Airsporter tap

[AdeC]

I've just finished restoring a mk2 airsporter and the accuracy isn't as good as I think it could be. There's a slight scuff on the side of the pellets which I think is due to the tap. It's a nice tight fit and there were no shims in place. Can't see how there would be room for shims anyway.
When looking through the cylinder it looks aligned.
Any ideas?

[Airsporter1st]

I've just finished restoring a mk2 airsporter and the accuracy isn't as good as I think it could be. There's a slight scuff on the side of the pellets which I think is due to the tap. It's a nice tight fit and there were no shims in place. Can't see how there would be room for shims anyway.
When looking through the cylinder it looks aligned.
Any ideas?

Have you checked the muzzle end? If there's any damage to the crowning, that will also cause scuffing/inaccuracy.

[AdeC]

I have, yes. Tidied it up with the round head screw and polish trick.
Seems to be a little better with rws hobbies rather than wasp blue.
I've got some superfields in the post so they may be better?

[AdeC]

Hmmm....not that brilliant with superfields either even though they're a nice tight fit.
Any tips on crowning?

[Airsporter1st]

I have, yes. Tidied it up with the round head screw and polish trick.
Seems to be a little better with rws hobbies rather than wasp blue.
I've got some superfields in the post so they may be better?

When I last used Wasp blues, any advantage gained by having the right size, was totally negated by the poor quality. I must admit, I haven't tried them recently and I did read somewhere that they had improved.

RWS Superdomes or Hobbys usually perform well, so it seems you may still have a problem. I've never recrowned a barrel; hopefully someone who has will be along soon to give you some pointers.

PS - another very experienced member has encountered the situation where a slightly bent lever on the loading tap would touch the stock before the tap was fully closed. Might be worth checking. Also reminds me that the index plate could be loose, having the same effect of misaligning the tap.

[AdeC]

Thanks for the pointers.
Definitely nothing loose as it's been completely rebuilt.
The firing cycle is pretty harsh though so it's not going to help accuracy I suppose

[ggggr]

Check to see if the tap arm touches the cylinder as I had this problem on one. I guess the gun had been dropped of banged against something. If that does not seem to be the problem, then see if someone else can try the gun to rule out your shooting. After that, I would be tempted to remove the tap and push a pellet through from the muzzle to the breech to see if there is anything obvious (tight spot or deformation of pellet). If everything seems ok, try a different mainspring to make the gun a bit "softer". If none of that works, then try the recrowning. Just a touch with a counter sinking tool or even one with a bit of wet or dry paper over it sometimes cures minor burrs. The BB with a bit of metal polish can be used as well.

Ps--I am assuming that the barrel has been cleaned? With a lot of guns that have been over lubed, they shoot hell of a lot better once the crud has been cleaned from the barrel. Webley pistols seem to suffer from this and a barrel clean really helps them.

[AdeC]

Yes, I had the bent tap handle too but that's sorted.
The barrel is also clean. Just used a brush though. No chemicals. Think I should try some? If so what?
It's not my shooting as it's all over the place even rested. I can shoot very tight groups with my other rifles.