Sythetic Flashpup Adventure Started

[Rallyshark]

They probably will after more SFPs are out in the wild, but I don't know how soon that'll be.  You're probably better off just getting it from Huma right now.  You could call or email Trenier and ask though.

[UCChris]

They probably will after more SFPs are out in the wild, but I don't know how soon that'll be.  You're probably better off just getting it from Huma right now.  You could call or email Trenier and ask though.

I'll give them a call in the morning and report back.

[UCChris]

So, I got my boss's synpup apart. Everything looks good, except that the cocking is super freaking rough. Like, disappointingly rough. I'm not sure what's going on.

[HunterWhite]

My Flash was like that. The hammer spring was so tight that it was very difficult to cock it. I pulled the hammer, cleaned it and reassembled it. I just lightened the hammer spring until it felt about right.  The result was a nice shot string curve.

Hunter

[UCChris]

My Flash was like that. The hammer spring was so tight that it was very difficult to cock it. I pulled the hammer, cleaned it and reassembled it. I just lightened the hammer spring until it felt about right.  The result was a nice shot string curve.

Hunter

Yeah, I've already pulled the HS spacer out and done 3 turns on the hammer spring. It's shooting right around 15 fpe, so I know that the HS isn't causing it. It's like the bolt handle is binding in its track.

[Rallyshark]

I would check out the little insert that the probe goes through on the breech.  I suspect that is the root of your evil, because the probe isn't brass on the SFP, so you've got steel on steel happening there.  It is held in by one grub screw.  I would make sure that little guy is good and polished.  I don't really see a need to polish the probe, but I suppose it wouldn't hurt.  Other than that, clean and lube should take care of it.   

Actually, I wonder how that little piece would do, if it were made of PEEK?  Hmmmmm...

[Thane]

Speaking of PEEK...

Made PEEK valve seal  @ 0.187", and PEEK hammer face insert. Reduced hammer mass by 5%, removed the clack sound spike and flattened the shot string. I also replaced the spring with a slightly thicker wire and longer.

So its at my goal with 24 shots (2 mags) using .22 JSBs 18.1 gr @ 919 FPS average 34FPE.
2.6% spread with no regulator (23 shots under2%). 

[Rallyshark]

Nice job Thane, that is a solid low spread tune tight there!  I'm sure the PEEK valve seat and insert helped quieten down the shot cycle very well.  The valve seat probably requires less hammer strike to open(less noise), and the insert takes away the metal on metal when the hammer hits the valve(less noise).  I like it!

Chris's problem with the rough loading has got me wanting to see if I have enough PEEK left to replace that insert that the probe goes through.  What I really want to do, is to come up with a modification to the HS adjustment process.  It is just a PITA having to remove the stock to do that, if I want to change tunes.  I have some ideas on that, I just need to get at trying to implement them...

[Thane]

...  What I really want to do, is to come up with a modification to the HS adjustment process.  It is just a PITA having to remove the stock to do that, if I want to change tunes.  I have some ideas on that, I just need to get at trying to implement them...

... and very tempting to operate out of stock, which is particularly bad with the trigger rod exposed. Ask my chrono...
I drilled a hole in rear stock, and opened rear bolt path by 1/4"  to uncover hammer set screw. Easy access with a long 4mm now, way better. It is also easy to check the spring/valve gap, it's visible and simple to move back and forward.

[Rallyshark]

...  What I really want to do, is to come up with a modification to the HS adjustment process.  It is just a PITA having to remove the stock to do that, if I want to change tunes.  I have some ideas on that, I just need to get at trying to implement them...

... and very tempting to operate out of stock, which is particularly bad with the trigger rod exposed. Ask my chrono...
I drilled a hole in rear stock, and opened rear bolt path by 1/4"  to uncover hammer set screw. Easy access with a long 4mm now, way better. It is also easy to check the spring/valve gap, it's visible and simple to move back and forward.

That is exactly how I would have done it with a regular Flashpup, BUT the Sythetic Flashpup has the adjustable butt pad for height and offset, so that complicates that thought process    My thought is along the lines of adjusting the depth the spring sits in the rear plug of the breech, or even adjusting that plug itself.  Either way, there will be some stock modifying that will have to happen.  That is kind of what I did with my Bullboss, and I can adjust the HS on it with just a flat head screwdriver, or my pocket knife even,lol. 

