Maionchi AZ20 cartridge test

Richard Atkins tests an old favourite Italian target load, the AZ20, in plastic and fibre wad versions.

I was pleased to see the return of Maionchi cartridges – and several of my clay shooting pals felt likewise. Back in the 1980s Maionchi was a leading choice among club shooters and serious competitors alike.

They achieved a keen following because the cartridges performed very well indeed and were keenly priced too. It’s relatively easy to make ‘budget’ cartridges, but there is a special knack to making cartridges that perform to a high standard without charging a premium price – that’s where Maionchi fitted into the market back in their heyday.

The cartridge world has changed since then, and has become ultra-competitive. Some names have disappeared, or in some cases became part of the small number of very large groups which dominate the market.

We haven’t seen cartridges bearing the Maionchi name for years, but it is still recalled with affection by many in the UK shooting community.

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Understanding the test results

  • Velocity is measured at 2.5 metres from the muzzle.
  • Pressure is the mean breech figure in Bar (as per CIP).
  • SD is Standard Deviation (consistency).
  • CD is the Central Density rating. This records the percentage of the total pellets landing in the 30-inch circle that were also within the inner 20-inch circle
  • Shot size is derived from actual pellet count per ounce and is listed to the nearest UK size, with < and > symbols where shot is slightly larger or smaller than the nearest size. UK No.7 = 340 pellets/oz; UK No.7.5 = 400 pellets/oz; UK No.8 = 450/oz; UK No. 9 = 580/oz.
  • Shot weight is the average actual shot load, measured in grains. 1 grain = 0.065 grams = 0.0023 oz. CV is Crush Value. This is the amount by which the shot is reduced in size when subjected to the standard crush test. A smaller value means harder lead, so a CV figure of 20% is harder than 30%, for pellets of similar size. Smaller shot crushes proportionately more than larger size.
  • Choke boring Nominal pattern percentages at 40 yards are: Half Choke 60%; Imp/ Mod (three quarter) choke 65%; Full choke 70%.

The AZ20 is the Maionchi cartridge that most shooters remember fondly, me included. It is good to see that the link with the past has been retained in the presentation.

The smart bright red, blue and yellow cartons closely follow the old style, and the cartridge cases are the light orange colour of the originals too – so there’s no mistaking that the AZ20 is back! Of course, we need to know what we get for our money and how they perform today.

Maionchi AZ20 28 Gram 8.5 Plastic

Shot load430 grains
Pellet (count per oz)428
UK shot (size / CV)<7.5 / 25%
Pellets in 30in dia (Av)278
Pellets in 20-30in 124
Pattern  66%
CD55%
Velocity375m/s (1,230fps)
SD4.7
Recoil (M) (unit= Ns)10.5
Pressure (unit = bar)496

Maionchi AZ20 28 Gram 8.5 Fibre

Shot load433 grains
Pellet (count per oz)423
UK shot (size / CV)<7.5 / 31%
Pellets in 30in dia (Av)262
Pellets in 20-30in 122
Pattern  62%
CD53.4%
Velocity364m/s (1,194fps)
SD7.9
Recoil (M) (unit= Ns)10.2
Pressure (unit = bar)504

Quality components

The cartridges are loaded into 70mm parallel plastic tube cases with 10 mm high brass plated steel heads. The crimps on both the plastic and fibre wad versions are very precisely formed, neatly turned over for a secure six-point star crimp closure that helps achieve maximum performance and consistency as well as aiding feeding in semi-auto shotguns. The 70mm case with higher metal head adds to the quality feel and clearly implies the AZ20 is aimed above the ‘budget’ sector.

Examining the fired cases, it’s clear they are high quality. The crimp folds are clearly retained in the memory of the extruded high density polyethylene cases.

This is characteristic of top grade materials and confirmed by the strength of resistance to squeezing the crimp folds together; compared with ‘budget’ plastic cases the difference in strength can be readily felt.

The cases used are produced by Martignoni, as are the primers. Martignoni are a major supplier of cartridge cases and primers.

The primers have a paper disc to seal the flash hole, preventing flakes of powder finding their way into the primer via the flash hole, with different colour paper used to identify types and strengths of primer.

These primers proved sensitive and consistent with no misfires, not even from my test gun with its original hammer spring and firing pin.

Maionchi literature states that the lead used contains 3 per cent antimony. This is a serious amount, only 1 per cent less than found in some ‘premium’ cartridges.

My lead shot crush test device revealed that the shot is hard, especially in the plastic wad loads which gave crush value readings closer to 4%. This bodes well as hard shot is key for improved pattern performance.

The shot size stated on the cartons and printed on each cartridge is the Italian size. The ‘8.5’ equates to the next larger UK size, ie UK No.8. As you will see from the charts on this page, the pellets in the test samples are in fact slightly larger than UK 8.

Wads and powder

Wads play an important part in cartridge performance, and those in the Maionchi AZ20s have pedigree. You may recall that the original AZ20 wad was a full pouch type with a cork insert under the shot. This is now obsolete and is replaced by another wad design from that era, the ‘GT’ wad.

