I'm new to posting on forums but have been reading your posts for some time. This may not be the best post to start with but I'm worrying myself.
I've just started to homeload for my .243 (T3 S/S, PES mod), with a Lee kit. So far so boring. I've kept all my factory fired brass and have a good stash of mixed cases, all nicely fireformed.
Cases are now sorted. Only neck sizing and all cases that I've checked so far under max length & trimmed if needed.
I'm using an 87grn V-Max head and CCI primers. I've Vhit N160 (double-duty for the 6.5, in time I hope!).
Anyway - I survived the first firing @ 42.0grn (much relief!) and wanted to get some load development going.
Loaded some Hornady brass (stamped Frontier) with 44.0grns (others have had success with this charge I believe) and got a tidy 3 shot group. No pressure signs.
45grn and over (0.5 increases) got hard extraction and marking on the head from the boltface - plus poorer groups. Under 44grns were not that special either.
So...44.0 it is.
Next batch went for 10 Federal cases, same prep. 44grns. Same seat depth (I'm finding it a struggle to get the depth really consistent - it seems to wander +/- a fraction). I have calipers.
Anyway...first firing fine.
Second, tiny mark on case head
Third, bright mark.
oh dear...forth - the flippin' primer fell out of the case as I extracted. Severe marking to case head. (I guess the primer was stuck to the boltface - not an under pressure load).
I took this to be a bad sign and went rapidly indoors and posted this!
Why is the pressure seemingly building shot on shot, and is some brass softer than others?
Incidentally, in the '08 Vhit data 44grns of n160 is under the min load.
I must be doing something seriously wrong yet had excellent results with the initial Frontier brass/load.
I look forward to your thoughts. Thank you!