Numbers!!!
I finally got a chrony (Combro!!!) and can now start some real tweaking and it’s needed! I have two strings one with H&N 31 and one with SureFire 6 rings. I am looking for power and good shot count (20) with the H&N’s 950 fps range. Straight power for the 6 rings. If I could get 5 or so shots at 875 fps range that’s way more than enough. Hunting is the guns main purpose. I think I need to tweak the TH but would like some input from the pro’s before I do 🙂
Gun specs —
– Condor new gen valve
– 18″ .25 WIH barrel.
– TH = .091 stock
– In .22 24″ I was using FPSI 2550 ish and PW 6/0 getting 30 shots no major POI change at 40 yards using JSB monsters 25gr. EPSI was about 1600.
– When I added the .25 barrel I noticed she became a little bit more accurate at PW 5/8 so I used that for these tests.
– No real mods except for .25 barrel, trigger and safety mods. Cleaning and polishing of parts, etc…. Did nothing to valve or TH.
1st string —
Pellet = H&N 31 gr
PW = 5/8
FPSI = 2550 ish.
1. 908
2. 901
3. 904
4. 889
5. 897
6. 897
7. 888
8. 885
9. 859
10. 826
I also played with PW / Fill combos and could not get over 909. She’s close.
2nd string —
Pellet = SureFire 6 ring
PW = 5/8
FPSI = 2550 ish.
1. 728
2. 688 – Pellet wasn’t tite and jiggled in the breach end of the barrel
3. 717
4. 721
5. 708 – Pellet wasn’t very tight in breech end of barrel
6. 722
7. 708 – Pellet was loose
8. 528 – Pellet was tite in breach but slid in about a 1/4″ deeper than normal.
9. 712
10. 700.
Uniformity in fitting the pellets seemed to play a big role in the large deviation. When I get them in consistently the fps is fairly consistent :). I did not weigh out any pellets so I will do that next time. I again toyed with different pressures and PW settings and the best I got was after filling to 2700 psi and shooting 8 shots on PW 2/8 in the 700-744 range & turned the PW up to 6/0 and got 806,764,763,702,706,703,749,749,730,723. Nothing real consistent and every combination I tried there after could not get over 720 so I think it was a fluke with the high numbers maybe. I didn’t spend much time as the fps is no where close to what I want. I have a few 7 rings I will try tonight also. But those gave me more issues with getting them in consistently (that’s what she said 🙂 )
Should I just start the whole tweaking process from setting the TH to .070 and PW low and go from there? I’m thinking a good approach is get the numbers where I want them generally and then tweak for shot to shot consistency. I will only setup for one pellet at a time I was just getting a quick baseline from both pellets. Both have been accurate at 50 yards. I am getting 2″ groups though on the 6 rings which would make sense since they are going so slow but 1″ at 50 and about 1 1/2″ at 75 with the H&N’s. All suggestions welcome!
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Viewing 15 replies - 1 through 15 (of 15 total)
You are on the right track. FILL THAT TANK MAN! 😀
Looks like I have to spend money to make money. Tested TH settings for the 6 rings of .002 from .070 to .104 at 2500 PSI PW 8/0. And until I fill higher 2700-2900 do I get a longer string of higher numbers. At .082 I get high 700’s a few 800’s and for about 10 shots then I hit the slope. This was at 2700 and PW 10/8. However if I go higher in fill pressure that string is longer but haven’t gotten a bath tube yet. The string just starts higher and has a longer straight away. Maybe the flat to downside of the tub? My girlfriend is gonna get me a hand pump for my birthday so I am going to wait till then to do more testing of the 6 rings. Also playing with numbers I got from a few 7 rings I had got me some okay number 705,716(80 fpe!) ,709,703,701 then it falls from there 696,err,687,681 but the fill was 2500ish, TH .086 & PW 11/0 so this could be improved and due to that physics thing the 7 rings may net me more power and more shots than the 6 rings (Jerry you da man! ) Got silver thumb pushing in all the SureFires so I had to take a break and mess with the H&N’s.
Thanks!
H&N’s 31 gr at .074 2500 PSI PW 8/0 get’s high 800’s / low 9’s at 2500 PSI. A 2750 fill, TH .074, PW 8/0 gave me the best (most powerful) string so far again it’s still that back side of the tub thing.
931,925,936,926,925,921,923,909,913,909,907,904,1068 :shock:, 470:shock:, 894,875,878,874,875,873,872,867,867,862,853,856.
End PSI 1900.
I was running low on air so I think a higher fill and lower PW could get me some numbers on the front side of the tub. Also with out those two freak shot could have got me another couple of shots in the 900’s for maybe 15 900 shots and fps drop of 30 fps. This string will be awesome if I can get the 900 – 930 – 900 tub. However at TH .066, FPSI 2390, PW 6/0 I got 845,869,875,895,877,900,err,891,888,884 EPSI – 2200. Which are a lil bit slow but air usage, noise are way down. With this I could see getting a whole lotta 50fpe shots with low air usage. No that would be cool beans too. Just save the SureFires for those larger critters and small critter hunt all day with the H&N’s. Most shots would be under 50 yards.
