- Joined
- Jan 17, 2021
The .357 and .44 mag are able to fire .38 and .44 spl because they both headspace on the rim and have the same rim dimensions. .40 S&W and 10mm headspace on the mouth of the case and with the case being .142” shorter on .40 S&W can lead to major issues eventually. At best you have excessive freebore which can lead to accuracy issues along with the lower pressure of .40 S&W to cause cycling issues in a 10mm gun. This assumes that you manage to get the .40 S&W round to stay where you need it for the firing pin to get a good hit. At worst the bullet can engage the rifling at an excessive angle and cause a bore obstruction.No, it just doesn't want to cycle. Before I put a heavier recoil spring in it kind of worked and could go a couple shots before jamming, but with my new recoil spring it won't reliably cycle one round.
I highly recommend you cease firing .40 in a 10mm.