More advice please, chaps, this time on the subject of pressure. Most of the info I can find is vague and more about feel than solid rules or measurements.
I’m trying to develop a load for the Fox 130gr bullet in a .308 with N140 (new PPU brass FL sized, CCI 200 primers and a Schultz & Larsen Victory). I’m new to the .308 and it’s making me a bit nervy about pressure as most of my test loads seem (to me at least…) to have exhibited some signs of it. I'm trying to be meticulous and really want to know where I am with it but I'm finding it considerably harder to read than I did with the .222.
I've only done a short pressure test based on Viht data for the Barnes equivalent bullet but I was worried they all felt a bit spicy so I aborted - slightly stiff on the bolt lift and an imprint left on the primer from the bolt face. Now post-testing I have noticed the bolt also imprints the factory ammunition I have tried in the rifle (Winchester PP and Hornady Superformance - see first two pics) so that might be a false alarm. I am also undecided on the flatness of the primers but you can certainly see a difference between the 43.5gr charge and the 45gr charge (see second two pics. 45gr was as high as I went, the Viht data max is 47.1gr).
If I rechamber the fired brass now without the firing pin there is some resistance when I turn down the bolt handle, and this is the case for all the charges. It’s nothing mad but more than fired factory (which is only really enough to hold the bolt up). So, is any resistance to rechambering after firing a warning? And if not, how stiff is too stiff? My confusion largely stems from the fact that the lowest charge exhibits this issue.
Just as a bit of fun I have measured the case web (I think - just above the extractor groove I gather) for various charges and compared with unfired, but nothing seems amiss based on comparison to factory brass (in fact it seems oddly uniform):
Hornady Superformance - 11.83mm unfired, 11.85mm fired
N140 homeloads in PPU brass - 11.85 unfired, 11.87mm fired
Generally I am not a complete idiot and I have had some success loading for my .222, but I am still a novice at this. I might be acting overly cautious but that seems the better direction! Any advice is most welcome and hopefully it will help others trying to learn the same thing.
I’m trying to develop a load for the Fox 130gr bullet in a .308 with N140 (new PPU brass FL sized, CCI 200 primers and a Schultz & Larsen Victory). I’m new to the .308 and it’s making me a bit nervy about pressure as most of my test loads seem (to me at least…) to have exhibited some signs of it. I'm trying to be meticulous and really want to know where I am with it but I'm finding it considerably harder to read than I did with the .222.
I've only done a short pressure test based on Viht data for the Barnes equivalent bullet but I was worried they all felt a bit spicy so I aborted - slightly stiff on the bolt lift and an imprint left on the primer from the bolt face. Now post-testing I have noticed the bolt also imprints the factory ammunition I have tried in the rifle (Winchester PP and Hornady Superformance - see first two pics) so that might be a false alarm. I am also undecided on the flatness of the primers but you can certainly see a difference between the 43.5gr charge and the 45gr charge (see second two pics. 45gr was as high as I went, the Viht data max is 47.1gr).
If I rechamber the fired brass now without the firing pin there is some resistance when I turn down the bolt handle, and this is the case for all the charges. It’s nothing mad but more than fired factory (which is only really enough to hold the bolt up). So, is any resistance to rechambering after firing a warning? And if not, how stiff is too stiff? My confusion largely stems from the fact that the lowest charge exhibits this issue.
Just as a bit of fun I have measured the case web (I think - just above the extractor groove I gather) for various charges and compared with unfired, but nothing seems amiss based on comparison to factory brass (in fact it seems oddly uniform):
Hornady Superformance - 11.83mm unfired, 11.85mm fired
N140 homeloads in PPU brass - 11.85 unfired, 11.87mm fired
Generally I am not a complete idiot and I have had some success loading for my .222, but I am still a novice at this. I might be acting overly cautious but that seems the better direction! Any advice is most welcome and hopefully it will help others trying to learn the same thing.
