Is it time to think about a 17 gram cartridge?

[rovercoupe]

Seen as we are all subject to the cartridge price increase thing is it time for a cheap clay cart with a mega light load? I was looking through the 410 website the other day and came across a article about mini shells and thought it might be worth a go! I shoot the 410 with anything from 9g to 19g loads so it seems its possible to break clays with a light load and make it cheaper with less lead and less powder.

 

Thoughts?

[Stonepark]

Why not just 21g steel?

 

Circa £150\1000

Edited April 26, 2017 by Stonepark

[Rupert]

Why not just 21g steel?

 

Circa £150\1000

For clays Steel is not well recieved at grounds.

[rovercoupe]

I have shot steel and it was ok, just thinking of how things have gone in the past. I still have some 36g 9s and these days the max clay load seems to be 28g and a 21g is what i mostly shoot in the 12 bore, my scores dont change if I go to a 24 or 28g load so thinking what are the light load limits.

[JohnfromUK]

I have shot steel and it was ok, just thinking of how things have gone in the past. I still have some 36g 9s and these days the max clay load seems to be 28g and a 21g is what i mostly shoot in the 12 bore, my scores dont change if I go to a 24 or 28g load so thinking what are the light load limits.

Like you - I now favour 21g, with no effect (noticeable anyway) on scores. There must be a lower limit (for a given bore size) below which its hard to keep a good pattern, but I have no idea if this is near 21g, or much less. I also suspect that choke may behave rather differently as the load reduces, but admit I haven't done any testing for this.

I don't use steel (I have several old guns with 2 1/2 chambers) and on the rare occasions I need a few non toxic, I do use one of the expensive variants - though in a 2 3/4 chambered gun.

[neutron619]

What shot size do you think you need? 21g of #7½ is about 300 pellets (and a perfectly adequate clay load, in my book) but if you go down to #9, you can get that number in 15g or so of shot. It all depends on pattern density in the end - you need enough to break the clay if you're on it but when you get down to the really small sizes, it becomes a question of striking energy too. You can get some strange effects at longer ranges with small shot, particularly where targets are side on (i.e. impact on the strongest part).

 

The best way to test a 17g load would be to try one, but there may be some issues. Those that come to mind, in no particular order, are:

• Smaller shot tends to get damaged proportionally more, and so fly less true. You make up for this by having more individual pellets, but if you're working at the limits - i.e. the bare minimum required pattern density to break a clay - you can find these things starting to be significant. You may not be able to replace 300 pellets with 300 pellets of a smaller size and keep the same pattern density - you might need 320 of the smaller size, for example.
• All things being equal, a decrease in bore size will tend to require more shot (i.e. number of pellets) to achieve equivalent pattern density. You may find, for example, that 17g of #8 gives you a beautiful, even 40-yard pattern out of a 10-gauge or 12-gauge, with almost all of the shot ending up in the circle, but that the same load from a .410 won't put even 25% of the shot on the paper. Taller shot columns lead to more pellet scrubbing which leads to more pellet deformation which generally leads to poorer patterns / performance.
• Lighter loads will tend to have higher muzzle velocities. Higher muzzle velocities damage pellets. And etc. as above. A cartridge needs a certain amount of pressure generated to work at all, so you'd be looking at ever faster powders to get proper burning as the load weight falls, if the size of the tube stays the same. If you reduce the powder to reduce the velocity, the powder itself has to burn faster still. This may itself be damaging, quite apart from pellets clattering through the choke at 1700fps+...
• Short shells of the kind described in the fourten.org.uk article might be cute, but when most guns have 3" chambers and no forcing cones to speak of (i.e. the chamber ends, the barrel begins and there's a hard edge between the two), it's a hell of a lot of travel for the shot column before it reaches the barrel "proper". Fibre wads will get sheared with a jump like that, shot may be damaged on impact with the hard edge at the end of the chamber, etc. Ironically perhaps, I'd only expect shells like the 1½" shells in the article to behave at their best in things like modern semi-automatics (I have a 3½" chambered Browning semi which has 4-5" forcing cones, for example) where the constriction to barrel diameter is gradual. Otherwise you're looking at the same issues as you see in the .410, where 2" shells in 3" chambers can perform noticeably less well than 2" shells in a genuine 2" chamber (though granted, there are never many pellets to "perform" in a cartridge that small).
• If you don't shorten the case, you may need a lot of packing material in a standard 70mm 12-gauge case to crimp such a light load. A specialized plastic wad might avoid this, but anything behind or in front of the shot which isn't quickly discarded - i.e. a plastic wad "petals" and slows down very quickly, letting the shot go on - has the potential to interfere with the performance and make it less consistent or damage it.

Edited April 27, 2017 by neutron619

[rovercoupe]

Thanks neutron some interesting thoughts there, I was thinking a load of 8s might be the best of both worlds as it will never be a long range cartridge. I suppose its going to be one of those make up some loads and get them tested and see if it works in the real world.

[TIGHTCHOKE]

Thanks neutron some interesting thoughts there, I was thinking a load of 8s might be the best of both worlds as it will never be a long range cartridge. I suppose its going to be one of those make up some loads and get them tested and see if it works in the real world.

 

Nail/head interface!