Originally Posted By: deaddogwalkinI had an old remington 243 that had alot of rounds shot through it. One spring day a couple of yrs ago I pulled it out of the safe and put a new scope on it and headed to the range to sight it in. Got it on target and started shooting some groups. Any time I shoot groups I have a lot of time between shots so I was checking the spent casings and started to notice that some of the primers had started to back out a long ways. I stopped shooting and headed to the gunsmith. Had him check the gun over and he found that there was a lot of throat wear. He told me that I could start neck sizing to help it out or I could set the barrel back slightly or have it rebarrel. Depending on how old the gun is you might want to have the gun checked out by a gunsmith. JMO. But it could also be a fluke round.
An eroded throat has NOTHING to do with this problem (you really need to get another gunsmith)... and you can not fix this problem by setting back the barrel.
Primers protruding from the back of the case means too much head space (it may not be the fault of the rifle), no matter what else is wrong... and too low a pressure to re-seat the primer..
The normal cycle when firing a cartridge is - the primer fires and pushes the loaded case forwards. If there is no space in front of the cartridge, then the case does not move, and the primer does not protrude. If there IS space in front of the cartridge (the cartridge is shorter than the chamber) the primer will protrude as the case is pushed forwards.
The powder builds pressure, and pushes the case walls against the chamber. If the chamber is "wet", that is, if there is oil or bore cleaner on the walls or case, then the whole case will slide back and expand to fill the chamber, and at the same time, it will RE-SEAT the primer.
If the chamber is DRY, the case walls will grab the chamber walls, and stick to the chamber - the pressure will force the back of the case to the bolt face, stretching the case just in front of the head (the web), making the wall thinner, and RE-SEAT the primer. Do this a few times, and the back of the case (the head) will fall off, leaving the body of the cartridge still in the gun (not fun to remove)
When the case or chamber is "wet" the case will always slide back, and re-seat the primer.
When the case or chamber is "dry" the case "head" will only move back when there is enough pressure to stretch the case (the pressure needed varies, depending on the calibre), and it will re-seat the primer.
When the case or chamber is "dry", and the load is light, the case will stick to the chamber walls, and NOT have enough force to stretch the case head and re-seat the primer... so the primer will be sticking out of the fired case
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... so we know know that that your chamber and case were dry, and the load was light. Easy
This is an easy problem to solve.
1 - Get a neck sizing die - it solves the short case problem - 99 & 44/100% of the time, when there is space in the chamber of a "normal" rifle, it is due to improper adjustment of an FL die.
The first time you fire a case, it will settle it self into "your" chamber... from that point on, you should do the least sizing possible, to get the reloaded cartridge back in the gun, with whatever level of ease/resistance you feel you need.
When I get a new rifle, and I am firing cases for the first time - I fire the case covered in light oil - it guarantees that the case will tightly fit the chamber, without any stretching in front of the head.
After that, I only size the necks when reloading - if the case becomes more difficult to chamber than I am willing to accept, I will adjust the FL (or Bump) die, so it just moves the shoulder back just a few thousandths - enough so the bolt closes to my satisfaction... on varmint and target rifles, this might mean that they are still a little tight and the bolt has some resistance when closing.
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As stated, problem headspace can come from an improperly adjusted FL die. This can be avoided by screwing the FL die down to the shell holder, and then backing it off a 1/4 of a turn, and then locking it.
Meow
