Thread: Factory loads exceeding reload speeds with less pressure signs

Greetings,
We need to remember that as the body of the case is sized down in the FL die the shoulder is pushed forward. If the die is set to not quite touch the shoulder then it is likely that the case will chamber hard or not at all. It is for this reason that bumping the shoulder back 0.002" (0.05mm) from the fired location is suggested. This is where the Hornady head space comparator gadget as it gives a definite measurement to work to rather than endless tiny adjustments accompanied by much frustration and swearing.
GPM.

Originally Posted by grandpamac

Greetings,
We need to remember that as the body of the case is sized down in the FL die the shoulder is pushed forward. If the die is set to not quite touch the shoulder then it is likely that the case will chamber hard or not at all. It is for this reason that bumping the shoulder back 0.002" (0.05mm) from the fired location is suggested. This is where the Hornady head space comparator gadget as it gives a definite measurement to work to rather than endless tiny adjustments accompanied by much frustration and swearing.
GPM.

Yep correct. But, with variances in these things (and to make it more difficult than it really needs to be) you can end up with a chamber that is longer than the die is fully wound down. I suspect that this is the situation - as I've experienced this exact issue once before. A friend has a BSA Safari Mauser action sporter rebarrelled with a Hawkins barrel in .308Win. This thing is jokingly referred to as the .308&1/2, as it will swallow everything except a field gauge with just the slightest stop short of fully closing on a no-go gauge. Been using it for years with factory ammo none the wiser, reloading was an eye opener. Had to basically treat it like a wildcat and segregate the reloads for it, size them long and run the gauntlet with being able to close the bolt on the body taper as that was the issue with chambering.

If the cases are already short, likely moving the shoulder forward a small amount is only going to help the situation but also you aren't going to know unless you try. It would be worthwhile measuring the fired cases to see if there is any primer protrusion remaining or if they've been squashed back to level with the case head. In that case, measuring a primer cup unfired to fired and seeing what the difference is could be worthwhile. Any event, I would think that this isn't going to be as bad as the BSA I mentioned above - that was quite extreme and in reality needed a skim off the back of the barrel by 1 turn and then a careful clean up of the chamber.

Originally Posted by No.3

Yep correct. But, with variances in these things (and to make it more difficult than it really needs to be) you can end up with a chamber that is longer than the die is fully wound down. I suspect that this is the situation - as I've experienced this exact issue once before. A friend has a BSA Safari Mauser action sporter rebarrelled with a Hawkins barrel in .308Win. This thing is jokingly referred to as the .308&1/2, as it will swallow everything except a field gauge with just the slightest stop short of fully closing on a no-go gauge. Been using it for years with factory ammo none the wiser, reloading was an eye opener. Had to basically treat it like a wildcat and segregate the reloads for it, size them long and run the gauntlet with being able to close the bolt on the body taper as that was the issue with chambering.

If the cases are already short, likely moving the shoulder forward a small amount is only going to help the situation but also you aren't going to know unless you try. It would be worthwhile measuring the fired cases to see if there is any primer protrusion remaining or if they've been squashed back to level with the case head. In that case, measuring a primer cup unfired to fired and seeing what the difference is could be worthwhile. Any event, I would think that this isn't going to be as bad as the BSA I mentioned above - that was quite extreme and in reality needed a skim off the back of the barrel by 1 turn and then a careful clean up of the chamber.

Greetings,
Almost all rifle chambers are longer to datum than a case when sized with the die hard down on the shell holder otherwise the case would not fit. Even at start pressures the case is likely to stretch to fill the chamber. The simplest check is to measure the fired case to datum on the shoulder with the Hornady kit and compare that to a sized case. Job done.
GPM.