So my 22cal. Streamline would shoot 1/2” groups at 50yds all day long. Last weekend the groups opened up quite a bit (1 to 2 inches). My first thought was the barrel needed cleaning. I’ve read that after cleaning it needs some pellets shot through it to season it. So I probably shot 150-200 pellets through it and there is no real difference. So I took off the DonnyFL Sumo to see if that would change things. No luck. I’m thinking that maybe the regulator has an issue so this weekend I’ll try it over a chronograph.... any thoughts on other possibilities?
FX Streamline lost it’s accuracy... Not sure why
- Thread starter porkchopxxx
- Start date
may be silly. but did you just start with a new batch of pellets? also possibility of your scope no longer tracking properly.
Upvote 0
So in what direction did your groups open up? I'm somewhat doubtful it is your regulator, but if it were the groups would be largely strung along the vertical axis only.
I think it is more likely something is just loose somewhere. A scope mount, one of the many threaded parts in FX's barrel liner system, etc. That is where I'd go looking. Really, ideally, you'd try to dig into it systematically, checking one thing at a time, so when you finally fix it you understand the cause and can avoid it in future.
I think it is more likely something is just loose somewhere. A scope mount, one of the many threaded parts in FX's barrel liner system, etc. That is where I'd go looking. Really, ideally, you'd try to dig into it systematically, checking one thing at a time, so when you finally fix it you understand the cause and can avoid it in future.
Upvote 0
I believe the Streamline has the same original ST barrel as my Royale, no sleeve/liner system. Those barrels are good about going a long time without cleaning, and are usually easy to clean when they finally need it. I doubt if the reg is the issue, even if it wasn't working at all, shouldn't give that result. If the chrono shows a big spread, I would be suspect of a dirty hammer/spring assembly.
Upvote 0
Its weird .... I'll get 4 or 5 in a tight group and then no defined pattern of misses (left, right up & down). Its not a new tin of pellets .... I ruled out the pellets (JSB 18gr.) because once this started happening I went to my sorted pellets from a previous tin (that before gave me incredible groups) and it was the same bad groups. My testing was not in windy conditions. The only difference from before to now is that I have used it in our Avocado grove to eliminate pests (squirrels). I have not bumped or dropped the rifle .... Put a sock on the end to keep out dirt/dust when driving around the grove.
Upvote 0
Do you have a different scope to try? I had a scope that the parallax adjustment went bad and right at 50yds it would shift the poi by almost 2 inches with just the tiniest turn of the wheel. Like STO said "check one thing at a time".
Upvote 0
I had the same problem with my FX Royal 400. After many false starts I changed the breech O-ring and the problem went away, even though the O-ring looked fine.
Upvote 0
+1 on changing the o ring It should have been the first suggestion listed. It is very common, and they wear out regularly.j
Upvote 0
This will be the first time taking a PCP apart .... Can you mark which o-ring on the diagram? Also, where is the best place to get them?
Upvote 0
the o ring store has them dirt cheap. But check with your local hardware store. Probably have what you need right off the shelf. ;<)
Knife
Knife
Upvote 0
+1 on checking the stock screw. Both of them came loose on mine and I even lost the little one from the trigger guard. Replaced it and snugged the other one and it all came back together for my groups. Over 1500 shots in the dark at starlings at ranges of 10-20 yrds and then all of a sudden I couldn’t hit anything at that distance. Replaced the screw and back to blasting them with surgical head shots.
Upvote 0
So I was able to shoot over a chronograph this weekend and the FPS is lower than originally. Basically from 860 FPS down to 782 FPS. The power wheel is set at 3. I have new breech o-rings and will try it out again this weekend. The number of shot before it falls off the regulator is the same.
