We all know you need to find the pellet that suits your particular gun/barrel in order to get the best consistency. MY question is why ? If you take quality pellets that are consistent in build weight etc and fire them down the same barrel with the same force why don't they hit the target at the same place. ? The components are the same, the driving force is the same but the outcome is different. If you try enough pellets you hopefully find one that suits your barrel and pellets that don't work well in your barrel work fine in others so that equates to swapping barrels. So what is the cause of the miss-match?
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the Daily hi thread
Matching Pellets to barrels.
- Thread starter Bardot
- Start date
GridNorth
Super member
Small discrepancies in the engineering and poor quality control in the production of both the pellets and the barrel. Considering the variables I'm happy we can get them to match at all.
What if you had one particular set up that loved exact 4.52, but then swapped the barrel over onto another rifle set at the same power would it still love exact 4.52? So then is it pellet barrel or air delivery.
But you can take a tin of pellets that you have tried and dis-guarded with one gun try them in another and they work fine so those small variances cant be the reason. And any issue with the barrel is still there when you find a pellet that suits it and works.
BallisticBill
Super member
This and barrel harmonics (for example).
Say the barrel is vibrating so the muzzle is moving up and down even though the action is still. The position of the muzzle and the angle of launch will vary with minute differences in time taken for the pellets to travel down the barrel. The rate of movement of the muzzle is greatest in the centre of its movement, and least when it reaches the limit and changes direction. So the combination of vibration and average pellet timing can determine whether the pellets are launched at similar or dissimilar angles. The relationship between vibration and pellet travel can be changed by tuning - for example, by changing the power and pellet velocity. Similarly, changes in ambient temperature (which changes power output) can change this relationship. It's generally easier for the shooter to find a pellet type that works well under different conditions than it is to tune the gun to a particular pellet.
If you move the barrel to a different gun, the source of the vibration and restraints on the barrel will be different so there's no guarantee the relationship between pellet and barrel will be the same.
I would expect them to work but maybe not.
I was just writting this reply before you posted LOL
I am thinking it may be due to tuning (of the nature barrel tuners try to reduce on fancy setups). If firing the gun causes vibration in the barrel the end of the barrel is vibrating up/down and side to side. If it is at the extreme end of that movement when a pellet exits it will scatter them. if a pellet tends to leave the gun when the vibration is mid way it is going to be accurate. Is it this sort of match that we are dealing with? If so is tuning of pellet guns a thing? or should it be ? By which I mean fitting tuners to the end of a barrel. Not standard tuning as we know it.
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BallisticBill
Super member
You might think that would be true... also if a node in the vibration occurs at the muzzle... but neither are correct. The muzzle needs to be still and the barrel angle consistent; these conditions are most likely where the barrel is at the peak of its movement.
GridNorth
Super member
I'm not convinced that your argument nullifies my statement but I will concede that it is perhaps an oversimplification.
Could it be that some types of pellet are larger or smaller in diameter than others? As well as trying different weights of pellets you should try different diameters as well. And this is where we disappear down the pellet testing rabbit hole!
Mick_Green
Busy member
The Rifling in every barrel is as unique as your fingerprint. The single defining point of every barrel and what it will or won’t like. No two barrels are the same.
Wing Commander
Member Extraordinaire
That is an excellent question.
Bearing in mind the miserable amount of power we are allowed to play with (sub 12ft.lb) it seems that every little detail makes a difference.
I have known pellets to be awful in certain barrels, but reducing the muzzle velocity by just 15fps makes them brilliant.
It's a journey of discovery, and it's all part of the fun of the game (shooting) we have chosen to play.
Having said that, the new QYS 8.64gr Streamlined pellets seem to be remarkably tolerant of different barrels and different velocities. . Very consistent and very accurate.
Ian Cartmell
Member Extraordinaire
Absolutely my least favourite pastime, finding the most suitable ammo for the latest new gun, it's an absolute pain in the sphincter 
GridNorth
Super member
I have to agree about QYS. At the club I I used to attend we did some serious and I mean serious testing of pellets. QYS proved to be the most consistent across a wide range of guns. So much so that we clubbed together and made a bulk purchase.
I don't know if I'm kidding my self but it seems to me that the more pellets I put through my guns the less fussy they become I generally only use baracuda ft's but now some seem to like 8's which I used to get the odd fliers with
jesim1
Member Extraordinaire
I think you have to remember we are talking about tiny differences which show up over relatively long distances compared to the size of the pellet while travelling pretty quickly and spinning into the bargain 
It's incredibly difficult to get consistent pellets to a high degree of quality, it's not just the size, shape and weight you have to think about, but also the hidden components of this like consistency of the lead mixture and distribution of weight within the pellet. Just think, the tiniest of air bubble or impurity in a pellet can make it a fraction off completely symmetrical on the inside, you can't see this, but it's enough to make a pellet wobble in flight, and that translates into inaccuracy.
If manufactures were to spend the time and effort creating the ultimate pellet in terms of consistency and build quality, then no one would spend the ridiculous price they would have to charge to make it commercially viable - £250 for a tin of top end pellets anyone? (and that a tin of 200)
It's incredibly difficult to get consistent pellets to a high degree of quality, it's not just the size, shape and weight you have to think about, but also the hidden components of this like consistency of the lead mixture and distribution of weight within the pellet. Just think, the tiniest of air bubble or impurity in a pellet can make it a fraction off completely symmetrical on the inside, you can't see this, but it's enough to make a pellet wobble in flight, and that translates into inaccuracy.
If manufactures were to spend the time and effort creating the ultimate pellet in terms of consistency and build quality, then no one would spend the ridiculous price they would have to charge to make it commercially viable - £250 for a tin of top end pellets anyone? (and that a tin of 200)
Ballisticboy
Super member
There is also the basic design of pellets, which makes them extremely susceptible to any imperfections in the way they leave the barrel. Anything which means they do not leave the barrel absolutely perfectly, will produce errors at the target which are made larger by the design of pellets, as opposed to other types of projectile. All of this means your pellet has to exactly match your barrel in every way, which it never will, and every pellet will be unmatched by different degrees due to manufacturing tolerances and imperfections.
Yes but my question was : If the barrel remains the same between shots (which it does albeit a minuscule change in leading etc.) and you use matching pellets WHY is there no consistance with some and there is with other. To put it another way what makes a good match a good match?
steevie dan
Member Extraordinaire
Glad mine isn't fussy, and it never gets cleaned either Edit. Thinking about it iv'e never had a barrel that was really fussy and i have had a lot over the years which also never got cleaned only if accuracy went to pot, very rare
Edit. Thinking about it iv'e never had a barrel that was really fussy and i have had a lot over the years which also never got cleaned only if accuracy went to pot, very rare
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Cometa
Busy member
It's because a gun, no matter what type, is a differentiator which are inherently unstable, the barrel is actually a mild integrator which gives the projectile its accuracy and then there are pellet geometry, centre of gravity, wind and ballistic coefficient.
Mick_Green
Busy member
Even if the pellets were 100% identical every time you loaded one it would engage with the rifling slightly differently and that also would cause the difference down range. And as we all know every pellet it as individual as your barrel.