I can post brass pictures later, but really scratching my head on this one.
Loading 6.5 PRC with RL26 and 156 EOL. Shooting Seekins Havak Element 21" barrel.
I posted a thread here earlier in the year about my load development. Think I did basically a OCW test and looked for pressure. Started 54 gn and went up in 0.5 gn increments. Everything grouped well. Got sliiiight heavy bolt lift at 58.5. This was at an indoor 100 yrd range ~75F. Loaded 10 at 58 gn and went to an outdoor 1000 yrd range and shot for velocity and to true at long range. No issues there, probably 85F and the load chrono'd at 2990, velocity obviously felt high with a 21" barrel, but everything felt good shooting.
Last week loaded 30 more. plan was 2 5 shot groups to verify rifle zero, another 10 to verify velo, then 10 to take hunting. Shot the groups at the indoor 100 yrd range, 75F, no issues at all. Good groups, nothing strange about the gun etc. Sunday morning went out to the 1000 yrd range to get velo, 55F, first round extremely heavy bolt lift and major ejector mark. WTF. grabbed a second round random from the box, same thing. Both still were going ~3000 fps. Stopped there. Went back home and pulled everything and loaded up rounds at 56.5 gn just to get me hunting in early Oct. Still there is a slight heavy bolt lift, something I would back off if doing full load development, but will probably live with for one more shot. 56.5 chrono'd 2930, still seems super fast.
Any ideas how there could be such a drastic change??? I'm shooting with an Ultra 7 on. I put 200 rounds through it before doing load development. All rounds are loaded from the same box of primers, same jug of RL26, save virgin ADG brass, same box of bullets. The 30 where 10 shot fine and 2 were over pressure were all loaded within 30 min of each other.
TL;DR
June:
3 shots in 75F - no pressure signs
10 shots in 85F - no pressure signs ~3000 FPS
August:
10 shots in 75F - no pressure signs
2 shots in 55F - extreme pressure signs ~3000 FPS
Loading 6.5 PRC with RL26 and 156 EOL. Shooting Seekins Havak Element 21" barrel.
I posted a thread here earlier in the year about my load development. Think I did basically a OCW test and looked for pressure. Started 54 gn and went up in 0.5 gn increments. Everything grouped well. Got sliiiight heavy bolt lift at 58.5. This was at an indoor 100 yrd range ~75F. Loaded 10 at 58 gn and went to an outdoor 1000 yrd range and shot for velocity and to true at long range. No issues there, probably 85F and the load chrono'd at 2990, velocity obviously felt high with a 21" barrel, but everything felt good shooting.
Last week loaded 30 more. plan was 2 5 shot groups to verify rifle zero, another 10 to verify velo, then 10 to take hunting. Shot the groups at the indoor 100 yrd range, 75F, no issues at all. Good groups, nothing strange about the gun etc. Sunday morning went out to the 1000 yrd range to get velo, 55F, first round extremely heavy bolt lift and major ejector mark. WTF. grabbed a second round random from the box, same thing. Both still were going ~3000 fps. Stopped there. Went back home and pulled everything and loaded up rounds at 56.5 gn just to get me hunting in early Oct. Still there is a slight heavy bolt lift, something I would back off if doing full load development, but will probably live with for one more shot. 56.5 chrono'd 2930, still seems super fast.
Any ideas how there could be such a drastic change??? I'm shooting with an Ultra 7 on. I put 200 rounds through it before doing load development. All rounds are loaded from the same box of primers, same jug of RL26, save virgin ADG brass, same box of bullets. The 30 where 10 shot fine and 2 were over pressure were all loaded within 30 min of each other.
TL;DR
June:
3 shots in 75F - no pressure signs
10 shots in 85F - no pressure signs ~3000 FPS
August:
10 shots in 75F - no pressure signs
2 shots in 55F - extreme pressure signs ~3000 FPS