Cast boolit weight

[43spanish]

I cast some soft lead (reclaimed lead roof vents) boolits with an RCBS 44-370-FN mold for my 43 Spanish. I expected them to weigh about 370gr but they weigh 404gr. What am I missing? Secondly, my rifle bore is .440 - .442. Would it be OK to fire these without sizing them down to see how they perform?
Thank you.

[kungfustyle]

Boolit molds are made to cast at a certain weight with a certain alloy. Lyman (iron) molds are designed for the Lyman #2 alloy aka 90/5/5 lead/antimony/tin and NOE's are designed after clip on wheel weights. So your yield is just about right. Just use the data for a 400g boolit and you'll be OK or start at the starting load of the mold design and slowly work up.

[trails4u]

I'd say the weight difference is maybe based on using dead soft lead..... As for the sizing, I wouldn't hesitate to shoot them and see what happens. I have, and use, the same mould for both rifles I own in .43 Spanish. YMMV.

[RedlegEd]

Hi. The density of pure lead is more than an alloy, so a bullet cast from it will weigh more than a binary or tertiary alloy. I believe Lyman mould bullet weights are based on the Lyman #2 alloy (95/5/5,) and I'm guessing the RCBS mould bullet weight is also based on an alloy other than pure lead. As for sizing them, what is the as cast diameter? With soft lead, you can safely shoot a soft bullet .002 - .005" over groove diameter. Hope this helps. Ed

[earlmck]

Your soft lead is going to run about 4% heavier than a boolit cast from Lyman #2 metal and about 6% more than one made from Linotype. So that's where some of the extra weight comes in -- RCBS is expecting you to use some alloy lighter than pure lead. But that doesn't explain all the extra weight -- your mold is going to throw a boolit closer to 380 or 385 even with a harder alloy. Just tolerances of mold making by the big guys.

And the test for whether safe to shoot isn't how much oversize the boolit is for the bore. Lead and lead alloys squeeze down real easy when they need to go through a smaller bore. The test is how the cartridge chambers: you want the chamber large enough that it doesn't interfere with releasing the boolit from the brass case at the moment of firing. If your cartridges loaded with unsized boolits chamber easily without binding at the neck from the oversized boolit then you are good to go. If chambering is difficult because of tight fit at the neck, don't shoot them -- size them down until they fit nicely in the chamber.

[43spanish]

Ok, I used a jewelers scale to weigh the boolits on the gr setting. Grains, I presume. The cast boolits mic .445. I’m ok with them being long because they won’t be seated very deep in order to be near the rifling. Now I will place one in an empty case and check the chamber fit. Thank you all!

[43spanish]

Ok, I used a jewelers scale to weigh the boolits on the gr setting. Grains, I presume. The cast boolits mic .445. I’m ok with them being long because they won’t be seated very deep in order to be near the rifling. Now I will place one in an empty case and check the chamber fit. Thank you all!

[43spanish]

The cast bullet fits very snugly into a fired case and chambers freely. The rifling marks on the bullet when I pushed it fully into the chamber are .12 inches long. Should I then seat the bullets an extra .15 inches deep? Seems nice that I can seat a bullet without resizing the case mouth.
250748

[43spanish]

The rifling scuff mark is visible in the pic.

[43spanish]

Pouring 76 grains by weight of Goex FFg black powder through a 23 inch tube fills a case to the point where seating a bullet would compress the powder mildly. I will try this load. Unless you all suggest otherwise. Thanks!

[Bent Ramrod]

It ought to shoot; how well remains to be seen.

My own Peabody in .43 Spanish seems to do its best work with the Ideal 451112, sized 0.452”; maybe 4”-6” at 100 yards. Fortunately, the chamber is cavernous enough to (barely) accept cartridges with the necks expanded for this boolit. The more conventional 439186 can be heard whizzing and tumbling downrange, and will eventually hit the ground, but that’s the extent to which it is accurate.

Big blackpowder cartridges with groove-diameter grease groove boolits and bore diameter paper-patch boolits have pretty much been sorted out over the last quarter-century or so, but the military-type bore (or less-than-groove) diameter grease-groove boolits are far from being down to an exact science yet. I’ll be interested to see your results.

[43spanish]

Shot at 50 yards today. 404 gr soft lead over 77 gr ffg Goex black powder. Large rifle primer. Thin card over powder, compressed mildly. First four shots grouped poorly and seemed low. I raised rear sight one notch, ran a tight clean patch thru the bore, left the brass rod out of the rifle, made sure I was resting the rifle very near the receiver and fired three consecutive shots into 2 inches, 10 inches above point of aim. If I can duplicate that consistently I’m happy. The bore is good with very distinct rifling except for about an inch at the muzzle where it is worn and has some pitting, and the crown is rather rough. But if it will shoot like that I’ll leave well enough alone. I afterward fired several shots using my previously cast harder lead bullets sized to .441 in order to fire form the casings. Like before, they were all over the place. However, no keyholing. The soft lead seems to have made a very big difference.
The fore stock moves forward about 1/8 inch when I fire. How do I secure it in place?