DREAMLINE .25 - FPS problem or something else?

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caesar

caesar

Member
Jul 28, 2020
93
13
MI, United States
dreamline .25 with power plenum and superior liner. reg@110-115. hammer on max, and allen adjustment near maxed out. fx hybrids and nsa 26.8’s running 890-900fps.

just put about 30 pellets and 70 slugs through the new superior liner.

50 and 65 yard groups got better as i shot. 1” to 1.25”. remember it’s a brand new liner.

heres the problem. i shot out to 80 yards and i see the tail of a slug or a pellet flying unstable. the tail is all over the place. there’s no wind today and i’m surrounded by trees. accuracy at 80 and beyond seems terrible. can’t check group at that distance i just have a 2” gong hanging in the wind. 

since the hammer allen adjustment is near maxed out i’m wondering if i’m blasting the pellet with air after it leaves the barrel. 

tried getting more velocity out of the slugs but the higher i set the reg the more velocity I seem to lose. 890-900 is about as fast as I can get with any pellet or slug. 

is 900fps about what everyone else is getting with these guns? bad tune job on my part or lower my expectations?


 
I have two Dream pup .30 calibers and yes your operating the gun near max output. Have you went over plateau of reg pressure with hammer tension? If you back off hammer do you pick up FPS? My regs are at 140 on one without plenum and 120 on other with plenum to achieve 855 FPS very very stable shot string with pellets. Just smoked crow at 99y while on pest duties yesterday. I shoot .5" @ 80y just bit over with both guns on calm day. Hope you are talking 600mm barrel.
 
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Slugs! I want to shoot Slugs! there cool...But not always.

I tuned my .25 Dreamline Classic Shooting JSB 25.39 Knock Outs shooting at 956 @ 140 bar with my hammerspring turned out 1.75 turns out from bottom. I shot these through the 600mm STX barrel and groups were a no go what ever I adjusted to, +- this or that. Not even close to acceptable. Game over and Plan B was in order.

I don't recommend the DL for slugs of this weight and this speed.

Why?

Tuning my DL up and down the FPS scale has taught me the limitations of this Dreamline platform. It is NOT like my Impact. My DL has limits as well.

My DL tuning experience is only with a .25 and 600mm STX barrel. 700/500mm STX and Supirior STX will yield different results with similar Reg Bar settings, but still has FPS limitations.

What I have learned from my hardware failures is that over time (short) the valve stem and/or delrin seat will fail with pressures that yield the mid 900fps, like the GenI Impacts, no lesson learned there FX?? This is documented.

Next was my original goal. To shoot JSB 33.95 MKII @ 860fps+. Classic, right? Wrong.

After much tuning I found out, like Ted's Holdover, that they loved 830fps out to 100yd+ and capable of MOA, no problem. These are amazing pellets that will deliver time and time again @ 53fpe. Whats not to like about that? Power and accuracy.

Keep your long term reliability sights set realistically for the .25 Dreamline and it will reward you handsomely. It loves pellets and some slugs in the 16.54 to 33.95 range with speeds of 650 to 915fps.

Tune it to what pellet/slug it likes at the speed it delivers accuracy and efficiency for your distance and it will always put a smile on you face, guaranteed. 



Be safe and shoot straight.



Patrick

.
 
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Yo, I took your advice too. The barrel looked clean, well looks ARE deceiving. Barrel was fairly dirty. Small chunks of black ‘grease?’ Haven’t shot it since I posted last.

Thanks for everyone’s help I will update the post as new information is gathered. 


everyone’s knowledge and experience here is valuable to me and I do appreciate it very much.
 
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UPDATE:

Remember this is a brand new gun, two weeks old. I made some progress, but I'm considering sending the gun off to a tuner. My confidence in the gun is not there yet. I took the bottle adapter off and there is an o-ring inside. There is also a tiny hole on the inside of the bottle adapter and the end of the o-ring was stuck in that hole. WTF? I put the o'ring along the bottom of the inside of the bottle adapter. That o'ring probably needs to be replaced.

Cleaning the barrel as Yo suggested made a big difference, projectiles stabilized in flight.

2L8 where are you getting .25 KnockOuts I can't find them anywhere?

I'm really new to this hobby/sport, just bought my first PCP, so I'm learning a lot every time I pick up the gun. It is so much fun!

Anyway here are some results after much tuning and a lot of ammunition. If anyone is interested in the target I made, i'm more than happy to share it or even create one to your specifications. The outside ring is 2", then 1.5" then 1" and center is 1/2".

50 yards on the dot measured with a range finder.

1596903211_3653661365f2ecf2b616146.41191988.jpg



 
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Now I'm getting somewhere! I cleaned out, and lubed the hammer and spring area with some graphite powder. It was a little sticky and there were some small metal shavings, that i'll have to keep an eye out for. I added a Huma dual-transfer port.

This is a 50 yard group with Nielsen 26.8's (full magazine). low shot was the sighter. tuned for velocity then listened to a video by Airgunner Bob_O on harmonic tuning. I bet these would do better if they were tighter in the breech. The 25.4 King and 33.95 King Heavies are harder to push into the Superior liner than the 26.8 slugs are. Still have work to do yet but I am loving this little Dreamline!

890fps - Regulator 110-115, Hammer on 5. Of all the changes I made, changing the hammer from max to 5 was what really tightened the group.

1597608341_7979014585f399195b95a49.71081830.jpg

 
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