I am getting ready to start working up a 9mm Luger load using HP-38 with some 115 grain bulk bullets that I bought some time ago. The bullets look like Hornady XTP bullets except that the transition from the body of the bullet to the ogive is not quite as abrupt as on the Hornady. The bullets are 0.355 in diameter and 0.547 in length.
For reference, the Hornady XTP is 0.355 diameter and 0.545 length.
I will be starting at 3.7 grains as I know from prior experience with similar bullets that the 3.5 grains recommended in Lyman #49 will not reliably cycle my pistol. 3.7 grains is still less than the starting load listed in Hornady #8, Speer #11 or Hodgdon's web site, so I believe that is reasonable.
I also know from prior experience with similar bullets that above 4.7 grains, I start to get pressure signs, so I will regard 4.7 grains and not the 4.9 grains given in Lyman #49 as the maximum loading. As the spread between minimum and maximum charge is 1.0 grain, I plan to select 0.1 grain as my increment.
My question has to do with C.O.L.
With 0.1 grain increments between 3.7 and 4.7 grain, I'm already committing 110 bullets from my bulk purchase just to load the various strings for load development and I don't want to spend a bunch more having to chase my tail over c.o.l. if I can get it nailed down a little better.
Thanks.
For reference, the Hornady XTP is 0.355 diameter and 0.545 length.
I will be starting at 3.7 grains as I know from prior experience with similar bullets that the 3.5 grains recommended in Lyman #49 will not reliably cycle my pistol. 3.7 grains is still less than the starting load listed in Hornady #8, Speer #11 or Hodgdon's web site, so I believe that is reasonable.
I also know from prior experience with similar bullets that above 4.7 grains, I start to get pressure signs, so I will regard 4.7 grains and not the 4.9 grains given in Lyman #49 as the maximum loading. As the spread between minimum and maximum charge is 1.0 grain, I plan to select 0.1 grain as my increment.
My question has to do with C.O.L.
- Hornady #8 says 1.075 with their 115 grain XTP. As my bulk bullet is 0.002 longer, this would suggest a length of 1.077 to keep cartridge volume the same.
- Lyman #49 gives a c.o.l. of 1.090 with an unidentified Jacketed Hollow point.
- Speer #11 doesn't recommend a c.o.l. for their 115 grain bullets, but does say 1.080 for the 100 grain and 1.100 for their 124 grain bullets. Interpolating between these two figures gives 1.093
- Hodgdon's website gives a c.o.l. of 1.125
- Should I be conservative and start with 1.125 and see how it does?
- Or go for the more-or-less consensus of 1.090-1.093 from Lyman and Speer?
- Use 1.077 because of the similarities of the bulk bullet to the Hornady XTP?
- Or something else entirely?
With 0.1 grain increments between 3.7 and 4.7 grain, I'm already committing 110 bullets from my bulk purchase just to load the various strings for load development and I don't want to spend a bunch more having to chase my tail over c.o.l. if I can get it nailed down a little better.
Thanks.