angrybear - you have no idea of what you are getting yourself into !!
I started at Hodgdon’s recommended minimum of 12g and have worked up to 12.5 so far.
40g V-Max
Lilgun 12g = 2640fps
12.2g = 2700fps
12.3g = 2800fps
12.5g = 2800fps.
Best accuracy so far with 12 – 12.3g. Started to open up with 12.5g.
Vectan powder is not available round here, another problem is that you can’t mail order bullet heads. I’ve found some suitable bullets at various suppliers but it’s a case of waiting for my RFD to order some or put up with what they stock.
I have found that the .22 Hornet requires a short bullet, that’s the problem with the 40g V-Max, it’s quite a bit longer than the 35g. The Nosler Varmagedon are suitable but very expensive, Speer 40g Spire are £10 per hundred cheaper. Sierra also make Hornet bullets.
I ended up loading to a coal of 1.775", just fits in the magazine but the ogive is just inside the tip of the brass so I crimped a fraction back from the tip, not ideal but seems to work until I get some shorter bullets.
I also looked into how far back from the rifling the bullet was sitting, apparently 0.020" is the optimum for accuracy but this is impractical for hunting use as you can't use a magazine.