BattleRife
CGN Ultra frequent flyer
- Location
- of No Fixed Address
The intended audience for this is a little mixed. There is definitely some good learnin' in here for the newbies, and I guess I am looking for some empathy and some ideas from the veteran loaders.
Last weekend, I was out at the range doing some load development. The rifles in question were a 1943 vintage Winchester M1 Garand (in generally ratty condition) and my weeks old Norinco M14S. I wasn’t doing anything fancy, just experimenting with powder charges trying to get some loads that would come close to duplicating standard ballistics for the M2 ball (150 grain flat base bullet at 2804 fps) and the 7.62x51mm NATO ball (147gr FMJBT at 2700 fps).
I was working with IMR 4895 and Hodgdon 335 in the M14, and just the 4895 for the Garand. Bullets for both were some arsenal-grade 147 FMJBT I have. Powder charges started 3-4 grains under where I expected to finish, and went up in 0.5gr increments (I won’t give charge numbers, as some ended up on the hot side, as you will see). Velocities were determined by shooting over my Chrony, which I didn’t measure, but guess was placed about 2.5m ahead of the bench. I loaded five rounds of each charge for the 7.62x51, and eight rounds of each for .30-06. I also chronied some surplus ammo I had, for 19 strings in total.
Now check out these velocities and deviations:
One asterisk means the shot in discussion had the lowest velocity.
Two asterisks means the shot in discussion had the highest velocity.
7.62x51mm loaded with IMR4895:
#1- Average Velocity: 2615 fps
Extreme Spread, including 1st shot: 100 fps *
Extreme Spread, not including 1st shot: 21 fps *
#2 - Average Velocity: 2662 fps
Extreme Spread, including 1st shot: 39 fps *
Extreme Spread, not including 1st shot: 22 fps *
#3 - Average Velocity: 2701 fps
Extreme Spread, including 1st shot: 64 fps
Extreme Spread, not including 1st shot: 64 fps
#4 - Average Velocity: 2730 fps
Extreme Spread, including last shot: 65 fps **
Extreme Spread, not including last shot: 13 fps **
#5 - Average Velocity: 2768 fps
Extreme Spread, including 1st shot: 23 fps **
Extreme Spread, not including 1st shot: 16 fps **
7.62x51mm loaded with H335:
#1- Average Velocity: 2637 fps
Extreme Spread, including 1st shot: 45 fps *
Extreme Spread, not including 1st shot: 19 fps *
#2 - Average Velocity: 2685 fps
Extreme Spread, including 1st shot: 57 fps *
Extreme Spread, not including 1st shot: 23 fps *
#3 - Average Velocity: 2711 fps
Extreme Spread, including 1st shot: 38 fps
Extreme Spread, not including 1st shot: 38 fps
#4 - Average Velocity: 2765 fps
Extreme Spread, including last shot: 27 fps **
Extreme Spread, not including last shot: 19 fps **
#5 - Average Velocity: 2787 fps
Extreme Spread, including 1st shot: 24 fps **
Extreme Spread, not including 1st shot: 16 fps **
.30-06 loaded with IMR4895:
#1- Average Velocity: 2475 fps
Extreme Spread, including 1st shot: 130 fps **
Extreme Spread, not including 1st shot: 65 fps **
#2 - Average Velocity: 2538 fps
Extreme Spread, including 1st shot: 172 fps **
Extreme Spread, not including 1st shot: 70 fps **
#3 - Average Velocity: 2555 fps
Extreme Spread, including 1st shot: 154 fps **
Extreme Spread, not including 1st shot: 50 fps **
#4 - Average Velocity: 2559 fps
Extreme Spread, including 1st shot: 72 fps *
Extreme Spread, not including 1st shot: 60 fps *
#5 - Average Velocity: 2587 fps
Extreme Spread, including 1st shot: 71 fps **
Extreme Spread, not including 1st shot: 54 fps **
#6 - Average Velocity: 2596 fps
Extreme Spread, including 1st shot: 45 fps
Extreme Spread, not including 1st shot: 45 fps
Milsurp Loads:
#1- Eight shots .30-06 M2 Ball (LC 69)
Average Velocity: 2568 fps
Extreme Spread, including last shot: 76 fps **
Extreme Spread, not including last shot: 65 fps **
#2 - Ten shots 7.62x51 Spanish Ball (SB-79)
Average Velocity: 2654 fps
Extreme Spread, including last shot: 85 fps **
Extreme Spread, not including last shot: 41 fps **
#3 - Ten shots 7.62 NATO Ball (FNM-76)
Average Velocity: 2701 fps
Extreme Spread, including 1st shot: 27 fps
Extreme Spread, not including 1st shot: 27 fps
Lots of data for sure. Here are the points that I thought were interesting.
