FX Tarantula-O-ring size?

Yes, try the vitons. They are more durable and will last longer.

Beautiful John. They are a pleasure to shoot. I consider the Tarantula to be the altiment classic pcp. They have oring kits for the rifle on ebay and I bet FX USA will also have them or get them for you.

Cheers

Check the FX website for the schematic. It is listed as the FX 2000. 
And yes, FX USA does have the o-rings.

View attachment 1572914867_6114718295dc0c6b38c6756.17586615_FX 2000 o-ring sizes.pdf





Handsome rifle John.

I have an FX2000 and Tarantula.. Both are very accurate.

Attached is a .pdf file I put together when resealing them. Maybe it will prove useful to someone else.

Steven

If you have to pull the valve for whatever reason it's important that the transfer port restricter screw is removed or at least backed out a bit.

Steven

My stock Webley FX2000 velocity with the transfer port screw 8 turns out from seated results

2900psi fill down to 1790psi

46 shots

JSB Exact Jumbo RS 13.43-----------------------------873fps 22.7fpe

ES of 40





The Tarantulas (pictured below) velocity is tamed down a bit with the transfer port adjustment screw only three turns out from seated.
JSB Exact Jumbo 15.89----------------------------------664fps 15.6fpe

Haven't had time to do the stats on this rifle yet.





Notice the barrel is shrouded. There are several baffles at the end which quiets the bark. It is also threaded for a moderator.