Caught in a trap: Finding the right chokes and cartridges

If you’re struggling to figure out the best combination of cartridge and chokes for your Trap shotgun, Richard Atkins might have some answers for you…

Different cartridges for different disciplines have been developed with the benefit of many years of experience in what works best and less well

The choices we have today comprise a broad range of guns and cartridges for clay shooting – we have never had it so good.

Different cartridges for different disciplines have been developed with the benefit of many years of experience in what works best and less well. Choices were minimal when I started clay shooting, even plastic wads were in their infancy so most Trap cartridges in UK were still loaded with felt or fibre wads. Interchangeable chokes weren’t common either so the chokes in your barrels had to be decided when you purchased your gun. That may seem odd today, when you have to search to find a gun without multiple chokes, but some fixed-choke guns still find a market.

Anyone who follows shotgun forums on social media will have discussed the evergreen topic: “What chokes do you guys use for Trap/Skeet/Sporting?” Fairly well represented among the responses will be: “I just stick to ¼ and ½/½ and ½/½ and ¾” or  “I never change them, I can’t see the point.”

When I read these comments I cannot help thinking what wonderful marketing it is that makes shooters buy a gun that has a set of interchangeable chokes that they neither want nor intend to use. It also tells me that a great many shooters have little idea what difference choke and cartridge choices can make.

Full choke is overkill for first barrel DTL, as the dense central sector shows

Having choice is good, but if those commenting really do not change their chokes then all they have done is bought a gun made more expensive by the work involved in making it suitable for multi-chokes. Cleaning is made more difficult by the need to remove and grease the choke tubes after shooting and if you don’t bother then they could corrode in position and cost a lot to put right.

But it goes beyond this: gun muzzles are usually made thicker, hence heavier, to accept choke tubes and this inevitably adds some weight right at the front of the gun where it is least wanted. It may not make too much difference for the slower Trap targets like DTL but for the faster disciplines, such as Universal Trench and Olympic Trap, a more swift-handling, better balanced gun can be more of an advantage. For these disciplines there is a lot to be said for a gun with fixed chokes.

Given that people were shooting and breaking clays, including Trap disciplines, long before plastic-wad ammunition came along, makers had to use other means of ensuring their ammunition could produce reliable clay-breaking patterns. They did this by several methods: better quality true felt wadding or harder shot and reduced velocity being two.

Today, these factors work just as well now as they did then. We have the universally available and widely used plastic wad to replace the fibre wad, a wider range of progressive powders and higher levels of antimony in the lead shot. This results in the hardest lead shot clay shooters have ever had the opportunity to buy. The patterning potential of today’s best OT and FITASC Sporting cartridges has reached levels barely dreamed of 50 years ago.

Improved Cylinder is too open with 7.5 shot, though distribution is good

It’s worth noting that the official shot load weight for Olympic Trap was once 36 grams, but is now down to just 24. Despite its faster targets sent out at the higher speeds, Olympic Trap is made all the harder by having the smallest shot load for the toughest discipline, which means cartridge makers have had to work hard to develop loads that will reliably smash the fast retreating, edge-on targets at considerable distance with fewer pellets. It’s worth considering what goes into producing cartridges that these shooters have come to rely on, because nobody wants to shoot a budget load at the Olympics.

The wad situation is simplified by the fact that Olympic layouts allow for the use of plastic wad ammunition (as do most, if not all, domestic Trap layouts). Some successful OT cartridge makers, Clever Mirage for one, go to extra lengths to ensure that wad cups will have separate petals. They cut the petals of the plastic wads they use even though they have moulded in petals anyway.

After many years of pattern testing, the one feature all top-grade ammunition has is the quality of the lead shot used. Shot samples in some of the Olympic-medal winning Trap cartridges reveal the most exquisite shot pellets you could find in any cartridge. The grading for size will be at least a double or triple-stage process, ensuring that the pellets are all round and uniform size. Such refinement isn’t as necessary in easier Trap disciplines where target speeds and angles vary less, especially as they can use 28-gram loads.

At 30 yards, 8 shot put 23 per cent more pellets in the outer 20-30in sector

Hard shot

Shot must be hard for two reasons: it deforms less under the acceleration of firing and patterns more closely than softer shot, which deforms more under the same acceleration. And Olympic Trap shooters often prefer a fast cartridge to help cope with the target speed. The extra speed will lead to extra acceleration forces and this can work against the need for close patterns. This is why cartridge manufacturers want to use the best plastic wad possible to help cushion the shot from acceleration crushing, as well as finding a propellant powder that will accelerate the shot load a fraction more progressively.

Being a relatively light shot load, recoil is not a major problem. Pellets in Olympic Trap shells are frequently nickel coated to ensure they don’t stick together – it also produces a slightly more even pattern. Nickel plating hard shot helps because the plating is not thick enough to add any hardness, but it can make it shoot a shade more evenly. Only pattern testing with the gun and choke to be used will reveal how well this works out.

