Ok, I am going to try this again concerning my chronographing of the A2400 I have along with Federal 150 primers and Starline cases from the same LOT.
First let me say this about my test.
1. I am not a ballistic lab.
2. I am not a ballistician.
3. I try to be consistant in what I do concerning chronographing.
4. I do not pretend to be anything Im not.
5. These results are ONLY what I found on Sept, 18, 2018 with a temperature of 75 degrees which climbed slightly while chrongraphing.
6. I did not check the position of the throttle valve lever or the dark of the moon switch.
7. The ammo was loaded with the normal care I give all my ammo.
Here are the results.
Smith and Wesson M629 MG with a 4 Inch barrel.
Hensley and Gibbs 503 "Keith", all from the same alloy and sized the same with the same lube, with the narrow front drive band width at an OAL of 1.685 and crimped with a Lee FC die crimped stiff.
Load was 19.5 grains of A2400 Lot # 782-Z020416, Federal 150 primers, Starline cases.
Average velocity was 1247 FPS at 10 feet.
Same load in a Ruger SBH with a 3.75 inch barrel was 1272 FPS
Same load in a M69 with a 2.75 inch barrel was 1112 FPS.
Now this is just what I found out and each one can take it for what it is worth to them. Not asking whether higher charges are safe, unsafe etc.. Each will have to follow who and what they want to follow.
Again I am not trolling, baiting or calling out anyone by my post. I mean no harm, hurt or anguish to anyone on here. This post is made based on my knowledge, experience and/or beliefs. Nothing more. Please take it that way. Thank you.