I loaded a few .243/106tap/ 7828ssc to check for pressure. New Tikka take off barrel cut to 17" with Raptor8, new Lapua lrp brass. My first 2 shots at my lowest charge of 45grains clearly showed ejector marks. How much should a person drop charge weight? I dropped 2 grains shot two over a chrono and had no pressure signs at about 2750fps. Loaded 20 to check group size that i haven'tshot yet. Just wondering if I'll be good once the barrel speeds up.
It is your face, eyes, and hands, so don't do anything your are not comfortable with; and don't take advice from people who have lost their Marbles (such as this poster). I'll share my point of view, but there is an art to interpreting things and if in doubt, the most conservative course is correct in high risk, low reward decisions.
I'm not sure what to make of Tikkas and ejector marks (I wonder if their chambers may come a touch too smooth). So I'm not really any help. If you have a second pressure sign, I would drop until they go away. If it is only an ejector mark, it could be a false pressure sign.
Ejector marks shows case thrust against the bolt, which may or may not be due to pressure above spec (such as moister, residual lubricant, or excessive head space). If only a certain load is causing them, I would be inclined to read it as pressure. Loose primer pockets can only be from high internal pressure and while other things can cause flat primers, I would assume a flat primer is due to excessive pressure unless there is good reason to think otherwise. If you are loading above book max, I would assume even without pressure signs you are over pressure, so even an ejector mark would automatically be a big red flag.
My 223 made some, but 2K plus rounds in I no longer see any. My Tikka 308 did not, then it made them really bad (to include on factory ammo to include on Wolf steel case, PMC 150 gr FMJs, South African mil surp, and Federal JSP hunting loads). I had some very light ejector marks on Berger 175 OTM factory loads, which use Lapua brass. I cleaned the snot out of it, and there was minimal change. With 178 gr factory Hornady precision hunter I'm getting ejector marks and heavy bolt lift from shaving brass. However, the primers are not flat, pockets are not loose, the Hornady primers do have a very slight (slight enough I cannot see it, but I can feel it and they turn ever so slightly when rolled) muffin top, though they are the only ones and it may be the dumb crimp Hornady puts on them.
The only large rifle primers I could get were BR4s, on reloads that will consistently give a heavy bolt lift and ejector mark the B stamped on the primer is still sharp and crisp. At 2.5 grs below book max load I stop getting ejector marks on the PMC brass.
Barrel is cut to 16.5 inches with a Raptor 8 on it, I'm getting 2415 fps on factory Hornady precision hunter. Hornady lists it as 2600, so I've lost the expected 25 fps/inch of barrel cut and velocity is reasonable.
I've disassembled the bolt and there is not a bure on the ejector nor the ejector hole.
I have a headspace gauge on the way. However, I'm not getting any light strikes.
Wolf steel
Factory Precision Hunter
Reload in PMC brass. 1.5 gr below book max.
Reload in GFL brass
Brass shavings on bolt face.
These were all shot in 30 degree weather.
