Sythetic Flashpup Adventure Started

[fgwhite]

yes you fellers are right on a bull boss the barrle was .600 and the flash pup is .550 the 20mm x18mm works good i used it on bull boss used the plastic step down bushing you guys are talking about in the i/d of the 18mm worked perfect sealed right up again action block i did not see a o ring on the flash pup dlp could you take a pict of the o ring you talk about i not yet put the 18mmx20mm on my pup yet i got a nother tube 14mmx18mm i going to try cut few peieces and glue them in both ends of the 20mm tube and see if they work for spacers in the past i have people build me spacers from hard plastic like uhmw and in pict did he haft to cut down the height of the ring for new rail and is there a steal insert in there or does it just screw in to plastic

[Thane]

Didn't think to add another set screw, definitely going to do that. I bonded the 19 OD x 19 1915 ID to the barrel so a 20 OD x 19 ID would be great for tension and replacing shim, another great insight, thanks Donny!Front rail is drilled and counter bored, new rail has a bottom channel, top of support notched/sloped to match channel stoping rotation on bolts. Bushing shim is drilled 19mm and turned to give a cone shape. The 20 x 14 mm carbon tube does not need shimming.

I sourced a carbon tube that is 19.75 OD x 14 ID exact QE and .22 barrel dimensions. It's a very tight fit on the .22 Wood FlashPup, no need for epoxy so I can tension it with LDC and no shimming. Ebay seller "EnvyGears" who does a great range of sizes in 500mm and 1000mm lengths:

https://www.ebay.com/itm/Glossy-20mm-OD-14mm-ID-500mm-Length-3K-Roll-Carbon-Fiber-Tube-20-14-500/283649629085?hash=item420ad5db9d:g:N0EAAOSwdJtdIxNa

[Thane]

Deed is done. No doubt the 20 x 14 carbon tube was near perfect, just cut to length, true ends, de-burr and relax the ID with some 500 grit sanding using a dowel (lathe sped things up, but could certainly be done by hand). Snug press fit with some heavy silicone oil, no hammering as I would like to be able to disassemble in the future.
LDC in tension pressed it home, snug fit in barrel ring with no shimming. Rail still needs some attention.

At $22 carbon sleeve high stiffness, simple execution and reversible. -no brainer-

[Thane]

... in pict did he haft to cut down the height of the ring for new rail and is there a steal insert in there or does it just screw in to plastic

Yes, ring was too high for rail riser/adapter and cantilever picatinny rail, sanded down, filed notchs, used existing captive nut for counter sunk bolt through rail.

[DLP]

There isn’t a stock Oring on the barrel or in the shroud. I just added one in place of the factory bushing at the reciever end of the barrel to take up the slop. I moved the bushing to the muzzle end to keep the muzzle propped up at the end of the air tube.  I have ordered 2 of the Hatsan bushings to replace the Oring. I really like the idea of a 20mm x 14mm CF tube also. I didn’t think about sanding the inside of the 14mm tube when I started this. I think I will order the 20/14 CF tube and redo mine. As I cut the 20/18 CF tube a little too short. I added another Oring between the LDC and barrel to hide my screw-up. Thanks for the link.

[fgwhite]

i seen this and said same thing i ordered a 18x20 15$ then a 14x18 18$ i had not idea to use a 14mmx20mm like thane did would been cheaper and better 22$ ant bad at all i may order one also i had pretty good luck gets stuff from hatsan in the past i see now on thane gun they have a metal nut right under the plastic on the bully tank cover you can see the littler square threaed peiece right under the weaver rail on the flash pup it must be open under it or the metal nut is foremed in side i see he had to cut probile 1/4 off the height of it for his rail to set right thanks guys for this info and on his wood pup i see the air cylender is alumion and longer than the air tube on my flash pup senthetic i think i read on a post the sen pup has a few difrent stuff then the wood versions

[Rallyshark]

Deed is done. No doubt the 20 x 14 carbon tube was near perfect, just cut to length, true ends, de-burr and relax the ID with some 500 grit sanding using a dowel (lathe sped things up, but could certainly be done by hand). Snug press fit with some heavy silicone oil, no hammering as I would like to be able to disassemble in the future.
LDC in tension pressed it home, snug fit in barrel ring with no shimming. Rail still needs some attention.

