What pellets do most use for the 1377 for accuracy?

I see Bob had tested with JSB 8.44.

My "mini-carbine" one, a Mk III with shoulder stock, Crosman steel breech and 4x32 scope is lazer-accurate (at garden ranges, at least) with the RWS Hobby.

My totally standard later one (later valve, lower power) had been delivering poor results with some RWS Geco that I was given when I bought my .177 HW45 last Autumn. A little bit of a session yesterday revealed the Hobby as better but the Superdome as better still. Very pleasing 10 shot group at about nine yards apart from one errant one which will have been pilot error!

I'll give it a go with some JSB 8.44 and 7.87 when I get the chance. Plus some H&N FTT and Baracuda FT to see if any of these fare even better than the 'Domes. Satisfactory performance with more cost-effective pellets would please me and would be more in keeping with the nature of the pistol. Shame it doesn't seem to like the Geco!