460S&W long COAL and H4198

obiwannabe · January 22, 2015, 01:04 PM

I have a 24" MGM 460 S&W barrel for my Encore that I've been working with for about a month now trying to get usable accuracy. The thread is here if you care.

The chamber has about 0.25" of freebore, which is a bit odd, BUT might also be useful. I can seat a 300gr XTP Mag out to a COAL of 2.323" and be 0.005" off the lands.

With that extra case capacity I was thinking about trying H4198. The Hodgdon manual doesn't list loads with H4198 until you get up to the 325gr Swift HP where it lists a compressed max load of 41gr (2.175" COAL) yielding 1695fps at 42.5K psi from a 10.75" barrel.

I can get 45.5gr into the case without compression. I'm just not sure where it will be on pressure. I've loaded a ladder starting at 42gr and going up to 45.5gr in 0.5gr increments.

Anybody tried anything similar or have any thoughts to share before I give it a whirl?

FWIW, I just ordered a copy of QuickLoad. Should be here in a few days, but I'm looking at some decent weather coming up this weekend.

TimSr · January 22, 2015, 10:18 PM

This post caught my attention as I was looking up some old data that had stuck in my head. This is about 1990 stuff, long before the 460, but I remembered some .44 magnum rifle loads. In the old IMR data brochure that you used to get free, it shows for .44 magnum a 240gr and a compressed load of 25.5gr 4198. The pressure was listed at 26,400 which is WAY below max. I just mention this in that it looks like in a .44 magnum case, it would be impossible to stuff it with anywhere near enough 4198 to run into pressure issues, and I woulss suspect the same is true with the 460. In any case, you would be safe using the larger bullet data, as 4198 has no issues being reduce loaded. I'm not sure what the pressure rating is for 460, but .454 Casull is like 60,000, so you have plenty of room to work with.

buck460XVR · January 23, 2015, 06:56 PM

First off, I would go back to crimping the bullet in the cannelure. Powders like IMR4227 and H110 need a consistent heavy crimp for consistent burn and best accuracy. I would also try IMR 4227 at slightly compressed levels. Hornady lists 42.4 as max with their 300 gr XTP-Mag. My go to powder in my .460 revolver with 300 grainers is IMR4227 with H110/W296 next. While 4227 does not give me the velocity that H110/W296 does, it has great accuracy and is quite consistent in extreme temperature variations.

Several years back since I already handloaded for my .460 revolver, my oldest son bought a Encore with a 20'' Pro Hunter Katahdin barrel. It too had a 1 in 16 twist. The loads that were extremely accurate outta my revolver were all over the place from my son's Encore. I went up and down the ladder with several different powders and a variety of bullets. Nuttin would do better than 4-5'' @ 100 yards. Our .44 mag carbines shot better than that, as did my .460 revolver. The gun shot better with .45 Colt loads than anything in .460. It also shot fairly well with factory 200 FTXs, but they have poor terminal performance outta my revolver on deer, so other than for yotes, they were not good for much outta the rifle. After a year of trying every combination I could find, my son gave up on the gun and traded it for a 1911. For the life of me, as easy as it was to find accurate loads for the .460 revolver, why we could never find anything satisfactory load for the long gun is still a mystery.

On your other thread you mention bulged cases. Sounds, like you have some case head separation about to happen. You may have a headspace issue or a bad chamber going on. As for brass, I prefer Starline over the Hornady. Hornady brass is the only one I have had split...and it was just above the web.

January 22, 2015, 01:04 PM	#1
obiwannabe Member Join Date: February 14, 2014 Posts: 40	460S&W long COAL and H4198 I have a 24" MGM 460 S&W barrel for my Encore that I've been working with for about a month now trying to get usable accuracy. The thread is here if you care. The chamber has about 0.25" of freebore, which is a bit odd, BUT might also be useful. I can seat a 300gr XTP Mag out to a COAL of 2.323" and be 0.005" off the lands. With that extra case capacity I was thinking about trying H4198. The Hodgdon manual doesn't list loads with H4198 until you get up to the 325gr Swift HP where it lists a compressed max load of 41gr (2.175" COAL) yielding 1695fps at 42.5K psi from a 10.75" barrel. I can get 45.5gr into the case without compression. I'm just not sure where it will be on pressure. I've loaded a ladder starting at 42gr and going up to 45.5gr in 0.5gr increments. Anybody tried anything similar or have any thoughts to share before I give it a whirl? FWIW, I just ordered a copy of QuickLoad. Should be here in a few days, but I'm looking at some decent weather coming up this weekend. Last edited by obiwannabe; January 22, 2015 at 01:21 PM.

January 22, 2015, 10:18 PM	#2
TimSr Senior Member Join Date: March 9, 2013 Location: Rittman, Ohio Posts: 2,074	This post caught my attention as I was looking up some old data that had stuck in my head. This is about 1990 stuff, long before the 460, but I remembered some .44 magnum rifle loads. In the old IMR data brochure that you used to get free, it shows for .44 magnum a 240gr and a compressed load of 25.5gr 4198. The pressure was listed at 26,400 which is WAY below max. I just mention this in that it looks like in a .44 magnum case, it would be impossible to stuff it with anywhere near enough 4198 to run into pressure issues, and I woulss suspect the same is true with the 460. In any case, you would be safe using the larger bullet data, as 4198 has no issues being reduce loaded. I'm not sure what the pressure rating is for 460, but .454 Casull is like 60,000, so you have plenty of room to work with.

January 23, 2015, 06:56 PM	#3
buck460XVR Senior Member Join Date: December 28, 2006 Posts: 4,342	First off, I would go back to crimping the bullet in the cannelure. Powders like IMR4227 and H110 need a consistent heavy crimp for consistent burn and best accuracy. I would also try IMR 4227 at slightly compressed levels. Hornady lists 42.4 as max with their 300 gr XTP-Mag. My go to powder in my .460 revolver with 300 grainers is IMR4227 with H110/W296 next. While 4227 does not give me the velocity that H110/W296 does, it has great accuracy and is quite consistent in extreme temperature variations. Several years back since I already handloaded for my .460 revolver, my oldest son bought a Encore with a 20'' Pro Hunter Katahdin barrel. It too had a 1 in 16 twist. The loads that were extremely accurate outta my revolver were all over the place from my son's Encore. I went up and down the ladder with several different powders and a variety of bullets. Nuttin would do better than 4-5'' @ 100 yards. Our .44 mag carbines shot better than that, as did my .460 revolver. The gun shot better with .45 Colt loads than anything in .460. It also shot fairly well with factory 200 FTXs, but they have poor terminal performance outta my revolver on deer, so other than for yotes, they were not good for much outta the rifle. After a year of trying every combination I could find, my son gave up on the gun and traded it for a 1911. For the life of me, as easy as it was to find accurate loads for the .460 revolver, why we could never find anything satisfactory load for the long gun is still a mystery. On your other thread you mention bulged cases. Sounds, like you have some case head separation about to happen. You may have a headspace issue or a bad chamber going on. As for brass, I prefer Starline over the Hornady. Hornady brass is the only one I have had split...and it was just above the web.