All these groups were shot at 50 yrds with the whole magazine
Before the problem
After the problem
Chrony Before
Created: 11/03/18 12:59 PM
Description: JSB Heavy 18.13
Notes 1:
Notes 2:
Distance to Chrono(FT): 4.00
Ballistic Coefficient: 0.035
Bullet Weight(gr): 18.13
Temp: N/A °F
BP: N/A inHg
Altitude: 934.00
# FPS FT-LBS PF
9 856 29.50 15.52
8 859 29.71 15.57
7 858 29.64 15.56
6 860 29.78 15.59
5 855 29.43 15.50
4 859 29.71 15.57
3 865 30.13 15.68
2 865 30.13 15.68
1 862 29.92 15.63
Average: 859.9 FPS
SD: 3.6 FPS
Min: 855 FPS
Max: 865 FPS
Spread: 10 FPS
Shot/sec: 0.1
True MV: 868 FPS
Group Size (in): 0.00
Chrony after the problem
Created: 10/10/19 02:39 PM
Description: JSB Heavy 18.13
Notes 1:
Notes 2:
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 0.035
Bullet Weight(gr): 18.13
Temp: N/A °F
BP: N/A inHg
Altitude: 934.00
# FPS FT-LBS PF
8 785 24.81 14.23
7 776 24.25 14.07
6 787 24.94 14.27
5 785 24.81 14.23
4 784 24.75 14.21
3 781 24.56 14.16
2 781 24.56 14.16
1 779 24.43 14.12
Average: 782.2 FPS
SD: 3.7 FPS
Min: 776 FPS
Max: 787 FPS
Spread: 11 FPS
Shot/sec: 0.2
True MV: 784 FPS
Group Size (in): 0.00
All these groups were shot at 50 yrds with the whole magazine
Before the problem
After the problem
Chrony Before
Created: 11/03/18 12:59 PM
Description: JSB Heavy 18.13
Notes 1:
Notes 2:
Distance to Chrono(FT): 4.00
Ballistic Coefficient: 0.035
Bullet Weight(gr): 18.13
Temp: N/A °F
BP: N/A inHg
Altitude: 934.00
# FPS FT-LBS PF
9 856 29.50 15.52
8 859 29.71 15.57
7 858 29.64 15.56
6 860 29.78 15.59
5 855 29.43 15.50
4 859 29.71 15.57
3 865 30.13 15.68
2 865 30.13 15.68
1 862 29.92 15.63
Average: 859.9 FPS
SD: 3.6 FPS
Min: 855 FPS
Max: 865 FPS
Spread: 10 FPS
Shot/sec: 0.1
True MV: 868 FPS
Group Size (in): 0.00
Chrony after the problem
Created: 10/10/19 02:39 PM
Description: JSB Heavy 18.13
Notes 1:
Notes 2:
Distance to Chrono(FT): 1.00
Ballistic Coefficient: 0.035
Bullet Weight(gr): 18.13
Temp: N/A °F
BP: N/A inHg
Altitude: 934.00
# FPS FT-LBS PF
8 785 24.81 14.23
7 776 24.25 14.07
6 787 24.94 14.27
5 785 24.81 14.23
4 784 24.75 14.21
3 781 24.56 14.16
2 781 24.56 14.16
1 779 24.43 14.12
Average: 782.2 FPS
SD: 3.7 FPS
Min: 776 FPS
Max: 787 FPS
Spread: 11 FPS
Shot/sec: 0.2
True MV: 784 FPS
Group Size (in): 0.00
Upvote 0
Turn the hammer spring adjusting nut in about a half turn and check your velocity. Looks like it might have loosened a little. Mark it with something so you can check for movement.
Upvote 0
I read that the hammer spring adjustment nut has loctite on the threads on the Streamlines. And you will strip it ...? Any advise?
Upvote 0
The chrono results indicate the breech o-ring is the problem. If that fails, the hammer nut has backed off - if it moved then you can adjust without a problem. If it is tight, then be careful moving it, as they can strip. Then again if it is tight, the hammer adjuster is probably not the problem.
Dan
Dan
Upvote 0