Brain Overlaod

[xilegend]

Finally ready to start my first loads. 45acp 230g jacketed round nose bullet. Using a Lee Challenger Press. My goal is to create a mid range round for target shooting, and am using Power Pistol with a vmd of .0889. My "problem" is that the Lyman book states loads should be 6.4 -7.2. However, my data sheets with the dies, shows a load of 7.1 -8.1. That is such a discrepancy that I look for additional input

 

[VERT]

Try Alliant Bullseye and Power Pistol Loads - Practical Handgun


OP I would start around 6.2. You mentioned VMD. Are you using an auto disk powder measure? If so the little disks only measure in about .3-.4 increments. The chart is close but you better double check on a scale.

 

[trophyhunter]

Your pressure ceiling from SAMMI is 21,000 psi for standard .45 acp load, here's some quick load predictions seating the bullet to a depth of 1.260 for the COL. Does that help give you some perspective of where a safe starting point is to work up your load?

Cartridge          : .45 Auto (ACP) (SAAMI)Bullet             : .451, 230, Hornady FMJ-RN ENC 45177
Useable Case Capaci: 13.303 grain H2O = 0.864 cm³
Cartridge O.A.L. L6: 1.260 inch = 32.00 mm
Barrel Length      : 4.0 inch = 101.6 mm
Powder             : Alliant POWER PISTOL


Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.


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


-20.0   58     5.60    671     230   10757   2726     63.4    0.759
-18.0   59     5.74    687     241   11239   2836     64.4    0.744
-16.0   60     5.88    702     251   11733   2946     65.4    0.729
-14.0   62     6.02    717     262   12240   3058     66.4    0.714
-12.0   63     6.16    732     274   12763   3171     67.4    0.700
-10.0   65     6.30    747     285   13306   3285     68.4    0.686
-08.0   66     6.44    762     297   13869   3400     69.3    0.673
-06.0   68     6.58    778     309   14452   3517     70.3    0.660
-04.0   69     6.72    793     321   15057   3634     71.2    0.648
-02.0   70     6.86    808     333   15683   3752     72.2    0.636
+00.0   72     7.00    823     346   16331   3871     73.1    0.624
+02.0   73     7.14    839     359   17002   3990     74.0    0.613
+04.0   75     7.28    854     372   17696   4110     74.9    0.601
+06.0   76     7.42    869     386   18414   4230     75.8    0.591  ! Near Maximum !
+08.0   78     7.56    884     399   19155   4351     76.7    0.580  ! Near Maximum !
+10.0   79     7.70    900     413   19922   4473     77.5    0.570  ! Near Maximum !

 

[VERT]

Based on the above chart I would be looking at 6.2 - 6.8 grains. The chart shows data for a 4" barrel. Also the actual bullet design and OAL will affect velocity a bit. But following the chart and the website I linked the power factor should be between 170 - 185 (velocity x bullet weight). For a little perspective USPSA requires a power factor of 165 to make "major". From what I have read military ball ammo is around 184 PF out of a 4.25" gun. Not exact I know but that gives you an idea.

 

[trophyhunter]

Pressure will remain constant, but for reference to say a 5" style 1911 here's a spreadsheet for the same load and a 5" barrel showing speed increase from the previous model at 4".

Cartridge          : .45 Auto (ACP) (SAAMI)Bullet             : .451, 230, Hornady FMJ-RN ENC 45177
Useable Case Capaci: 13.303 grain H2O = 0.864 cm³
Cartridge O.A.L. L6: 1.260 inch = 32.00 mm
Barrel Length      : 5.0 inch = 127.0 mm
Powder             : Alliant POWER PISTOL


Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.


