Normal
Some rifle barrels are fast and some are slow so comparing just a couple rifles in different calibers will not prove beyond a doubt what velocity spread there will be.This is an 18" barrel my Savage 10SR in .308 shooting 150gr flat base speer spizter bullet.Charge weight 45.5-47.5 in .5gr steps IMR 4064 Looks like it topped out at 2,863 fps before velocity began falling off.Bullets seated 2.762" = .005 off the lands#1......... 2796 fps measured at 20 feet from the muzzle.#2.........2804 fps.#3.........2863 fps.#4..........2740 fps.#5..... error.This is a Ruger American with 22" barrel same powder and same steps.Bullet also seated .005" off the lands but seated longer 2.793"so .031" longer.#1 .......2756 fps. same 20 feet from muzzle.#2........2787 fps.#3........2898 fps.#4........2880 fps.#5........2793 fps.35 fps faster from the Longer barrel Ruger before velocity fell off.My accuracy node in my 30-06 Mossberg with 22" barrel and 150 gr flat base bullet was 3,030 fps.That was 52.5gr IMR 4064That is 132 fps difference with same barrel lengths.But that is not the fastest it would go and that is a book load.My fastest most accurate load was a 155 Sierra Palma bullet with a bunch of H43503,176 fps That thing was a laser but that bullet would pencil through a deer so i quit that load and bullet.Now my Savage 308 that had the 24" barrel was fast.That same sierra palma bullet #2156 seated to 2.898 which was .010" off the lands would go 29.0-2919 fps with 46.5gr Varget in Winchester cases.47.5 gr 2978 fps.175 Nosler Custom Competition seated into the lands OAL at 2.810" and 43.5 gr Varget was 2749 fps.308 Flat point 30-30 bullet with 45.7 Varget was 2940 fps in that 24" Savage heavy barrel.Those were all very accurate loads in my rifles.So the 24" 308 with the Palma bullet 2,978 FPS.Mossberg 22" 30-06 same bullet was 3,176 FPS.Both very accurate. and 198 FPS difference between the 2.Yea that 30-06 was loaded to modern pressures not old school pressures.I actually tested it at 100°F and went even more powder and broke over 3200 fps and got sticky bolt lift and backed off.That bullet has a very short bearing surface and did not shoot well going slow in those 10 twist barrels.I had to push it to get tight groups.Not something I care to do really.Fun with numbers.
Some rifle barrels are fast and some are slow so comparing just a couple rifles in different calibers will not prove beyond a doubt what velocity spread there will be.
This is an 18" barrel my Savage 10SR in .308 shooting 150gr flat base speer spizter bullet.
Charge weight 45.5-47.5 in .5gr steps IMR 4064 Looks like it topped out at 2,863 fps before velocity began falling off.
Bullets seated 2.762" = .005 off the lands
#1......... 2796 fps measured at 20 feet from the muzzle.
#2.........2804 fps.
#3.........2863 fps.
#4..........2740 fps.
#5..... error.
This is a Ruger American with 22" barrel same powder and same steps.
Bullet also seated .005" off the lands but seated longer 2.793"
so .031" longer.
#1 .......2756 fps. same 20 feet from muzzle.
#2........2787 fps.
#3........2898 fps.
#4........2880 fps.
#5........2793 fps.
35 fps faster from the Longer barrel Ruger before velocity fell off.
My accuracy node in my 30-06 Mossberg with 22" barrel and 150 gr flat base bullet was 3,030 fps.
That was 52.5gr IMR 4064
That is 132 fps difference with same barrel lengths.
But that is not the fastest it would go and that is a book load.
My fastest most accurate load was a 155 Sierra Palma bullet with a bunch of H4350
3,176 fps That thing was a laser but that bullet would pencil through a deer so i quit that load and bullet.
Now my Savage 308 that had the 24" barrel was fast.
That same sierra palma bullet #2156 seated to 2.898 which was .010" off the lands would go 29.0-2919 fps with 46.5gr Varget in Winchester cases.
47.5 gr 2978 fps.
175 Nosler Custom Competition seated into the lands OAL at 2.810" and 43.5 gr Varget was 2749 fps.
308 Flat point 30-30 bullet with 45.7 Varget was 2940 fps in that 24" Savage heavy barrel.
Those were all very accurate loads in my rifles.
So the 24" 308 with the Palma bullet 2,978 FPS.
Mossberg 22" 30-06 same bullet was 3,176 FPS.
Both very accurate. and 198 FPS difference between the 2.
Yea that 30-06 was loaded to modern pressures not old school pressures.
I actually tested it at 100°F and went even more powder and broke over 3200 fps and got sticky bolt lift and backed off.
That bullet has a very short bearing surface and did not shoot well going slow in those 10 twist barrels.
I had to push it to get tight groups.
Not something I care to do really.
Fun with numbers.