Air Arms Owners Club

Ok as I read 57mm dose that mean from factory it's screwed always in to the valve body?

As.ry177 wrote: ↑

Sat Mar 17, 2018 2:42 pm

Ok as I read 57mm dose that mean from factory it's screwed always in to the valve body?

it means its the best place to start when setting your power using the firing pot .

Correct me if I'm wrong, but I think you'll find it's glued (Loctite) not screwed.

Hi Tony, the pot is screwed into the firing valve body, but the sections of the actual pot are quite often loctited together. I'm sure you know that really.Rog

Yes, but to adjust the volume of the pot (as I think the 57mm refers) you have to remove and re-glue?

Sorry Tony, that's not the case, you have to slacken grub screw in the firing valve body, then you can screw the pot in or out to get the 57mm starting point. Rog

Had to re-glue mine as it came unstuck of its own accord!

It's not the first time that has happened, the measurement is from the firing valve body to the end of the pot, nothing to do with the volume in the pot, hope that explains it better. Rog

So am I missing something, Rog? My understanding is the adjustment on the pot reduces/increases the volume on the pot, limiting/increasing air available (particularly at lower cylinder pressure) per shot, which has the effect of reducing peak power and flattening the power curve as volume is reduced. If screwing/unscrewing doesn't affect the volume of the pot, what is the point of making it adjustable and what does it do?

Right, when the hammer strikes the firing valve, it opens to let air into the transfer port, if you slacken the pot it relieves spring pressure on the firing valve making it easier for the hammer to open it, screwing the pot in makes it harder for the hammer to open the firing valve, by adjusting the pot either in or out, you get more air flow or less, and the best starting point is about 57mm. Does that explain it better, it's the same with regs, it's all a balance, Rog