m9a1 strange recoil impulse

[shootist26]

I have an Beretta M9A1 with an unusual recoil impulse. After I touch off a shot, I see the front sight lift up normally, but after that is what is strange. The front sight then seems to dip below the rear sight momentarily, then comes up but exhibits a brief twisting motion before finally settling back down level with the rear sight. The front of the gun feels like its going "boing boing boingggg" like a spring. Is this due to my WML mounted on it? Or maybe the stock recoil spring is too heavy for some reason?

I have another 92FS that I used for a long time in IDPA/USPSA which tracks perfectly when shooting at speed. Front sight lifts up and comes straight back down level to the rear sight. Same with my Sig P-series. So I'm comfortable eliminating any technique issues. This strange impulse is very brief, but noticeable and I can't shoot the M9A1 quite as fast as my 92FS or my Sigs.

[Artemas2]

that sounds like it's over sprung. My LTT was like trying to hold on to an angry fish when shooting. Luckily it's a cheap and easy thing to try first. The 12.5# recoil spring fixed it for me.

[shootist26]

that sounds like it's over sprung. My LTT was like trying to hold on to an angry fish when shooting. Luckily it's a cheap and easy thing to try first. The 12.5# recoil spring fixed it for me.You were right. I put a 12.5lb spring in and it shoots amazing. Almost like a new gun. Sights track perfectly up and down with zero weird sideways impulse.

Fascinating how it could be so bad with a stock spring