Thread: Myth? - shorter barrel = use faster powder?

Originally Posted by Magnetite

I put some numbers through GRT for entertainment:

6.5x55 SE with 129gr Interlocks, 20" vs 29" barrel.

Max Loads (same charge, barrel length doesn't change the load)
20" 29"
2206H 2732 2983
2208 2713 2953
2209 2760 3041
2213SC 2738 3011
2217 2808 3105 (over 100% fill)

Optimal Barrel Time (Node 6.5 for 20" and 4.5 for 29")
20" 29"
2206H 2661 2938
2208 2620 2888
2209 2665 2968
2213SC 2640 2937
2217 2717 3023 (over 100% fill)

So if velocity is your sole criteria it looks like the barrel length is irrelevant. However for accuracy you would have to test it.

Yeah it's interesting. I've never used this type of program before .... really helpful.