At $22 carbon sleeve high stiffness, simple execution and reversible. -no brainer-

That should be a good stiff piece of carbon right there!  Can you tell a difference in the stiffness of the barrel with it tensioned?  I got the rail bits in the mail today, and played around with it.  I used a UTG dovetail to weaver adapter that was a little higher, and put a spacer under the front end of the rail.  I wanted to raise the whole rail a wee bit higher, so I could use some medium rings I had floating around. 

You were correct, that is a good sturdy solution for the rail.  It is definitely stiffer than the factory setup.  It certainly helps with the SFP.  The Turkenstein is another story..I guess due to the carbon support on the front rail mount, it didn't make any real difference in my barrel stiffness though.  I'm also using a 24" barrel, so there's a lot of barrel sticking out on that gun.  I'm going to tension the barrel on the SFP and the Turkenstein I think.  I'm interested to hear how the tensioning worked on your gun Thane! 

Oh yeah, how long does the shipping take from that ebay seller?

[Thane]

Very stiff tube and the tensioned barrel on the WFP is marginally better than the bonded SFP due to tension. When you pinch the joint at the breach block and torque on the barrel the tensioned barrel has no shifting you can feel with finger tips. The bonded barrel has very slight motions at the barrel insertion to breach block since there is only the set screws and carbon sitting adjacent with no tension . I'll be slipping a 20x19 tube over it, tensioning and loose the shim. I would try tensioning the largest diameter tube I could fit on the Turkenstein, functions like a truss.

There are so many rails out there, let us know how the UTG works out. I'm trying a one piece different/higher one for the WFP with a longer rail connection no adapter.

The ebay seller delivered one order in nine days and a second order in 6 days, well packages in PVC pipe. I doubt even the USPS could break these carbon tubes.

I notice Hatsan is starting to trickle out some SFP Refurbs today, a couple of lucky dogs picked up a .22 an .177 for $250 ea.

[Rallyshark]

Very stiff tube and the tensioned barrel on the WFP is marginally better than the bonded SFP due to tension. When you pinch the joint at the breach block and torque on the barrel the tensioned barrel has no shifting you can feel with finger tips. The bonded barrel has very slight motions at the barrel insertion to breach block since there is only the set screws and carbon sitting adjacent with no tension . I'll be slipping a 20x19 tube over it, tensioning and loose the shim. I would try tensioning the largest diameter tube I could fit on the Turkenstein, functions like a truss.

There are so many rails out there, let us know how the UTG works out. I'm trying a one piece different/higher one for the WFP with a longer rail connection no adapter.

The ebay seller delivered one order in nine days and a second order in 6 days, well packages in PVC pipe. I doubt even the USPS could break these carbon tubes.

I notice Hatsan is starting to trickle out some SFP Refurbs today, a couple of lucky dogs picked up a .22 an .177 for $250 ea.

Both my SFP and Turkenstein are wearing barrels that I machined to fit pretty snug into the breech block.  I made them slightly larger than factory to remove the slop.  The "rail redo" made absolutely no difference on the Turkenstein, so that tells me the carbon reinforcement is doing it's job.  I do think tensioning the barrel on that one will be the way to go for sure.  I'm gonna go with the new rail on the SFP though, because I don't want to make another carbon support.  That was  a bear...  The SFP has a 20" barrel on it, so it is less prone to flex, but I'm probably gonna tension it as well.  I've already bonded 8mm ID x 16mm OD carbon fiber on the barrel, since it was made using an FX slug liner   I still think some tension will help though.  Those slug liners seem to shoot pellets really well too.  I also have the 15" shorty standard LW for the SFP, with 14mm ID x 16mm OD carbon tube bonded to that barrel.  It is so short, I don't think it really needs any tension. 

