I'm wondering if I am the only one who has had this powder bridge on him in the powder measure. Recently I have had a serious mishap in a Krag using 21 grains with 311284. The first shot seemed (sounded, felt) a trifle off, but not enough to raise any flags. The shot after that felt like a 300 magnum, the bolt stuck and had to be pounded open. The primer was gone and pocket enlarged. the shot printed a foot or more high. I checked the bolt lug and there was no crack. The bore was leaded stem to stern. I have used this powder a lot (among others) and never had an issue. After i got home, I took the remaining rounds apart to see if there was some repetition and discovered that the next cartridge in line had seven or eight kernels of powder inside the case. The balance were normal.
I have had trouble with 4759 the same way, but i always caught it and learned to weigh each dropped charge before dumping the powder into the case. Yesterday i loaded more Krags with 5744 and weighed each charge. It may have been that my powder can was very nearly empty recently and the column of powder in the RCBS measure didn't have enough volume/weight to supply the force to move the powder downward. Anyone care to comment? i will say that over the years i have gotten some very tight groups with five krags with 5744. Indeed, just prior to pulling the trigger on the grenade load four out of five shots touched each other at a hundred yards. This with a receiver sight. yesterday i took the measure apart and wiped out the interior surfaces but found it virtually clean to start with.I think i may have isolated the trouble with the powder column, but your thoughts are welcome.