Newb 300 win mag charge question

[Ftpeck300]

Rifle is a bergara ridge 300 win, vergin Winchester brass, h1000, and 215 Berger's.

When figuring out Max charge I went all the way up to 78gr sitting 10 tho off the lands, and still not really any pressure signs. I loaded 6 up at that weight and only one had very faint ejector marks(only visable in the sun). It was only about 50 outside.. the gun groups decent about moa. I'm just nervous to fine-tune around this charge weight as it's quite a bit higher than most load data I have seen and with it being cold outside I'm worried about when it warms up..any Advice? Thanns

 

[WeiserBucks]

I've done load development for a few 300 WM rifles and they all settled around 76 grains of H1000 with the 215s. Do you have a chronograph? How's your bolt lift ?

 

[Ftpeck300]

I have a crono but being new to reloading it was advised by a few co-workers to find powder nodes via ladder vs throwing a crono in the mix. I hit nodes at 74 and 76.4 I think I'd hit another one at 78.5ish as 78 was decent but not as good at 76.5 bolt lift was easy, I'm not good at reading primer flatting, but there was no cratering whatsoever

 

[Ftpeck300]

My guns only a 24" forgot to mention that, not sure if that's a big deal or not

 

[WeiserBucks]

My personal 300 WM is 24" also. I would use the chronograph along with whatever development process you choose. If you have abnormally high velocity without pressure signs, the pressure is still there just not easily recognized.

 

[Ftpeck300]

What typical velocity am I looking for? Or am I looking for a drastic spread when I start hitting over pressure? Thanks

 

[WeiserBucks]

Mine is 24" and makes 2830 fps with 76.0 grains of H1000 and CCI 250s in Norma brass with no pressure signs. As I moved above 76 grains my accuracy went south and had very obvious pressure signs the closer I got to 2900 FPS .

Every barrel and lot of powder is different, you may get higher or lower velocity than I do. In my opinion, if you're producing 2900+ FPS with a 24" barrel you're most likely over pressure.

 

[Ftpeck300]

Thanks for the help I drop down to 75 and start over