Frustration with Alliant 4000MR

[fyrewall]

I have developed three good loads with Alliant 4000 MR. My .243 W (1-8) using 87 grain VMax bullets and 45.5 grains of 4000MR produces close to one hole groups at 100 and close to or slightly under 1 inch groups at 300. Same for the 105 Amax with 42.5. Using 4000MR in the .300 Win mag makes me happy, with accuracy about the same as the .243W using the 178 Hornady hpbt/AMax with 71.5 4000MR and the CCI 250 primer. All three loads jiggle steel plates way out there and the .243W & 87 Vmax picks off rodents just below the horizon.

Thinking to transfer this good 4000MR fortune to my new 6mm Rem, I started to work up loads. I was satisfied the 6mm was capable of good accuracy, getting similar results with the 87 VMax and H4350 as with the .243W 87 VMax/4000MR load.

Using 4000MR was a great disappointment - I failed. Looking at the case capacity using Alliant data for bullets of similar size and type (85 Speer BT vs. 87 VMax) and 105 Amax far less case capacity was realized than with the .243 with Alliant loads - looking at percent capacity. Groups were terrible, about 1.5 plus at 100 and shooting at 300 would be a waste or time and components.

I like 4000MR, it appears to be sort of an extruded ball powder similar in burning rate to Re19. One end of the tiny cylinder grain is round and the other cut off square. It meters extremely well from my powder measure with no grain cutting or bridging, 4000MR is a double base powder.

My guess is that the problem may be not enough case filling for max pressures for the 4000MR, a double base, higher density ball powder.

Re 23 shows promise and H4831 might work. Having access to good supplies of H4350 is comforting but it costs about $10 more per pound than the 4000 MR.

 

[Dusty Stevens]

So you found a powder that works with light bullets in a 243 AND excellent results in a 300 win mag? Consider yourself lucky because those 2 cartridges couldnt be farther from even similar. Id say just be happy with what you have and just go ahead and get a more mainstream powder for your 6mm and start over. Evidently that 4000 isnt a good match. I like 4350 or h1000 in a 6mm myself. Good luck. Life is too short to spend too much time trying to force something into working. Keep it movin man and have fun!

 

[Alliant Reloading]

Great response from Dusty Stevens; I don't think I could improve on that.
Thank you for experimenting with our powders fryewall.
Shoot well,
Paul

 

[DocBII]

Great response from Dusty Stevens; I don't think I could improve on that.
Thank you for experimenting with our powders fryewall.
Shoot well,
Paul

Just wish you would release data to QL. I had good luck with 2000 MR by using VV N-550 as an analogue, no such luck with 4000. 16 lbs. just getting old.

DocBII

 

[fyrewall]

How can something like 4000MR work so well in the .243W with 87 and 105 grain bullets and be less than acceptable in the 6mm Rem with the same bullets??? Both cartridges are not hugely different but apparently different enough. Using H4350 as a standard shows my 1-8 6mm Rem to be a good shooter with the 87 Vmax, multiple hits near the center of 3 inch steel at 300 2 days ago showed this. This past summer I got some 400 plus yard rodents using my 1-8 .243W with 4000MR, 87 Vmax bullets, CCI 200 primers and PPU and Winchester Brass.

 

[fyrewall]

Upon checking stuff, my 6mm brass needed to be trimmed a tiny bit. I at first trimmed the brass to the suggested trim length in the Hornady manual but apparently more trimming was needed. Loading 47 grains of 4000 MR with the 87 VMax in the 6mm Rem produced great results. Groups during a windy day session at 100 ran between .5 and .75. I was able to repeatedly hit my 3.5 inch mild steel target at 300 with this load. I normally shoot at a 3 inch target but that target got shot up so bad I replaced it.

The best performer with 4000 MR during that range session was with my 6mm AI. Loading 50 grains of 4000MR and the 87 Vmax in the 6mm AI produced essentially the same size groups at 100 at the 6mm Rem but at 300 a noticed improvement. Multiple hits on the repainted target blowing 3/8 or deeper craters into the mild steel target real close to each other to make one real big crater - higher velocity flatter trajectory less wind effect. The target swung in bigger arcs, more impact sound. This gotta be one good rodent load!

Next to be tested are .375-.338 loads with the 300 grain Sierra Game King and 72.2 grains of 4000MR. COAL is 3.3 inches and the base of the boat tail appears to be imbedded into the powder by .050 inches making it slightly compressed. Shooting the .375-.338 at ranges of 300 yard or so shows the .375-.338 a good performer with 250-270 grain bullets.