If you we're shooting a Barnes TSX banded boat tail bullet with a certain weight of powder, and then switched to a "standard" soft point boat tail bullet with the same weight of powder:

Which bullet would you suspect to have a greater velocity?

Which bullet would you suspect to cause the greater pressure?



(Assume bullets of same weight, and caliber, shot from the same rifle)

quote:

Originally posted by Scott:
Which bullet would you suspect to have a greater velocity?

Which bullet would you suspect to cause the greater pressure?

From recent experience with two different calibers, I'd expect the "standard" (i.e. non TSX) bullet to generate the higher pressures. Under normal circumstances, this would probably also translate to higher velocity for the "standard" bullet.

In one of the recent instances of comparison TSX vs. "standard" bullet, max load for the standard bullet was established quite a bit below max for TSX. It was therefore possible to get higher velocity (at what was deemed safe pressures) from the TSX (but TSX loaded to higher max charge). My friend, who did the reloading, explained the higher pressure for the "standard" bullet as a result of "higher engraving force".

In the other case, I was dealing with a 9.3x62 loaded with RL 15 in Lapua cases, CCI 200 over 250 grs TSX or Nosler Accubond. I was loading up toward a max of 63 grs (listed by John Barsness in Rifle magazine). I did not see any pressure signs all the way up to 63 grs, but found very good accuracy at 62 grs, so decided to stay there. When I chronograped the loads at 5 degree Celcius (approx 40 deg. F), I got about 2540 fps for the TSX load and slightly below 2600 fps for Nosler Accubond load.

I was rather surprised at these results - in particular comparing to the original X bullet, which was rather prone to produce high pressures.

- mike