View Full Version : 450 Marlin 404G Cast Load

10-18-2009, 04:14 PM
OOPS - EDIT: 405Grain cast bullets...........

Hello All,

New to this forum but not new to casting and reloading. I *think* I know where I'm going with this but would rather know for SURE, I like shooting guns, not bombs.

I've got a Marlin 1895GG in .450 Marlin --- LOVE this gun for hunting but hate it for benrest. I've got a bunch of 405G hard cast GC bullets I've made up plus some of Beartooth's 405G hard casts. I'm having a heckuva time coming up with a powder load for this documentation wise, maybe I should invest in some new load manuals as the dozen or so I've got now were copyrighted before .450 Marlin was released.

The powder I'm going to use is 4198 (IMR or Hodgdon take your pick I've got lots of both as that's what I use for my .444 Marlin....) and I know I can use 45-70 load data for a starting point even though .450 Marlin cases are a bit smaller in capacity than the 45-70.

I've searched all the forums I know of and can't find hardly anything on this load -- can anyone point me in the right direction or do any of you load cast bullets for this gun?

Many Thanks,


10-18-2009, 05:07 PM
No lever gun from .30-30 on up is any fun at the bench. A past recoil shield or a Lead Sled will take the abuse out of it.

Data isn't going to be easy to come by until or unless the round gets a bit more popular. For cast bullets I would simply use .45-70 data for the trapdoor rifles. Get a Lyman Cast Bullet Handbook just because you should read it and have it in your library, regardless of whether or not it has .450 data (my 3rd ed does not). Lyman's 49th ed Handbook (the regular manual) does, and it includes data for 400gr cast, which is what you're looking for.

"Hard cast" and hunting bullets do not go well together. Most especially when the source is a commercial one and the bullets are undersized (read: the same as a jacketed bullet). A few undersized hard cast bullets through your barrel and you are going to need a Lweis Tool to mine the lead fouling out of it, especially if you are trying to get higher velocities. Remember that millions of bison were killed with soft lead bullets fired from muzzle loaders and bp cartridge rifles. What worked for them still works best, but now we can use smokeless powders and not have to deal with the cleaning issues. A slow heavy bullet is what works with cast.

First, slug your barrel to find out its real groove diameter. Use a mic, not a caliper to measure the slug as calipers are not accurate enough. (Even if you have a fancy electronic caliper that reads out four digits, it is still only accurate to +/- .005", and you need +/- .0005" that a mic will give you.) You need to do this because manufacturer's specs are fine for jacketed bullets, but there is too much actual variation between barrels that are still within specs. You want a bullet that is .002-.003" over your measured groove diameter. Once you have some accurate numbers, then you know what diameter sizer you will need. While you're at it, mic some of the commercial bullets you've got and see what size they really are. If they're too small, shoot them with light loads and don't expect much in the way of accuracy.

10-18-2009, 05:28 PM
Thanks Vers,

Yup, have two versions of Lymans cast bullet handbook I've bought over the years, first was in 1980 second around 1990, maybe I'll just have to update.

VERY good advice. Not trying to hunt with this bullet, just plunk targets. It is a gas check mold and I am not trying to push it out to ungodly velocities, hate cleaning out leading due to my own stupidity, just don't want to blow up my rifle -- *some* powders will go "BANG" real loud if you cut the load down too far, been there in my youth and not going back....

I *thought* I could probably use trapdoor info for 45-70 and be safe, could probably use Lyman's published Marlin loads for 45-70 and still be safe but there's that leading thing again.

.450 has Ballard type rifling and not the micro-groove so it should be OK on what I'm doing, I'll give you a follow up if I work up the nerve to put that thing to my shoulder on the bench again. Just want to play R. Lee Ermey and blow up my old friend "The Watermelon"

*Sigh*........time to buy another new manual, I keep outliving their use......or maybe I should just try not buying new calibers.........OK scratch that idea...

Many Thanks,


Old Guy
11-15-2009, 05:39 AM
Try 40% of Black powder charge using IMR 4198 and stuff the case full of dacron fluff till it is lightly compressed. Ross Seyfried uses this formula to regulate old double guns. It worked great for me in 45-70 Guide Gun. Five shots in one hole at 50 yds, light recoil and no leading

11-16-2009, 12:29 AM
This is from the last IMR paper Handloader's Guide; now you'll have to look on Hodgdon's data center at hodgdon.com or imrpowder.com (same site/owner).

458" DIA.; 24" BBL.; 2.512" C.O.L.
IMR 4198 40.0 1820fps 40000psi

I actually found that version of the IMR guide (05/03?) in pdf form online. Let me know if you are interested and I'll try to find the link.

There is also a 15Mb pdf Hodgdon Basic Manual for download, with data for all 3 brands, and their Annual should be out fairly soon.

If you are looking for a sweet load, 4198 can be reduced by a good amount as you should see in Cowboy or low end (old guns) 45-70 loads.