The Big Bomb Conundrum by Max Cope
The Big-Bomb Conundrum by Max Cope, Gun Room Manager
Over the past two decades, I have noticed a distinctive perceived need to launch exceedingly heavy loads at gamebirds that fall within the bracket of ‘normal distance’. I am sure that us all like minded guns want nothing more than clean, ethical kill, however the implementation of 36 grams of 4 shot on a 30 yard pheasant seems to be rather absurd.
I would surmise this recent trend of ‘bigger is better’ is down to a few main factors and mindsets:
Heavier, softer recoiling sporter-style guns now transitioning into the field.
Media portraying crack-shots dropping birds at extreme range in well-edited videos that encourage the ethos of ‘I could do that’ or “I need what he’s using”.
They’re available, so why not have the largest load I can get away with as this will help my chances.
I’ve seen others using them on my shoot so I don’t want to be undergunned.
The ever common over-estimation of range where many would label a 40 yard bird as 60!
Perceived heavy recoil being associated with killing power and speed.
From many conversations out on game days and the gunroom it does seem there is a serious amount of misinformation and misunderstanding out there. In this situation, there really is a case for ‘less is more’. Even in the cases where a gun may be lucky enough to be standing under genuine 50 or 60 yard birds, they may even find the lighter load to perform more effectively and cause less fatigue. The art of the shotgun cartridge may not be on the level of precision as rifle loads, however there still exists a level of witchcraft to hone the perfect recipe.
An interesting visual to quantify the actual altitude of game birds is referencing the height of electricity pylons. If you can imagine the height of a person compared to the door of the house in the image below, it becomes clear that most birds are no higher than 38m standard pylon (42 yards). Realistically most of normal game is shot at the first 26m (28 yard) pylon! The ‘new’ 57 m (62 yard) pylon would represent the bird of lifetime to most shots – and I am sure the anecdote would go something like: “did you see that 80 yarder I just shot?!”
If one is to imagine what actually occurs in the 0.002 seconds it takes for the shot payload to exit the barrel, the idea of lighter load may start to become more appealing. The soft lead pellets are subject to extreme forces as they are accelerated by the burning propellant gases. If you can imagine that the higher the gram weight of the shell, the higher the stack of pellets inside the cartridge and therefore more of them to be compressed into one another. Referred to in the writings of the renowned shooting journalist, Gough Thomas, the phenomenon of a ‘square load’ is still absolutely relevant today. This is achieved when the height of the shot is equal to its width whilst contained in the cartridge. This square ratio minimises shot deformation and therefore maximises pattern density – non-round pellets do not fly true!
Another important factor to consider is powder burn rate. A slow burning powder provides a more gradual acceleration of the shot and does not necessarily limit speed. The final muzzle velocity is not determined by the rate of burn as it is entirely possible for end chrono readings to be identical compared to a load using a fast burning charge. The difference being the slow burning powder takes the majority of the barrel to achieve target velocity, while the fast charge takes a less length to match this. Ultimately a fast powder will provide the highest velocity if required, but this isn’t actually what we want for the most effective cartridge. There is a sweet spot in speed and generally falls somewhere between 1250-1350 feet per second – I know, how shocking – not what is often claimed! This sweet spot is the golden ratio between pattern quality and pellet energy. You can very easily send your pellets screaming out the barrel as fast as possible, but how many of these will strike your bird at 50 yards when the majority are ‘squashed’? The most effective method to produce a clean kill is multiple pellet strikes, produced from a dense, high quality pattern. These pellets do need to be carrying energy, however such a small, un-aerodynamic and relatively light object slows at a considerable rate due to air resistance. Down range, a ‘quick’ and a ‘slow’ cartridge will actually be much closer in velocity than at the point of leaving the muzzle.
With a gradual burning, pushing less mass the inevitable, very pleasant byproduct is a smooth recoil impulse – not to be confused with a ‘soft’ or ‘weak’ load as I often heard muttered in gunroom conversations. This allows a smoother transition to your second barrel (many of us kill on our second as we keep the gun accelerating after the first poorly timed shot) and less fatigue.
I would challenge any big bomb aficionado reading this to try a lighter load this season. Fall high birds (40 yards +), if you are 36 or 34 regular, I would suggest a 32gm 5 or 4 in Hull High Pheasant Extreme, Gamebore UER or Eley Zenith. For all other normal pheasant and partridge shooting (up to 40 yards, with an occasional 50 yard poke!) I would suggest a 28gm or 26gm 5/6 from Hull in Imperial Game format (the 26gm 6 is a personal favorite), or a Gamebore Grouse Extreme 29gm 5.5.
If you are dubious still, I would suggest a test on our newly operational pattern board where the results will speak for themselves – and 40 yards looks further than you might expect!
All of the above are kept in stock at Thimbleby all season!