Performance Data
| Date | Range | Choke (Nominal) | 30" Circle Impacts (Total) | Performance (Nominal) |
|---|---|---|---|---|
| 24/09/2017 | 20 Yards | 0.020" (Improved Modified) | 86 (100) | 86% (< Cylinder) |
| 24/09/2017 | 30 Yards | 0.015" (Modified) | 61 (100) | 61% (Cylinder) |
| 24/09/2017 | 30 Yards | 0.015" (Modified) | 72 (100) | 72% (Improved Cylinder) |
| 24/09/2017 | 30 Yards | 0.020" (Improved Modified) | 78 (100) | 78% (Improved Cylinder) |
| 24/09/2017 | 30 Yards | 0.020" (Improved Modified) | 55 (100) | 55% (< Cylinder) |
Performance Analysis
It is extremely depressing to note that the major design flaw associated with this cartridge (i.e. a shot size of 2.7mm, which is far too big for any .410 cartridge) is probably the only thing which rescues its performance “on paper” and gives it the appearance of being even moderately good, when in practice, its performance is (and can only be) thoroughly awful.
The SmallBoreShotguns team were genuinely surprised, having tested the GFL36 loading, that it did not produce the very worst patterns we have ever seen, but pellet counts of 55-78 at 30 yards were not far off achieving that degree of notoriety. That the cartridge achieved even that level of performance is almost certainly due to a combination of low muzzle velocity and proportionately-lesser pellet deformation due to the (absurdly) large shot size.
The powder extracted during initial examination, as yet unidentified, burned as unreliably as we have ever seen any powder burn in open air; testing in the field revealed un-burned powder flakes in the barrel of the Yildiz test gun after firing every cartridge. It is for this reason that we suspect pressure and muzzle velocity may be comparitively low, although retrieved wads showed significant damage, particularly around the skirt.
Ignoring the over-large shot, the cartridge appears to represent a catalogue of design errors. A rolled turnover has the effect of substantially increasing the variability of the cartridge, giving a 30-yard average of 66½ pellets in the standard circle, plus or minus 11½ percent! The combination of primer and powder appears, even in hot weather, to result in incomplete combustion, suggesting either that the primer is too hot (i.e. too “fast”) or that the powder is too slow to sustain the required pressure for complete combustion. Furthermore, the wad, although we expect it to be damaged under firing, appears sometimes to split at the skirt, resulting in combustion gases passing up the sides of the petals and ahead of the shot – perhaps a cause of the apparently low pressure? Admittedly, test-firing the cartridge in a gun with a 3″ chamber may exacerbate some of these issues.
In short, this is the little cartridge that can’t. There aren’t enough pellets in the shell, prior to firing, to produce a bare minimum pattern density for winged game and with high variability and field experience suggesting that it isn’t reliably capable at even 20 yards, let alone 30, we cannot recommend its use.
The Hull cartridge of equivalent loading – albeit, with an English (2.6mm) rather than Italian (2.7mm) #6 -produces a marginally greater average absolute pellet count and with greater consistency, although at a lower percentage performance. However, having demonstrated similar inadequacies to the GFL36, we feel we may have been unduly lenient on the former cartridge in our earlier analysis. These tiny charges of gigantic shot in .410 cases have no utility outside of – perhaps – humane dispatch, should not be used in the field and we wish that manufacturers would stop making them.
Example Patterns
