Not to beat a dead horse but....has anyone heard anything new regarding the .450 Mongo? For the past 30 years I've carried my .45 LC Ruger Blackhawk during deer season along with my my .45-70 Marlin. I bought a new .45 LC barrel for my .44 Mag 94 Marlin, planning to build a 1/2 magazine baby carbine but the project is kind of backburnered since the NEF single shot bug has bitten! When H&R ships everything back I'll have a total of 14 barrels on 4 different actions to play with - all rimmed centerfire calibers and shotgun, have most of my dies and bullet molds, also most of the brass and powders. Of course I've further complicated things with 12, 20 & .410 brass shotshells - can't find a whole lot of loading data for brass shotshells, but not expecting too much trouble with light shotloads or buckshot, slugs for rifled and smoothbore should be a little more challenging though! The real problem I'm afraid will be that stupid .45/410 barrel that I just couldn't pass on! I ordered it on one of my late production SB-2 actions, figuring it should handle my warm Ruger Blackhawk loads safely. I'll still be faced with the abominable accuracy (or lack of) with the .45 LC in this barrel, but can at least share ammo with my handgun. Then there's the issue of no sights, only a shotgun bead, but I believe I can finagle a peep on the rear along with a ramp w/bead right before the choke. Then there's the issue of brass .410 shells (or .444 cases - got both). With a rifled .452 bore and then the reverse spin on the the rifled choke, and light loads of 7 1/2 or 9 lead shot and no plastic wad column, I thought I'd try a .003" mylar wrap on the shot to hopefully prevent excessive leading and maybe end up with a reasonable pattern at 15-30 yds. - we'll see on that part. If anyone has patterned their .45/410 with conventional .410 plastic shells and wads, I'd appreciate any info or experiences you might have had. Everything I've read or heard about the accuracy of .45 pistol rounds, whether in an NEF or Rossi or TC Contender, seemed to generally express it as a pattern - not a group. This is generally attributed to the extr-long lead required to accept a .410 shell, and seemed to be the excuse for the .450 Mongo (.444 Marlin blown out to accept a .452 slug). On the surface, on an SB-2 frame, I'd guess one could nearly duplicate catagory 2 .45-70 loads, but someone was supposedly sending some handloads out for tests, but haven't heard about it in months - anyone else? My only goal in using the .444 case with a .452 bullet would be to push a 250-300 grain jacketed bullet at 1100-1200 fps (equivalent to my Ruger handgun loads) but with acceptable accuracy, around 4" group at 50 yds. I've also thought about trying a Speer .45 shot capsule to protect the shotloads. I'm trying to come up with a shotload for the occaisional partridge, also that 300 grain .45 slug @ 1100 fps that will group in 4" @ 25 yds (last year's deer was at 35', the seson before less than 50 yds-heavy cover here on my place in southern Maine!) As much as I want to share ammo between rifle and handgun, I guess unless I finish my 94 Marlin I'll be stuck with a marginal accuracy load in something that'll still look and feel like my .45-70s.
Any experience with that .45/410 combo would be appreciated and I'll certainly share my findings (or frustration!) later into the Summer.
Joe

Here's an earlier thread on this forum you might find useful.

http://shootersforum.com/showthread.htm?t=4711

In the above thread, this link below is offered - and here's what is contains in case you have problems getting it to open...

http://members.tripod.com/~cdk357/mongo.html

......450 MONGO......

Discussion: http://members.tripod.com/~cdk357/mongo.html

Glen Bolen <boleng@metro.or.gov>

Below is a reponse to a post asking about the .450 Mongo.

This comes to us from Ben Sansing ben.sansing@grapevine.lrk.ar.us

About a year ago, I came up with a "wildcat" I called the .450 Mongo, which used expanded .444 marlin brass in my TC .45/.410 barrel as a sort of "Poor Man's .45-70". I announced this "great marvel" on the TC List, and people got excited about it. Some other folks have tried it, with varied rates of success. Apparently, TC has changed the chamber dimensions of their .45/.410 barrels over the years. In some barrels, the .444 brass works great. In other barrels, the chamber tapers too much or something and it won't accept .444 brass that's been expanded to .452" at the mouth. I kinda suspect they may have done this deliberately, to prevent people from using ".450 Mongo", since I'm sure I was not the first to come up with the idea of expanding and using .444 Marlin brass in .45/.410. I guess TC wants you to go buy a .45-70 barrel instead.

It should be a simple task to "open up" a TC .45/.410 chamber to accept the expanded .444 brass, and then you'd have a .45/.410/.450 Mongo! Older barrels (mine is one of the original octagon ones - and *may* have been rechambered outside the TC factory, I don't know (it has the screw-on choke, but is stamped ".45 Colt" with no mention of .410, though it chambers 3" .410s just fine)... anyway, older barrels *may* work "as-is".

Good luck, Ben



--------------------------------------------------------------------------------

From bkmiller@pipeline.com

To Ben Sansing and all those interested in the 450 Mongo thread. As I previously reported, after preparing a number of 450 Mongo cartridges for fireforming, my friends and I found that none of them would chamber in any of the 3, 45 colt/410 barrels we have between us. I had my barrel shipped back to me from Arizona and I now know what the problem was and how to fix it. In flaring the cases I used a fairly steep tapered punch to start the expansion and a 45 acp expander to finish it. Because the expansion was tapered, I found that after seating a bullet in the case, a bulge in the case of several thousands was created immediately below the base of the bullet. the case measured .474-.475 around the body of the bullet (including case wall) but at the base of the bullet measured .480-.481. This bulge was enough to case the case to jam in the chamber and prevent full seating. I solved this problem by using a combination of dies (22/250, 45 Colt sizer and 45 ACP sizer) to resize the case WITH the bullet seated. The final step being to force the case (lubed, even though it was a carbide sizer) though the 45 ACP sizer. This reduced the outer dimension of the case to below .470 and solved the seating problem. As these cases are soley for the purpose of fireforming, I am not concerned waith accuracy. It would seem that the expansion of the case and bullet seating are critical to the successful preparation of cases for fireforming, Though I have been told by a gunsmith I spoke to that there have been changes in TC chamber dimension. A certain variation in chambers would be normal from the begining to end of the chambering process in any event. I think I may have found a better solution to the problem of case preparation and fireforming. As we all know, 410 shotshells may be fired in the 45/410 barrels. As a long time skeet shooter and shot shell reloader, It occured to me that the answer may be, for purposes of fireforming, to turn the 444 Marlin case into a brass shotshell. There would be absolutely no problem seating an unexpanded 444 Marlin case in the barrel. I seated a Winchester WWAA41 410 wad (for 2 1/2 inch AA cases) in the 444 Marlin and found it would seat perfectly. After checking a number of manuals and finding that all of them listed 10 grains of Unique as a safe load for 250gr bullets in the 45 colt (in a Contender), I primed a case charged it with 10 grains of Unique and seated the 410 wad. I then filled the case with number 9 shot to the top of the wad and weighed the shot. The shot weighed in at 190 grains. I then weighed one of the wads and found it to be 15 grains. The combination of wad and shot at 205 grains is substantially less then 250 grains, leading me to believe that 10 grains of Unique SHOULD be a safe load to fire. I then cut a thin cardboard overshot wad and sealed the case with a layer of 5 minute epoxy. Whether it will prove to be adequate to fuylly fieform the case is yet to be seen as I must first send them out to Arizona to be tested. I think this may prove to be the easiest way to form 450 Mongo cases and will report the results in a few weeks. Comments are welcome. --

Barry Miller bkmiller@pipeline.com


GOOD LUCK! ;)