Daystate Huntsman Revere or DNT TNC225R?

[blackdog899]

Got to shoot a little today. Set up with a Muellar 8x32 temporarily till my ArKen epl4 4x16 arrives. Was going through a test set of Diablo pellets. All are one hole not ragged but my cellar range is only 13 yards. After shooting all 4 different ones I figured I’d see how many shots on a full tank in the same hole.
filled gun to about 240 bar loaded 34.95 diabolos and started shooting
First shot was 590fps and gradually climbed to a high of 776fps on shot 29. Tank was about 155bar at this point.
From shot 30 till shot 47 speed dropped from 775fps to 608fps still in same basic hole at pressure of 120 bar.
After this speed dropped under 600fps and went low out of main hole. Shot 51 the tank read 50bar.

I don’t get the gradual climb to 776fps. I get the gradual decrease .

 

[blackdog899]

 

[blackdog899]

Forgot to state it’s a 25 unregulated

 

[Peskådot671]

For an unregulated airgun, start filling from a lower pressure. With the Huntsman, a good starting point is around 200 BAR. At the peak of your velocity, you'll know your Extreme Spread (ES) and then comes back down to the velocity of your first shot. If you still don't like the ES, fill a little higher like around 205, 210 BAR and check your ES and shot count to where you feel comfortable with it. Also check for accuracy out to at least 50 yards.

 

[blackdog899]

Thankyou for the reply. I was shooting today and was ready to post a question I’m now confused about.
Why when filling to the max does the speed go from a low to a high. After the high I understand fps going
down . Specifically this happened, I was shooting 16.54 diabolos till about 155bar I then switched to 33.95s
and started at 781fps after 4 shots it dropped to 765fps and I filled tank to 240bar. The next shot was 570fps
and it climbed to 714fps in 14 shots.
I don’t get it… the filling and dropping to a minimum and building back up to max before dropping again.
Mike

 

[coastal drifter]

There is a balance between pressure and valve opening and closing and the hammer strike which opens the valve. This is what all the external adjustments on guns like the FX Impact are all about, so you can adjust all the settings to shoot the projectiles and weights/grains to maximize your guns performance. Looks like AOA tested your gun with the (25gr. JSBs). I would try what Peskadot671 above posted for maximum performance/accuracy. I have found diabolo pellets like speeds between 840-920fps generally speaking and the 33.9 JSBs shot best out of my .25cal @910fps. The 25gr. like it a little slower, around 880ish. 50yards is going to tell you a lot about what your gun likes for pellets and speeds.
Beautiful gun BTW.

 

[cavedweller]

AOA changed my order to a regulated 22 caliber. I think by spending just a little more will get me the rifle I wanted. Thanks for everyone's input. Hopefully it gets shipped out quick and maybe I'll get by the weekend.

Revere everyday all day

 

[Peskådot671]

Thank you for the reply. I was shooting today and was ready to post a question I’m now confused about.
Why when filling to the max does the speed go from a low to a high. After the high I understand fps going down.
Specifically this happened, I was shooting 16.54 diabolos till about 155bar I then switched to 33.95s
and started at 781fps after 4 shots it dropped to 765fps and I filled tank to 240bar. The next shot was 570fps
and it climbed to 714fps in 14 shots.
I don’t get it… the filling and dropping to a minimum and building back up to max before dropping again.
Mike

Because you filled it to a high pressure, the hammer and spring tension behind it has a harder time opening the valve when it strikes the valve stem to release the air on the first few shots. This is why your velocity is lower at the beginning of the shot string. As the air pressure in the air tank starts to decrease, the valve gets easier to open when the hammer strikes the valve stem releasing more air, hence higher velocity. The velocity will start coming down when the air pressure in your airgun's cylinder decreases. This is what's called a bell curve in an unregulated PCP. Velocity (FPS) will start from low to high and back to low. When testing with a chronograph, don't switch between different ammo during the shot string. It will only confuse you.