DrMike
Ballistician
- Nov 8, 2006
- 37,316
- 5,986
I had opportunity to go to the range yesterday to shoot a variety of rifles and conduct several tests. I finished some work with my 7mm RM. I was shooting 160 grain PT and Supreme 780. However, I have much better results from last winter with the PTs and H100V, so this data will be ignored. I also did some work with IMR 8208 XBR in my 30-06. I was using Sierra 165 grain SPBT and Hornady 150 grain SST. The groups averaged a little more than one inch, which isn't bad. I can likely fix that with some adjustment to the seating depth. However, velocities were not at all spectacular. IMR 4350 and/or IMR 4831 yield far better velocities and accuracy, so I'm not likely to exchange what I have for this. As I reported previously, I had very good success accuracy wise with the 168 grain E-Tip and Hunter, although velocities were about what I saw with the IMR 8202 XBR. Again, I'll likely stick with the older powders in this instance.
I was asked to work on a 7mm STW which just doesn't want to shoot the limited selection of commercial ammunition. I had worked up a couple of sets of loads with ABs and TSXs previously. The first work-up with AB did not shoot well at all, and the TSX showed promise. I narrowed the range for the group that shot well with the TSX and worked up a second set for the AB, and found what shows promise.
With 76 grains of H1000 (Nosler brass and F215 primers) the 160 grain AB shot a 0.66 inch group, which can be covered with a penny. Take my word for it fellows, a Canadian penny is the same size as a US penny. It may be worth more shortly. The following photo is somewhat blurred, but it at least gives an idea of what was popping.
Using 82 grains of Magnum (Nosler brass and F215 primers) coupled with 160 grain TSXs, I produced a 0.42 inch group. Across the spectrum of loads tested, all were sub-MOA, which was very good for a new rifle and working under pressure as the owner wants it for a sheep hunt. I had to rush this out of my lab by this week.
Here's a shot of the best TSX group, readily covered by a Canadian dime. Again, that is the same size as a US dime, though it is gaining in strength.
The gunsmiths and the owner of the rifle were pleased and agreed that they would take these results. I suspect that the rifle is capable of much better, and I could demonstrate that if I had more time. I have another 7mm STW waiting on me for load development, but I will have a little more time with it, I believe.
I also took my new 300 WSM to the range with me. I made up a series of loads to test both the 168 grain E-Tip and the 165 grain GMX. I used WLRM primers, IMR 4350 and WW brass in both sets of tests. Other than charge and seating depth, the components were constant. The GMX was quite inaccurate (up to 2.75 inch groups), though the SD was very good and quite consistent. I seated these 0.010 off the lands, as per conversations with ballisticians at Hornady. I seated the E-Tips 0.100 inch off the lands, and the SD was very good and very consistent in all the loads, and all the groups were right at one inch. I suspect that by playing with the seating depth, I'll find a tack driver with this bullet. I will be working with it again shortly while I have opportunity before hunting season.
I also tested some old 165 grain Combined Technology Fail Safes that were not being used. The groups were all in the one inch range and velocities ranged upward to 3025 fps. This might be worth playing with to use up these old bullets.
So where does the sixteen cents come from. I also tested a load using 200 grain Sierra SBT in this rifle. Across the spectrum of charges of VN560 powder used (with WLRM primers and virgin Norma brass), I saw a consistent one inch shooter with one load jumping out to 0.63 inches as I approached maximum charge.
I do believe this would be a thumper of a load, for certain. Hopefully, I'll be able to transfer this grouping to the 200 grain AB when I test it shortly.
All in all, it was a productive day at the range. Temperatures began at about 23 C and crept upward to 34 C, which is scorching for northern British Columbia. The warmer weather is supposed to hold for the week, so it is possible I'll be able to complete all my television work and slip away to the range again before the week is out.
I was asked to work on a 7mm STW which just doesn't want to shoot the limited selection of commercial ammunition. I had worked up a couple of sets of loads with ABs and TSXs previously. The first work-up with AB did not shoot well at all, and the TSX showed promise. I narrowed the range for the group that shot well with the TSX and worked up a second set for the AB, and found what shows promise.
With 76 grains of H1000 (Nosler brass and F215 primers) the 160 grain AB shot a 0.66 inch group, which can be covered with a penny. Take my word for it fellows, a Canadian penny is the same size as a US penny. It may be worth more shortly. The following photo is somewhat blurred, but it at least gives an idea of what was popping.
Using 82 grains of Magnum (Nosler brass and F215 primers) coupled with 160 grain TSXs, I produced a 0.42 inch group. Across the spectrum of loads tested, all were sub-MOA, which was very good for a new rifle and working under pressure as the owner wants it for a sheep hunt. I had to rush this out of my lab by this week.
Here's a shot of the best TSX group, readily covered by a Canadian dime. Again, that is the same size as a US dime, though it is gaining in strength.
The gunsmiths and the owner of the rifle were pleased and agreed that they would take these results. I suspect that the rifle is capable of much better, and I could demonstrate that if I had more time. I have another 7mm STW waiting on me for load development, but I will have a little more time with it, I believe.
I also took my new 300 WSM to the range with me. I made up a series of loads to test both the 168 grain E-Tip and the 165 grain GMX. I used WLRM primers, IMR 4350 and WW brass in both sets of tests. Other than charge and seating depth, the components were constant. The GMX was quite inaccurate (up to 2.75 inch groups), though the SD was very good and quite consistent. I seated these 0.010 off the lands, as per conversations with ballisticians at Hornady. I seated the E-Tips 0.100 inch off the lands, and the SD was very good and very consistent in all the loads, and all the groups were right at one inch. I suspect that by playing with the seating depth, I'll find a tack driver with this bullet. I will be working with it again shortly while I have opportunity before hunting season.
I also tested some old 165 grain Combined Technology Fail Safes that were not being used. The groups were all in the one inch range and velocities ranged upward to 3025 fps. This might be worth playing with to use up these old bullets.
So where does the sixteen cents come from. I also tested a load using 200 grain Sierra SBT in this rifle. Across the spectrum of charges of VN560 powder used (with WLRM primers and virgin Norma brass), I saw a consistent one inch shooter with one load jumping out to 0.63 inches as I approached maximum charge.
I do believe this would be a thumper of a load, for certain. Hopefully, I'll be able to transfer this grouping to the 200 grain AB when I test it shortly.
All in all, it was a productive day at the range. Temperatures began at about 23 C and crept upward to 34 C, which is scorching for northern British Columbia. The warmer weather is supposed to hold for the week, so it is possible I'll be able to complete all my television work and slip away to the range again before the week is out.
