40 S&W: Lube fouling

C

C17A

New member
Thank you for your help, in advance.

Loading up cast bullet loads in 40 S&W with Lee 401-175-TC, has single lube groove, lubed with 50-50 NRA formula, shot out of an H-K USP. So far have shot ten or twenty boxes with this load.

I cast my own, and use a Lyman 450 lube-sizer. I have loaded thousands of 38, 357, 44Mag, and 45ACP using the 50-50 lube. None of the cast loads have had lead fouling or lube fouling--until the 40 S&W.

No leading, and good accuracy, but getting lots of lube fouling right at the step at the end of the chamber. This then prevents the next round from chambering. At times it gets so bad we have to stop and scrape it out within 20 rounds or so, sometimes 100 rounds are OK and feed normally. It's like hardened lube mixed with carbon fouling, comes off in chips and chunks. This does not happen when I shoot my standard 45ACP cast load in a 1911 or Glock with 50-50 lube.

Looking to change lubes, would like one that does not need a heater for the lube-sizer.

I welcome your opinions....looking to try White Label Lube BAC, 2500, or Carnauba Blue.
 
If they fit your magazine, try seating the bullets out so the loaded cartridge headspaces on the bullet (the bullet making contact with the throat rather than the case mouth meeting the step at the end of the case portion of the chamber). With a lead bullet in a short case pistol cartridge, this doesn't raise the peak pressure as it does with a jacketed bullet in a rifle. (Nonetheless, always err on the side of caution and run the first ones 10% light on charge.)

What this does is both center the bullet in the barrel so it can't shave lead or lube off against the case mouth step in the chamber. It also starts the round out with the bore sealed, so it cuts out the gas bypass around the bullet that occurs with standard seating and headspacing as the case expands to release the bullet and before the pressure has overcome the bullet's inertia to get it into the bore. Gauge the bullet length by seating it out until a round dropped into the barrel has the back of its case head just level with the barrel extension (hood) at the top of the back of the chamber.

When I changed to loading .45 Auto this way, accuracy improved and leading stopped other than traces.

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Try a soft lube , one that doesn't need a heater .
I use a Lithium - Beeswax soft lube known as Lithi-Bee .
The formula is 1 part Lithium Grease (like Lucas Red-N-Tacky)
with 3 parts Beeswax , heated and blended untill it's well mixed.

The soft lubes don't build up , I think they work better and if the bullet groove holds more of the soft lube than is needed ... just fill 1/2 the groove with a light press on the fill handle . You don't have to fill the groove up all the way around .
I have a 38 special mould that has 3 lube grooves on it , with lithi-bee lube and light target loads I only fill one groove ..get better accuracy ...some times you have too much lube , so just back off the amount .
Gary
 
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