I have a box of 140 gr Sierra BTHP.to load for my 270. What is the difference between the SBT and the SBTHP Gamekings?

Tony,
The basic difference is what the initials stand for. The BTHP is the Boat Tail Hollow Point. The SPBT is Soft Point Boat Tail. The soft point will have an exposed lead tip and the other will have a hollow tip.

Both tend to be very accurate in the 270 Win's I've owned.

Good hunting,
Steve

Tony: I asked the good folks at Sierra the same question, some time ago. They told me that the BTHP has a much thicker jacker and is the toughest bullet they produce. My eperience with these bullets bears this out. I have killed about 50 whitetails with the 165gr BTHP in the 30-06 and the 300 Weatherby. I have NEVER recovered one of these slugs. In all cases, penetration, regardless of shot angle, was complete. Hope this helps. Stoney

The differance between the SP-soft point and the S- spitzer are slight, but has to do with the shape of the bullet. If I read you post right you have the gameking which is designed for hunting, if the box says matchking, the jackets are thicker and desined for target shooting. Sierra has BTHP in both gameking and matchking bullets. The matchking would tend to penetrate soft skinned game with little or no expantion.