I think I am making some progress (hopefully)___
Yesterday morning I took my digital caliper out to my range then measured slide to barrel hood depth after a manual slide drop then after first fired round. I got some discrepancy in the measurements with manual dropped slide showing .005"-.006" difference. (caliper isn't the best tool for this measurement though)
So with a little more investigation it looked like the slide face where the rear of the round slides up was fairly rough. So I lightly sanded then polished that slide face (not mirror as I didn't want to remove much metal) just tidied up the rough surface a bit).
My grandson was visiting (he loves to shoot) & I have a bunch of old NATO 9mm (real strong stuff) so I let him shoot about 350 rounds of that hot stuff (he loves it, I hate it myself).
This morning I shot one magazine of rounds off a sand bag & they all seemed to go into the same group (sort of as it was pretty ragged group but just under 2" @25 yards. Unfortunately I don't know where the first shot went in the group but it definitely wasn't way high left.
This was just a sample of one magazine so time will tell but it sort of looks promising anyhow.
Cujo,
While I’m happy you are finding improvements, it does seem curious to me why such a “fix”, as described, would have cured an anomaly that occurred only on your first round fired.
So it’s always the first round? If this is so let’s think about this. What is different about anyones first shot?
This assumes there has been no changes to the firearm, ammunition or significant change in shooting position/stance from first shot to follow on shots.
Weapon
- Cold bore (previously discussed)
- Chambering procedure is vastly different than follow on shots
Shooter
- First shot CAN be a flyer (potential, and slight flinch anticipating recoil), I have experienced this, then I settle in
- shooting position (again, getting settled in)
- Some external influence
Other than the above, I got nothing. Good luck.
GS