The last 3 Hornady 150gr BTSP .270 cartridges I had loaded emptied the current box of bullets, and I discarded the box so I can’t list the lot number.
My RCBS die was set to seat the bullets 0.02” from the leade and they measured 2.821” from case base to ogive.
I opened a new box and seated 3 rounds, then measured them, as usual. I was surprised they measured 2.855.” These were 0.034” longer and would have jammed into the leade, which was even more important because I was experimenting with magnum primers using H4831 56.0gr (max 58.0gr).
I reset the die to seat the new loads to the desired 2.821” keeping in mind that they now were 0.034” deeper in the case, which might also increase pressure but I thought it should not be as high as having them jammed.
I went to the range and fired the last 3 from the previous box of bullets at 100 yards and they landed 2-1/4 to 2/12 inches high about ¾ of an inch on either side of the center, giving a group size of 1.598”.
The newer lot number produced 3 shots that were 2.0 -2/34” high, all within 0 to ¼” of center, in a group that measured 0.973”. I then fired 2 shots at 200 yards and both landed 2 inches on either side of the bull , neither high nor low. I’m not unhappy about that because I used a green circle 6-1/2” wide and my vision isn’t what it used to be. I used a 12-power scope and the green dot edges were blurred anyway.
Now, of course, I’ll confirm the validity of the load with more shots but it seems as though I have enough of a winner to hunt deer this year.
I guess the lesson learned is don’t consider a new lot number of the same bullets from the same manufacturer to be exactly like the last lot number. I purposely measured these rounds because in the past I had a box of Hornady 150gr BTSP that I purchased in 1979, and when I bought a new box (date unknown) it was instantly obvious that the cannelure location had been changed on the new lot number. The base-to-cannelure on the “old” bullet was 0.470” with a base-to-ogive of 0.716”.
The new bullet had a base-to-cannelure of 0.520” and a base-to-ogive of 0.705”. I was disappointed that there was no mention on the new box about the change, which may have been overlooked by neophyte reloaders who used the cannelure as their seating depth indicator.
My RCBS die was set to seat the bullets 0.02” from the leade and they measured 2.821” from case base to ogive.
I opened a new box and seated 3 rounds, then measured them, as usual. I was surprised they measured 2.855.” These were 0.034” longer and would have jammed into the leade, which was even more important because I was experimenting with magnum primers using H4831 56.0gr (max 58.0gr).
I reset the die to seat the new loads to the desired 2.821” keeping in mind that they now were 0.034” deeper in the case, which might also increase pressure but I thought it should not be as high as having them jammed.
I went to the range and fired the last 3 from the previous box of bullets at 100 yards and they landed 2-1/4 to 2/12 inches high about ¾ of an inch on either side of the center, giving a group size of 1.598”.
The newer lot number produced 3 shots that were 2.0 -2/34” high, all within 0 to ¼” of center, in a group that measured 0.973”. I then fired 2 shots at 200 yards and both landed 2 inches on either side of the bull , neither high nor low. I’m not unhappy about that because I used a green circle 6-1/2” wide and my vision isn’t what it used to be. I used a 12-power scope and the green dot edges were blurred anyway.
Now, of course, I’ll confirm the validity of the load with more shots but it seems as though I have enough of a winner to hunt deer this year.
I guess the lesson learned is don’t consider a new lot number of the same bullets from the same manufacturer to be exactly like the last lot number. I purposely measured these rounds because in the past I had a box of Hornady 150gr BTSP that I purchased in 1979, and when I bought a new box (date unknown) it was instantly obvious that the cannelure location had been changed on the new lot number. The base-to-cannelure on the “old” bullet was 0.470” with a base-to-ogive of 0.716”.
The new bullet had a base-to-cannelure of 0.520” and a base-to-ogive of 0.705”. I was disappointed that there was no mention on the new box about the change, which may have been overlooked by neophyte reloaders who used the cannelure as their seating depth indicator.