Flash BT, XL?

[Rallyshark]

I'm leaning towards Flash XL.  I've long suspected that the BT65/Galatian air cylinder would fit on the Flash valve, and I finally got to test that theory.  It turns out I was correct!  165cc just became 255cc   Thanks to blackdiesel(Norman), I acquired a BT65 cylinder to test out.  It fits the valve and the gun with no issues at all.  It screws right onto the Flash valve.  On a side note, the BT65 valve will fit the aluminum Flash cylinder too, but I don't know why anyone would do that.

Before everyone with a Flash variant starts scheming, this will not work on the Sythetic Flashpup or Flash Wood, due to those models using the steel cylinder.  Those have a different size valve threading and won't fit.  In other words, it will only work on the regular Flash or Flashpup Wood.  I suppose you could just order the regular Flash or Flashpup valve to make it work if you wanted.  The other downside is barrel length.  By my "calculations", you will need a minimum barrel length of around 22.5-23".  The BT cylinder is a little over 6" longer than the standard aluminum Flash cylinder, so the QE won't clear and neither will an LDC with the factory barrel.  This isn't an issue for the gun I'm playing with, since I have a 23.8" LW unchoked polygon barrel on the gun. 

Now, the good side of things...  Of course, you get increased shot count(almost double on my particular slug tune).  Another Huge benefit is that you can get a high power reg/plenum(BT carnivore .30) from the good folks at Huma!  That means you guys running high power tunes can keep them, and be regulated!  That would yield a good shot count increase and good power, especially for you .25 guys out there.  It doesn't necessarily work that way for my gun in it's current state of tune, because you have to push things pretty hard to shoot .177 slugs at the speeds I'm shooting them, and the shot count is actually lower with the Carnivore reg/plenum installed.  If I lower the speed down, it will be a different story.  As for the extra weight of the longer cylinder, it isn't that much.  It probably just puts it in the ball park of the steel cylinder Flash, maybe slightly more.  I think it would barely be noticeable on the pup especially.

I will update this with pictures when I get my Flashpup Wood in, and relocate the barrel to it.  I will also go through everything on the gun and tune it for the best flow I can.  Currently, my Flash .177 is shooting 21 grain NSA slugs at 962 fps for 22 shots with an ES of 29 fps(3%) using the BT cylinder.  If I were going for one magazine(14 shots), the ES would be under 20 fps.  I may be able to better that slightly with some attention to detail on the porting.  That isn't this guns max power with these slugs, but that is where it is happy shooting a decent string.  My results could vary a little with a different gun, so we'll see   The unchoked polygon is doing very well with the NSA 21 grain and 18 grain slugs!  The 18 grain are shooting great, even at 1025fps    I will also be testing some 23 and 24 grain Griffin slugs in it soon, so stay tuned on that front. 

Anywho, I just wanted to let you guys know that there is a solution for more air on the aluminum cylindered Flash and Flashpup, along with a reg with a proper plenum.  Just for reference, you can get a refurb BT/Galatian cylinder from Hatsan for $99, so not too bad.  Hopefully, some of tinkerers out there will find this info useful.  More to come!

[VaporTrail]

Ah...but scheming is allowed for us "maybe" future owners of a regular Flash, then?

Crying shame it won't work with the wood version...it makes it such a pretty gun!

[Rallyshark]

Ah...but scheming is allowed for us "maybe" future owners of a regular Flash, then?

Crying shame it won't work with the wood version...it makes it such a pretty gun!

You could make it work, if you replaced the valve with the one in the regular Flash.  Of course, there's the barrel length issue too, so you'd need a longer barrel.  Fitment issues aside, I imagine you could get an insane shot count regulated at mid and low power ranges  

[Rallyshark]

Another positive I forgot to mention is the gauges.  The gauge on the cylinder will show the cylinder pressure, and the gauge on the gun would show regulated pressure if a reg was added.

