Sweet spot

[Hairybiker59]

I've just acquired a pre anti tamper s410 in .177 and going to chrono it to find the sweet spot.
Do I fill to 190 bar and shoot down to 100 bar and put up the results

[Mark112]

I shoot mine until the velocity drops to the ones you started with. Then start to refill and make a note of the pressure on the gauge you filled with. Post all the results up here in fps. Start and end pressures and pellets used. Boring job though

[Blackbaronfish]

You could start at 190 but 180 would be better.

BBF

[Geordie]

My .177 410 liked a high fill at 190, so I'd go from there if t was me.

Covers all the bases.

[poguemahone]

My .177 410 liked a high fill at 190, so I'd go from there if t was me.

Covers all the bases.

gordons right mate, 190 is where its at for the 1st chrono session of an unknown gun
i reckon 95%+ of s410/400's never get filled to 190 again unless you change the valve and have a mess about inside

[davyt63]

i usually fill to 190 bar and shoot down to about 70bar,it will depend on each rifle,and it will differ buy about 10/20bar from when the sweet spot is reached and dropped of.

so your sweet spot could start at 160/140 bar and drop of at 70/80 bar,it will also depend on muzzle energy between 10.8/11.5

but once you have done it,anything over your sweet spot for a fill,is wasting air,unless your just plinking.

good luck in your quest!

regards

Davy

[devonhunter]

My s410 carbine is not too good and I prefer to fill to 140 and shoot to 110!! Don't know why but it is a little frustrating

[poguemahone]

My s410 carbine is not too good and I prefer to fill to 140 and shoot to 110!! Don't know why but it is a little frustrating

sounds like exhaust valve extrusion.
i had a pig of a job with mine earlier in the year, and had to seek the advice of mike (cloverleaf) with regard to the valve housing seat.
for those who dont know mike, he's an absolute messiah on 410/400's, and a very decent bloke too he noticed that the black valves suffered with extrusion after a certain amount of time, or 35,000 shots in my case.
check the valve and change it, if its extruded it might damage the valve housing seat (like wot mine did)
hope this helps.