C3622 .22

[Nukall856]

 I wrote this up some time ago I won't edit it and I'll leave the dates on. Been abit busy so I thought I'd post this before I end up not doing so.


7.16.2024

C3622
Steel Breech
Svitvu 3-9x32mm HMD
AGM LDC

  Today using heavy pellets Apolo Pointed 18.0gr. The shot string below, it appears I need to turn up the tension on the hammerspring as the shot string shows continuous decline in power. I'll have to turn up the power and retest possibly with lighter 15-16gr pellets.

APT 18.0gr
Starting at >2000 PSI

1. 645
2. 638
3. 634
4. 629
5. 633
Spread< 16 FPS
Avg 636 FPS
16.2 FPE
6. 638
7. 633
8. 629
9. 624
10. 626
Spread< 14 FPS
Avg 630 FPS
15.9 FPE
11. 626
12. 615
13. 611
14. 601
15. 596
Spread< 30 FPS
Avg 610 FPS
14.9 FPE
21. 551
12.1 FPE
25. 516
10.6 FPE
30.448
8.0 FPE
-----------
I Adjusted the hammerspring 1.5 turns in from previous setting.

CPHP 14.3gr
1. 670
5. 629
10. 572

Setting is way too high.

Refill to >2000 PSI
 Readjusted to lower spring tension. To nearly fully backed out. +.5 turns from where it would no longer back out.

CPP 14.3gr
1. 704 < 15.7 FPE
5. 706 < 15.8 FPE
10. 700 < 15.6 FPE
15. 681 < 14.7 FPE
20. 648 < 13.3 FPE
25. 618 < 12.1 FPE

 Looks as though I have around 12-13 shots within 20 FPS. I'm wondering if I use a 2240 hammerspring if I would get more consistent shots though at a slightly lower power.  But... I like that I'm getting 15.7-14.7 FPE in the first 15 shots. Though changing pellets would change it up a bit. The first setting i had with the APT 18 was good with the first 11 shots very close in output.
 When the weather clears I'll check to see how many shots the spread will stay under 15 FPS, possibly 12 shots. And later check performance with other pellets. I'm thinking to open the TP a little bit, little bit...
 
Current setting
Sight in for 30 yards.
Shot 26 hits 20 yards.

8.2.2024
50°F
Windy and Rainy
Not a good shooting day,, the fall rains are here, berries are nearly ready, fall hunting for subsistence begins soon. Alot of adventures to be had.

NVak

[James340]

I wrote this up some time ago I won't edit it and I'll leave the dates on. Been abit busy so I thought I'd post this before I end up not doing so.


7.16.2024

C3622
Steel Breech
Svitvu 3-9x32mm HMD
AGM LDC

  Today using heavy pellets Apolo Pointed 18.0gr. The shot string below, it appears I need to turn up the tension on the hammerspring as the shot string shows continuous decline in power. I'll have to turn up the power and retest possibly with lighter 15-16gr pellets.

APT 18.0gr
Starting at >2000 PSI

1. 645
2. 638
3. 634
4. 629
5. 633
Spread< 16 FPS
Avg 636 FPS
16.2 FPE
6. 638
7. 633
8. 629
9. 624
10. 626
Spread< 14 FPS
Avg 630 FPS
15.9 FPE
11. 626
12. 615
13. 611
14. 601
15. 596
Spread< 30 FPS
Avg 610 FPS
14.9 FPE
21. 551
12.1 FPE
25. 516
10.6 FPE
30.448
8.0 FPE
-----------
I Adjusted the hammerspring 1.5 turns in from previous setting.

CPHP 14.3gr
1. 670
5. 629
10. 572

Setting is way too high.

Refill to >2000 PSI
 Readjusted to lower spring tension. To nearly fully backed out. +.5 turns from where it would no longer back out.

