I went to Edmonton's Phoenix indoor range today. Very nice people run the immaculately clean and well maintained place. There are also very nice changes to the 40-yard range vs what this range was in 2020. I thought the range was going to let me borrow a Labradar chrono (the older orange one), but I had to rent it for $15 per hour, which was acceptable because I only needed it for one hour and should not need a chrono again in the future.
I did the experiment that I previously said I was going to perform, but I'm not going to report all loads because I felt it unnecessary. The chart below shows grains Titegroup (TG) across the top row versus FPS for each charge underneath. After that is a series of photos of the headstamp area of the 7.0 grain through 9.0 grain brass.
I short, I could not detect any negative effects of increasing loads of TG up to and including 9 grains. The spent cases look fine to me and the action of the bolt to remove the cases was always the same. I included the headstamp area of a PMC bronze 3200 fps that I fired first thing today (big, big bang and an amazing ball of fire) in the photo of the three 9-grain cases. I'll be taking particular note of any changes in new-primer installation in the spent 9-grain cases. If they insert a bit too easily, I can drop the load back to, say, 8 grains and still be close to 2000 fps, but I do not expect this to be necessary.
Again, my "rif-tol" is a BCL MRX Bronco Howitzer bolt action 223 Wylde with a 9.5" barrel (about 7.5" of which is rifled). Campro 55 grain FMJ bullets; Campro small rifle primers; once-fired Winchester brass (again, except for one PMC bronze 3200 fps round fired today for headstamp area comaparison with that of 9 grains TG cases).
I used a Lee Loader Classic to reload the ammo.
The Labradar did not detect a few rounds, which means that what was supposed to be three rounds at each charge sometimes turned into two.
From now on I'll be routinely shooting 3.0 to 3.5 grains TG for punching paper, and, when I want a bigger bang, fire 9 grains (which fulfills my happy-goal of 10 cents of powder for 2000+-fps; close enough to commercial). BTW, there was no flash whatsoever when using 9 grains. Of course if the range was darker, I probably would have seen at least
some flash.
I hope this information helps someone with something.
7.0 grains of TG
7.5 grains TG
8.0 grains TG
8.5 grains TG
3 Winchesters with 9.0 grains TG and one PMC bronze 3200 fps commercial round for comparison
Edit: I reloaded the 3 9-grain cases and the installation of the primers was as it was for all other empties of various loads -- normal.
After deciding that I would continue to load at least some rounds with 9 grains, I created from a fired 223 case and a short length of copper tubing a custom powder scoop that delivers very close to 9.0 grains of TG. This scoop makes it much easier and faster for me to reload than weighing every charge on my RCBS beam scale. (I have a similar custom scoop, made from a 22LR case, that delivers 3.1 grains TG for the vast majority of rounds.)
