoction)....and outside of scorcher days , in timed events, when blow tubing just don't keep up with dryin', ...............I don't have leading problems................period. Ok.......the ocassional "whisker", on a patch ...............and that's about these goofy square bottomed grooves in contemporary barrels ( someone PLEASE........... cut some Metford pattern BPCR barrels).

..............So, if we can at least agree that wad failure is ONE potential gremlin in leading of fine target rifle bores...this dialogue can, and should roll right on in to an exploration of other potential sources of this vile phenomenon.

PWOP ( paper wad over primer) ditto's............we've pretty much found the same, with E.S.'s

I guess it's time to look at alloy composition a bit.A coupla days ago, I was discussing your comments...........about softer slugs leading less..............with "Ceramic media Dave" Maurer.................He agreed wholeheartedly, and sagely nodded that experienced noggin of his...........We also both agreed that antimony wasn't too awful cool in BPCR, and Schuetzen..................With a strong proviso that some of the guys are doin' GREAT , with WW.........

These NASA slug designs, and the recent breakthrough into lubes like Dan T's "White lightning".........probably makin' this a more , and more viable alloy choice.........

"Leading is damn sure being caused by something. i don't know what is causing it but I feel that the wad is not the culprit. So what is? "

....................alloy composition, lube failure, phase of the moon, falure to change one's socks to those that allow one to shoot better................?....................Dunno either,

.........................but it's a damned interestin' subject, ain't it?

GTC

Gunny, from your posts above I construe that you use soft alloys, and your experience parallels my own. Now I don't think wads are immune to mutilation, but I do think that if backed up by full and unfailing obturation they are as leak proof as, well, more than Morton Thiokol's O-rings anyway. I have no basis for the presumption that given little or no obturation, or poorly sized(all in context of hard)er) cast alloys) that such undergarments will get torched, but presume I do. Such in my dogma. I do think there is a world of difference is how bullets get along with barrels, the comparison being between them what's nekkid and them that ain't. Heat has an effect on those au natural, and the powder grains too, I see the grain imprint on the bullet bases most of the time. When you mangle your bullet base the sun may rise in the West. Or elsewhere.

I once experimented with PP round balls, loaded one atop the other. They shot better than I had a right to expect, placing two groups about 8" apart on the target, center of impact centered on the X, groups measuring about 3" each. Looked like two different strings actually. Anyway, patching round balls is a chore, and I have no idea how Seyfried manages to do it so neatly for his bore rifles. <img src="/ubbthreads/images/graemlins/confused.gif" alt="" /> Well, I toyed with them for several months. No sign of blow by there either, at least until I started getting aggressive with the loads. You gotta appreciate a bronze brush when you trip the Chrony at near 2400 fps with one of those. Have no idea where the ball went, it missed a 24"X30" target board at 25 yards. Could be that the Chrony measured paper patch velocity 'cause I think all the lead was left in the barrel. Hooo boy, I ain't goin' there again, no sir.

I do like the idea of your underpowder wad. Never heard that one before, must try it out. Do you perforate the center or just let the primer burst do the trick? <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />

I shall not debate the wad thing either. It works sometimes, sometimes it don't. Your mileage may vary.

.............." more than Morton Thiokol's O-rings anyway. "

Dan, ...........................that is cruel.

GTC

[Quote] "this time it looks like shooter vs crank" <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" />

Pssst... Don't tell Gunny but if he's claimin' to be "just a shooter" he has trespassed onto 'crank' territory (with scavenging for wads to re-shoot)<img src="/ubbthreads/images/graemlins/smirk.gif" alt="" />
<img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

DD: I use a .38 cal wad cutter to make the OP wad with. That diameter nicely drops down into the center if the .45-parent cartridge cases (inner)head nicely.

Didn't mean it to be. Those O-Rings always leak some, mebbe we should invite them to the Campfire? In their world some blow by is accepted, man rated systems or not.