CPP 14.3gr
1. 704 < 15.7 FPE
5. 706 < 15.8 FPE
10. 700 < 15.6 FPE
15. 681 < 14.7 FPE
20. 648 < 13.3 FPE
25. 618 < 12.1 FPE

 Looks as though I have around 12-13 shots within 20 FPS. I'm wondering if I use a 2240 hammerspring if I would get more consistent shots though at a slightly lower power.  But... I like that I'm getting 15.7-14.7 FPE in the first 15 shots. Though changing pellets would change it up a bit. The first setting i had with the APT 18 was good with the first 11 shots very close in output.
 When the weather clears I'll check to see how many shots the spread will stay under 15 FPS, possibly 12 shots. And later check performance with other pellets. I'm thinking to open the TP a little bit, little bit...
 
Current setting
Sight in for 30 yards.
Shot 26 hits 20 yards.

8.2.2024
50°F
Windy and Rainy
Not a good shooting day,, the fall rains are here, berries are nearly ready, fall hunting for subsistence begins soon. Alot of adventures to be had.

NVakI

I have a unregulated pistol and I found a lower fill pressure gave me 24 consistent shot's.625 fps going up to 650 then coming back to 625.It is 177 but the plenum pressure was keeping the beginning shots low when it had a higher fill pressure.At max pressure and a hard hammer strike velocity was 450 fps going up to 700.

[Nukall856]

James340,
 Excellent Work,
-------
C3622 .22

  I found a good setting. I backed out the spring adjustment by 1/3 of a turn. This made for a sequence of 670-650-670-700-690 setting is too low. So I added 1/6th turn in. Resulting in this nice long stretched out string all good with in 30 FPS from shot 3-28. Shots 9-27 are with in 20 FPS. Good very good. With shot 29 through, while Refilling the valve opened at 1200 PSI. Takes around 35 pumps to refill to 2000 PSI with a 4uncles Hand pump.. Fun... Now I want another C3622 XD XP

45°F

CPHP 14.3gr
1. 670
3. 681
5. 683
7. 685
9. 692
11. 692
13. 696
15. 707
17. 707
19. 710
21. 709
23. 708
25. 694
27. 691
29. 673

One shot through chrono next shot at target. It was abit windy yesterday, today is a lot calmer out.

NVak

[James340]

That's a good shot string.When I was first looking for a PCP I thought it needed a regulator to be consistent but as happens so often I was wrong

[Blowpipe Sam]

It's nice to see someone working to wring maximum power from this gun.  I've been playing with mine to find a good mid-power tune with a flat velocity curve and a long sweet spot.  The information you posted about your velocities and pressures was very helpful to me in setting up my gun.  Starting from a 1800 PS fill I backed the adjuster off 1/2 turn from the factory setting and got a string that peaked at 670 fps with a long flat string within 10fps.  13-14 FPE is plenty for the small game I hunt and I'm getting better than 20 shots in the zone.

[Gramps-Too]

This is a very informative thread, makes me want to get my 3622 out & start messing with it again. I had pretty much given up on it & it became a wall hanger. You guys have inspired me to get it down & try tuning it again.

[Mzq284]

Nukall,
Thanks for sharing.  I think I need to tweak mine yet, you've given us a good idea what's possible.  Your numbers look pretty good.
Almost forgot to ask, is that a TKO, and do you have to remove it for every fill?

[Nukall856]

James340,
I am still "New" to PCP as I have 3 of PCP Airguns. A Beeman2027 .177 and a UxOrigin.25 and this C3622.

BlowpipeSam,
Gramps-Too,
Mzq284,

Thankyou for reading and replying, ExcellentWork.
The first setting was as is from the factory. That setting showed a continuous decline in power, this meant the hammerspring was set too high. Next setting was way too high and showed rapid power loss. then backed nearly all the way out and added half a turn in. This gave me a good setting with the first 15 shots. Backing out further I got the weird sequence of 670-650-670-700-690, that setting was way too low. I then added 1/6 turn in to find the nice string.
I did shoot Paper yesterday and found CPUM 14.3 did better than CPHP 14.3 and CPP 14.3. I end up getting busy before taking a pic of the 15 yard targets. Abit raining and windy today so I'll see if the targets are still on and post the pic of the 15 yard paper. Next is to check for pellets that will do better than the CPUM 14.3gr. I know CPUM 14.3gr are consistent in fit and shape, work very good in some barrels.