Selecting chokes and cartridges

Selecting the chokes and cartridges likely to be best suited for each Trap discipline produces quite an array of options. However, thinking about the target speeds (hence distance they are likely to be engaged at) also the height and angular variations, it soon becomes clear that some situations are more demanding than others. With DTL still the most popular Trap game in UK, I will concentrate upon that.

Light Mod chokes are more than adequate for first-barrel DTL

DTL

You are allowed to use a heavier shot load for DTL than OT, even though target speeds and spread of angle are lower. Logic says that if 24 grams in Olympic Trap competitions will smash a 40-45-yard target then that’s all you need for DTL.

However, as you are allowed more shot you may as well take advantage of that option and so I suggest thinking about making the best use of the extra shot. Something worth thinking about is using a more open choke because you have more pellets to fill the pattern. With 7.5 shot breaking OT targets, this shot size is evidently up to the task. After much testing over many years, 8 shot has proved a good shot size for DTL – particularly in the all-important first barrel.

DTL target speeds and angles may be less demanding but, if any second shots are required, these cost a point. Therefore, if you can add a few inches to your effective pattern by using an open choke, then it really is worth experimenting to see if a smaller shot size and more open choke works for you.

If you are recoil sensitive, you might wish use 24-gram 8 shot for your first barrel. This may require going back up one choke restriction to ½ choke but a pattern test check and then some practice on the DTL layout will tell you if this is good for you. Some find the substantially lessened recoil, aids maintain form and concentration over a 100-bird competitions, plus a ahoot-off.

If you prefer to have more back-up pellet energy in the event a second barrel, then use 7.5 in your top barrel. I would use no more than ¾ if interchangeable and probably.

I shoot a variety of things, including some DTL. I don’t have the concentration to excel these days but a couple of years back I entered the 100-bird County Championship. Having shot only a few practice rounds after a long time away from Down The Line, I put choke in my Browning Citori Trap gun’s bottom barrel, and after missing the first target out I went on to shoot 98/289 with a 25/75 and 25/74 round to top score my class. This indicated to me that more open choke was certainly beneficial for me in opening the pattern up for the first barrel. The odd point makes all the difference in DTL with second barrel shots punished. Each shooter who is really interested in maximising their performance might well find it by taking a closer interest in the cartridges they use and their performance.

A good way to confirm how your gun/choke/cartridge selection is performing is to spend some time on a pattern plate and practice range

With concentration key to success, note that velocity need not be so high for DTL as the first target will be taken quite quickly and at a shorter range. This too has benefits: recoil will be less and patterns more dense. Patterns can be perfectly good with less hard lead rather than is required for OT ammunition: this helps keep the cost down, because high antimony shot is more expensive.

As we have different techniques and some shoot much faster than others, no-one can state what is best for anyone else without working with them, but these hints and tips might help show why that bit of extra effort can be valuable.

Having concentrated on DTL, space is short for comment on the other Trap disciplines. The principles discussed here apply, it mainly requires the target speeds, angles and any shot load differences to be considered in the same way.

Speed and angle in ABT have been trimmed back since 2 October 2016. This brings speed and angles closer to DTL and so the difference in any choke restrictions required could be lessened for those who shoot both.

Olympic and Double Trap are specialised disciplines with fast targets and weight restrictions. They require particular thought and experiment to fine tune the shooter and the gun/cartridge/choke combination. Universal Trench has the speeds and angles of OT but fewer traps and a heavier shot load restriction at 28 grams. A good coach familiar with the disciplines is likely to be a benefit to anyone tackling these disciplines as progress without can be difficult.

A good way to confirm how your gun/choke/cartridge selection is performing is to spend some time on a pattern plate and practice range. You can count the pellets in the 20 and 30in circles with a selection of chokes and cartridges to see how they perform.

Be sure to count the pellets in a couple of cartridges to be tested to check pellet size and count. Do not assume a notional count because the cartridge box says they contain 28 grams of 7.5 shot. I have recently seen well-known brands marked as containing 28 grams of shot size 7.5 that should have around 392 pellets actually contain 319, closer to 6.5. If I’d not checked actual shot size and pellet count, the apparent pattern percentage would have been only 55 per cent (or ¼ choke) pattern result from the Imp Mod (¾) barrel. It is pellets that break targets, not percentages, and that is where the balance between shot size/target distance and choke comes in.

I know it is too much hassle for many, but those who make the effort are better placed to make a judgement. It will not make up for poor technique but, especially when you are starting to shoot well, it can mean the odd extra target that makes the differences between a top placing or not.


This article originally appeared in the April 2017 issue of Clay Shooting magazine. For more great content like this, subscribe today at our secure online store www.myfavouritemagazines.co.uk

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Posted in Advice and tips, Trap

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