Stai ka raso vienas auksarankis anglas:
BSA are currently providing hundreds of barrel blanks every week for their production in Spain where BSA guns are made under licence. However the Spanish factory have been reporting loss of velocity with the BSA blanks compared to their other barrel provider, and rather than redesign the pneumatics, BSA have chosen to change the barrel internal bore sizings. There have been criticisms in the past that BSA barrel bores are tight, but I think this is one of their strengths, and they certainly have a very good choke which enables them to fire a large range of different pellet types and from different manufacturers, even damaged pellets with a great deal of accuracy. So they are pellet unfussy .... a lot of people get this the wrong way round, and of course have their own unique rifling style and design.
BSA now though in January this year have made minuscule changes to their Carbide mandrels for the hammer forging process, making the bore slightly bigger, and this has produced the desired velocity effect for the Spanish guns, but I'm not at all happy about this due to the fantastic results I've had with BSA barrels prior to the change. I've machined barrels from some of this new batch for Rapid Sevens and these have gone to the USA and South Africa. Owners have been pleased with the improved accuracy results, but I wonder if this might have been better with the older bore sizings.
So in all honesty I can't really tell that a new barrel will be a guaranteed improvement, it is unfortunately a case of you have to do the exercise to try it.