Yeah, I'm a bit confused as well.
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Lube on the base of the bullet can contaminate the powder charge, especially if it is a very soft lube and/or the weather is warm causing the lube to soften and infiltrate the powder. Lube on the base can also cause the wad to stick to the base of the bullet and affect accuracy. Wipe the bullet base and use a thin newspaper wad between the main wad and base of the bullet.
Jerry Liles
The thread concerns a cartridge with a grease cookie beneath the bullet, i.e. over the powder. So there must be a wad between grease and powder, regardless of the base of the bullet.
Indeed, which is why it is not a good idea to keep such cartridges fully assembled for months. I prepare case + powder + wad, and only insert grease + bullet just before a shooting session.
No wad on base = no problem.
The essence of my argument with respect to Patrick Villiers' cartridge (NOT a trapdoor, I think?) is that he is using a hollow-base bullet. The first thing that happens when the charge ignites is that the combustion pressure of the powder will ram the wad into the hollow base. It cannot provide any scraper or sealing effect, and will probably detach itself downrange in an unpredictable direction thus causing a slight and unpredictable skew to the bullet.
Please note, this is about hollow-base bullets - in effect minié bullets. How they work and how they react to different hollow depths, various base plugs or none, is a subject on which there has been considerable thought and experiment over about 160 years. A wad directly beneath a hollow base is a total waste of time with a possibly negative ballistic effect.
With regard to holding back, I doubt it. I am moderately familiar with the international BP/muzzleloading fraternity, having participated in competitions in England, France, Germany, Italy and Austria, and find that people are quite willing to discuss how and why they do what. The behaviour of minié-style (hollow-base) bullets has been studied intensively for more than a century. I am also one of the relatively few contributors to use my own name, and am correspondingly unimpressed by hints of secret knowledge possessed by anonymous persons who cannot produce a single competition result to back up their opinions.:D
If I am wrong, let's have names and facts!
OK. then! The fellow who I thought might be holding back has the initials PC. ;)
ETA: which in this case turns out to be "Polite" Chadwick.
BTW, I'm current;y cleaning out a honeybee nest out of a ceiling in my house, since the bees decided to leave. So am overrun with beeswax that needs refining! Have gone from hunter to gatherer not by choice but to beat the scavengers
This leakage effect is exacerbated by compressing the powder charge. In discussions on the BPCR and Long Range Muzzleloaders forums it has been repeatedly stated that compressing Swiss powder can lead to unpredictable ballistic variations (grain crushing?). Tapping down the powder charge when loading, and then no more than about 1/16" of compression seems to be the general opinion.
---------- Post added at 07:07 AM ---------- Previous post was at 07:05 AM ----------
Never met him.
Yes, it´s for the Werder carbine with the smaller case. The main concern (after solving the bullet mould, powder charge, grease cookie and expander problems) was with filling the bullet cannelures with grease. Commercial lube-sized bullets look so much better. I´m coming round to the point where topping the grease cookie with a further cork disk might well be counter productive (can´t see the bullet leaving the barrel with much grease left in the hollow base). Not loading until they´re needed is excellent advice. During the really hot summer, the grease would definitely have contaminated the powder. And exerting too much pressure on the bullet also presses the grease past the cork disk into the powder (I pulled a bullet to find that out), it distorts the bullet AND the case. Compressing the powder with the expander does NOT have much effect on the level in the case, BP doesn´t seem to be all that compressable and the pressure easily distorts the case.
BTW, I never compete (except against myself). It´s just for the fun of the thing.
Well, actually, except for really large bottleneck cartridges like the 577-450 compression of the charge to various degrees seems to produce more consistent results. Some powders seem to require more and others less. Swiss seems to be one that requires less while Goex requires more. If you disassemble some original cartridges you'll find the charge is compressed into a near solid. Of course it is possible to over do it and cause the case to distort from the pressure.
As for hollow base bullets, I agree, don't use a wad. The question I was answering was why wipe the bullet base. Leakage of the lube is not exacerbated by compressing the powder unless you use the bullet to compress as you are seating it on the charge. With the hollow base bullet if your lube grooves are full of lube than the lube cookie isn't needed. The only time I use a cookie is when shooting paper patched bullets (577-450).
I've been shooting BPCR for several years and load for .45-70, .45-90, .50-70, 577-450, and .38-50 in original and modern rifles shooting from bayonet range to 1000 yards. All these rifles performed their best, except the 577-450, with compressed loads and bullets cast to fit the groove diameter of the barrel or (for the Trapdoors) cast of a soft enough alloy and large enough diameter to "bump up" to fill the grooves. You might find some of Croft Barker's books helpful, especially "The Single Shot MIlitary Rifle Handbook." It does not include the Werder (what a fascinating action it is) but does cover his experience with the similar cartridge in the Werndl.
Jerry Liles