Reading about pressure signs in books and on the internet is one thing; experiencing excess pressure is another. No bad experiences today, simply some learning opportunities that I would like to share, and ask our members to weigh in and fill in the gaps in my understanding.
First, a bit about what I was doing today at the range. I was working with two new-to-me rifles from the CMP, an M1903A3 and an M1917. I had on hand some Greek surplus M2 Ball from the CMP, as well as a few handloads I had put together. I was mainly evaluating for function, and a general idea of accuracy.
My first lesson is that excess pressure in one rifle may not necessarily display signs of excess pressure in another. I presume this is due to a number of differences in how the chamber is cut, wear on the throat, etc. Anyway, the Greek M2 showed no problems in the 03A3, but when I tried it in the 1917 I experienced my first "sticky bolt". I had read about it, and know it is a clear indication of overpressure, but I was surprised by the amount of force required to lift the bolt handle. Secondly, the primers were significantly cratered. Pictures do not do justice to this condition, but now I have seen first-hand.
Another new lesson, or at least experience, was that of a blown primer. Call me lucky, but in over two years of handloading I have never had any cartridge failure of any sort until today. This particular lot of handloads were assembled with the intent of doing a ladder test on another rifle, which I never did...so I used them in the 03A3 and 1917, incrementally and carefully, always checking the previous casing for signs before firing the next. I think of myself as a careful reloader--anything other than "volume-nowhere near max" type of loads is individually trickled and weighed. Anyway, I went from "fine" to "blown primer" with just a 0.3 grain increase. Needless to say, no more rounds from that lot were expended, and the remainder will be pulled. If it blows in one rifle, I have no desire to try again with another!
My lesson learned today? well, maybe not a lesson, but at least my plan for my USA mil-surp .30/06 is to stick with IMR 4895, and find a middle of the road charge weight that both rifles shoot okay. Not expecting spectacular accuracy, but they are fun to shoot. My sore shoulder can attest to that!
First, a bit about what I was doing today at the range. I was working with two new-to-me rifles from the CMP, an M1903A3 and an M1917. I had on hand some Greek surplus M2 Ball from the CMP, as well as a few handloads I had put together. I was mainly evaluating for function, and a general idea of accuracy.
My first lesson is that excess pressure in one rifle may not necessarily display signs of excess pressure in another. I presume this is due to a number of differences in how the chamber is cut, wear on the throat, etc. Anyway, the Greek M2 showed no problems in the 03A3, but when I tried it in the 1917 I experienced my first "sticky bolt". I had read about it, and know it is a clear indication of overpressure, but I was surprised by the amount of force required to lift the bolt handle. Secondly, the primers were significantly cratered. Pictures do not do justice to this condition, but now I have seen first-hand.
Another new lesson, or at least experience, was that of a blown primer. Call me lucky, but in over two years of handloading I have never had any cartridge failure of any sort until today. This particular lot of handloads were assembled with the intent of doing a ladder test on another rifle, which I never did...so I used them in the 03A3 and 1917, incrementally and carefully, always checking the previous casing for signs before firing the next. I think of myself as a careful reloader--anything other than "volume-nowhere near max" type of loads is individually trickled and weighed. Anyway, I went from "fine" to "blown primer" with just a 0.3 grain increase. Needless to say, no more rounds from that lot were expended, and the remainder will be pulled. If it blows in one rifle, I have no desire to try again with another!
My lesson learned today? well, maybe not a lesson, but at least my plan for my USA mil-surp .30/06 is to stick with IMR 4895, and find a middle of the road charge weight that both rifles shoot okay. Not expecting spectacular accuracy, but they are fun to shoot. My sore shoulder can attest to that!