- Out of 19 strings, the first shot was highest or lowest on 11 of them.
- Of the remaining eight strings, the last shot was highest or lowest on four
- Of the 11 instances where the first shot was the culprit, it "blew" (added at least 50% to) the extreme spread eight times.
- The IMR and Hodgdon loads for the 7.62 were extremely similar, even following the same pattern of first shot low, first shot low,first shot not a factor, last shot high, first shot high.
- Both extreme spread and the problem with terminal shots blowing the stats diminish as charges go higher.
- A load for H335 that according to my Hodgdon No.25 manual is a bit under max is clearly over pressure in my situation. It might be the Federal Match brass.
- Portuguese NATO ball is excellent. I want more.
While flipping through my Hatcher's Notebook the other day, I found a paragraph on how the position of powder in the case affected velocities in the .30-06 M1 ball cartridge. Studies showed that if they primer was in the rear of the case against the primer, velocities were about 50 fps higher than if the powder was at the front of the case, near the bullet. I think that this explains much of the first shot variation, as loading a round by dropping the bolt from the HOD is much gentler than the slamming it gets when the gun is self-loading. This is especially true in my ratty Garand, which requires a strong bump on the op rod to strip the first round from the clip. It also explains why the problem gets less pronounced as the case gets more full.
What I have no explanation for is why the last seems over-represented in messing up my data.
I am also soliciting opinions on loads for the Garand. Strictly velocity wise, it seems I have room to go, but the surplus ammo doesn't get close to its nominal ballistics, either. What do people think? Should I try to do better, or is a shot-out barrel that spent most of 1965-67 in a rice paddy incapable of reaching spec velocity with safe pressures?
Last weekend, I was out at the range doing some load development. The rifles in question were a 1943 vintage Winchester M1 Garand (in generally ratty condition) and my weeks old Norinco M14S. I wasn’t doing anything fancy, just experimenting with powder charges trying to get some loads that would come close to duplicating standard ballistics for the M2 ball (150 grain flat base bullet at 2804 fps) and the 7.62x51mm NATO ball (147gr FMJBT at 2700 fps).
I was working with IMR 4895 and Hodgdon 335 in the M14, and just the 4895 for the Garand. Bullets for both were some arsenal-grade 147 FMJBT I have. Powder charges started 3-4 grains under where I expected to finish, and went up in 0.5gr increments (I won’t give charge numbers, as some ended up on the hot side, as you will see). Velocities were determined by shooting over my Chrony, which I didn’t measure, but guess was placed about 2.5m ahead of the bench. I loaded five rounds of each charge for the 7.62x51, and eight rounds of each for .30-06. I also chronied some surplus ammo I had, for 19 strings in total.
Now check out these velocities and deviations:
One asterisk means the shot in discussion had the lowest velocity.
Two asterisks means the shot in discussion had the highest velocity.
