Load Development: should I stop?

[DIM]

Few weeks ago, I decide to utilize ball powder H335 which I had, and used for .223 but now I decide to use it with .308, so I been tweaking this load and it seems 43.5 grains of H335 was most suitable for me 2760 fps sound reasonable with 155 grain Nosler Custom Competition bullet. So here is picture of the target I shot today at 100 yards, groups on the right are marked Unknown since I couldn't find what powder I loaded, I packed them sometimes last year for hunting season, that was one shot deal. I think I used IMR 4064, which is awesome powder and I have load already developed just for it, 5 shot groups stay within 0.3" - 0.4", The one on the bottom is probably Reloader 17, no matter what I do with it it does this fliers. So you think with H335 I reached the end in the load development or there are more room for improvements?

 

[LiveLife]

DIM, I don't currently reload for rifle but looking at getting a bull barrel upper for my Bushmaster lower. Recalling from shooting my friend's 24" bull barrel upper with Black Hills ammo, the shot groups were similar (about less than 1" at 100 yards).

Mind telling us which rifle/barrel you used for these shot groups?

 

[DIM]

That's Thompson Center match heavy barrel 5R from TC Icon Precision Hunter

 

[DIM]

I guess adding few tenth of the grain in powder might produce better result, it definitely doesn't like to be to close to the lands and 2.803 is the sweet spot but I might raise bullet just a bit I'll post my findings in a few weeks.

 

[Walkalong]

One or two groups means very little. Nothing shabby about your groups mind you, it just isn't enough to bet the house on.