45 Colt Tier II Load: Alliant 2400 in 10" Barrel?

Going to send in my FA83 to get the barrel switched out from a 6" to a 10". For typical Tier II 45 colt loads, is 2400 still a good powder to use or should I go with a slower burn rate? Will the longer barrel change the pressure or affect leading in any crazy way?

The load I currently use is 16gr/2400/250 WFNGC but I will be bumping up the powder to get faster speeds over the next couple of developments. Most published load data is for 5.5-7.5" barrels so I want to make sure I'm not overlooking something basic here.

thanks
Mat

Nope. Pressure is on the decline in the 6”, so 10 is moot. The old adage is to use the longest barrel for lead, so if ya get a good barrel, performance should improve. 2400? Accuracy is where you find it.

Pressure? Not affected by barrel length. Peak pressure will occur while the boolit is still in the cylinder.

2400 does not erode barrel faces and forcing cones like the ball powders H110/W296, Lil’Gun and similar. 2400 can get you some serious loads in a heavy 45 Colt cylinder.

Only possible downside is you might run out of lube before the boolit can exit that long bore. It’ll be traveling mighty fast that last couple of inches and it wouldn’t be surprising if you get some leading near the muzzle. If it happens, then you start looking for a better lube. If it doesn’t, then you already have a great lube!

Keep us posted on how it goes.

For my uses, most of which involve carrying the revolver, 3 to 5” is my sweet spot. My 7.5” guns rarely get out.

great info, very helpful. thank you

:popcorn:

Will be watching this thread with interest. I have limited experience with my .45 Colt 7.5" Blackhawk. I intended to keep my shots on Whitetail under 50 yards. I settled on the RCBS 270SAA bullet cast at 12bhn, pushed by 18 grains of Alliant 2400, for about 1150 fps. If I remember correctly, that is the top of 'Tier II' loads with that bullet? At the time I purchased a NOE 270 grain wfn hollowpoint mold, decided the 270SAA was all I needed. Both my shots at around 20 yards were complete pass throughs, didn't find either. I didn't plan on or expect any significant expansion. Bears aren't a concern for me, so the above load works fine. I 'stand hunt', so carrying my 7.5" Blackhawk is OK. hc18flyer

I have found that there seems to be little change in accuracy demands from shorter barrels to the longer ones. Except for the very slowest of powders, most of the powder's work is about done by the time the bullet enters the forcing cone.

I have a Colt New Service, which I consider to be a fairly heavy revolver, but not really quite reaching up into the TIER II area. My normal everyday load for the 250 gr. Keith type Lyman 454424 is 8.8 gr. of Unique for right at 915 fps, which is probably approaching close to the top pressure area for many weaker 45 Colt revolvers. In my 5 1/2" Colt New Service it is a tack driver load.

I wanted to work up a hunting load for the RCBS 270 45 SAA bullet, which actually drops out of the mold with normal hardness alloy at more like 280 gr. I wished to stay under 20,000 psi Max. for my warmest loads, even though that is a good bit higher pressure than many 45 Colt revolvers should endure. I would only shoot that much pressure with my hunting loads even though the big Colt New Service could likely handle it okay on a regular basis. I do not, however, want to push the old revolver too hard though. After all, it is getting up there in age. It was born in 1939 and is even 13 years older than I am.

I tried working up loads for the 280 gr. RCBS bullet using the appropriate slower ball powders as well as 2400. I found that most of the ball powders in this category needed more pressure to attain accuracy than I was willing to subject the Colt New Service to, or certainly greater than 20k psi. Likewise for the 2400. I found that 16 gr. loads of 2400 were starting to attain the better accuracy and even healthier loads of 2400 even increased that accuracy. But for sure, the pressure needed to get efficient powder burn was really starting to get up there. More than I thought the decently heavy framed Colt New Service should be tasked with.

Lil'Gun powder came to my rescue as I was able to push the big 280 gr. RCBS bullet to a lightning flash speed of 925 fps. with great accuracy without showing such high pressure. I settled on that load for my heavy hunting load. Not TIER II load level though.

I always liked 2400 for my heavy .44 mag. loads as well as in my heavier .357 mag. loadings. The 2400 powder works well and is very accurate with enough pressure, so I would imagine, from thinking about my results during my distant past testing, 2400 used in TIER II 45 Colt revolvers should do just fine as it will be able to achieve the pressures needed to burn very consistently and give one a good everyday load.

But, give the ball powders a test. Lil'Gun and WC-820/AA-#9 as well as 296/H110 might just do you well. Likely a bit harder on the forcing cone perhaps, but still worth testing.