12-05-2022, 02:20 AM
(This post was last modified: 12-05-2022, 02:58 AM by Burt Gummer.)
I ended up going to the range today against better judgement. Let’s just say I had a late night and a few too many beverages last night. The end results were somewhat mixed. The late night could be part of it or the other mistake I made by seating the bullets deeper than before. I made up some rounds with W748 to play with and normally seat them very deep at 2.236 inches base to tip or 1.6 inches base to ogive. When loading for the RL15.5 I continued doing this. In the prior load I was loading the ammo to mag length which was around 2.289 inches base to bullet tip. I’ll just stick with the best few loads of each different brass and primer combination. Same as prior testing including 112 Matchburners. For W748 I used Hornady brass with BR4 primers over 27.1 gr and 112 Matchburners. Haven’t made a move yet on a drop tube system so loaded with a standard frankford arsenal aluminum powder funnel:
Starline Brass 4 shots:
28.6 gr = 2590 fps Avg, ES = 18, SD = 6.82, .9 MOA
28.8 gr = 2609 fps ES = 24, SD = 8.85, .85 MOA
Hornady Brass 5 shots for 28.4 and 28.6. 4 shots for 28.8:
28.4 gr = 2575 fps Avg, ES = 56, SD = 9 , 1.29 MOA
28.6 gr = 2575 fps Avg, ES = 14, SD = 1.9, 1.09 MOA
28.8 gr = 2590 fps Avg, ES = 16, SD = 4.8, .90 MOA
For fun I also grouped five shots of the few remaining factory Hornady 108 ELD-M’s I have left:
= 2623 fps Avg, ES = 43, SD = 16, .92 MOA
And 4 shots of W748:
27.1 gr = 2482 fps Avg, ES = 57, SD = 8.1, 1.35 MOA
I didn’t think the 28.4 gr of RL 15.5 was that impressive but I wanted to provide it just to show how much the average velocity has stabilized at this point. The lack of movement in velocity between them has me wanting to really drill down on the 28.6 gr and see just how accurate I can make this load. The ES/SD’s at this point are just too good. It’s worrisome that the accuracy wasn’t there but once again I might not have been at my best today and the seating depth can certainly be experimented with to see how much tighter I can get it. This will be the next test. I’ll inevitability throw in some other powder charges when implementing but a temperature stable powder at 2575 fps out of an 18” barrel is really getting my attention at this point.
The loads shown above are most likely over pressure. Ejector swipes are appearing on the brass slightly heavier than what I noticed on the factory Hornady rounds. Willing to push the guns limits for this powder and don’t guess I’m too much over pressure if so. I achieved a .56 MOA at 27.6 with Avg 2480 fps and an ES of 26. If further testing won’t get me around .5 MOA I might try to play around in this area but the numbers seem to be screaming at me to try out the 28.6 weight.
Starline Brass 4 shots:
28.6 gr = 2590 fps Avg, ES = 18, SD = 6.82, .9 MOA
28.8 gr = 2609 fps ES = 24, SD = 8.85, .85 MOA
Hornady Brass 5 shots for 28.4 and 28.6. 4 shots for 28.8:
28.4 gr = 2575 fps Avg, ES = 56, SD = 9 , 1.29 MOA
28.6 gr = 2575 fps Avg, ES = 14, SD = 1.9, 1.09 MOA
28.8 gr = 2590 fps Avg, ES = 16, SD = 4.8, .90 MOA
For fun I also grouped five shots of the few remaining factory Hornady 108 ELD-M’s I have left:
= 2623 fps Avg, ES = 43, SD = 16, .92 MOA
And 4 shots of W748:
27.1 gr = 2482 fps Avg, ES = 57, SD = 8.1, 1.35 MOA
I didn’t think the 28.4 gr of RL 15.5 was that impressive but I wanted to provide it just to show how much the average velocity has stabilized at this point. The lack of movement in velocity between them has me wanting to really drill down on the 28.6 gr and see just how accurate I can make this load. The ES/SD’s at this point are just too good. It’s worrisome that the accuracy wasn’t there but once again I might not have been at my best today and the seating depth can certainly be experimented with to see how much tighter I can get it. This will be the next test. I’ll inevitability throw in some other powder charges when implementing but a temperature stable powder at 2575 fps out of an 18” barrel is really getting my attention at this point.
The loads shown above are most likely over pressure. Ejector swipes are appearing on the brass slightly heavier than what I noticed on the factory Hornady rounds. Willing to push the guns limits for this powder and don’t guess I’m too much over pressure if so. I achieved a .56 MOA at 27.6 with Avg 2480 fps and an ES of 26. If further testing won’t get me around .5 MOA I might try to play around in this area but the numbers seem to be screaming at me to try out the 28.6 weight.