ARC amps and 6550C Winged "C" small pins

Has any ARC amp owners experienced loose tubes in the sockets after replacing old 6550C Winged 'C' with new ones. The old tubes are snug and tight. The new ones fit quite "loose". Tubes came from Upscale Audio and were Cryo'd. However, i have ordered some 6550C from The Tube Store a few months ago and the pins were smaller than the originals i purchased in Jan. 2004. My Amps are Classic 120 mono's with GNSC Ref Upgrades. If those tubes were mounted horizontally in any of the VT series amps they would likely fall off.
What an odd thing. Tightning the little metal flaps in the tube sockets with a tiny jewler screwdriver is not very effective.
Yes. I got into a tiff with the local ARC dealer who gave me a hard time for buying tubes from a known tube supplier. The tech (the owner's brother as it turns out) told me the tubes were the wrong ones for my VT-100 Mk III and wanted to sell me "ARC" tubes for about $700.00 CAD. He showed me what he said were the right tubes and those were the tubes used on the VS series... The next tech I brought the amp to to have the tubes biased showed me that the sockets could be made tighter by closing the metal sheaths a little with a small pointed tool (a skewer works fine). Since he told me he couldn't be bothered doing it himself, I wound up doing it myself: like someone told me on AA, it's not brain surgery.

Honestly, for the money, I think ARC should provide better sockets.

Good luck!
I bought 8 power tubes from upscale audio, SED 6550, and they feel like they are tight fitting.
I had the same thing, replaced ARC tubes with tubes from Upscale Audio, no problem. Then replaced the Upscale tubes with Tube store, the pins seemed a little loose in sockets.

In the end, I just left them in (VTM200) and they never gave me any problems.