Post by Who? on May 23, 2022 17:25:55 GMT
In all the forums I've looked/participated in, there is a persistent assertion that the head size quoted on the JSB tins is not a reliable indicator of what is in the tin. Oddly, for such a persistent assertion, it seems not to be widely known of.
In recent weeks there have been conversations on the subject between a few GARC members, along with the usual "...my gun likes the 4.52..." (or whatever head size that person believes).
WARNING - the next bit might well be misplaced belief... and therefore complete nonsense -
On a few occasions I've used a "Pelletgage" to 'measure' the pellet head size. The pellet gauge (UK spelling rather than the USA 'gage') has ten holes in a thin sheet of stainless steel, these holes are marked 4.46, 4.47... to 4.55. Using the Pelletgage, involves seeing which hole the pellet head passes through (if it goes through 4.52 hole, but not the 4.51 hole, is the head 4.51 or 4.52?). I don't get too hung up with the actual size, preferring to sort the pellets by which hole they pass through and which gives the 'tightest grouping'. I've also weighed the pellets. I'm not claiming the scales are correct, but they are consistent - if a pellets is shown as weighing 8.54gr, the scales will show it as 8.54gr each time it is weighed.
As we can only include three pictures per post, you are going to have to look at the post below to see all the pictures I took. I 'measured' four different batches of JSB Exact 8.44gr, one batch of JSB Heavy 10.34gr and (for comparison) one batch of H&N Baracuda Match 10.65gr. In the pictures you will see I placed the pellets into a grid; it can be clearly seen, there is no correlation between head size and weight.
Not sure it has proven anything, except:
1. the head size and weight on the tin is only loosely indicative of the spread of size/weight in the tin.
So. If, in my (deluded?) view, you had a tin that grouped well, and it said 4.52, don't think by buying another tin of 4.52 that you'll get the same performance.
jsb 51110018-1.pdf (135.49 KB)
jsb 50560019.pdf (139.35 KB)
jsb 56540021-0.pdf (164.88 KB)
In recent weeks there have been conversations on the subject between a few GARC members, along with the usual "...my gun likes the 4.52..." (or whatever head size that person believes).
WARNING - the next bit might well be misplaced belief... and therefore complete nonsense -
On a few occasions I've used a "Pelletgage" to 'measure' the pellet head size. The pellet gauge (UK spelling rather than the USA 'gage') has ten holes in a thin sheet of stainless steel, these holes are marked 4.46, 4.47... to 4.55. Using the Pelletgage, involves seeing which hole the pellet head passes through (if it goes through 4.52 hole, but not the 4.51 hole, is the head 4.51 or 4.52?). I don't get too hung up with the actual size, preferring to sort the pellets by which hole they pass through and which gives the 'tightest grouping'. I've also weighed the pellets. I'm not claiming the scales are correct, but they are consistent - if a pellets is shown as weighing 8.54gr, the scales will show it as 8.54gr each time it is weighed.
As we can only include three pictures per post, you are going to have to look at the post below to see all the pictures I took. I 'measured' four different batches of JSB Exact 8.44gr, one batch of JSB Heavy 10.34gr and (for comparison) one batch of H&N Baracuda Match 10.65gr. In the pictures you will see I placed the pellets into a grid; it can be clearly seen, there is no correlation between head size and weight.
Not sure it has proven anything, except:
1. the head size and weight on the tin is only loosely indicative of the spread of size/weight in the tin.
So. If, in my (deluded?) view, you had a tin that grouped well, and it said 4.52, don't think by buying another tin of 4.52 that you'll get the same performance.
jsb 51110018-1.pdf (135.49 KB)
jsb 50560019.pdf (139.35 KB)
jsb 56540021-0.pdf (164.88 KB)