Also would turning the power wheel up in the middle of a string to produce higher numbers (still same range as previous shots) as the psi drops mimick the use of a heavy hammer? I was swag’n stuff and found as the shot fps lowered, if I upped the PW it would keep the numbers the same (more or less) for a longer consistent string.
Well Bennee I’m subscribed to this thread to see what works out for you.
Actually my first string was that and I was getting high 600’s to low 700’s. I went up by .002 till .082 and didn’t see a 800 fps shot. I went by whole numbers 2/0 to 12/0 on the preload wheel on each TH setting. I did get some high 700’s which aren’t bad power wise though. So I said the hell with it let me start from the other way 😆
Cool
Try 2500 Psi., top hat at .070 and lets see what you get.
They all seem to do that. Will read ERR but if you press the fps button, it shows you the speed fine. I think its whats known as a ‘ massive number error’ IE, it has a hissy and can’t work out the fpe for you.
Thanks guys. The stem had two dimples from the factory! I think I’m have a little fat short stubby bath tube going on!!! I need to get a hand pump cause SCBA is kind of a pain in the ass with this testing. I feel I will be able to get a more exact fill number with the hand pump. Plus the high fills which I think I will be needing will be few with the tank and shouldn’t take too long with the hand pump for the quick top offs.
TH .099
PW 11/8
FPSI 2900’ish
EPSI 2400
1. 769
2. 769
3. 828
4. 828
5. 837
6. 797
7. 800
8. 791
9. 797
10. 770
TH .102
PW 10/8
FPSI 3000’ish
EPSI 2300
1. 703
2. 626
3. 829
4. 766
5. 856 !!!! 97.82 fpe!!! Getting there 😈 😈 😈
6. 755
7. 838
9. 789
10. 806
11. 820
12. 772
13. 785
14. 765
15. 749
Nice long string. Shorten it up and get some more power in there and this good be a winner.
TH .103
PW 10/0
FPSI 2750’ish – Running low on air so I said hey lets try it.
EPSI 2200
1. 738
2. 782
3. 785
4. 803
5. 804
6. 784
7. 800
8. 777
9. 778
10. 747
Why the hell did I wait so long to get a chrony!!! Man this shit is fun!!! So fun my girlfriend is starting to get annoyed because she is loosing attention lol 🙂
Still not very shot to shot consistent but that will need that fine tuning. Also the combro started Err’n on me when I set the pellet weight to 60.11. Shows the speed just fine but gives the error. Just a observation. Anyone else notice this? Again I appreciate the help guys!!!
Get a tight fitting drill bit so that you can drop it down inside the stem and play with the T.H. settings and not have to worry about putting dents in the stem.
Give the adjustments you’re comfortable with a chance. I think you can probably get pretty good performance without having to make any hardware changes.
That was the understanding I had 🙂 Damn physics! My goal with the SureFire’s would be power( I know my barrel is short don’t laugh ). I’m not too concerned with shot count there. 5 good power shots would be plenty. Unreasonable you think? 3 maybe? The slug fitting problem is definitely user error 🙂 I think the method you suggest is the way I will go about it. If I don’t get the required power from just PW/PSI/TH changes you think I should start looking at different hammer weights. Oh ya also my TH is at .091 officially.
Dammit Pab you suck!!!! 🙂 You think 800 fps too big of a number? I kind of figured 850 would be hard to reach with a stock valve, hammer and short barrel syndrome 🙂 How about my goals of 950’ish with the lighter pellets?
Ben,
You’re not going to be able to use the same set-up for both pellets. Your best bet is to just set out with the understanding that you’ll have two set-ups to choose from depending on the pellet choice.
With an 18″ barrel you have to resign yourself to wasting some air and reduced shot count. With less length to accelerate, you have to accelerate faster to get to a given speed. That is less efficient due to unsurmountable laws of physics but also a known issue when one decided to have the easier to handle gun length.
For best accuracy you want to load the slugs as straight as possible to avoid loading induced deformation…yeah, easier said then done.
Then set the gun to high power with pre-load and top hat settings to get the slugs up to a speed where they fly good. Then dial back the settings for efficiency until you see a drop in performance, then go back to the last setting that gave good groups at your intended range and power.
At least that’s how I would do it! Maybe you get half the shots of the setting you use for lighter slugs. If so, you’re probably doing pretty darn good as the energy to shoot twice as fast or twice the mass probably varies like horsepower in a dragster; it doesn’t take twice the power to go twice as fast, it varies as a cubic function so going twice as fast takes about 8 times the power!
Ben’, if you want big numbers for the Jerry slugs, you are gonna need a longer barrel.
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Sweet! Thanks dude!