Hello everyone. I’m new here, and I found this thread, because I was looking for some info regarding my FX T1 in 22, and its problems.
Now, to the ST barrel and JSB accuracy, here is my experience.I shoot it with different pellets, Gamo magnums (16gr), JSB (26gr), Gamo long range (22gr), Crosmans (14+gr)…and results are really interesting..
The best group of those were with Gamo magnums (16gr)…about 2-3mm (cca 1/10in) at 10m ..and by far the worst with RWS 10gr wadcutters (2 cm and even more – say around an inch).
At the time I’m waiting for JSB heavy’s , since they are about the same weight as Gamo magnums, only of much higher quality. I’ll tell more, when I get them
JSB monsters (26gr) gave me a bit bigger group than 16gr gamos, but not much, (another mm or two…well that is 50% more
)I belive (and, If I’m wrong – well who cares), “problem” lies in timing. In ST barrel, the pellet hits rifling at the end of barrel (last two inches). Pellet is moving there at the top of its speed, so if ther isn’t much material that rifling could grab to – and wadcutters have enough material only at allready soft skirts – they are just skimmed..
On the other hand, if the barrel is fully rifled, pellet gets grabbed by rifling from speed 0 to full speed, so the “meat” of pellet is less important that used in ST.
Also, if you have really heavy pellets, regardless if they are “fully bodied”, they have a lot more of inertia because of its weight, so they also need more time in rifled part of barrel to give them full rotation…and those two inches at their speed , litteraly don’t cut it. Besides, heavy pellets usually need higher twist rate, to get properly stabelized… so I guess in case of ST barrels, there is a compromise of speed of pellet and actual rotation that they get becasue od their mass, ws. the material (that lands it self of their mass) that they provide to rifling…
I belive, only real advantage of ST is manufacturing cost.. I think it is cheaper to make precision ST barrel then full rifled precison barrel. Now, how that precision at ST is marketed onwards..that is different thing
So that advantage is only for manufacturer.
Now, to the ST barrel and JSB accuracy, here is my experience.I shoot it with different pellets, Gamo magnums (16gr), JSB (26gr), Gamo long range (22gr), Crosmans (14+gr)…and results are really interesting..
The best group of those were with Gamo magnums (16gr)…about 2-3mm (cca 1/10in) at 10m ..and by far the worst with RWS 10gr wadcutters (2 cm and even more – say around an inch).
At the time I’m waiting for JSB heavy’s , since they are about the same weight as Gamo magnums, only of much higher quality. I’ll tell more, when I get them
JSB monsters (26gr) gave me a bit bigger group than 16gr gamos, but not much, (another mm or two…well that is 50% more
)I belive (and, If I’m wrong – well who cares), “problem” lies in timing. In ST barrel, the pellet hits rifling at the end of barrel (last two inches). Pellet is moving there at the top of its speed, so if ther isn’t much material that rifling could grab to – and wadcutters have enough material only at allready soft skirts – they are just skimmed..On the other hand, if the barrel is fully rifled, pellet gets grabbed by rifling from speed 0 to full speed, so the “meat” of pellet is less important that used in ST.
Also, if you have really heavy pellets, regardless if they are “fully bodied”, they have a lot more of inertia because of its weight, so they also need more time in rifled part of barrel to give them full rotation…and those two inches at their speed , litteraly don’t cut it
. Besides, heavy pellets usually need higher twist rate, to get properly stabelized… so I guess in case of ST barrels, there is a compromise of speed of pellet and actual rotation that they get becasue od their mass, ws. the material (that lands it self of their mass) that they provide to rifling…I belive, only real advantage of ST is manufacturing cost.. I think it is cheaper to make precision ST barrel then full rifled precison barrel. Now, how that precision at ST is marketed onwards..that is different thing
So that advantage is only for manufacturer.