This wad has built an excellent reputation and has long been used in some top-of-the-range cartridges from different makers and is now produced within the Nobel Sport stable.

It has a very efficient gas sealing skirt and a multi-layer honeycomb central section that protects the shot pellets from acceleration forces, while modifying the recoil signature. The shot cup, with four moulded petals, has a full 28 gram capacity and so protects even the topmost layers of pellets from barrel wall contact, for maximum pattern advantage.

In the fibre wad cartridges, the wads used are a one-piece design with laminate ends to prevent pellets sticking into the fibre. These are made by by leading fibre wad producer Diana. The wad is used in conjunction with a Diana 4mm thick over powder card.

The 70mm cases allow a 20mm long main driving wad to be used. Together with the 4mm card, this provides a good length of driving wad to improve the gas seal. This worked well in the standard bore and forcing cone of my pattern test barrel and my similarly bored test guns.

Also now part of the Nobel Sport group is the French powder producer, SNPE. Both the fibre and plastic cartridges here use one of their very well respected Vectan powders.

With a mix of green and pink square-cut flakes, this appears to be Vectan AS – a single-base nitrocellulose propellant that is clean burning, consistent and economical, and is used by several major cartridge makers around the world.

The powder load in the plastic wad version averaged a consistent 21 grains while the fibre wad version contained just a shade more powder at 21.9 grains.

Plastic wad
Fibre wad

Performance testing

Both cartridge types were submitted to the Birmingham CIP Proof Laboratory for pressure, velocity and momentum testing to industry standards.

Pattern tests were conducted at 40 yards from a 30in barrel with 2¾in (70mm) chamber. This barrel has a standard bore size with standard length (short) forcing cone and is bored Imp Mod (UK three-quarters) choke.

The laboratory clearly reveal excellent ballistic results. Notable are the low SD figures which show that velocities are very consistent. As is usual when comparing otherwise similar plastic and fibre wad loads, the plastic results are tighter than the fibre, but the figures for both are very good and more consistent than any shooter could detect in use.

I was interested to see that velocity levels were quite moderate, with Maionchi clearly not chasing any speed records. That can be more advantageous that some ‘speed junkies’ might imagine!

The combination of quality components and sensible speeds resulted in some desirable performance features. Most noticeable is that these are smooth to shoot with very pleasant recoil characteristics – this was especially noticeable when testing on the clays with an O/U Sporter of modest weight.

The really significant feature was found on the pattern plate, however. The AZ20 produced excellent patterns. The plastic wad load produced patterns that were tighter than the Imp Mod (three-quarters) choke test barrel and, more importantly than that, pattern results were very consistent too.

If you have done serious pattern testing (at least 5 patterns per test) you’ll know that shotgun patterns vary. High quality cartridges can reduce pattern variations to a minimum. I base my tests on six patterns, or more if there are wide variations in those six).

The AZ 20 plastic wad held the test patterns to less than 12 per cent variation, well inside the ‘premium’ category for consistency. It’s harder to get this consistency with fibre wads, but the AZ20 maintained a maximum 17 per cent variation. That’s a premium grade pattern result; there are plenty of plastic wad loads struggling to match that consistency!

Both types felt perfectly crisp with no discernable loss in ‘quickness into the target’. Higher muzzle velocities don’t make as much difference as you think. Air resistance increases with the square of velocity, so pellets that start off faster don’t arrive at the target much earlier. Higher velocity also means increased recoil, and potentially increased pattern spread.

I set up several shooting scenarios at different distances including going-away DTL type targets, some quartering-away shots and a straight crossing target. I often do this as an adjunct to testing on the range, as I can measure and repeat the targets, but Covid-19 closures made it essential this time.

What this enabled me to do was assess that both the plastic and fibre AZ20 gave excellent kills to a range greater than I had anticipated, especially bearing in mind the stated 8.5 shot size.

With my crosser at 40 yards and just Mod (half) choke in the Sporter, I was still able to get good breaks when I stood another four paces back. Note the pellets are between 7.5 and 8 in UK size and, being hard, clearly retained their roundness to pattern well and retain pellet energy.

Summing up

Do the new AZ20s live up to the promise of their history, providing great performance at a very keen price? Yes! They proved consistent, effective, clean burning and comfortable to shoot.

The UK distributor, Garlands Ltd of Edingale in Staffordshire, are importing and distributing the AZ20 in 21, 24 and 28 gram shot loads, all in plastic and fibre wad. The 21 and 24 gram come in Italian 7.5 shot shot size (2.4mm), while the 28 gram loads offer Italian 7.5 or 8.5.

There’s also a 28 gram 9.5 option in plastic wad only. Suggested retail prices start at £176 per 1,000 for 21 gram plastic up to £196 per 1,000 for 28 gram fibre.

Many shooters will try the Maionchi AZ20s out of nostalgia. I’m also sure that more will enjoy them. Keenly priced with a great performance, that combination will surely be welcomed and successful.

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