Quote Originally Posted by Artfull-Bodger View Post
Makes you wonder if one of their mandrels is a bit dodgy?
Maybe ... or just tolerances like you said earlier.

I remember the old Webley 0.22 barrels that were always oversized compared to the Continental stuff from the Germans etc.

Wasp pellets used to come in 2 sizes ... 5.5mm for German barrels and 5.6mm for British barrels as the barrels were slightly oversize. Strangely enough I used to find the generally large American Crosman pellets went well in my old Webleys.

So maybe the barrels are slightly generally oversize in the 0.177 BSA barrels. The 0.22 seem much better and less pellet fussy.

So if you have slightly oversized bores and you get a barrel that is at the large size of tolerance then maybe that is a fussy barrel and will only shoot the larger/longer pellets well?

When I first started posting about my BSA 0.177 problems a lot of lads from Rivi said to use JSB 4.53.

Now I have a lot of respect for the lads on the boards who post saying that the numbers on the tins of JSB/AA are basically pointless ( mainly Bri and RobF ). I too have found that. Just to be contrary I have also found that on the odd tin the numbers do make sense and the 4.52 or 4.53 are generally larger ( there's always a big mix of sizes within each tin ).

In general I've always found that the actual sizes of pellet heads are much smaller than any of the sizes stated.

I found the head sizes of Bis Mags/Barracudas tended to be closer to what it said on the tin ... and the boxed Crosman Prems ( which also go well in the 0.177 BSA barrels ) are massive.

I have actually found the odd batch of JSB that have shot quite well in the BSA barrel and no surprise that the heads were actually on the larger side.

When I've probed pellets through the BSA barrel, in all cases there is more resistance at the start and at the end with less resistance through the middle section. Trying the smaller pellets and through the middle section there is no felt resistance and they seem to fall through.

So maybe if you get a mix of a slack end tolerance BSA 0.177 barrel and a smaller head batch JSB pellet ... you've got problems and it takes the larger/longer pellets to go well in that barrel. Maybe if you get a tight end tolerance BSA 0.177 barrel and a larger head batch JSB pellet ... then they shoot well. Hence two groups of shooters on the boards ... one claiming no good with anything other than Bis Mags etc and the others saying great with JSB.

Or ... maybe it's down to the imperfections and polishing etc. Some barrels have less imperfections and will shoot JSB ok but some have bad imperfections that do need polishing out.

So we've arrived back at your " ... one of their mandrels is a bit dodgy? ".

I drove myself mad trying to sort out that BSA barrel. I've still got the rifle and that barrel. I read all sorts of stuff. People saying that the type of end on the bolt probe on the BSA meant that some pellet tails went better than other pellet tails due to the shape of the probe. That seemed to make sense also as the bolt probe is a larger diameter and the bases of the Crosman Prems and Bis Mags maybe coped better that the thinner, more flimsy tails of the JSB.