How fast can a Lee 405 FN be pushed without leading?

I'm picking up a new Marlin 1895 SBL .45-70 Saturday and plan to shoot a lot of the Gould 330 HP boolits out of it, but I'm also looking at getting the LEE plain base 405 FN mold to try out. Depending upon how the boolits drop cast of WW +2% tin I will size them either .459 or .460 and lube with 45-45-10. I'll load with 3031. How fast do you think the Lee boolit can be pushed without leading the bore? Before I shoot it I plan to run several patches of Butch's Bore Paste through it to polish it a bit. GF

I bought my Marlin 1895 22" barrel in Atlanta. I first polished the barrel with J-B polishing compound to smooth things uo. I shot all of Lee bullets through it withoput leading. Some with up to 50 grains of 3031. The Lee 500 grain is accurate but causes a headache. I killed T-Rex in Stone Mountain Park and have not used it since. I always chase the barrel with a gas checked bullet for final clean.

Ill take a stab at it. Lots of variables and one gun might lead at 1200 fps and the very same brand and model in the next gun might do 2000. Id say on average using a ww alloy like that with a good lube and no gas check probably 1500-1600 in a marlin. Use a gas check, a real good lube, size precisely for your barrel and go to an alloy like #2 and you can probably push them as hard as that marlin is capable of handling.

They can be pushed faster than I can stand. The recoil out of my 1895 is a limiting factor. These rifles are basically a lightweight 30/30 carbine with cannon barrel attached.

Like Sage said, T-Rex, Rhino, Bigfoot, or Panzer IV, the 1895 can stop it.

I have a cowboy 26" and push some 400gr RCBS with gascheck to 1900fps.
That will rattle my fillings good!

Your alloy and no check i would say the beast lives on the high side of 1600fps.

no doubt. I had my old guide gun at camp one day loaded with 500s at about 1600 fps and also had my #1 458 loaded with the same bullet at 2000 and everyone that was there that shot it said the marlin was much meaner. They will rattle your fillings before you can push them so hard that you hurt them.

This: "They can be pushed faster than I can stand. The recoil out of my 1895 is a limiting factor. These rifles are basically a lightweight 30/30 carbine with cannon barrel attached." ...Hickok

The choice of powder will play a big role. One powder might build a faster pressure curve.....one might not. Most leading in plain base boolits come from the heat and pressure vaporizing the lead from the base of boolits and depositing it down the barrel. Same process with copper in high power/high pressure rifles.

Barrel leading. Over 14-1500 fps leading is a real possibility. Tip: Purchase a mold that drops its cast .002 or .003 ths over bore if you don't have a way to resize your cast to that (above) diameter. A loose fitting to bore bullet is the primary cause of leading irregardless of its lead BHN figure. The other leading causes. Flame cutting of a bullets base. And a poor choice of bullet lube.

A higher priority than the worry of leading is the need find the rifles accuracy or (sweet spot). There are high & low speed accuracy sweet spots. Hopefully you can find you're rifles low side sweet spot before meeting the terminal speed where leading is assured.

When I push the my casts to those higher speeds of jacketed which is far beyond 1500 fps. I make sure my casts are either mold dropped to the (above) measurement/s or Lubed Resized to those oversize diameters.
To assure no leading of my cast at jacketed speeds or near jacketed speeds. As a precaution many times not only are my casts grease groves filled and compressed with a proper store bought waxy >rifle< bullet lube. I also tumble lube em in White Label 45-45-10 liquid bullet lube.

I don't mind leading in my pistols occasionally as I have a tool for lead removal in pistol bores.. But I abhor it happening in my rifles. As the only way I know to remove lead streeking from a rifles bore is with a Chore Boy copper pot scrubber.

First, I had little success with Lee’s 457-405F mold. Using the same alloy as you, it was dropping right at .457. The bore on my rifle is right at .458 making this casting a bit small. All I got past 25 yards were keyholes. I replaced it with Lee’s 459-405-HB. Lee in their infinite wisdom only offers a bullet sizer in .457 so had to have them custom make one in .459 for me.

I powder coat and, for extra insurance, tumble them in RJL. Loaded with 28.5gr of H4198 these hollow base average about 1312 fps with zero leading. Could I push them harder?.... probably. Would I want to…. NO. Anything faster is a tradeoff of speed vs pain. Getting nearly an ounce of lead going that fast is going to make whatever it hits wish it were somewhere else. For what it’s worth PC’ing has pretty much eliminated leading in any firearm I shoot up to 1500 fps.