Hi, I bought a custom gun .300 win mag and bought new brass (winchester brass) and the new brass was .003 to .005 under sized at the base above the belt, I neck sized them and figured I would fire form them. So I went out and fired fifty rounds and some of them got stuck in chamber but I could get them out with little force. Load was at the start charge. I don't know if the casings expanded to much due to them being under sized or I have to tight of a chamber. 7 rounds got stuck. I went home and set the 7 casings a side and neck sized the rest and went back out and 80% of them did the same thing. I have never had any problems with any of my other rifles but they are are all factory. I was just wondering if anyone else Has had this problem and How to fix it. Rounds chamber easy and dont come out easy after firing. I have never owned a precision gun before now. Should I have full sized brass after first firing?
New brass.
- Thread starter garradh
- Start date
Hi. Congrats on the new gun. By "new" is it brand new or new to you? Any chance the chamber needs to be cleaned? Can you tell from the extracted brass where the sticking seems to be occuring? (rub-marks, shiney areas) Yes, once brass has been fired in a chamber it should should be full sized.
Have you tried any factory ammo?
rnbra-shooter
CGN Ultra frequent flyer
- Location
- New Brunswick
A rough or dirty chamber will make it difficult to extract a fired case. Radial tool marks in the chamber will really hold the case in there - are there radial "imprints" on your fired cases that might indicate this?
Wrap a largish cleaning patch onto a .45 cal bore brush, and use that to "swab" out your chamber; see if there is any rust/dirt/gunk/etc in there. And once you've cleaned the chamber, have a look and see if you see any marks (though it can be difficult to get a good look at the chamber with the barrel mounted in the action, since it holds your eye a good 6" away from it)
Wrap a largish cleaning patch onto a .45 cal bore brush, and use that to "swab" out your chamber; see if there is any rust/dirt/gunk/etc in there. And once you've cleaned the chamber, have a look and see if you see any marks (though it can be difficult to get a good look at the chamber with the barrel mounted in the action, since it holds your eye a good 6" away from it)
Some custom rifles have an undersized neck that requires turning case necks. Compare the neck diameter of a fired case to a sized case and see if there is enough room for expansion to release the bullet with out excessive pressures. This is unlikely but possible in a custom chamber, especially a target rifle.
rnbra-shooter
CGN Ultra frequent flyer
- Location
- New Brunswick
Even easier is to check if a bullet will freely drop into the mouth of a fired case. If not, the chamber neck was too tight.
This doesn't necessarily apply to your sticking problem, but its been my experience, that Winchester makes its brass about .005 thous under SAAMI diameter spec. at .200 above the base.
European brass is much closer to SAAMI. Try some of that.
NormB
How did you end up fixing the problem?