 The moderator is a AGM3622 LDC idk I think they are TKO unless I am wrong. I don't have to remove the LDC to refill as the LDC has an area to allow the pump end to fit.
Excellent Work Stay Alert

NVak

[Back_Roads]

 I just ordered the AGM LDC and got a free tiger kit included  https://www.airgunmods.com/3622.html

[Nukall856]

Back_Roads,
 Free trigger kit? Fancy,.,.,.,. man that's a good deal if they added a free trigger I did have my eye on one of the C362 triggers they make, but that will be for when I get a new C362 or C3622..
 Today I'm abit distracted by the new long box that got in. Nothing extraordinary,That willl be another story, I think..
Excellent Work Back_Roads
Stay Alert

NVak

[CraigH]

Excellent example of PCP tuning of an otherwise stock gun.   

[Nukall856]

C3677x24" x724-051
Steel breech
Stainless Extended Probe Bolt
OAL 38, 5/8" < 981mm

  I ordered the 24" barrel from Buck-Rail for around $50+  including shipping. Also I bought the 3622 from A-Z when they were on sale low price for $121.
 I received the barrel a few days ago. It was well packed including 2 printed barrel end protectors. The crown was Very crooked. So I cleaned the barrel then inserted a consistent shaped pellet into the muzzle just to where the skirt ends on the lowest part of the crown. I then used a file to remove material until the muzzle face was even with the pellet skirt. Next I recrowned by hand turning a stone cone bit until a shallow even crown was made. I then covered the exposed metal nonchalantly with a Sharpie. Good looks good now it wears a even shallow crown. I then worked on my C362 moving parts around, different story.

  Today I gathered the tools I needed including a steel breech I had removed from a 13xx and also moved parts to get an extended probe bolt and began on changing the C3622 into a C3677x24". I added a small taper to the valve exhaust, I also added taper to the transfer port and on the barrel. Next I cut a half circle on the stock to allow Hammer spring changes without having to remove the stock.
  At a later time I will see if I add an LDC I have around, but for now it is wearing the hooded front sight. I also need to figure out what scope I will be mounting. But for now I have Alot of time as there won't be much shooting opportunities until spring comes.

 I did not make any changes to the hammer
spring adjustment, looks to be set low. It is much too cold out to be shooting so I went outside and let off 3 shots

4 Uncle's 3 stage Hand pump< 0-2000PSI < 66 Pumps.

0°F
C3677x24"
CPHP 7.9gr

1. 927
2. 934
3. 927
Avg 929 FPS
15.1 FPE

  It Appears i have a Hott Stepper, turn it up. The low high low appears to show the spring set abit low. So I will slowly turn hammer in until I find a setting with a good shot string. When weather warms up I'll be able to get to testing.
 I have been thinking to add a 2000PSI Manometer or Pressure Gauge to the two C3622s I have. I found the gauges the drillbit, thread tap and tap handle needed to perform the installation, but I haven't done such a thing before..
Thankyou for reading.
Excellent Work Stay Alert

NVak

[avator]

I put my fake 3617 back together this morning with some help from Rocker's care package. I used a full length hammer spring and the front half of a valve he sent. There wasn't a poppet in there so I just ordered one. The one I have is cracked but it seems to not be leaking... we'll see by this afternoon. I replaced the tiny oring in the fill assy. check and I think that may have been the culprit.
No silencer of this one... if I don't hit 'em I'll scare 'em to death. Don't matter either way as long as they get the notice... "don't bring that mess 'round here, Alvin. Better call yer cousin Rocky and tell him too."   

[Nukall856]

avator,
 I don't think it's a fake 3617, nah it is an avators Tinker Model 3617. Great to see you putting your AG to work.
 The C3677 I put together has been shot all of three times. It has been much too cold and alot of bad weather to even try taking the C3677 out.
 For now I have a Svitvu 3-9x32mm HMD scope on it. I have yet to put an LDC on it. Shot report is snappy like a sharp whip without an LDC on.
 When weather is good I'll be taking out the C3677 to find what pellets the barrel likes and also find a good setting with a certain number of shots within 30 FPS.
 Excellent Work avator
 Stay Alert