[fatmike]

I received my syn pup yesterday. I didnt have much time to mess with it but overall I like it except for the ping and valve noise right to the ear when shooting. It's pretty loud for a qe.  I'd love a tune as Thane has produced but im not skilled with airgun smithing. I think I'll have to just keep it stock and/or add a regulator for consistency. Maybe someone can come up with a bolt on kit to get the power and consistency  that you all have gained. 

[Rallyshark]

I received my syn pup yesterday. I didnt have much time to mess with it but overall I like it except for the ping and valve noise right to the ear when shooting. It's pretty loud for a qe.  I'd love a tune as Thane has produced but im not skilled with airgun smithing. I think I'll have to just keep it stock and/or add a regulator for consistency. Maybe someone can come up with a bolt on kit to get the power and consistency  that you all have gained.

I regulator will definitely help with the ping.  They are pretty consistent without a reg though.  You just have to find out what pressures the gun shoots the best string with on a given tune.  You can't bolt on more power, because that gain comes from opening up the porting and valve.  People making any after market parts for Hatsans are few and far between.  The biggest benefit of the Hatsans is the ability to modify them without having to purchase after market parts.  You can also put a bottle brush or something like that in the cylinder to absorb the vibration and lessen the ping, but I've never been a big fan of that myself.  They are still pretty good little guns for the $$, either way you look at it

[Ribbonstone]

I just shot it enough to break in, adjusted the trigger, and experimented with the settings.

It pretty well behaved like any non-reg PCP....and pretty much how I play with any non-regged PCP.

1. Cranked the spring up to see what the most the standard guts could produce. Shot count was real poor (started fast and declined rapidly...cocking was quite stiff....which is typical for any non-reged PCP).  In a shot graph,looking for the 4% shots, this basically was a downward graph from the middle of the plateau on down.

Which can be a useful setting if you really need/want max. stock parts power and can live with a short shot string. I'd hunt with it when I expect just one or two particualr larger critters to be on the agenda (make a good opossum killer).

If you wanted even more power (and evidently that is an attraction with Flashpups),would look at some changes/mods to the "guts"as you've already found the most to get from the issue parts.

LArger/smoother air path from tank to pellet base would be the way to go (wihting pressure design limits). Better air flow around the valve stem and larger and smoother passage to the pellet. The good shot count will fall, but the total energy will be about the same (in that 42 foot pounds X 20 shots is about the same enery as 55 foot pounds X 15 shots).

2. Tried backing the spring tension way out, and like any non-regPCP,it shot a whole lot slower and started to increase in velocity as the pressure droped.  BAsically, this was a long up-slope on a shot graph to a nice little pateau, then the fall off.

Would make a useful lower pressure tune (why fill it all the way up with the best shots are down around 2200-1300PSI?) for target shooting, plinking, or hunting small critters.
If that's not enough low power shots, will have to do some mods. 

Simple (although it doesn't really help efficiency all that much) would be to strangle off the air passage.   The full monty would be harder: making the valve dwell faster (lighter striker most likely), leave the passageways open, and accept harder cocking.

3. Fiddled a few more times, looking for something in the middle that started at a velocity that was at least useful, peaked, and fell over a longer useful shot count. 
Which (after 5 or 6 little fiddle adjustments) turned out to be in the 28-32foot pound range, which suits my uses....but likely not most folks.
And yes, the little amounts of adjusting (nudges more than changes) do make a difference...also don't know exactly why (but a suspsicion it's about harmonic/sync. of motion.)

DSCN2070 by Robert Dean, on Flickr

At which point (back in July) I left it alone and won't been back inside until something leaks, breaks, or changes (and sooner or later it will...it's the nature of PCP's).

I DO HATE THE FLASHPUP DESIGN for this kind of fiddling around.  Normally, I'd not bother to put the metal back in the stock for the above kind of testing.  But that long transfer bar between the trigger blade and the trigger unit is just begging for a slight slip and an accidental discharge.

External adjustment would be a good thing (for any PCP)...esp, for this one.