The mistake of STS-51L as I recall was not MT's, it was NASA's decision to commit to launch outside of established launch parameters. We can't be so accepting lest things go astray with each squeeze of the trigger.




I am speechless in awe of your innovation. Wouldn't have occurred to me in 12,000 years.

[DD-Quote;] "I am speechless in awe of your innovation. Wouldn't have occurred to me in 12,000 years"

'Small things for small minds' / 'outta the mouths of babes' and all that $--tt<img src="/ubbthreads/images/graemlins/smirk.gif" alt="" />
(actuallly if you try to fit a disc of paper cut with a .45 punch into a .45-70/90/100, etc. case the inner-shape causes a 'pinch' and you have to poke the damn thing down like a dish) It may/may not center; just trying to save you a step in the learning curve <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />

DD; Speaking of learning curve, you would do well to ask Crossfire to educate you on the proper paper to use on the OP wad. THAT simple step could save you a lot of research also <img src="/ubbthreads/images/graemlins/shocked.gif" alt="" />

looks that this is the "Leading" thread, huh guys? My match rifle a Meacham 45-70 Highwall has never reaqlly had a leading problem. There have been those times when I mined a little lead out of it, but the next day there was almost none. So I don't think I have had a comsistant leading problem. The lead in my barrel has always been easy to remove even on those bad days, with a tight fitting patch soaked in Kroil Oil. Just slivers reaLLy and some lead coming off of a lead bullet sqooting down a steele barrel at I'm outta here speed is to be expected to some degree I think. Lube is a big part of any leading problem I feel but there I once again have always gone with what works for me, SPG is as good of a lube as I need. I shoot mostly in very hot weather, summer time temps almost always over a 105 or so and humidity into the single degits some days. SPG has never let me down and I see no reason to change at this point. I pan lube almost all of my bullets and in the pan lubeing process the lube is "tempered" this is a must step for almost all lubes when you shoot in as hot of a weather conditions as I do. Even the few bullets I use a lube sizer on I temper this lube before it goes into the sizer.

The over powder wads I use are newsprint. I shoot them as punched by me with a hand punch and a hammer. i punch them with a 45 caliber punch and seat them into the bottom of the case with a dowel. Everytime I tried an under size over primer wad the cocked and where a pain in the ass.

The nose slump thing is a real serious problem with the 550 grn or so bullets we shoot. Even a bore rider has a unsupported portion of the nose hanging out there. Probably the best nose profil to shot is a bullet built around the Govt round nose. Trouble is they don't shoot worth a damn. but this bullet with its long nose at bore size and then a sudden round nose, almost all of this bullet is supported, these cast from "PURE" lead should not nose slump. But what the hell difference does it make if they don't slump and still won't hit anything? Lead alloy still needs some work, I am not happy with the 30-1 i shoot most of the time. I am in the process of changing that now and to tell the truth 80-1 shows real promise. It is still castable kinda, no leading at all not even the slivers, and in my Meacham it is very accurate. Now with that said the few bullets I am recovering all have deformed noses. I don't know if this is slump at ignition or that sudden stop when the hit the sand I shoot into. One of those is cool the sand part is after the dance and all of the drinks and that cigarette that says I am fulfilled. The "at ignition" part is before the music starts and you have no idea what is happening next. Shooting will decide what is really going on, a lot of shooting.

Gunny

Must you always pull some new 'trick' from your hat?
WTH; is "tempered lube" <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />

And this goes to support the 'differerent strokes...' thing:

I NEVER have a problem with the .38 wad centering in the .45 case as long as I peek down the mouth and maybe tap an occasional one to center it. I found the .45 wad and the dowel to produce more off-center sets. "Whatever works" I guess... <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

HO,

Tempering of lube is a way to make the lube more heat resistant. Steve Garbe wrote an artical about this 4 or 5 years ago in his mag. i simple remember what i read son.

