Patterning and adjusting fire!

Obi_Wan

Active member
Well, I went out and patterned some guns today. Not going to post photos yet or talk numbers just overall results because I have to make some adjustments to even be useful. All patterns were shot at 40 yards. Freehand and with a rest to see if there was a difference. There wasn’t enough to care one way or the other.

Browning A5 16ga. IM and M Briley chokes. #5 Fiocchi Golden Pheasant and #6 Browning Pheasant loads. I shot two shots with each and had my brother in law shoot one to see if the issue was me. It wasn’t. He got the exact same results. All patterns were high and left. And when I say high and left, I mean significantly high and significantly left. Using two circles 20 and 30:”, the lower right quad of my 30 inch circle would be in the single digits of hits. Lower right of 20” would be less than 20 hits. With 35-40 hits in the upper left. Could see the bulk of the pattern on the upper left corner of the paper.

Benelli Legacy 20 ga. M Carlson’s choke. #6 Kent Fast Lead. Low and left. The upper right quad had less than 10 hits. I made a change to the shims before I shot that I may need to change back.

Neither of these guns would be acceptable (for me) to hunt with as is. I have the Benelli legacy’s stock washer set for cast off. I can change the drop up and down. I have the shim in the Browning for cast off. I can go back to neutral or leave as is and go up or down with the drop. Question is, what insight can I get from you guys?

Now the positive. Franchi 48 AL 28 gauge with Trulock IM and M chokes. B&P 15/16 oz Heavy Dove 2 3/4” load. The M choke was about a 60/40 pattern very evenly spaced. It was a great pattern at 40 yards and would be killer at that distance with that load. Very impressed. It had 20 pellets less in the 30” circle than the 1/18 oz 16 ga loads and only like 35 less than the 1 1/4 12 ga loads. The IM choke was not a good one. Definitely no advantage of going up in choke. Had my BIL shoot the M choke and his results were the same. We shot his SBE 12 ga with factory M choke with Kent fast Lead 1 1/4 oz #5 and Fed. Prairie Storm 1 1/4 oz #5. Patterns were high right. Probably close to 80/20 or 90/10.
 
Sounds like shimming is in order. How does the LOP fit you for each gun? I would recommend shooting just one gun at a time and making adjustments then moving on to the next gun.
LOP is good for each gun. I kind of did what you mentioned. I shot the 16 ga until I had shot it all I was going to for data. Then the 20 the same way. then the 28. My intent now is to make changes to the 16 and see if I can get it to shoot for me. If not, I’ll have to figure out what is next. Whether its a trip back to browning or to a stock fitter or it finds its way down the road. Then I’ll do the same for the 20. Although I’ve already been considering selling the 20 since I have more.
 
Very important data! I have one gun that shoots a bit left of center…not bad up or down, but about 8” left of center….had shot lots of birds with that gun before patterning…I shoot clays with it a few times each august to confirm that I break clays reasonably well….but I wish it wasn’t shooting left! I’ve patterned about 8 other guns, all doubles, no issues…never patterned my auto’s, they’re pretty darned deadly…but I’m gonna do it now…
 
My Browning 625 spreads just right at 60/40.
Very important data! I have one gun that shoots a bit left of center…not bad up or down, but about 8” left of center….had shot lots of birds with that gun before patterning…I shoot clays with it a few times each august to confirm that I break clays reasonably well….but I wish it wasn’t shooting left! I’ve patterned about 8 other guns, all doubles, no issues…never patterned my auto’s, they’re pretty darned deadly…but I’m gonna do it now…
wouldn't that likely be a choke problem from being poorly machined so not to point straight?
 
You should first fired the gun off a bench or other steady rest to confirm that the gun's point of impact matches the point of aim. Fire 2-3 shots at the same target, say 16 yards.

If a gun doesn't shoot to point of aim, the issues can be non-concentric choke or barrel harmonics. I have also restored the concentricity of a damaged barrel by pounding a tapered socket into the muzzle.

I have corrected the point of impact of several guns by replacing damaged choke tubes or grinding the interior of a fixed choke.

After checking for or correcting for those issues, you can adjust the point of impact to yourself via gun fitting.
 
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