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Lead alloy for marlin microgroove rifling
Posted: Sat Mar 03, 2007 4:34 pm
by 444Marlin
As my nickname suggests I have a 444 Marlin. I want to use cast projectiles but always have leading problems, even with a gascheck. I have used straight wheelweight (ww), ww with tin, lead with tin. Is there anywhere I can get linotype or perhaps some antimony? Any help appreciated.
Posted: Sat Mar 03, 2007 8:58 pm
by Kenny
444,
Most printing shops (old newpapers) have a mountain of Lino type laying about and will gladly sell it to you, our local bloke gave away a stack of it to fisherman for making sinkers
KY
Posted: Sun Mar 04, 2007 6:01 pm
by JFE
444 eh ? Thats a heck of a varmint round !
In my Marlin microgroove 45/70 I use an alloy that is approx 50% WW and 50% lino and I also quench them as they fall out of the mould. The alloy is probably too hard but it works well. I think I can cut it to 75/25 and still be OK. Used it on buffalo and it is a real hammer. When my eyes were sharper this load would print around 1.5 moa with open sights. Accuracy and performance are better than jacketed. Straight lino will be too hard by itself.
In your application use a mould with as cast diameter of .431/.432 and dont size any smaller. The 444 can be made to sing with lead, its just a little more tricky to do that in microgroove bbls. A GC helps a lot but it is really bullet size, throat fit and alloy that are important. My best accuracy was obtained by firing as cast, hand lubed bullets. I fitted the GC by partially inserting into the lube-sizer. Its a bit fiddly though.
Good luck and let us know how you get on.
Joe
444 Marlin
Posted: Mon Mar 05, 2007 3:14 pm
by Flash Gordon
I don't think alloy is your problem. Suspect bullet diameter is a bit small.Have used alloys with a lot of lead ¬ much WW in .35 Whelen up to &over 2,000 fps. They were quenched from the mould.
Flash.
Posted: Mon Mar 05, 2007 7:15 pm
by JFE
Flash - a bit OT but both the 358 Win and 35 Whelan are supposed to be very good candidates for cast. Been thinking of setting up a 35 cal with cast in mind and appreciate you sharing your views and experiences with the Whelan.
Back to the cactus....
Unlike conventional rifled barrels, microgroove barrels have a reputation for working best with harder alloys. The other point I didnt mention about M/G bbls is that they also appear to need bullets to be driven hard to get best results. This has been my experience as well.
As I mentioned the alloy I use is probably harder than required, however I messed around for a long time with softer alloys and different bullet designs until I found something that worked and I simply stuck with it.
In reality in the larger bores, within reason, there is little downside in using a harder alloy, apart possibly from a little extra cost.
Joe
Lead alloy for marlin microgroove rifling
Posted: Mon Mar 05, 2007 11:13 pm
by 444Marlin
Guys, thanks for the advice. I use a .430 sizing die and will open it up to .431/.432. I will try the local paper for some linotype as well as quenching from the mould. My current projectiles are about 9 Bhn and I will let you know the outcome.
Posted: Wed Mar 07, 2007 6:58 am
by Col. Pogy
Hello. There is yet another option to try to solve the leading problem. Change your lube. I suggest you try Lee liquid alox, thinned with lighter fluid or similar to a thin syrup consistency. Put the naked bullets in a small container with a lid, use enough of this to coat evenly when you carefully tumble the bullets gently. Pick them out and set base down on a piece of plastic bag to dry. Bullets should be + .oo1 or a little larger, wheel weight hard or a little better, and not sized. Press your gas checks on carefully for square seating after the bullets dry. Wipe the lube off the noses so the seating stem cavity does not collect excess lube. I run wheel weight .258 diameter Lyman 257420s @ 2000 fps using AA1680 in a Marlin 25-20 this way with absolutely no leading and a perfect lube star on the muzzle. Aus bullet design though. Ha! Good luck.
Posted: Fri Mar 30, 2007 10:50 pm
by Nardoo
Two points:
1. Undersize boolits is probably your problem not alloy hardness.
Slug your bore and use a boolit 1 or 2 thou greater in diameter. Do not worry about Lino. WW (plus 2% Sn for better fill out in your mold) will be fine. Actually you could probably use 50/50 WW - Pb at your velocities and get fine accuracy with the bonus of some terminal boolit expansion.
2. Check your powder types.
Use the slowest powders listed. If you use the fast burning pistol or shotgun powders many manuals suggest you will need to keep the velocities way down. These fast powders rely on high pressures to get velocity, often more than the boolit can take.