5 shots on one fill at 285 yards 4000 to 3200
Andy,
You wanted to know how much spread there was on a single fill at 285 yards, here it is.
Shot one 0
shot 2-3 5 inches drop
shot 4 7 inches of drop
shot 5 16 inches drop
Regards,
Roachcreek
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Those numbers are on 3300 psi fill. With 3500 psi fill I got 1104 fps.
I don’t have enough hammer or spring right now to get anymore. Second shot was 1090 something. So I know there is more at 3500 psi.
I’m now thinking about building a frame for both my .308 and .257.
Doug,
Yes I need to get a fill level so that I can get three good shots, perhaps now that it is raining again, and I can’t shoot long range, I will do that.
So far with this 257420, 1145 has been my top velocity, your so dang close to that now.
I really wonder what my TSSS would do if I had you rebarrel it, right at 21.5, which as as far as I can go and still stay in the SS forma with the cap, and then put one of your super valves on it.
Just takes money, and the next big purchase will be a booster pump and since you won’t be nice enough to sell me back my Booster pump for $50.00 😛 , I will have to pay full price for anotheer one, and I really need one for this stuff.
I have high hopes for this tapered bullet I have coming, if it shoots well, I will need to get the barrel moved back a small ways and a lead cut or that bullet.
With a bore rideing front band and tapering to 258, it would not take much of a lead to accomplish that.
In theory, the black powder schuetzen shooters of the 1890 to 1910’s have paved the way on this for us they were a little hotter in velocity, we just don’t have the added pain in the ass of Black Powder and corrosive fouling.
RC
50 psi is my valve with 62 ci tank shooting 1060 something 5 shot average.
100 psi seems pretty high Tofaz are you sure, I thought Doug was saying like 50psi a shot, man these bb guns are getting more powerful.
Good info RC.
You gun uses about 300 psi per shot on average and my peashooter uses 100 psi per shot.
Im gonna have to try that test one day. that’s cool
Doug,
I would think it is around 1045 or so.
But still it is just a 3 shooter at that range. at 40 yards it will shoot under an inch for 5 shots but as the range increases it really spreads them out as the velocity drops so does the poi.
A drop in velocity of 75 FPS will drop it 13 or 14 inches at 285, and in a 5 shot string you will see that much of a drop.
Nature of the beast with a tube gun.
RC
What is your guns fps at 3200 psi? I was shooing tethered at 3250 yesterday. Today I was filling to 3300 psi and shooing off the tank.
Seems to shoot good down to 2000 psi. Yes POI starts to drop but not that bad. I think I got around 30 shots.
Butcher,
That was the heaviest spring I have, I have not played with the others yet.
Now when you look at that one high shot, if I had been paying attention, I would have written down the pressure after the first shot, then I can fill to that level and hopefully get a tight 3 shot untethered cluster.
Andy,
I have a Ranger 45, it is really a 2 shooter past 100 yards, but those first two shots at times are touching at 100 yards with 415 grain bullets.
RC
RC, that is very interesting, and actually surprising the drop was not more than that at that 285 yd range. You were right the first 3 shots are nearest to consistent and then it falls off quick after that, however to me it seems the drop is not that much considering the 4500 went down around 3000. Thanks a bunch. Way cool of you to oblige me. I learned a lot from that. Leads me to believe that in hunting conditions, if a guy knew how the trajectory performs, as each consecutive shot is taken in string, then it would be possible to accurately estimate holdover, or possibly learn how to use multiple ballistic drop reticles on the center crosshair post, to stay accurate and in the kill zone if he knew the range and how many shots had already been fired. I Bet the drop would fall off even faster when using bigger bigbore calibers that increase in size, like from your 257, up to a 308, or a 45 cal. ? Since more air pressure is likely lost from each consecutive shot.
That is really cool- I appreciate you posting this. makes me want to get a regulator for teathering so followup shots stay as close to consistent as the first.
Cheers,
Andy
What spring set-up is being used for that string again?
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Did a little crony testing after I got home from my 9 hr drive.
I was able to get 1084 out of 3250 psi. I lubed up the breech with krytox grease.
3500 psi got me this
1100
1099
1098
1096
1092
Shot 6 was 1083 fps. Not sure if teathering effected that string. I turned off the tank.
I need to make a 120 gr hammer so I can catch up to your fps RC.