So this topic comes up fairly regularly. I thought I would post a little process on how to trouble shoot the common problem of “Why doesn’t my ammo fit my gun”. There are lots of reasons why your ammo may not be fitting your specific barrel. Remember every gun’s barrel is different. Don’t expect what works in one barrel to work in another barrel. Let’s see if we can figure this stuff out. 1) Using a case gauge vs a barrel. A case gauge is a tool that is meant to mimic a pistols chamber. Most do not make any attempt to mimic a barrels “throat”. The throat is the part of the barrel that the bullet projects into. No case gauge is going to be the same as your barrel but your barrel is also not going to check the entire round because the ramp is usually cut away a little and the rim of the case does not go into most barrels around the entire perimeter. So both have their pros and cons. The best option is barrel because it will test the throat area and that is where a lot of people have issues. 2) Let’s talk about “Sizing Issue”. Many people who load for Glocks say we have a “Glock Bulge issue”. That may be true but believe it or not a good sizing die will take out the Glock Bulge. Not all dies are created equally. Some have a pretty large taper going into the die that moves the carbide ring farther from the base and as a result the ring doesn’t size as low. Dillon and RCBS are known for this. Lee is known for sizing lower. Hornady is pretty good in this regard as well. Redding makes both kinds of dies, single stage version (no taper) and progressive version (tapered). I have not used the Redding. So how do we trouble shoot a Sizing Issue. Pretty easily. Size a bunch of cases and drop them in your barrel. No bullets. Just sized cases. Feel the way they hit the end of the chamber. Listen to the sound. Notice the depth it goes in the chamber. That’s how your loaded round should look, feel and sound when you drop it in the chamber. Sizing issues are diagnosed before you load any powder or seat the bullet. Simple isn’t it? If it doesn’t drop in cleanly you need to lower the sizing die. It can just touch the shellplate and still not bind. You need to be sure to not let the setup bind on a progressive press. If lowering the die doesn’t help you may need a better sizing die. The manufacture may give you a “Small base die” that might solve the issue. Or you can try a Lee/Hornady/Redding. You shouldn’t need to go to a push through die for the vast majority of barrels. Some manufactures of aftermarket barrels have a history of making some tight chambers. They will often work with you to open it up if you ask. 3) So the next area that gives people trouble is bullet seating issues. You run into problems in several areas. One is when you seat the bullet it can go in a little sideways causing a bulge on one side of the case that is not on the other side of the case. Usually, you can visually see the issue. Then the loaded round is too big on that side and it won’t properly chamber. This is going to normally solved with a little more flare. Flare the case .015” over the size of a sized but unflared case is normally going to be fine. You don’t need to measure it after you have become accustomed to what works and what doesn’t. If this doesn’t solve the issue you may need a custom seating stem that better match’s your bullet style.