Spotting pressure in an AI rifle.

[OzzyO20]

I have started doing a few ladder tests to see what my rifle likes, and also to get some practice in reloading. I've had a few promising groups, but I was curious about ejector marks with an AI rifle specifically. My buddy showed me what they look like out of his Surgeon, and they're clear as day circles. However, the ejector pin on an AI is rounded. Will pressure still be very obvious? I've had no sticky bolt, but again the AI bolt almost lifts itself after a moment. In my opinion the primers look fine, but I'm still new.

I've already crept above the Hornady manual recommendation for H4350, and I'm aware they publish on the side of safety and caution, I just don't want to get to far over from shear ignorance and do damage. I'll post a few pictures of the ejector and some brass.

Thank you everyone.

 

[OzzyO20]

Pics. Wish I hadn’t pulled the 5th shot on 42.0 grain group.

 

[spife7980]

The ejector itself isnt what makes the mark, its the brass flowing back into the ejectors hole, the ejector itself just pushes back in with finger pressure. Causing a solid case head to flow into a ejector hole means too much pressure.

https://www.primalrights.com/library/articles/understanding-pressure

Lapua is hardy stuff, I dont see any round marks but I do see some swiping. Not enough that I would be concerned, is that the first firing on the brass?

 

[OzzyO20]

The ejector itself isnt what makes the mark, its the brass flowing back into the ejectors hole, the ejector itself just pushes back in with finger pressure. Causing a solid case head to flow into a ejector hole means too much pressure.

https://www.primalrights.com/library/articles/understanding-pressure

Lapua is hardy stuff, I dont see any round marks but I do see some swiping. Not enough that I would be concerned, is that the first firing on the brass?

That's another issue. Half this brass was fired in aforementioned buddies Surgeon and the other half my old custom 700.

Do you think it's safe to proceed up the ladder?

EDIT: So this is the second firing.

 

[redneckbmxer24]

AI's will show a circle from brass flow into the ejector just like most other rifles. I stop when I see this and not when I get an actual swipe from it, IMO that's too much pressure especially in small primer Lapua brass.

Assuming you're loading 140's, you should be able to go a little higher but I wouldn't go too much higher. 42.5-42.7 is typically same in Creedmoor with H4350 and 140's. There's usually some really solid nodes from 42-42.7gr as well. I'd load a round of each every .1gr and that will tell you where they are as well as let you watch for pressure.

43gr and above is where it starts getting iffy. I've seen people go well over but then they're blowing primers when there's a little bit of rain or they build a slight carbon ring. I personally like to stay right around 42gr which is pretty much a solid load in every creedmoor.

 

[OzzyO20]

For now I’m using some old 130
bergers to learn on. I went up to 42.8 and still didn’t see anything that jumped out at me, but accuracy suffered.

I read the article spife posted, and it was extremely helpful. I am still curious though, in the hierarchy of pressure, is a swipe worse than a circle ejector mark? Seems like the full blown circle would be worse in my mind, and a swipe is a prewarning to that?

 

[OzzyO20]

3 pieces under better lighting from the 42.8 lot