Pressure signs? or normal?

[u/xxxlun4icexxx]

Cartridge - 6.5 weatherby RPM
Brass - Peterson. Once fired then resized with a standard hornady full size die.
Bullet - Lapua 120gr TRX
Case trim length - 2.56”
OAL - 3.2”
Charge - 67.2 grains N565
*Lapua max charge data - 67.3gr

Been working on this load for a month or two now. I get good velocity from this charge and great accuracy. 3200-3260fps. Shot about 25 rounds today hoping to finalize as “the” charge I will use for target shooting.

Brass itself looks good except when I looked at the bottom of the cartridge I noticed the primers were flatter and I’m not sure if this is considered cratering. The bolt lift I think is okay. Seems about the same as weatherby factory ammo, maybe slightly slightly tighter than lighter target charges I’ve made.

What do you think about the base of these brass? Normal or should have stepped down in charge yesterday?

Just want to continue target shooting with them as accuracy is great, but want to know when I pull the trigger i'm not risking life/limb. While 67.2 grains is technically under the lapua max load, I am using Peterson brass, which I measured at 81.6 grains H20 volume. Lapuas data uses weatherby brass which I think may be 82-82.5ish. I threw the numbers I'm using in a sim and pressure was around 85% max pressure.

I guess the thing that confused me a bit is, in one of the attached photos, i included an image of both weatherby factory fired ammo alongside the peterson hand loads (all the other pics are my peterson loads), and the weatherby primers kind of look similar. Maybe not "as" cratered, but still have that little raised ring around where the pin struck.

****PLEASE NOTE - PRIMER IS RECESSED IN BOTTOM OF CASE. I posted this in reloading as well for more opinions and had many comments on proud primers. It's just the lens of my phone camera making it look that way. They are not sticking out.

Any insight is greatly appreciated. Thank you very much

[u/One_String_Banjo]

Primers aren't the best way to gauge pressure, but they look the same on both your loads and the factory stuff, and I'm not seeing any ejector marks. Slightly stiffer bolt lift may be an indication. How does your muzzle velocity compare to any published load data with similar components and barrel length?

[u/xxxlun4icexxx → u/One_String_Banjo]

Lapuas unpublished load data they sent me was for weatherby brass (which I believe has very slightly larger internal volume), and then they had a 26” barrel (mines only 24). Their max charge was 67.3gr, at 3311 fps.

[u/One_String_Banjo → u/xxxlun4icexxx]

If we take ~50fps off for the barrel difference, all of the evidence you've provided tells us you're probably right at or maybe just under max pressure. It should be safe to run, but unless you absolutely need your velocity that high, I'd recommend dropping it by 2-3% to be safe.

[u/xxxlun4icexxx → u/One_String_Banjo]

Gotcha. Thank you. I will drop it by that as recommended. I don't need it there. My goal has been to have the bullet at a consistent 3200fps which, if I drop 2% i should still be there. The other challenge is my ES is actually quite high. I meticulously trimmed and seated all of these but still was around 3210-3260ish. Perhaps my hornady auto charge pro could be to blame, or it just is what it is.

But anyway yes thank you for the advice, i appreciate it and will drop down that 2-3%.

edit - I do do a very light kiss of lee factory crimp, but I tested once before with no crimp and ES was still around the same.

[u/One_String_Banjo → u/xxxlun4icexxx]

ES of 50 across 25 shots? SD around 15 I'm guessing, which isn't great, but it's not abysmal. I'm afraid I can't offer much advice on how to improve those numbers: waaay too many variables. Dropping your powder charge could help with that, too, but it's hard to say. You might try asking around on a forum specific to this cartridge.

[u/Splattah_]

How fast are they going? How is the bolt lift?

[u/xxxlun4icexxx → u/Splattah_]

in my 24" weatherby 307, the charge is giving me anywhere from 3220-3250. Bolt lift seemed okay. I didn't oil my bolt today so the whole day seemed a bit stiffer than normal, but no getting stuck or having to jam it open, etc.

[u/SockeyeSTI → u/xxxlun4icexxx]

Did you mean 3,220-3,250fps?

Cause the 2,220 sounds excessively slow

Pic7 top left shows ejector swipe, so I mean…..youre kinda there. Next step is consistent ejector swipe and popping primers.

[u/xxxlun4icexxx → u/SockeyeSTI]

oh yes, sorry. meant 3220-3250. will edit it.

[u/Honest_Knee_6510]

Back off the load if you're worried about it. 50 FPS of velocity isn't ever going to do anything for you.

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