7.62x51mm loaded with IMR4895:
#1- Average Velocity: 2615 fps
Extreme Spread, including 1st shot: 100 fps *
Extreme Spread, not including 1st shot: 21 fps *
#2 - Average Velocity: 2662 fps
Extreme Spread, including 1st shot: 39 fps *
Extreme Spread, not including 1st shot: 22 fps *
#3 - Average Velocity: 2701 fps
Extreme Spread, including 1st shot: 64 fps
Extreme Spread, not including 1st shot: 64 fps
#4 - Average Velocity: 2730 fps
Extreme Spread, including last shot: 65 fps **
Extreme Spread, not including last shot: 13 fps **
#5 - Average Velocity: 2768 fps
Extreme Spread, including 1st shot: 23 fps **
Extreme Spread, not including 1st shot: 16 fps **
7.62x51mm loaded with H335:
#1- Average Velocity: 2637 fps
Extreme Spread, including 1st shot: 45 fps *
Extreme Spread, not including 1st shot: 19 fps *
#2 - Average Velocity: 2685 fps
Extreme Spread, including 1st shot: 57 fps *
Extreme Spread, not including 1st shot: 23 fps *
#3 - Average Velocity: 2711 fps
Extreme Spread, including 1st shot: 38 fps
Extreme Spread, not including 1st shot: 38 fps
#4 - Average Velocity: 2765 fps
Extreme Spread, including last shot: 27 fps **
Extreme Spread, not including last shot: 19 fps **
#5 - Average Velocity: 2787 fps
Extreme Spread, including 1st shot: 24 fps **
Extreme Spread, not including 1st shot: 16 fps **
.30-06 loaded with IMR4895:
#1- Average Velocity: 2475 fps
Extreme Spread, including 1st shot: 130 fps **
Extreme Spread, not including 1st shot: 65 fps **
#2 - Average Velocity: 2538 fps
Extreme Spread, including 1st shot: 172 fps **
Extreme Spread, not including 1st shot: 70 fps **
#3 - Average Velocity: 2555 fps
Extreme Spread, including 1st shot: 154 fps **
Extreme Spread, not including 1st shot: 50 fps **
#4 - Average Velocity: 2559 fps
Extreme Spread, including 1st shot: 72 fps *
Extreme Spread, not including 1st shot: 60 fps *
#5 - Average Velocity: 2587 fps
Extreme Spread, including 1st shot: 71 fps **
Extreme Spread, not including 1st shot: 54 fps **
#6 - Average Velocity: 2596 fps
Extreme Spread, including 1st shot: 45 fps
Extreme Spread, not including 1st shot: 45 fps
Milsurp Loads:
#1- Eight shots .30-06 M2 Ball (LC 69)
Average Velocity: 2568 fps
Extreme Spread, including last shot: 76 fps **
Extreme Spread, not including last shot: 65 fps **
#2 - Ten shots 7.62x51 Spanish Ball (SB-79)
Average Velocity: 2654 fps
Extreme Spread, including last shot: 85 fps **
Extreme Spread, not including last shot: 41 fps **
#3 - Ten shots 7.62 NATO Ball (FNM-76)
Average Velocity: 2701 fps
Extreme Spread, including 1st shot: 27 fps
Extreme Spread, not including 1st shot: 27 fps
Lots of data for sure. Here are the points that I thought were interesting.
- Out of 19 strings, the first shot was highest or lowest on 11 of them.
- Of the remaining eight strings, the last shot was highest or lowest on four
- Of the 11 instances where the first shot was the culprit, it "blew" (added at least 50% to) the extreme spread eight times.
- The IMR and Hodgdon loads for the 7.62 were extremely similar, even following the same pattern of first shot low, first shot low,first shot not a factor, last shot high, first shot high.
- Both extreme spread and the problem with terminal shots blowing the stats diminish as charges go higher.
- A load for H335 that according to my Hodgdon No.25 manual is a bit under max is clearly over pressure in my situation. It might be the Federal Match brass.
- Portuguese NATO ball is excellent. I want more.
While flipping through my Hatcher's Notebook the other day, I found a paragraph on how the position of powder in the case affected velocities in the .30-06 M1 ball cartridge. Studies showed that if they primer was in the rear of the case against the primer, velocities were about 50 fps higher than if the powder was at the front of the case, near the bullet. I think that this explains much of the first shot variation, as loading a round by dropping the bolt from the HOD is much gentler than the slamming it gets when the gun is self-loading. This is especially true in my ratty Garand, which requires a strong bump on the op rod to strip the first round from the clip. It also explains why the problem gets less pronounced as the case gets more full.
What I have no explanation for is why the last seems over-represented in messing up my data.
I am also soliciting opinions on loads for the Garand. Strictly velocity wise, it seems I have room to go, but the surplus ammo doesn't get close to its nominal ballistics, either. What do people think? Should I try to do better, or is a shot-out barrel that spent most of 1965-67 in a rice paddy incapable of reaching spec velocity with safe pressures?
