Trying to work up a 20,00 CUP load in a Ruger New Vaquero

[Tripplebeards]

I used Hodgon data to try and do the math. It says loaded at 1.600” out of a 7.5” barrel using 255 cast at 4.5 grains lists 8,800 cup with a velocity of 606 FPS. The max listed was 5.8 grains at 12,700 cup and 727 FPS. Well I load long at 1.650” so I have extra room for powder. I marked my case and compressing trailboss would be 10.2 grains. I loaded a few at 5.2 grain with a magnum primer and had an average velocity of 575 FPS. I am Guessing the magnum primer bumped my velocity a little. My plan is to use standard large primers this time around and try to get to 20,000 cup level 2 performance . I have been doing the math and at 5.2 grains loaded longer like I did with a magnum primer I’m approximately a 100 FPS slower. It looks like approx 9.3 FPS and 300 CUP is gained per every one tenth of a grain increment. If so, and I did my math correctly, 8.2 grains would take me to 20,000 CUP? I know I’ve shot 8.5 grains of TB through my NV with a led 255 grain boolit at an OAL of 1.650” and it was about the same recoil (or even a little less) as the black hills ammo.

Does anyone have quick load they can run my data through to see what my max load of TB I can run to get to 20,000 CUP loaded with a 255 grain cast boolit with an OAL of 1.650”? Thanks for the help. I always have read you can load all the way up to the boolit base with out compressing trail boss abs it still won’t be at max pressures? According to my math it would be way over 20,000 cup with the 10 grains I could fit in it without compressing. It’s the only powder I have currently on hand I can use in my NV that will keep it under 20,000 CUP. My goal is to get a velocity around a a 1000 FPS for a good deer load out of the 4 3/4” barrel.

I do have some 280 grain cast HP’s PC and GC in 50/50 alloy I can use as well.

[Harter66]

I'm told that TB gets erratic under 85% of case and won't take any compression .

9.5 Hercules Unique with a 452 255 @ 265 gr will go 1050 fps in NM BH 7.5" .
8.5 of same brings it back down to about 850 , there is little difference between this and the same with the NOE version of the 454424 @250 gr for velocity .

[P Flados]

QL is reasonably close to factory test data on velocity, but it is not a good tool for determining pressure in straight wall cases.

The hodgdon data has pressures much higher than reported by QL

I ran the table mode to show how velocities increase with increasing charges (see bottom of post).

QL shows 5087 psi at 4.5 gr where test data was 8800 psi. QL is 58% of test.
QL shows 7636 psi at 5.8 gr where test data was 12700 psi, QL is 60% of test

Lets say the QL/test ratio at your target 20000 is a conservative 56% or 11200 psi

Based on the table below, 7.25 gr is just under 11200 psi.

QL uses muzzle to breech for barrel length. Using 6.5" for this value, QL says 806 fps at 7.25 gr.

The above is rough estimate of a max load not to exceed 20000 psi and is well short of your desired 1000 fps.

Now even though I ran all of the above, I do not think I would push a nice gun that close to its limits using trailboss based my "guestimates" given that the program was so far off of test data for that powder.

From the Hodgdon data, CFE pistol would be your best bet in terms of velocity at max pressure. However, but QL does not have this powder so I could not estimate how much would be required for your target velocity.

The next best powder for 45 colt and 250 gr bullet from Hodgdon was HS-6. For some reason, QL with HS-6 is closer to test data for both pressure and velocity. My guess is that 13 gr of HS-6 would be close to your 20000 psi limit and would increase your velocity to very close to 1000 fps in your gun.

The HS-6 matched a whole lot better and seems better suited to getting close to your target velocity with a reasonable margin to the pressure limit for the gun.

Cartridge : .45 Colt (CIP)
Bullet : .452, 250, LYM LFN 454190
Useable Case Capaci: 29.422 grain H2O = 1.910 cm³
Cartridge O.A.L. L6: 1.600 inch = 40.64 mm
Barrel Length : 7.3 inch = 184.2 mm
Powder : IMR TrailBoss

Predicted data by increasing and decreasing the given charge,
incremented in steps of 3.571% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-35.7 49 4.50 603 202 5087 1149 99.9 1.593
-32.1 52 4.75 627 218 5528 1201 100.0 1.534
-28.6 55 5.00 650 234 5994 1252 100.0 1.481
-25.0 57 5.25 672 250 6482 1303 100.0 1.432
-21.4 60 5.50 693 266 6993 1354 100.0 1.387
-17.9 63 5.75 713 282 7526 1405 100.0 1.344
-14.3 66 6.00 733 298 8082 1456 100.0 1.305
-10.7 68 6.25 753 314 8660 1506 100.0 1.268
-07.1 71 6.50 772 330 9259 1557 100.0 1.234
-03.6 74 6.75 790 347 9880 1608 100.0 1.201
+00.0 77 7.00 808 363 10523 1658 100.0 1.171
+03.6 79 7.25 826 379 11187 1708 100.0 1.142
+07.1 82 7.50 843 395 11872 1758 100.0 1.114
+10.7 85 7.75 860 411 12579 1808 100.0 1.084
+14.3 88 8.00 877 427 13308 1858 100.0 1.056
+17.9 90 8.25 894 443 14058 1908 100.0 1.029 ! Near Maximum !

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 77 7.00 823 376 11933 1624 100.0 1.120
Data for burning rate decreased by 10% relative to nominal value:
-Ba 77 7.00 786 343 9053 1707 100.0 1.259

[P Flados]

Ok, just looking at the Alliant web site, I found that they list 9.5 gr Unique for a Speer 250 LSWC with 941 fps from a 5.5" barrel as a standard pressure 45 colt load.

Herco and Blue Dot are both shown with over 1000 fps.

[contender1]

If you notice,, the above posters have mentioned the use of different powders to achieve your goal.

There are reasons for this.

No one powder does it all.
Each gun is different.
Accuracy should be the main goal,, not math.
If hunting is to be the use,, then accuracy along with a proper bullet selection is necessary.
Using pressure numbers as a guide can be hard to calculate, due to many variations.

My suggestions;
Get a few different powders. I'd start with Unique as the first one, due to it's versatility. Especially with your stated goals.
Get a few more loading manuals,, and study what they say & suggest to meet your goals.
Select a good hunting bullet.
Work up a load using the manuals, and your bullet. Let your gun show you what it likes.

[Tripplebeards]

I hit the LGS today. They had one pound of HS-6 for $26.99, one pound of tite group for $21.99, and 4 one pound cans of unique in stock for $26.99 each. I ended up buying the last can of HS-6. I haven't read to many users simg titegroup . The only reading I found was an fear of overcharging with it. I know everyone like unique as well. I did read alot had good accuracy with around 13 grains of HS-6 and the lad data I found said I can run it up to 13.5 grains and stay in the 20,000 cup limit for level 2 performance with a 280 grain boolit. I will also use the powder for 9mm. My can had been there for a while as it had a good amount of dust on it.