What is better for 230 gr XPT .45ACP. Bullseye or Unique (witch I have a lot of) or something else. I have no more W231 left
I consider Bullseye pistol powder the standard powder for the 45 ACP. We know from Clawson's book, the original powder used in the cartridges for the 1910 tests, which were the last before the 1911 was adopted, was Bullseye Pistol powder. The charge was 5.0 grains with a 230 FMJ at 800 fps. This load was a common Hardball target load by 2700 Bullseye Pistol competitors. If you search, you will find a number of old military drawings where the specified powder is Bullseye pistol powder.
Most of the 2700 Bullseye Pistol competitors I know use Bullseye pistol powder, followed by Titegroup, and a couple of WST users. That sport requires an accurate powder that burns well, functions the pistol with minimum recoil. All of these powders do that. Bullseye/Titegroup are well suited to the 1911 they have a fast pressure rise, followed by a quick pressure drop which ideal for this mechanism. A swift kick to the slide followed by a pressure drop that keeps the case from clinging to the chamber during extraction. You want all the bolt thrust imparted to the breech face, you don't want case friction slowing the mechanism. You also don't want a powder with a slow pressure drop as that will over accelerate the slide which will damage the pistol in time. You can find lots of cracked slide pictures on 1911forum, and I think I saw one where the slide nose cracked. Those guys are shooting tens of thousands of rounds, and hard recoil shows up as fatigue fractures. There are lots of slower powders than Bullseye/Titegroup, I don't know if there are faster, or why anyone would want faster. In so far as the 1911, it was developed around Bullseye pistol powder, and 230 gr bullets.
These are old loads for the 1911, and you can see the allowed velocity spread.
I chronograph my loads and tailor them so 230 gr bullets are moving at 800 fps plus or minus at 70 to 80 degrees. I have determined that a 230 with 5.0 grs of Bullseye Pistol powder moves around 800 fps, plus or minus. I think Unique is an excellent powder in the 45 ACP, and to get 800 fps I used 5.5 grs of Unique. In colder weather, the bullet moves slower, don't we all
if you can find AA#5, it shoots well in the 1911
the secret to impressive looking groups, is not to place the target too far away from the muzzle.
some Unique data with 230 grain bullets
Kimber Custom Classic
230 LRN Valiant 5.5 grs Unique lot UN331 1989 Mixed brass WLP (brass)
OAL 1.250" taper crimped 0.469"
16-May-09 high 83 °F
Ave Vel = 827.4
Std Dev = 17.63
ES = 85.68
High = 871.6
Low = 785.9
Number rds= 31
230 LRN Valiant 6.0 grs Unique lot UN387 6/21/93 Mixed brass WLP
OAL 1.250" taper crimped 0.469"
18-Mar-07 T = 62 °F
Ave Vel = 898
Std Dev = 21.44
ES = 75.58
High = 944.3
Low = 868.7
N = 25
accurate lots recoil 15' foot ejection
230 LRN Valiant 6.0 grs Unique lot 6/21/1998 Mixed brass WLP (nickle)
OAL 1.250" taper crimped 0.469"
16-May-09 high 83 ° F
Ave Vel = 885
Std Dev = 16.79
ES = 67.26
High = 917.8
Low = 850.5
N = 30
strong recoil 15' foot ejection
230 LRN Valiant 6.5 grs Unique lot UN387 6/21/93 Mixed brass WLP
OAL 1.250" taper crimped 0.469"
18-Mar-07 T = 62 °F
Ave Vel = 926.4
Std Dev = 16.64
ES = 71.16
High = 963.4
Low = 892.3
N = 32
light leading accurate centered hard recoil 20 foot ejection