FX Dreamline 177 Accuracy Issues

So far, I have tried:

• Polished the brass throat and port area
• Removing the moderator - still spirals
• JSB 10.34, JSB 13.43 MK I, JSB 13.43 MK II, H&N Barracuda Match, H&N Barracuda FT
  • Barracuda's were slower, shot a bit better, but still had lots of flyers
• Adjusting the regulator down to 90 BAR, still has JSB 10.34's going 870 + fps. The hammer adjustment has no meaningful effect at this pressure - that is min setting work just as well as max.
• Min Port setting - only does 690 fps.
• Cleaned/JB Polished the barrel again and again - very dirty after 200-300 shots already

I suspect my answer lies with the hammer weight and the behavior at low reg pressures. I suspect that the hammer weight is way too much for 177 (hence the very high speeds with heavy pellets). This results in pushing too much air down the barrel and may be kicking the pellet in the A$$ on the way out of the bore - hence a spiral. I am trying a higher reg pressure (150bar) and min hammer setting later today - should be much less air. The heavy hammer may also be affecting the efficiency and noise as well, as I am not getting many shots per fill and it is quite loud. Alternatively, the jump from the brass throat to the STX liner may be affecting the pellet.

My Daughter's Streamline with the older ST barrel shoots just fine with no cleaning, so FX can do 177. Just don't know if the Dreamline can...

More testing to come.

Dan

In looking at the FX Support site (which is awesome for providing parts/o-rings), it looks like there is a different hammer weight. My serial number is 191,XXX - so looks like it has "hammer weight additional". I will have to open it up to see if I can reduce the hammer weight (or maybe change out springs).





BTW, I am shooting over the new FX Chrony, so get real-time feedback.

Some more troubleshooting tonight. The higher regulator pressure gave a much better speed and very low noise - I suspect that it is better at not pushing too much air. However, still having accuracy issues. 

It appears to be shaving pellets in the transition from the brass transfer section to the barrel liner. The barrel liner is actually smaller diameter than the transfer section! So it takes extra force to push past this transition, based on pushing some pellets through. Now, the barrel liner will not unscrew from the shroud properly, as shown in the videos. It unscrews at the back, then the shroud and the barrel liner comes out of the part in the receiver. I suspect that there is grease causing "hydrolock" not allowing either the LDC or barrel system to unscrew properly.

Should I contact FX to have them repair or just return for a refund? Unfortunately, this was to be my Wife's field target gun.

So I contacted Pyramyd Air and they got back to me the next day on the issue. They suggested that I contact FX, as their mechanics/gunsmiths have not dealt with these yet. FX was prompt to get back to me as well - both calling and emailing. They sent me a label for shipping it back - it is boxed up and ready to go back tomorrow.

Anyway, I was thinking about the issue quite a bit. Is it possible that the barrel liner could get mis-aligned in the brass/steel transfer port setting? In shotguns, the choke tubes are supposed to set in a v-notch so that there is a smooth recessed transition. Otherwise, they could get ripped out - I have seen a couple of these and it's not pretty. I don't think that the dreamline has anything similar. That could mean that a lead shaving or other dirt could off-set the barrel and cause further shaving. Does anyone know if there is a recessed channel for the barrel liner to mate up in? This could be the underlying cause of some issues that people have experienced. I always worried about this on the Streamline.

Dan

I received my Wife's Dreamline back last Friday. FX was great to deal with - they emailed and called several times (I did poke them once after about a week and a half). I talked to the Tech before they shipped it out. They used heat to unscrew the parts no problem. There also must have been a broken screw, as there was some shavings in the hammer chamber that I cleaned out. They indicated that they added two orings on the barrel and used larger diameter ones to better stabilize the inner liner. They also adjusted the reg back down to 90 bar and set it up for Min Hammer and Min Port = 12 fpe and Min Hammer + 177/22 Port = 20 fpe with 10.34's. They even sent a test shot of 10 shots at 50 yards - nice tight group with 1 flier on 12 fpe. Overall - FX was great to deal with.

I tested it out at home on the bench rest with a stable bipod - just not impressed with the 20 fpe setting. The 10.34's were going 920fps and just not grouping too well. With a bit of wind I was getting 2+" groups. I shot my Brocock at the same time and it was much tighter. I tried the 13.43s - the MK 1s were ok, MK2's were scatter guns. I noticed that the gun was "blowing" a lot of air with muzzle jump. The FX service folks admitted that the hammer weight might be too much for 177. Talking about it - my wife said return it. I have confidence that Pyramyd Air would make good on a refund, but was bound and determined to see what is up. Hence, I dis-assembled and found the shavings. 

Anyway, I figured that the 10.34s were going too fast and needed to slow it down a bit - how to do that on min hammer and 177/22 port? Two ways, reduce hammer weight or lighter springs. I found some 3/8" springs on Amazon for cheap and thought - that's the deal. I ordered a few sets - unfortunately they were a bit too small inside. So I polished the hammer down a bit to allow them to fit. Not much had to come off - just a bit on the drill press. The hammer is really soft, so easy to file/sand/polish. The first spring try - 18 fpe at 5 hammer and 177/22 port. This was perfect and the groups really tightened up. On hammer 1, I was getting 12 fpe. I tried the 25/30 port and it did not affect the speed at all. Now, the gun was quieter, blowing less air and I was getting many more shots, 60 plus on a full fill. Plus I can go back to the heavier spring very easily if I wanted a 22 or 25.

Unfortunately, the thing that came to light, is although the gun is highly adjustable, it is an ergonomic train-wreck for precise shooting. Like AR's the cheek piece sits way too high - above barrel level - so super high scope mount needed. With my highest scope mount, the head position was still very poor for the stock and I can't get comfortable. The AR stock wobbles a lot - I tightened up with some tape, but not satisfied with that. The pressure tube is no great resting spot for the HFT bipod - lots of wobbel. I may look into the the Scandinavian Stock that is coming out or an Aeron - I just need to keep it lighter for my wife. Unfortunately, both adds quite a bit of cost. Also, the Aeron needs the hammer adjustment piece removed. I may also design/build a better stock setup, as I do like the simple hammer adjustability. Alternatively, the traditional stock version might have been a much better choice.

So overall, I have the Dreamline working well now, just need the ergonomics figured out. 

Dan