NVak

[avator]

avator,
 I don't think it's a fake 3617, nah it is an avators Tinker Model 3617. Great to see you putting your AG to work.
 The C3677 I put together has been shot all of three times. It has been much too cold and alot of bad weather to even try taking the C3677 out.
 For now I have a Svitvu 3-9x32mm HMD scope on it. I have yet to put an LDC on it. Shot report is snappy like a sharp whip without an LDC on.
 When weather is good I'll be taking out the C3677 to find what pellets the barrel likes and also find a good setting with a certain number of shots within 30 FPS.
 Excellent Work avator
 Stay Alert

NVak

Thanks..
I was rumaging around and found a .22 barrel in a drawer. It's an inch or so longer so it won't be a 36" overall gun if I swap it but, I think the gun will sling a .22 14.3 pellet pretty good. My hopes is that it will shoot my cast 20gr pellets too.

[avator]

avator,
 I don't think it's a fake 3617, nah it is an avators Tinker Model 3617. Great to see you putting your AG to work.
 The C3677 I put together has been shot all of three times. It has been much too cold and alot of bad weather to even try taking the C3677 out.
 For now I have a Svitvu 3-9x32mm HMD scope on it. I have yet to put an LDC on it. Shot report is snappy like a sharp whip without an LDC on.
 When weather is good I'll be taking out the C3677 to find what pellets the barrel likes and also find a good setting with a certain number of shots within 30 FPS.
 Excellent Work avator
 Stay Alert

NVak

Thanks..
I was rumaging around and found a .22 barrel in a drawer. It's an inch or so longer so it won't be a 36" overall gun if I swap it but, I think the gun will sling a .22 14.3 pellet pretty good. My hopes is that it will shoot my cast 20gr pellets too.

Went back out to the shop and made the barrel swap... it's a .22 now. So now I got 4 on the list to get out for some sighting in and testing tomorrow.

[Nukall856]

4.19.2025

C3677x24"

33°F
Hammer Spring backed out all the way< 0 turns

2000 PSI start
Apolo Dome Heavy
ADH 9.0gr

1. 852
3. 857
5. 874
7. 871
9. 863
10. 862
11. 861
13. 847
15. 829
17. 816
19. 815
FPE Peak < 15.3 FPE
13 shots within 30 FPS.

------------

4.22.2025
36°F
Shortened Hammer Spring

I removed a little over one coil from the hammer spring. The Stock hammer set at all the way backed out had around 13 shots before exceeding 30 FPS spread. Short climb and quick decline. I wanted more shots per fill so I shortened the hammer spring. Now it has 19 shots. A small adjustment out I should get at least 20 shots within 30 FPS.
 
> 2000PSI Start - took Two shots 640FPS and 710FPS at lower settings before finding the 794FPS start.

@ +1.5 turns in
ADH 9.0gr

1. 794
3. 795
5. 800
7.809
9. 807
11. 822
13. 809
15. 816
17. 806
19.794
20. 787
FPE Peak < 13.5 FPE
19 Shots within 30 FPS

  I will refill and retest the current setting and again with the HS backed out around 1/6 of a turn from current +1.5 turns.


NVak

[Nukall856]

4.26.2025
35°F

C3677x24"

Shortened C3622 hammer spring
HS adjustment turned in all the way

2000 PSI Start
ADH 9.0gr

1. 623
3. 661
5. 661
7. 677
9. 712
11. 736
13. 748

Ok this is acting like the Rear Breech screw is binding on the Hammer Spring, so I shortened the rear Breech screw with a file. I also took a 1377 hammer spring that I shortened by 1.5 coils. Reassemble, refill and retest.
--- ------ ---------

4.27.2025
37°F

 I removed the rear airtube cover/ HS adjustment and using a knife I removed the glue of some type meant to keep the adjustment from backing out too far. Doing this I added around 2 turns out. I reassembled using a shortened 1377 spring.

Backed out All the way.
2000 PSI Start
Apolo Champion Heavy
ACH 8.5gr

1. 778 @ 0 turns
2. 835 @ .5turns
3. 838
5. 830
7. 834
9. 842
11. 844
13. 844
15. 841
17. 832
19. 814
21. 804
FPE Peak < 13.4 FPE

  I can back out 1/6 of a turn I should find the magic setting that would have this AG set for 20+ shots. Much too windy today to shoot for groups.


NVak