Correct sizing diameter?

[vanilla_gorilla]

I don't have any pure lead on hand, but I used some boolits I have on hand. Measured them at .4295 and .430, and each went through each of the throats in my Model 29 with light pressure from a rod. Now, if I remember correctly, I should be sizing at .430 or .431, and specifically avoid .429. Is that right?

[MtGun44]

Well, that is basically correct, altho it isn't ultra critical. Generally, you
want the boolit to be equal to throat diameter or greater for best
accuracy. Many revolvers do their best accuracy with about .001 or
as much as .002" (or more) larger than throat diameter. Some shoot fine with
boolits .001" less than throat diameter. Others will not.

Groove diameter does enter into it, as does boolit hardness and
configuration. You would ideally have the throat diameter the same
or .001" larger than the barrel groove diameter. A hard boolit that
fits the throat well, but where the throat is quite a bit smaller than
the barrel groove diameter is unlikely to shoot with top accuracy. A
softer boolit may slug up from the undersized throat and fill the
bore and shoot well - and hollow base boolits are especially good
at adapting to mismatched throats and groove sizes.

Each revolver is a thing unto itself, and some are just naturally ornery.
Others will shoot excellent groups with darn near everything.

The rules most often work for most revolvers.

So - if your throats are about .430 and IF your groove diameter slugs
at .430 or .429, and you shoot .430 or .431 or even .432 boolits,
you are most likely to have good accuracy, no leading, and other
good things. Probably .429 boolits, especially hard cast, will give
less accuracy and are more likely to lead the bore.

Bill

[vanilla_gorilla]

Thank you. I do understand that there are myriad different variables in the process, but I didn't want to start out with the very first thing (size) being a mistake. I'll size them at .430.

[EDK]

I've been playing with diameters and alloys for a dozen different 44 magnum RUGER VAQUEROS/BLACKHAWKS/BISLEYS for awhile. They will all let a .430+ boolit slide through the throats, but a .432- will not go. (I'm using an elderly STARRETT micrometer.) Since RANCH DOG recommends .432 for his 44 boolits, I've tried that diameter and his LLA dip lubing method. I can't tell a lot of difference on accuracy BUT the barrels are definitely getting de-leaded after 5-to-10 rounds of the gas checked RDs. The boolits with standard type lube grooves are using 50/50, 2500, B-A-C, and Carnauba from LARS with no great difference in performance or leading.

I've got a model 29 from the early 70s, a 629 from late 80s/early 90s, and a recently acquired 624 (mid 80s?) that I need to check out and see if they do the same as the RUGERS.

Has anyone else noticed the de-leading from XLOX/LLA and gas checked boolits?

:Fire::cbpour::redneck:

[Bass Ackward]

Has anyone else noticed the de-leading from XLOX/LLA and gas checked boolits? :Fire::cbpour::redneck:


It's all about how you shoot and what it takes to seal.

The deleading is from seal and increased bullet friction as the bullet shoots out of what was left behind. LLA adds about .0005 of soft diameter to what you are using over other lubes for seal. Sometimes more if you aren't cutting it and using double coats.

And another thing, LLA over antimony bullets will break a gun in faster than other lubes. So lead ain't the only thing coming outta there. :grin:

So you are having a double factor at work.

[FN in MT]

In HANDLOADER 256 theres a good article on the relationship between cyl throat diameter, cast slug diameters and ACCURACY. Makes a lot of sense.

FN in MT

[454PB]

All good advice. If you do use a slightly "oversize" boolit, make sure the loaded round chambers OK. In my .454 revolvers, any size over .452" will not chamber easily.

[EDK]

I'm on second shift this week and have access to a lathe and ball hones for the die for my STAR. This sounds like a good time to take it out another .001 larger and see how it does.

Some of the guns haven't gotten to 1000 rounds yet, so they need some smoothing out...or possibly fire-lapping. I think I'll "start low" and "double dip lube" some more boolits with the XLOX and try them for awhile before trying fire lapping.

Until I got the TLC 432 265 moulds from RANCH DOG, I'd never done anything with XLOX/LLA...and I've been casting boolits since 1966. The guys here have been a treasure trove of information and it's a poor day that doesn't show me something new to think over.

Thanks again guys

:Fire::cbpour::redneck:

[Wayne Smith]

Vanilla

Measure them after they come out of the throat, not before they go in! I can put a lot of pressure on a dowel rod, and .002" isn't much to push through when we are talking lead alloys.

[vanilla_gorilla]

Wayne, I thought about that after I posted last night, as well. Same size coming and going: .4295 and .430. With cleaning rod, it takes only slightly more pressure than the weight of the cleaning rod itself to push the bullets through.

[Bass Ackward]

WayWith cleaning rod, it takes only slightly more pressure than the weight of the cleaning rod itself to push the bullets through.


That is excellent and seldom seen.