The following load in my home built 6.5 grendel; hiperfire trigger, Odin works barrel/bcg combo.

Hornady brass
CCI small mag rifle
Reloader 15
123gr eld

First outing in August, I posted before is my 28.9 grain load. It's the max I loaded.


This pic above was at 300 and the 100yd group had similar results.

Then earlier this week I had 13 last bullets so I made them with 28.9gr. Below is 100 and 300. The 100yd group is 3 shot.





It was a fairly winding day. Not trying to make excuses but phone said 10-15 in the area and it was from 2 o'clock to 8 o'clock direction relative to shot.
Is the vertical spread something I can take as a good sign for this load?

Should I try higher loads?
Some details, this is my first try at a gas gun. I kinda like the fact that bullet seating is limited and headspacing I'm doing fl. It's at least one less variable to confuse this newb. So headspace fl and it's 0.005 short of max mag allowable.

Btw, no sighs of over pressure on the brass.

What was your ladder increment and how many steps did it have on each side of the 28.9 load? I would also say that the load looks great based on the 100y grouping. And if it were my shooting I would blame the 300y expansion on my vision. I would call .599 a keeper.

It was my highest load of the ones I loaded. The ones leading up to it did shoot progressively better as charge weight increased.
No true ladder test like shooting various loads on one target.

I do t think I would quit going up in charge until groups opened up instead of shrinking or you start seeing signs of pressure. You could easily be leaving better groups on the table.

Not picking at you but when you subtract that bullet it’s .264 not .260.

.599-.264=.335”

I do not know the max charge for RL15 with that bullet to keep you at 50000 psi but think it is a bit higher. Would not hurt to go up a little and see what you can get accuracy is key though. Know some are loading a good bit higher. Oh and sometimes a target is more of a weather report than a definite check of accuracy especially in varying wind conditions

I haven't loaded with RL15 but what I loaded it seems to all work well!

For the 6.5 Grendel, 29 Gr of RL-15 for the 123 gr ELD is the Maximum load in the Hornady 10th edition manual. Shows 2400 fps from an Alexander 18" barrel.