13.0 gr 2400 = 6.5 gr Unique

[Low Budget Shooter]

Here's a bit of chrony data. It is a small sample, but someone might find it useful sometime. It shows that with a 158-ish grain bullet, in a 6" revolver, 6.5 grains Unique and 13.0 grains 2400 give similar average velocity.

6" Barrel S&W 19-3
Federal 357 Cases
S&B SPP
80 degrees
359429 hollowpoint 160 grains

6.5 grains Unique 1105 fps average
-powder forward 1097, 1051
-powder rearward 1160, 1113

13.0 gr 2400 1117 fps average
-powder forward 1099, 1104, 1115
-powder rearward 1134, 1134 (yes, two different shots)

Here's some more data from the same session. Everything is the same except the bullet weight and powder charge.

358429 solid 170 grains

6.0 grains Unique 975 fps
-powder forward 953, 962, 955
-powder rearward 1026, 975

12.2 grains 2400 1040 fps
-powder forward 1012, 1065, 1059
-powder rearward 1063, 1005

[Hick]

Yes-- Unique is a significantly faster burning powder-- which means it reaches peak pressure faster with less powder. On the other hand, 2400 will give a somewhat more gentle acceleration-- but still reach the same velocity-- but it takes more powder. I've seen threads talking about the trade-offs between fast high pressure versus more gentle acceleration, but I can't say I fully understand how to decide which is best in a given situation.

[WALLNUTT]

In 30-06 10g Unique= 12gr 2400 with 175gr bullet. Around 1340fps

[Geezer in NH]

Don't care about speed, started with the Lyman 311291, 13 grains red dot = 2 1/2 at 50 yards, 7 grains of unique = 4 inches, 18 grains of 2400 = 1 inch at 50 yards.

[swheeler]

Don't care about speed, started with the Lyman 311291, 13 grains red dot = 2 1/2 at 50 yards, 7 grains of unique = 4 inches, 18 grains of 2400 = 1 inch at 50 yards.

A little load development would yield different results with those powders, seek the sweet spot.

[Geezer in NH]

No doubt but, 1 Inch is sweet to me so I shoot more and am happy. Not looking for the cheapest load.

[waco]

Yes-- Unique is a significantly faster burning powder-- which means it reaches peak pressure faster with less powder. On the other hand, 2400 will give a somewhat more gentle acceleration-- but still reach the same velocity-- but it takes more powder. I've seen threads talking about the trade-offs between fast high pressure versus more gentle acceleration, but I can't say I fully understand how to decide which is best in a given situation.

Matching the pressure of the load to the strength of your alloy is something to consider....

[dg31872]

Geezer, was that in a 30-06?

[robg]

More pleasant to shoot with 2400 more of a push than a jab .

[Geezer in NH]

Geezer, was that in a 30-06?

Yes 30/06 rem 700 BDL

[Kosh75287]

It's been my experience that, the harder one pushes things, the faster, tighter, and cleaner that Unique shoots, at least in .357 Magnum. The choice between Unique and 2400 may also have as much to do with barrel length of the weapon in question. I use 7.5/Unique/158LSWC or RNFP in my 4" Ruger Police Service Six, I've never seen much in the way of un-burned powder or other signs of incomplete combustion in the bore. If I shoot 14.0-15.0/2400/158LSWC/RNFP, I can gain about 25 f/s, but the revolver grimes up quickly. I've never been able to get 2400 to burn completely in a 6" barrel, but the extra 2" of barrel gave rise to velocity increases of 100 - 150 f/s. I CAN get Alliant 2400 to burn nearly completely in my 7.5" .45 Colt Ruger Redhawk, if I exceed 19.0gr/2400/250RNFP, but I find accuracy drops off (MIGHT be me, but I don't think so) compared to 18.5/2400/250RNFP.

[Low Budget Shooter]

Interesting info. I never fail to learn something helpful from you guys.