9MM failing case gauge
Quote from Reloader on December 7, 2020, 2:06 pmAbout 30-40% of my 9mm reloads are dailing case gauge and i dont know why. My rounds are coming out with a strange shape (you can see the base of the bullet through the brass). Wish i could post a picture.
About 30-40% of my 9mm reloads are dailing case gauge and i dont know why. My rounds are coming out with a strange shape (you can see the base of the bullet through the brass). Wish i could post a picture.
Quote from Reloader on December 8, 2020, 1:35 amThe case gauge can have tolerances that are even tighter than the chamber on your firearm. This makes me inquire whether the rounds that don't easily gauge will still chamber. If they will, then shoot them.
Back to the loader with your brass, and you should methodically check your brass from stage one. Once decapped and resized, does it gauge easily? If not, then look at perhaps screwing down your size die a bit more until it actually "cams over" until your brass is sufficiently resized. Then look at stage two for a potential adjustment. The powder measure should slightly bell the case mouth, but if adjusted down too far, the potential exists for this stage to actually crush down and widen the brass. Lastly, evaluate your crimp die. Remember the 9mm requires a slight taper crimp and nothing more. It's hard--but not impossible--to over crimp, leaving your finished round with an appearance resembling a "wasp waist". Good luck.Best
Terry
The case gauge can have tolerances that are even tighter than the chamber on your firearm. This makes me inquire whether the rounds that don't easily gauge will still chamber. If they will, then shoot them.
Back to the loader with your brass, and you should methodically check your brass from stage one. Once decapped and resized, does it gauge easily? If not, then look at perhaps screwing down your size die a bit more until it actually "cams over" until your brass is sufficiently resized. Then look at stage two for a potential adjustment. The powder measure should slightly bell the case mouth, but if adjusted down too far, the potential exists for this stage to actually crush down and widen the brass. Lastly, evaluate your crimp die. Remember the 9mm requires a slight taper crimp and nothing more. It's hard--but not impossible--to over crimp, leaving your finished round with an appearance resembling a "wasp waist". Good luck.
Best
Terry
Quote from Reloader on February 22, 2021, 4:59 pmIf it's not new brass, most likely the cause is case bulge. Some guns, to make it easier to feed ammo, open up the bottom of the chamber near the ramp. When fired, the brass would bulge in one direction. This type of bulge is difficult to remove with a regular sizing die. The only solution that I've discovered so far for 9mm tapered round is something called "rollsizer". Unfortunately, the tool is too expensive for my pocket so I can't say how well that works.
Alternatively, the issue may be in the quality of the brass itself. I find that certain brands of factory ammo, especially the low-cost ones, tend to have brass that is not dimensionally consistent. Checking factory ammo from different brands in my case gauge I discovered that some brands have as much as 50% of bullets failing to fit the case gauge. As a result, now I test all factory 9mm ammo first and separate out of spec ones from the rest. Out of spec factory rounds do get shot: mostly plinking and I do not pick up that brass for reloading. Stright to the range brass bucket they go!
After I started sorting factory ammo before shooting, the brass that does get picked up is usually good to go for another reload, I typically get 1 case out of 100 being out of spec. Now I have some much good brass, I doubt I'll ever need to buy factory ammo again.
If it's not new brass, most likely the cause is case bulge. Some guns, to make it easier to feed ammo, open up the bottom of the chamber near the ramp. When fired, the brass would bulge in one direction. This type of bulge is difficult to remove with a regular sizing die. The only solution that I've discovered so far for 9mm tapered round is something called "rollsizer". Unfortunately, the tool is too expensive for my pocket so I can't say how well that works.
Alternatively, the issue may be in the quality of the brass itself. I find that certain brands of factory ammo, especially the low-cost ones, tend to have brass that is not dimensionally consistent. Checking factory ammo from different brands in my case gauge I discovered that some brands have as much as 50% of bullets failing to fit the case gauge. As a result, now I test all factory 9mm ammo first and separate out of spec ones from the rest. Out of spec factory rounds do get shot: mostly plinking and I do not pick up that brass for reloading. Stright to the range brass bucket they go!
After I started sorting factory ammo before shooting, the brass that does get picked up is usually good to go for another reload, I typically get 1 case out of 100 being out of spec. Now I have some much good brass, I doubt I'll ever need to buy factory ammo again.