Simple Question about Leading

[Jeff82]

My Marlin 1894c had been plagued by leading over the last year. A funny thing happened today at the range. I was a little low on ammo. Due to the primer shortage, I've been rationing my shooting. I've been trying to solve me leading problem by reducing velocity and reducing the BHN of my Lee Cowboy bullets to about 10. Accuracy was lousy today at 100 yards, lots of flyers. So, I figured that my I'd reduced the BHn too much, or put on too hard of a crimp, or something. But, when I got home I was shocked to find that I had absolutely no leading.

Then I got to thinking. Normally I'll shoot 250 rounds threw that gun at each sitting, and run a patch through after each 75 rounds. Today, one big difference is that I only fired 125 rounds total. Does anyone know if lube loses its ability to prevent leading, if it's being fired in a barrel with some amount of fouling? I'm trying to figure out if my bullet tweaks that ruined accuracy actually solved my leading problem, or if maybe I've just been firing too many rounds as a single setting.

--Jeff

[btroj]

It has nothing to do with lube failure because of a large number of rounds fired.
No leading was most likely because your bullets were soft enough to slug up and seal the bore.

What size are you sizing to? What powder charge? Mag or specials? What bullet?

My Marlin likes a .359 bullet. I don't get leading at all. Mine prefers mag cases with a bullet like the Mihec 359640. Mine shoots better the harder I drive em. Mine hasn't ever done well with anything in a special case. I think this is all because mine has a very sharp throat angle and that bullet manages to center up when loaded in a mag case. Anything else hits the throat and doesn't enter the same shot to shot. That leads to large groups.

Keep shooting however many you want. I bet a larger bullet would stop most of your leading.

[geargnasher]

I have barrels that haven't even had a cleaning rod pointed at them in years. If you have any kind of accumulation in your bore over several hundred or even thousand rounds something is out of whack.

Gear

[williamwaco]

BNH 10 is about perfect for that. I assume it is a .357 or .44 Mag cartridge.

Since you didn't mention it I am guessing your prior bullets were too hard and too small.
That is a perfect storm for severe leading.

I have owned several .357's and one .44 mags in lever action with 16 to 20 inch bbls.

I find BNH 9, 10, 11 to be perfect for up to about 1700 fps in my .357 ( No gas check needed and zero leading. )

[sthwestvictoria]

As per gear, if the projectile, load is right for the rifle, there should be no leading or need to clean. Now that I've got a working load I have stopped cleaning my 30-30. I treat the bore like a big .22LR - if there is a good coating of greasy fouling with rifling still sharp then it doesn't get cleaned, much like my .22LR. The exception is if there is any precipitation or temp fluctuations (out camping with cool nights) the bore gets a clean and oil to ensure no moisture then back to the safe with hydroscopic moisture wicks in it.

Maybe the softer lead bumped up a bit in the bore to reduce leading? Was it the same powder charge as your prior loads? Or did you reduce this for economy as well - certainly less velocity may be part of the leading equation.

Although still a novice I realise there are no simple questions with leading!

Good luck figuring it out - this is why I like cast, there is always some struggle to keep you guessing!

[Jeff82]

Yep, always something to keep you guessing.

I'm shooting Lee 158 grain RNFPs with 5.2 grains of Universal (velocity was about 1,200 fps) and magnum primers. The bullet is sized to 359 with a BHN of about 10. I'd be really thrilled with the absence of leading, but I was surprized at the loss of accuracy. For three months I've been stepping down the load and BHN. With each reduction in BHN I've seen improvements in accuracy, but no improvement in leading. My best bullet so far was at a BHN of 11. One possible explaination is that I put on a harder than normal crimp. Strange day at the range.

[missionary5155]

Good morning Jeff82
Where is the leading ? If it is in the chamber area.. the throat... the first three inches of the barrel near the chamber ?? If so you are probably using a too narrow boolit.
Marlins are all fat throated. They designed them this way so hunters using jacketed bullets would never have a problem chambering a cartrige.
It causes havoc for us and lead. That is why Ranch Dog designed the fat nose fat body molds.
I treat all my modern Marlins the same.. Fat boolits. I take an unprimed brass and try a .362 sized boolit... if that chambers guess what I load. No banging on the lever.. Slight resistance closing is my goal. If too fat .361 and so forth. My marlin caliber .357 mag gets fed that way. Each boolit from a diffent mold gets tried out first this way.

All my Marlins get this routine. 45/70, 375, 41 mag... all get the same test. No regrets ! No leading until I get into high base pressure. Micro groove or Ballard type.. fat is good. Maybe playing a little more with a lesser diameter would yield 1/2 inch better groups at 50 yards but I played long enough with my Marlin lever flippers to find out it seldom happened.

My old Winchesters and Marlins are the same on this. Rossi.. the same. I start fat then work down to a less diameter. I know this is may not be real scientific but if a boolit is not at least .002 over groove I get shivers.
My JES bored Marlin 414 Supermag is an exception. My JES bored Marlin 38-55 and 375 Win another two exceptions. But these are custom barrels. Custom throats. But they still get fatter than groove boolits.
So there is my Marlin Factory Rifle plan for my Marlins. Fat is in ! If it will chamber that is where I start testing. Again I do not force the lever closed but I do not mind a little resistence. Do not forget to crimp. A belled case mouth causes alot of chambering resistence. Hopefully you have a kinetic boolit puller as you need one. You can make one with a 2 foot long chunk of hardwood but the real tool works alot easier. I get alot of use out of mine with the initial testing of my fat boolit plan. But if not you can pop the test boolits out with a steel rod the size of the empty primer hole.
Mike in Peru

[northmn]

I have been using the Lee Tumble Lube with good success. According to some, leading is primarily caused by too loose a bullet, where the gases get by the base. I have been using bullets at least .001 over bore size and lately .002 with best results. Too soft can also do it but I think the biggest culprit is using bullets sized to bore size. When I used the 357 I used as cast at 360.

DP