One of the problems with shooting a soft pliable lube like that required for BPCR is the lube all of them to some extent have the tendency to be so solft that in real temps the lube melts right off of the bullet and contaminates the powder, and also makes this round lube free. Not a good thing. Steve wrote that for hot weather shooting SPG needed to be tempered, kinda like chacolate needs to be tempered. This done in a double boiler fixes the suspension of the ingredants in the lube and makes the lube "VERY" heat resistant. Since I pan lube the actually process of melting the lube for the pan tempers the lube. I noticed long ago that a lot of folks using SPG where having problems with there lube melting in hot weather. I was not having these problems and after checking around some, I found that those who where having problems all used a lube sizer. I tried severeal experaments both with tempered as well untempered lube. I would suggest tryinhg thisd experament for yourself, you will be amazed at the results with fouling control.

Also "HO" your comments about the .38 caliber wads. I have indeed tried this and I just found it to be a pain. The 45 caliber wads once seated with the dowel have never given me a problem at all. I probably have shot close to 60,000 or 70,000 of the things that way. Damn I need to get a life!! Too much time casting and shooting. I'm taking up fishing next.

Gunny

Well I'll be doggoned! Learnin somethin new all the time <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />
I always use a lube sizer as I am all thumbs with pan-lubing (more of that 'ole "shoe fits...." , thingie <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />)
I almost tossed out the SPG 'cause it was so damn messy [but it worked so good] so, instead, I mixed an old personal concoction dubbed 'purple haze' 50/50 and got all the attributes of SPG without the mess <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

PS: If you start a 'fishin, I sure hope you are bettern' me at it <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />
<img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Well, ..............................We use a .40cal punch, and a dowell profiled to fit the inside radius of the case used..

And only with a super secret paper........for OUR PWOPS....

Send a $50.00 money order, and a SASE..........we'll reveal our secret

BWAHHAAhhahhaaa.. ..............must be the heat, in AZ.

GTC

Charmin I'll betcha. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> Always good to keep a supply handy. This is an evolving thread, and interesting. Never dreamed I could turn 5W-30 into 20W-50 with just a stove. Hope the wife doesn't mind the smell.

Imagine what will come with the next topic! <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />

DigitalDan,

Don't knowquite how to take that last post. Are you doubting that this works? Or are you just trying to be cleaver? Now I don't know nothing about turning 5W into 20W, but I do know how to control fouling in extreme conditions. This kind of knowledge comes from remebering what I read and then putting some of that into use. The things that work you keep the ones that don't you don't. Come on guys tempering lube is BPCR 101 for begineers. No dark deep secret here.

Gunny

My remark was in regards to Crossfire's secret recipe for UPW. A joke. You use newsprint, I was speculating in regards to his "secret". OK? <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />

X-fier DOES have a 'secret' (bet on it)... but looks like it's 'a gonna cost someone $50.00 and a SAS envelope to get it tho <img src="/ubbthreads/images/graemlins/smirk.gif" alt="" />

Gunny,

For the problematic wad seating over the primer hole (trapped air), try inserting them BEFORE priming the case.

Guys,
I had the opportunity to watch Michael Rix put some last minute loads together at his loading bench & while loading those newspaper wads, he said that he believed that he ALWAYS got better groups out of those made out of the funny paper section! <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />
Gunny, I have always Pan Lubed, because I don't even have a lube sizer- guess I have been tempering and not knowing it!
I've used SPG, DGL, Black Magic, White Lightening, Michael's Eagle Lube & some of my own BW-Crisco-olive oil+lube guard and they all seem to work fine. But, just out of curiosity Gunny, what is your preferance after sending many a thousand rds. down range? ...Dennis <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />

Gunny,
Sorry, reading back I see that you said that you use SPG & don't look back <img src="/ubbthreads/images/graemlins/blush.gif" alt="" />!!! I did put some Soy wax, avacodo oil & lamb tallow together recently- very clear & slippery. Lubed some bullets, but have not tried it yet- will be back in DC for a few days & will try it out when I get back. ...Hello, my name is Dennis and yes I am a LUBEAHOLIC!