Hang Fires

[Rifleman]

I took my first batch of reloads to the range and it did not go well, nothing but hang fires. I am shooting 7.7x58 Jap PPU brass (brand new)/150 gr PPU soft point with 41g of BL-C (2) using CCI #200 large rifle primers. I fired 5 rounds, 4 were 1 second hang fires, the last never fired but did have enough oompf to push the bullet into the rifling. I feel the primer is the issue and not the correct choice, what are your thoughts and recommendations?

Going forward I have two pounds of IMR 4895 coming.

[lyman]

how old are the primers?

take a few empty cases, prime, and chamber them,
fire them (in a safe place etc etc)

that will tell you if the primers are going bang like they should,,


wondering if you may benefit from Magnum primers?

[Art]

Primers are the first suspect, but how light are your loads? This can sometimes (rarely) happen with not enough powder in the case.

[Parashooter]

41 grains of BLC2 is a significant underload. QuickLOAD estimates the pressure at ~26,000 psi (CIP piezo measurement) - far below the CIP maximum of ~45,000psi. Medium to slow spherical rifle powders like BLC2 achieve their progressive burning performance via heavy deterrent coatings on the small granules. This means they won't ignite and burn well at pressures/temperatures significantly below normal working pressure. You'll need to shovel in more coal to get the fire burning hot enough to ignite the entire charge.

Below is a listing of QuickLOAD estimates (NOT TESTED DATA!) that should give you something to work on -

Cartridge : 7.7 mm x 58 Japan (Arisaka)
Bullet : .311 , 150 ,PrviPartizan SP BT B-382
Cartridge O.A.L. L6: 3.100 inch or 78.74 mm
Barrel Length : 25.0 inch or 635.0 mm
Powder : Hodgdon BL-C2

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.087% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

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

-10.9 71 41.00 2316 1787 25724 6455 90.5 1.578
-09.8 72 41.50 2343 1829 26520 6554 91.1 1.559
-08.7 72 42.00 2370 1871 27342 6651 91.7 1.540
-07.6 73 42.50 2398 1915 28189 6748 92.2 1.521
-06.5 74 43.00 2425 1958 29063 6842 92.7 1.502
-05.4 75 43.50 2452 2002 29966 6936 93.2 1.484
-04.3 76 44.00 2479 2046 30897 7027 93.7 1.466
-03.3 77 44.50 2506 2091 31852 7117 94.2 1.448
-02.2 78 45.00 2533 2137 32832 7206 94.7 1.430
-01.1 78 45.50 2560 2183 33837 7292 95.1 1.412
+00.0 79 46.00 2587 2229 34867 7376 95.6 1.395
+01.1 80 46.50 2614 2276 35924 7459 96.0 1.378
+02.2 81 47.00 2641 2323 37013 7539 96.3 1.361
+03.3 82 47.50 2668 2370 38134 7618 96.7 1.342
+04.3 83 48.00 2694 2418 39290 7694 97.1 1.324 ! Near Maximum !
+05.4 84 48.50 2721 2466 40480 7767 97.4 1.306 ! Near Maximum !

Based on these estimates, if I were loading for my own Type 99 with these components, I'd start at 46 grains and work up cautiously, not exceeding 50 grains. Be careful, though, this kind of exercise can be hazardous, especially for beginners.

[nf1e]

Some loaders feel that magnum primers are necessary for good ignition of BL-c (2) powder. Short firing pin protrusion can also cause slow fire in the oven.

[Rifleman]

With the primer shortage I have not been able to revisit the BL-C (2) powder but will in the future. I got my hands on 2 pounds of IMR 4895 and called Hodgdon for a recommended load, started at 41.5 and went to 43.5 using CCI #200 primers. Not one problem/hang fire and had my best group of 1.1 inch @ 50 yards firing off hand (42gr).

[bruce]

Re: 4895. Buy more! Sincerely. bruce.

[PWC]

If you have to keep this load, tip the barrel up to position the powder against the primer rather than just laying in the bottom of the case. Driving the bolt home will cause the powder to move toward the bullet, away from the primer.

[barretcreek]

Or switch to a cast bullet and use a filler.

[jjrothWA]

Make sure the primers are seated afar into the primer pocket.

You might not be completely seated.

Recently helped my friens with reloading for his 7.7 using the PPU case, made five cases per charge and all fired nicely.