[Rallyshark]

I'm working on that adjustment part when I get some time, so stay tuned on that front!


Now, onto some other stuff...  I got a chance to shoot some targets finally, and it turns out my SFP's favorite ammo are the JSB Monster Redesigned, and the H&N Barracuda Power(copper plated).  I was shooting pieces of gravel off a gate at 88 yards no problem, and was tagging cans at 120 yards pretty easily as well   I haven't touched the barrel, other than the transfer port.  I'm going to do some polishing on it, to see if I can get it to agree with some other ammo.

The bigger news is HUMA LDCs!  I don't know why more folks aren't talking about them?!  I got a Standard+ in the MOD40, and WOW!  After all was said and done, it was only about $140(we don't get charged VAT) to my door, which ain't bad for what you get. I got the the .25 version, just to be sure to avoid any clipping issues.  Here's the Link for the one I got: 
https://www.huma-air.com/Modular-Moderator-MOD40-4/1-(Standard)-SALE

All testing was done with the gun shooting 38 fpe.  The base piece which threads onto the barrel has the kevlar insulation, and the 40mm sections do too.  The 20mm section has no insulation.  The insulation can be removed to give more air space as well.  In the "mini" configuration, which is the base piece, with one 40mm section and one 20mm section it is quieter than the QE.  With the short configuration and no QE, the SFP is only 29.5" long, and still backyard friendly.  That makes that gun really short for wandering through the bush.  With the longest configuration(base piece, three 40mm sections, one 20mm section), the gun is still only 33.75" long, and insanely quiet.  Me being the constant tinkerer, I love the fact that you can configure these anyway you like for your guns.  Here's a couple of pictures with the shorter and longer variations.  Sorry for the quality, it was dark and I took them with my phone.  The gun will look much better when I sleeve that barrel with CF too. 

[HunterWhite]

I'm going to do some polishing on it, to see if I can get it to agree with some other ammo.

Donny, if I had a rifle that shot that well, I wouldn't touch a thing.

Hunter

[Rallyshark]

I have this disease, where I can't leave anything alone,lol!  No, in all honesty though, I can't get it to shoot any of my HP pellets well.  Since my primary use for my airguns is hunting, an airgun that won't shoot any type of HP well is useless to me.  I'm not going to do anything crazy to the barrel though.  I'm just going to give a decent polish, and maybe a bit more so at the choke.  I've had good luck doing that in the past.  If that doesn't work, then I guess I have an excuse to put a longer barrel on it, hahaha! 

[Chilihead]

Donny, how does that moderator attach to the pup?

[UCChris]

Donny, how does that moderator attach to the pup?

You remove the stock QE shroud by unscrewing it, then the LDC attaches via the now-exposed 1/2-20 threads.

[Thane]

Picked up an SFP in .25 and it does not disappoint. With only a bore cleaning it pushed 21 shots @ 37FPE under 4% ES (center 16 @2%). Made 4-5 shot groups all under 1/4" center to center, no flyers.

So with 50 rounds on the odometer I'm thinking about cutting it up a bit, borrowed Donny's photo and doing some blocking out for feasibility. 0.35L bottle with reg will need some clearancing, but will add some juice.

[Rallyshark]

Picked up an SFP in .25 and it does not disappoint. With only a bore cleaning it pushed 21 shots @ 37FPE under 4% ES (center 16 @2%). Made 4-5 shot groups all under 1/4" center to center, no flyers.

So with 50 rounds on the odometer I'm thinking about cutting it up a bit, borrowed Donny's photo and doing some blocking out for feasibility. 0.35L bottle with reg will need some clearancing, but will add some juice.

That's great that you got a good shooter   The bottle design sure would be sweet if you were able to do it!  I'm pretty sure you'll have to add a drop block of some sort to a shortened section of the tube to make it work.  You may have to get a custom tube section made, IF you want to be able to operate at the bottle's pressure.  The valve can handle 250 bar, but I'm not so sure about that factory air cylinder material being able to handle 250 bar.  Of course, That wouldn't be as much of an issue if you regulated it at the bottle, and used the shortened section of tube as the plenum.  That would be an awesome little gun