I'll let you know how the rail works out on the SFP, when I get a chance to get it on a target   Man, somebody did get some deals on those refurbs!  I would have got one and ordered WFP valve to put in it, if they'd had them when I ordered the WFP.  Despite all of our monkeying around, I really do like the SFP a lot. 

[Rallyshark]

I went ahead and tensioned the barrel with some 20mm OD x 18mm ID carbon fiber(I prefer matte).  I didn't want it to be a super tight fit around the barrel, so it would have full freedom to tension the barrel and pull itself good and straight in the process.  I also made bushings to go on each end of the tube out of black derlin.  They fit good and snug on the barrel and outer tube as well.  I used the bushings make sure things square up well, and squared off the ends of the carbon fiber to make sure I didn't have any clipping issues.  The tube with the bushings is a little longer than the barrel to the base of the LDC, so it is pulling tight by the time the LDC is tightened all the way down. 

This make a rather larger difference on my gun.  The slightly longer tube let me crank down the LDC with some good tension on the barrel.  If feels quite solid now!  Thane, I wonder if your outer tube being too tight around your barrel is keeping it from tensioning well, or maybe the ends of the tube aren't square?  I know you said it only made a little difference on yours, but it made a lot of difference on mine.  So much so, I'm not going to bother changing out the rail at this point. 

Below are a few pictures showing the ends with the bushings I made, and one of the whole gun.  I think she looks nice wearing that 20" barrel, 20mm carbon, and the Huma LDC  

[DLP]

Nice job on the bushings. Hatsan is sending me 2. I didn’t have a way of making my own. You saved yourself $25 shipped for 2! I did order a 20mm x 14mm CF tube also. Figured I would see which works better. I can use one or the other set-up on my .22 Flashpup too.

[Rallyshark]

Nice job on the bushings. Hatsan is sending me 2. I didn’t have a way of making my own. You saved yourself $25 shipped for 2! I did order a 20mm x 14mm CF tube also. Figured I would see which works better. I can use one or the other set-up on my .22 Flashpup too.

Buying a used mini lathe was one of the best purchases I've ever made   The 20mm x 14mm should be super stiff, which is a good thing.  You just have to make sure it doesn't fit too tight around the barrel, or it won't really be able to tension the barrel as well as you'd like(I think).  Of course, if it is a tight fit on the barrel, that will be one stiff barrel either way.

I was going to use the factory QE bushings, but they were too small to fit over my barrels that are 16mm OD   I think the ones I made probably worked out better for me though.  It was just a little more work for me is all.  I look forward to hearing how yours works out!

[Thane]

Donny those delrin bushings are a great add, probably compress a bit, squaring and contributing to maintain tension through compression. Looks good too!

The 20 x 14 slides back as the Huma LDC threads down, so I'm certain the tension is making it back to the breach block. I'm also sure the carbon fiber to aluminum is riding on high spots even though I can't see it. Time to turn some delrin bushings...

Mini lathes really make projects great, very easy to fab up pieces for testing.

[Rallyshark]

Donny those delrin bushings are a great add, probably compress a bit, squaring and contributing to maintain tension through compression. Looks good too!

The 20 x 14 slides back as the Huma LDC threads down, so I'm certain the tension is making it back to the breach block. I'm also sure the carbon fiber to aluminum is riding on high spots even though I can't see it. Time to turn some delrin bushings...

Mini lathes really make projects great, very easy to fab up pieces for testing.

Yessir, the bushings do compress a little, and I think they give a little leeway if the carbon tube isn't completely square.  I also like the idea of them not scuffing up the gun or LDC, and making a solid seal on the LDC.  I should have gotten a mini lathe years ago!  I had no idea what I was missing. 

