Barrel Leading Question

[Thomas Traddles]

I shoot cast boolits in my LCR and SP101 -- RCBS 38-148-WC and RCBS 38-158 CM. I size both to .359 to match the chamber throats and load them over 3.5g Red Dot. The bullets are cast from a 20-1 alloy yielding a BHN of 11-12. I tumble lube the boolits in 50/50 LLA-mineral spirits. I am observing that the 148 WC causes severe leading in my guns, but the 158 CM, which is an RNFP, in comparison, leads the barrel hardly at all. Has anyone had this experience when using two different types of bullets?

With the 148 WC, the leading in the form of thick smears. With the 158 CM it appears that the leading follows the rifling of the barrel. Is it possible that I have not got enough lube on the bullets? Any help/advice would be appreciated.

[John Boy]

Is it possible that I have not got enough lube on the bullets? Could be but first slug the bore to determine if the bullet diameter is too small to obturate in the grooves

[MtGun44]

Not likely that .359 boolits, from .359 throats (assuming that these dimensions are accurate) will
not fit the grooves. BUT sizes need to be verified.

Frankly, I do not trust the alox thin film approach to always work reliably like the conventional
lube (NRA 50-50 or LBT soft blue, or many others that are well established to work in a wide
variety of conditions) much better for reliable service. Many succeed with the alox system,
but many fail. One thing to try is to lube with undiluted liquid alox, and maybe even do it
twice, and see if this fixes it. This is a marginal lube system at best, and just doesn't always
work. Don't fall for suggestions that 11 or 12 BHN is inadequate hardness. Hardness is
substantially overrated as a protection from leading.

Are you using a micrometer to measure? Calipers are not accurate enough for this work,
regardless of protestations to the contrary.

Have you slugged the bore?

Delivering a well lubricated and slightly (.001 is enough) oversized boolit to
the barrel will not result in leading in 99% or more of barrels. Some do have
extremely rough surfaces that will lead regardless, but these are rare and
can be smoothed by shooting jbullets or fire lapping. This is rarely required.

Bill

[Thomas Traddles]

Bill, I have not slugged the bore, but I have used pin gauges to measure the cylinder throats and they are .359. I've read that revolver bullets need to be sized to fit the throats rather than the bore, as in semi-autos. I also lube the bullets twice -- once before sizing and once afterwards. But I will try a different lube to see if that works. I just find it strange that the same sized bullets give different results re leading, even though they are differently configured. It just may be that the 158 RNFP bullets take the lube better.

T

[MtGun44]

Are you measuring your boolits with a mic or a caliper?

It is possible that the groove diam is larger than .359, but that would be unusual. You are correct
about matching the throats, but an assumption is that the throats are about .001 larger than the
groove diam, which is not guaranteed to be the case.

Bill

[Thomas Traddles]

Bill, I'm using a micrometer.

T

[country gent]

Another consideration is the 148 wc has more bearing area that the 158 grn roundnose flat point does. I dont see an isuue with alloy but with the added bearing surface of the WC. Tru LLA undiluted and maybe even 2 coats. Are you sizing before or after sizing? sizing may be removing a lot of the lube from the bearing surfaces leaving very light coat in grooves. Try lubing sizing and relubing to replace whats pushed of sizing.

[Thomas Traddles]

country gent, I lube before and after sizing. I will try using a bit more lube and hit the range to see what results I get then. Thanks for your suggestion.

[twc1964]

Try a double dip in 45-45-10.i have been shooting the lee .358-158rf with my homade brew of the afore mentioned lube with zero leading. So easy and it shoots nice.

[trapper9260]

I lube all my with lube I made that is the old NRA lube with ATF and use it in every thing I shoot it out of all my and have no leading.As for the hardnest you are usen should work because that is what I use in my BH and my Rossi for the same cal as you are also use the same lube in all my 30cal and 44mag and 9mm.

[44man]

Boolits are too soft! Lube the worst you can use. You live in slump city. Lube is gone in an inch, Out the gap along with lead.
20 to 1 in a .44 mag or nine??? Need to get real. Stuff won't work in a .38!
The wad cutter is getting the edge wiped off at the cone and is starting crooked, opening gas channels. The other boolit has better luck pulling the cylinder.
Why is a revolver so hard to understand?

[Petrol & Powder]

I know some people get good results with the tumble lube process but if you're sizing bullets anyway, why not just use a lubersizer ? I've never been a fan of tumble lube. It seems to be a solution in search of a problem. I understand how it can speed up the production of bullets but if you have to size the bullets you've lost that advantage.

[gpidaho]

A proper fit is what is required. Lube is the least important factor in my opinion just about any lube right down to ear wax will lube a properly fitting boolit. You can over power your alloy to the point to induce skidding and some bores are just rough. Some thing is wrong in the fit somewhere or maybe a restriction in the bore where barrel threads in, investigate a little more you will get it figured out. GP

[too many things]

don't thin the lube. heat it , it will dry and not be sticky unless you are in 90 + heat. I have a box of 38 wad cutters that have no grooves and a powder coat of some type. and they don't lead.
I heat the bottle in hot tap water and it works good. just sit them up on wax paper and the base will be clean.

[44man]

A proper fit is what is required. Lube is the least important factor in my opinion just about any lube right down to ear wax will lube a properly fitting boolit. You can over power your alloy to the point to induce skidding and some bores are just rough. Some thing is wrong in the fit somewhere or maybe a restriction in the bore where barrel threads in, investigate a little more you will get it figured out. GP
I have made hundreds of lube tests and some will make shotgun patterns while another will be under 1". if you think lubes are the same you are wrong.