leading in 450 marlin ?

[happyfast79]

i have a 1895 marlin mxlr with a 24" barrel and am very new to shooting cast bullets. i bought a 340 gr pb lee mold and cast useing straight wheelwieght and let them air cool. then i lightly tumbled them with lee liquid alox and i do mean lightly so there was just a light sheen on them. then i loaded them with 37 gr of imr 4198 but i found that they didnt have very much neck tension after the light belling of the case mouth so i lightly crimped the cases.. but after fireing 20 rounds it had a decent amout of lead coming out on the patch when i cleaned the rifle. do i need more lube or am i running them to fast? i didnt crony them

[onondaga]

Do you really have leading? are there shavings of lead on your patch? Is there visible slivers of lead in your rifling? Or, are you just getting really black patches.

Really black patches does not mean leading. If you are getting leading your boolits are too small in diameter for your barrel more than any other reason.

I use that Lee boolit in my .458 Win Mag. From my modified Lee molds they drop at .460-.461". The mold dropped .458" new and I enlarged it by the Leementing method discussed on the board. My rifle slugs at .4570" groove to groove and I size the Lee boolit to .459" a full .002" bigger than my Land to Land slugging measurement. I truly get zero leading at velocities I have tested up 2000 fps but begin to lose accuracy after 1610 fps with that plain base boolit.

Slug your bore, measure the slug and measure your cast boolits too. It is common for Marlins to have bores definitely over .457" and that Lee boolit, hate it or love it, has been reported to cast as small as .456 to as large as .462"

You describe low neck tension. That makes your boolits sound small. Really small if you are full length sizing.A heavy crimp will hold them in the case but that same heavy crimp will also be a funnel for your boolits to squeeze through and become even smaller.

With my boolits at .459" They will bulge the full length sized cases. So I backed off my sizing die to adjust for that and get good neck tension without bulging brass. I had to back off my sizing die about 1/4 inch from the shell holder to accommodate my boolits.

I also only use a .004" case mouth flair before seating boolits and factory crimp .004" smaller than sized mouth diameter.

4198 is widely used in 45-70 but H4895 will get the velocity with a softer pressure start that cast boolits prefer. That softer start can also make a difference in reducing or eliminating leading, if, of course, your boolits fit first.


Gary

[white eagle]

lots of very good advice :goodpost:

[happyfast79]

Do you really have leading? are there shavings of lead on your patch? Is there visible slivers of lead in your rifling? Or, are you just getting really black patches.

Really black patches does not mean leading. If you are getting leading your boolits are too small in diameter for your barrel more than any other reason.

I use that Lee boolit in my .458 Win Mag. From my modified Lee molds they drop at .460-.461". The mold dropped .458" new and I enlarged it by the Leementing method discussed on the board. My rifle slugs at .4570" groove to groove and I size the Lee boolit to .459" a full .002" bigger than my Land to Land slugging measurement. I truly get zero leading at velocities I have tested up 2000 fps but begin to lose accuracy after 1610 fps with that plain base boolit.

Slug your bore, measure the slug and measure your cast boolits too. It is common for Marlins to have bores definitely over .457" and that Lee boolit, hate it or love it, has been reported to cast as small as .456 to as large as .462"

You describe low neck tension. That makes your boolits sound small. Really small if you are full length sizing.A heavy crimp will hold them in the case but that same heavy crimp will also be a funnel for your boolits to squeeze through and become even smaller.

With my boolits at .459" They will bulge the full length sized cases. So I backed off my sizing die to adjust for that and get good neck tension without bulging brass. I had to back off my sizing die about 1/4 inch from the shell holder to accommodate my boolits.

I also only use a .004" case mouth flair before seating boolits and factory crimp .004" smaller than sized mouth diameter.

4198 is widely used in 45-70 but H4895 will get the velocity with a softer pressure start that cast boolits prefer. That softer start can also make a difference in reducing or eliminating leading, if, of course, your boolits fit first.


Gary

Thanks for the info ill try to slug the barrel. it was leading as i had chunks of lead coming out with my patches. also the 450 marlin case is taperd so if i bell the case to seat the bullet isnt that going to take away my neck tension as the case get wider the closer to the rim you get? i orderd a gas checked 350 gr .460 mold from ranch dog with a 30-30 mold. so hopefully those with work better in it all also look into enlarging my lee mold i have now. i also have a 500 gr fn gc lee mold that im shooting out of my .458 socom but havent had time to check for leading. so i may have to modify that one also.. thanks again!

[onondaga]

The .458 WM is also tapered similar to the 450M. The .004" flair is fine. The RD molds cast nice and big, at worst you can use them un-sized and seat your checks with a .461 boolit sizing die if your bore is really on the big side.. Slug that bore and you will know where you are. Boolits .002-.003 over are generally great to stop leading and shoot true with cast in the 450M.

When your boolits are the right size, just back off your case sizing die till case bulging just stops when seating boolits and try the rounds in your chamber.

I don't know how experienced of a caster you are . I have been casting since 1956, boolits since 57 but only got my first 6 cavity this year it is the RD CTL-460-350 like your new one. If you are new be patient and read up-- they are not easy to start with even if you are experienced but not with a 6 cavity. Watch the CowboyT videos. .

Gary

[happyfast79]

cool! thank you Sir!!

[Larry Gibson]

Use more lube. A good heavy coat around and in the lube grooves is needed to prevent leading with LLA.

Larry Gibson

[happyfast79]

i just got done slugging my barrel twice and measured .452 between the lands and .455.5 between the groves??? seems way to small maybe i should bring home my 1" mic from work as im useing my digital calipers?


i tried useing one of my bullets first and thought that the act of beating it through the bore would expand it into the rifleing and it seemed to work but it was also made of wheel wieghts and rather on the hard side then i used one of my .454 round balls for my cap and ball revolver and smashed it to a little over .500 and then tapped it down the bore and it came out the exact same size as the bullet did.

what do you guys think im doing wrong?

[onondaga]

SAAMI specks for a .450 Marlin bullet size on the drawings I have are .4583 for the diameter for a jacketed bullet and an OD brass diameter at the mouth of .4808. SAAMI bullet sizes are generally .001" larger than groove to groove bore measurement. An easy example to understand is the .308 Winchester. jacketed bullet specifies a .308" diameter bullet and G-G standard is .307 for the bore. Cast boolit recommendation is .309- .310"-- a full a full .002-.003 over G-G in the SAAMI measurements of a .308 Win.

The .4555 land to land slugging measurement you give sounds very wrong for a 450Marlin.

If your .450M is close to SAAMI standards it requires a .460-.461" cast boolit or a .4583" jacketed bullet. Your slug measurements are very wrong for a .450 Marlin.

Are you getting really good detail in the slug in the lands and grooves. Use a quality micrometer like a Starrett, not a dial gauge or digital caliper. The barrel should be heavily greased before slugging and need a hard rap to start the ball into the muzzle then medium hard raps to get it all the way through to the chamber from the muzzle. Impressed rifling marks on the ball should be hard, shining and sharp unless your bore is horrible or the slugging ball was too small. There is a link in the stickies on how to slug a barrel or search Google videos.

Hope I can help you through this.

I use a .490" cast soft lead round ball for slugging 45 caliber rifles. If you really don't know what you are doing slugging a bore.....STOP.... and get help, you could damage your firearm.


Gary