by LF (7/98)
My piece on the NATO L110 tracer round generated a fair amount of responses, so I thought that I'd plumb the same basic ground with a bit on shotgun buckshot patterning. I've read dozens of gun articles and books that mention the importance of learning the size of the groups that come from a "tactical" shotgun, for the obvious reason that this will establish the distance at which a round can reliably be expected to achieve the shooter's desired goal.
Be warned that a major point of this exercise is that EVERY SHOTGUN IS DIFFERENT, so do not take my results as a guide for your own firearm. Go to a gun show or a well-stocked shop and buy as many different large-pellet loads as you can find, and then go through a similar process before settling upon your own choice!
I took nine different 00-buck loads to the range one day, and ran them through my original Beretta 1201FP, which has a 20-inch unchoked barrel with rifle sights. I decided to do the testing at 15 yards, and used a single B-27 silhouette for each series. I fired five rounds of each brand, stopping after every shot to patch up the target with a different-color paster. It was a hot day, and I had a cheap tape measure, so I only figured the resulting holes to the nearest quarter of an inch. None of the pellets landed off their target, so no "make-up" shots were necessary:
Average Group Size: 19.3"
Average Group Size: 16.5"
Average Group Size: 14.2"
Average Group Size: 13.9"
Average Group Size: 13.9"
Average Group Size: 13.4"
Average Group Size: 13.1"
Average Group Size: 12.33"
Average Group Size: 11.2"
The next weekend, I pulled out my second 1201FP and just tested the three tightest-shooting loads. The results were:
Average Group Size: 13.6"
Average Group Size: 10.6"
Average Group Size: 10.4"
Notice that the relative positions bounced around a mite. Better yet, my second gun (again, the exact same model, purchased three or four months after the first) shot two of the loads tighter than my original one.
Oh-ho, but it gets even better! I was intrigued by the differing results, and fired another series with my first Beretta with the Federal Tactical. Three rounds into this, I ran out of the original boxes I started out with (the rest were already stored in ammo cans back home), and switched to members of a second 250-round case lot that I just got in. Suddenly I started tossing much larger groups!
The first three averaged 10.8", but the next two rounds patterned at 16" and 12" respectively.
I finally straightened this discrepancy out this weekend, ending up with the following in a side-by-side comparison:
Average Group Size: 12.66"
Average Group Size: 10.5"
The moral of this story? Cripes, I guess that the consistency of shotgun cartridges is one heck of a lot trickier to predict than rifle or pistol ammo. If you find something that you like, try to get more of the same case lot!