I’ve discovered various interesting things about the garden gun and 20 gauge in the last 24 hours.
To answer the oldest question first, the barrel of the garden gun is stamped with “Modern Arms Company Ltd. London & Bromley” which dates it to between 1928 and 1942, making it between 75 and 89 years old. I don’t believe it will be possible to age it more accurately than this, at least until I take the action out of the stock to look for more engravings (i.e. a date code).
Another helpful piece of information which has popped up today is the fact that the acorns embossed on the head stamps of the cartridges I was given with the gun are typical of ammunition manufactured by RWS, which means that I have been able to identify the #10 cartridges as their “double shot” loading. This will allow me to put a second “official” pattern testing page for the garden gun onto the site and formalizes the data we have for the gauge so far.
I’ve been able to count the patterns and the picture remains largely the same as yesterday. The RWS #10 cartridge produced good, dense patterns at 20 yards, averaging 162 in the standard circle, but adequate penetration for any use on live game at this distance remains doubtful.
The as-yet-unidentified nickel-cased cartridge patterned relatively poorly as expected, averaging 90 in the standard circle at 20 yards. The Fiocchi loading is perhaps borderline usable on small game, provided one aims the gun, placing and average of 51 pellets into a 20″ circle at 20 yards, though the patterns, such as they were, still seemed rather uneven. I remain curious to pattern that brand with a larger shot size – perhaps #9.
So far, I haven’t deconstructed any of the 9mm shells to discover their contents, but the full data (and an estimate of the shot size of the nickel cartridge) will be published when I have provided that “context”.
One point of confusion remains. The Fiocchi cartridge, patterned at 10 yards, placed only 46 pellets onto the paper, yet the 20-yard patterns contained at least that many pellets in the circle, with more in the spread outside it. At present, I cannot explain this anomaly and continue to ponder how, beyond that particular cartridge having been incompletely loaded, it could possibly have occurred.
I counted the 40-yard pattern I shot with the 20 gauge before the 20- and 30-yard patterns. It quickly became clear that it wasn’t necessary to count the shorter range patterns as the pellet count of 184 (of 237) pellets in the circle at 40 yards is more than sufficient. In fact, that represents a percentage performance of approximately 78%, which is much, much better than the 57-60% one would expect for a nominal half choke.
Although that’s only a single pattern, the other two shot are clearly close to 100% patterns, given the spread, so the chance of the 40-yard pattern being a “one off” is low. (I will count the shorter distance patterns later, when there is less of interest than needs to be analyzed and written up!) Even if I lost 20% of the pellets in that circle, it would still be a good pattern, so there’s plenty of wiggle room, so to speak.
I suspect, having examined the shot and on the basis of my experiences trying to find a performant cartridge for my .410, that there really must be something worthwhile about the “diamond shot” that Gamebore advertise – it must be very, very hard indeed to give this kind of performance in an ordinary, lightly-choked gun. Unfortunately, their .410 “Hunting” cartridge appears not to feature that kind of lead.
I suppose if I were to buy a super-fast cartridge loaded with #7 shot, I might just make the Accacio into a short-range gun, using the greater pellet deformation and spread to my advantage, but really, it appears that, once again, the tight-shooting gun / cartridge combinations have searched me out and found me and that for deliberately-limited-to-20-yard performance, I’m going to have to resort to my .410 with 2″ #9 shells or the new 9mm…