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


-20.0   58     5.60    715     261   10757   2172     66.3    0.879
-18.0   59     5.74    731     273   11239   2257     67.4    0.861
-16.0   60     5.88    747     285   11733   2343     68.4    0.844
-14.0   62     6.02    762     297   12240   2430     69.4    0.827
-12.0   63     6.16    778     309   12763   2518     70.4    0.810
-10.0   65     6.30    794     322   13306   2606     71.4    0.795
-08.0   66     6.44    810     335   13869   2695     72.4    0.779
-06.0   68     6.58    826     349   14452   2784     73.3    0.764
-04.0   69     6.72    842     362   15057   2874     74.3    0.750
-02.0   70     6.86    858     376   15683   2964     75.2    0.736
+00.0   72     7.00    874     390   16331   3055     76.1    0.722
+02.0   73     7.14    890     404   17002   3146     77.0    0.709
+04.0   75     7.28    906     419   17696   3237     77.9    0.696
+06.0   76     7.42    922     434   18414   3328     78.7    0.684  ! Near Maximum !
+08.0   78     7.56    938     449   19155   3419     79.6    0.671  ! Near Maximum !
+10.0   79     7.70    954     464   19922   3511     80.4    0.660  ! Near Maximum !

 

[xilegend]

based upon what I am seeing, a 6.6g charge should be just fine. became concerned when the lee chart was as high as it was, and did not want an "undersize" load. And yes, I have verified the measurement with a scale, Shooting a Taurus (mine) and a Rock Island (wife's) both with 5" barrels

 

[SSGSAD]

First loads, for this cal., gun, or period..... Remember, that a semi auto, minimum, will need to be "powerful" enough to work the action .....

 

[trophyhunter]

based upon what I am seeing, a 6.6g charge should be just fine. became concerned when the lee chart was as high as it was, and did not want an "undersize" load. And yes, I have verified the measurement with a scale, Shooting a Taurus (mine) and a Rock Island (wife's) both with 5" barrels

You're probably just shy of the sweet spot at 6.6g, since powder is so scarce right now I'll just give you my pet load for 230g FMJRN and Power Pistol it's really close to where you're thinking it's 6.8 grains with a COL of 1.250 that load duplicates the National Match load data for 1929 In Hatcher's Textbook of Pistols and Revolvers written in 1935 that calls for 230gr ball at 816 fps 25' from the muzzle.

It sure doesn't hurt to hand weigh charges and load 15 of each in increments to shoot 3 groups of five in each charge weight but I tested it for groups and chronographed it many times over the years with different lot numbers of power pistol and never deviated from the load of 6.8g

I just wanted you to see some of the science involved first, and good on you for being leery of anything Lee publishes. That company to the best of my knowledge has never once tested a single load they publish it's just reprinted from various source material in their tool insert guides and manuals.

 

[AllenM]

Power pistol is one of my favorite powders in 45. 6.8 grs under a 230 round nose seating at 1.260 is a nice accurate load. it is toward the top end though.
I have went higher. but 6.8 was the sweet spot for accuracy in all my 5" 1911's
I think power pistol likes to run toward the top end of the scale.
If you want plinking loads I would try Win 231

 

[VERT]

Well I have some Power Pistol. Might have to get some 230 grain ball and give it a shot.

 

[xilegend]

Thanx trophy hunter, since I haven't made any yet, will go ahead and bump up to 6.8g. Win 231 would have been my first choice, but when there isn't any, you use what can you get. Will warm up enough this weekend looking forward to heading to the range, and will let you know the end results. Very familiar with the "science" part of this, have spent many years working with black powder and various loads for muzzleloaders. But black powder is a lot more predictable than the plethora of gun powders, that are available.

 

[trophyhunter]

Glad to help, power pistol, AA#5, HS-6 just to name a few are excellent powders for making that load but require enough minimum pressure to burn uniformly and produce consistent velocities and groups. Powder puff (range loads) as many call them using those powders perform poorly and leave your gun looking like the ash clean out pan on a wood stove.

You'll read threads all the time of people complaining they hate powder brand X, gun is filthy etc. They just have no idea how to construct and test for a proper load, at the end of the day when you're doing load work up's and shooting groups with samples of various charge weights your gun will tell you when you have it right.

I would encourage you to hand weigh and charge a couple batches in lesser increments just to shoot a few groups working up to that load to see it for yourself. As you work toward that load of 6.8 you should feel the recoil impulse become smooth and consistent and the groups on paper tighten up.