[fgwhite]

i going to buy me a mini lathe also i had people build me bushing like you just made with lathes and last time guy 3d printed me one i checked the i/d on the 14mmx18mm crabon tube its like .550 and my barrle is .550 i dont have a lathe to sand down the full 15 inch carbon tube i going to go this way i going to cut 2 peces of the 14mm i/d tube sand them out on in side a little glue them in the m18x20 tube on both ends then slide it on barrle and let ldc hold it to action you guys think that work ok

[Rallyshark]

i going to buy me a mini lathe also i had people build me bushing like you just made with lathes and last time guy 3d printed me one i checked the i/d on the 14mmx18mm crabon tube its like .550 and my barrle is .550 i dont have a lathe to sand down the full 15 inch carbon tube i going to go this way i going to cut 2 peces of the 14mm i/d tube sand them out on in side a little glue them in the m18x20 tube on both ends then slide it on barrle and let ldc hold it to action you guys think that work ok

How about you just chuck a wooden dowel rod into the drill, and roll up some sand paper on it.  Then, you can just use the dowel rod and drill to reach the whole length of the carbon tube.  Any other long rod that you could figure a way to fix some sand paper on should work too.  I wouldn't chop the tube in half, because you'd effectively be taking away the benefit of that really stiff tube.  The benefit of that 14mm ID tube isn't for strength under tension, but the fact that the thick carbon tube is extremely rigid.  If you chop it in half, you'd probably be just as well off just not using it, and simply using the 18mm ID tube for tension.  It is plenty strong enough to handle the tension by itself. 

[Rallyshark]

I did a quick tune on the SFP to get it ready for target testing(hopefully on Sunday).  It is currently tuned for mid/high power.  Right now it is shooting the 30 grain H&N slugs around 875fps for 16 shots with an ES of 19.  Those slugs showed promise shooting around 880 fps when I was last testing slugs.  I want to see if that promise is still there, and that is a good tune for the JSB Monsters as well as the 25/27 grain slugs.  After that, I'll probably tune it down to shoot the 21 grain slugs around 925 for 25-30 shots and see how they do.  Then, I will move on to testing my preferred hunting pellets that range from 16-18 grains at even lower power...

I'm currently thinking I'm gonna leave it tuned for the heavy stuff, since I'll have my .177 tuned for a little lower power.  I don't know for sure, until I see how everything is shooting with that new tensioned barrel set up.  I'm really liking how the gun feels with the tensioned barrel though, and feel like it should be much more consistent.  All of this is with it wearing a 500mm FX slug liner with about 8mm of carbon bonded to it(16mm OD) with a brass thimble(leade), and the 20mm carbon tube tensioning it , fyi. 

[DLP]

It was 50* and calm today. So at lunch, I set targets out every 5 yards from 10 to 50 yards. I already had the .25 sighted in at 35 yards and wanted to see where it was really hitting at all ranges. I am within 1/2” high/low from 15 out to 50. I can’t believe how much tighter it is shooting since the new shroud. At 50, it’s 1 ragged out hole. I also shot a mag at 75. 9 out of 10 were within a Nickole with a 1” flier. Was hoping to hunt this weekend. But it’s predicted 40 mph wind, 1 to 2” of rain and 1” of ice.

[Rallyshark]

It was 50* and calm today. So at lunch, I set targets out every 5 yards from 10 to 50 yards. I already had the .25 sighted in at 35 yards and wanted to see where it was really hitting at all ranges. I am within 1/2” high/low from 15 out to 50. I can’t believe how much tighter it is shooting since the new shroud. At 50, it’s 1 ragged out hole. I also shot a mag at 75. 9 out of 10 were within a Nickole with a 1” flier. Was hoping to hunt this weekend. But it’s predicted 40 mph wind, 1 to 2” of rain and 1” of ice.

That's great, and it sounds like that gun is spot on now!  You can't really ask for anything better than that for sure.  Too bad about the weather, but at least you know you gun will do it's part when the time comes.  I'm at the mercy of the weather this weekend too   It is supposed to be storming all day tomorrow, and may still rain on Sunday...  What kind of tune are you running on that gun?  This is very promising news, regardless!

[fgwhite]

i cut 2 peces of the m14xm18 tube man they were so tight going on i could not get them all the way on i guled them in side the m18xm20 tube and still would not just slide on i even putoil on barrle lol i am now in the porcess opening up the i/d a little with a round file i probile get a dol rod and use sand paper like you said i think this work i shure if a man used the m14x20m would be perfect but for shure it haft to be sanded all the way down the i/d its very very tight