Did I go past the max with .45 ACP and VV N320?

[buenhec]

I just loaded about 700 rounds of .45 ACP. I used 5.25 of VV N320, using a 200 grain lswc. According to a Lee book I have 5.4 is the max. I just check out the Vit chart which shows 5.1 as the max. My scale is pretty accurate give or take .1.

Am I safe and just getting close to the threshold or am I pushing +p? I usually use a STI 1911 or a Sig P220.

 

[fastbike]

I'm getting the feeling that this is a new load for you and you didn't shoot a few to check for issues before you loaded a bunch.

The 0.1 grain likely won't be a big issue considering .45 acp is a pretty forgiving round, but you might want to check before loading anymore.

 

[Walkalong]

Vihtavuori's second edition (1995) load book shows 5.5 Grs of N320 as max with a 200 Gr @ 1.240 O.A.L. for 1010 FPS at 20,000 PSI It shows 5.8 Grs N320 as max for the Hornady 200 Gr FMJ-CT (SWC) @ 1.240 O.A.L. for 983 FPS at 20,000 PSI.

Their online data stops at 5.1 Grs with the 200 Gr LSWC and 5.4 Grs with the Hornady bullet.

I have shot 5.4 Grs N320 with a Berry's 200 Gr HP @ 1.200 O.A.L. and 5.4 Grs N320 with a Hornady 200 Gr FMJ-CT (SWC) @ 1.260 O.A.L. with no problems. I was only getting a little over 700 FPS from a 4" 1911 with those loads with NO sign of pressure.

These loads were safe in my guns with my load procedure. Use at your own risk.

 

[buenhec]

I worked up some loads a few weeks ago at 4.7 grains, it gave me about 830 FPS. I really though I was loading at 5.1, I check and recheck all the time, for some reason my scale was off calibration by .2 or so and I ended up at 5.3. I will try them out and chrono them to see what they do.

 

[Afy]

Cartridge : .45 Auto (ACP) (CIP)
Bullet : .451, 200, Hornady FMJ-C/T 45157
Useable Case Capaci: 15.614 grain H2O = 1.014 cm³
Cartridge O.A.L. L6: 1.240 inch = 31.50 mm
Barrel Length : 5.5 inch = 139.7 mm
Powder : Vihtavuori N320

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

-20.0 55 4.64 857 326 12931 1962 100.0 0.817
-18.0 56 4.76 872 338 13514 1999 100.0 0.801
-16.0 58 4.87 887 350 14116 2035 100.0 0.785
-14.0 59 4.99 902 361 14737 2072 100.0 0.769
-12.0 60 5.10 917 373 15378 2108 100.0 0.755
-10.0 62 5.22 931 385 16039 2144 100.0 0.740 ! Near Maximum !
-08.0 63 5.34 945 397 16720 2180 100.0 0.727 ! Near Maximum !
-06.0 65 5.45 959 409 17420 2216 100.0 0.713 ! Near Maximum !
-04.0 66 5.57 973 420 18142 2252 100.0 0.701 !DANGEROUS LOAD-DO NOT USE!
-02.0 67 5.68 987 432 18883 2287 100.0 0.688 !DANGEROUS LOAD-DO NOT USE!
+00.0 69 5.80 1000 444 19646 2323 100.0 0.676 !DANGEROUS LOAD-DO NOT USE!
+02.0 70 5.92 1013 456 20430 2358 100.0 0.664 !DANGEROUS LOAD-DO NOT USE!
+04.0 71 6.03 1026 468 21235 2394 100.0 0.653 !DANGEROUS LOAD-DO NOT USE!
+06.0 73 6.15 1039 480 22062 2429 100.0 0.642 !DANGEROUS LOAD-DO NOT USE!
+08.0 74 6.26 1052 492 22911 2464 100.0 0.632 !DANGEROUS LOAD-DO NOT USE!
+10.0 76 6.38 1065 504 23782 2499 100.0 0.621 !DANGEROUS LOAD-DO NOT USE!

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 69 5.80 1022 464 22694 2254 100.0 0.642 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 69 5.80 966 414 16595 2424 100.0 0.719 ! Near Maximum !

 

[buenhec]

Great info AFY. Since I am using Cast Lead, do these figures vary a bit? Where did you get this data?

 

[Ridgerunner665]

Hornady book says 5.4 grains for 200 grain lead bullets
Sierra book says 6 grains for 200 grain jacketed bullets

 

[Afy]

buenhec: Quickload. Its the best bit of kit you can get.

 

[Halo]

What scale do you have that measures hundredths of a grain (5.25)?