Cheese - if you want to be able to cycle that Marlin faster you may have to seat those slugs a hair deeper. I ran into the same problem with my Winchester Bib Bores in 444 - if I seated the bullet to the crimp groove I would have to be vewy careful cycling the action; but if I seated them just one hair deeper (no kiddin') cycling was smooth and problem free.
Also, before buying a mold and trying to get that to work, try the above mentioned methodology first (if ya would humor me) and then see if you can get some samples of the other types of bullets you may like to try to see if they work any better. And in examining my fired cases after having seated my slugs just a bit more deeply I can find no signs of excess pressure; the primers look no different than with a factory load, and the cases eject very smoothly (and resize very easily).
In addition, your Marlin may not shoot smaller (.429, .430) cast slugs very well as Marlin rifles seem to have oversized bores for pistol cartridges. Your best bet is to slug the bore and use slugs at least .001 larger. Each of my 3 Winchester Big Bores in 444 wears a different twist barrel and the last two are straight from Marlin - one shoots .432 slugs the most accurately and the other prefers .431s. the first one had a standard Marlin 12 groove barrel with a 1:38 twist but I had it rebarrelled. You may also need to fire lap your bore to help smooth out that 12 groove barrel to get the best accuracy from cast slugs.
My levers also do not like long Keith style semi-wads unless I roll the case moouth just over the shoulder - with levers I believe it is not just a matter of cartridge length but also a matter of design, which is why the LBT design may work better in a lever.
300gnJHP - to answer your original question, put the cast bullet either through or just behind the shoulder and you won't lose your deer.
Catshooter45: I agree with your argument concerning the sharp shouldered Keith style slugs and the LBT designs by Veral. To put it simply, as I simply do not have either the testing capability or the design genius of guys like Veral Smith and Elmer Keith, I figure that the hole a bullet makes in a paper target is about what it will be like going through tissue and that seems to have held up. I think Elmer's designs work with his sharp shoulder application, and it is just that you cannot tell from ballistic gelatin tests whether Veral's or Elmer's designs work better as the shock wave set up by either the metplat or the shoulder really squirrels one's ability to accurately measure the effect of one over the other.
Veral's designs are incredible. His flatnosed slugs carry just enough ogive to allow easy lever cycling or cylinder loading and his metplats are big, and when combined with the added weight of his castings which make heavy for the bore flatnosed slugs you have a incredibly effective combination on game.
My only wish is that Veral, or someone somewhere would come out with either a Keith style or LBT style slug for use in the new 327, which could also be used in the 32 H&R and other 32 revolver calibers, as well as the 7.62x25mm Tok and the 7.65mm Luger. But, as my Grandaddy once said - wish in one hand and crap in the other and see which one fills up first.......
jmtcw.