[rdtricks]

OK, now you have me thinking about my flash with the QE shroud and a way to utilise the BT65 air cylinder.  Would a BT65 QE shroud fit onto the Flash block and maybe the barrel for the respective caliber?  What the heck, since you are looking at seeing what kind of parts swap would work.

[anti-squirrel]

I need to avoid this thread like the plague.  Last thing I need is to grow the pile of parts to build a FrankenTurk PCP.


Oh... who am I kidding! subscribed!

[ghost5]

Out of curiosity from someone new at mods, what is the cost of the LW barrel and where do you locate one? I just got a Flashpup wood in 25 cal and think I want a slug barrel. I'm guessing from reading the posts other mods are need such as enlarging ports.

[Rallyshark]

OK, now you have me thinking about my flash with the QE shroud and a way to utilise the BT65 air cylinder.  Would a BT65 QE shroud fit onto the Flash block and maybe the barrel for the respective caliber?  What the heck, since you are looking at seeing what kind of parts swap would work.

The Flash actually uses the BT65 barrel band, so the shroud would fit, but the barrel itself won't fit.  Unfortunately, you'd have to get a barrel machined to fit.  The diameter where the barrel fits into the breech is different.  It would be nice if it was the same, because you could just order another barrel from Hatsan then.  The BT65, AT44, Bullboss, Air Max, and Nova all use the same barrel.  Too bad the Flash uses a different one

I need to avoid this thread like the plague.  Last thing I need is to grow the pile of parts to build a FrankenTurk PCP.


Oh... who am I kidding! subscribed!

Haha, how about a Turkenstein  

Out of curiosity from someone new at mods, what is the cost of the LW barrel and where do you locate one? I just got a Flashpup wood in 25 cal and think I want a slug barrel. I'm guessing from reading the posts other mods are need such as enlarging ports.

I think the LW barrel blanks are $115, and you can order them from LW.  Just google LW airgun barrels, and you'll find their site.  Of course, you'll still have to get the barrel machined to fit the gun.  As far as mods go, it doesn't really require anything too crazy.  Just open up the porting and install a PEEK valve seat(which you will also have to make).  You can also just open up the factory valve seat a little and it will do pretty well.  A longer barrel on these guns helps a lot with power too. 

[gendoc]

Hey Donny,
will that new style cocking handle work on the syn-flash rifle??

it would be nice if it did !!
looks like it wont get hung up in hunting clothes like the original does.

[Rallyshark]

Sorry John, no luck on that one.  The one from the SFP is held in place with a screw that goes into the probe from the left side of the gun through a hole in the breech block.  The regular Flash doesn't have that hole in the breech block, and the bolt handle is screwed down from the right side onto the probe.

[gendoc]

Sorry John, no luck on that one.  The one from the SFP is held in place with a screw that goes into the probe from the left side of the gun through a hole in the breech block.  The regular Flash doesn't have that hole in the breech block, and the bolt handle is screwed down from the right side onto the probe.

well shoot !!!
anyway, thanks for the info...much appreciated 

[VaporTrail]

Ah...but scheming is allowed for us "maybe" future owners of a regular Flash, then?

Crying shame it won't work with the wood version...it makes it such a pretty gun!

You could make it work, if you replaced the valve with the one in the regular Flash.  Of course, there's the barrel length issue too, so you'd need a longer barrel.  Fitment issues aside, I imagine you could get an insane shot count regulated at mid and low power ranges

Hmm...now that has the gears turning. I probably wouldn't need a regulator for low energy tunes, though.

I just had a little shooting session today with my stock BB. Its turned waaay down low...something like 400FPS with the 14.3gr Crosmans. Good enough to take out a pigeon at 30yds...and more than enough for plinking. 230cc cylinder gave me 100 shots...from 200bar down to about 145. 

I have a feeling the Galatian cylinder will give me something similar with the Flash. 

[Rallyshark]

If I were you, I'd stick that regulator you have in that BB that you're shooting low power at, and I bet you could beat that 100 shots easily at that power level.  Just set the reg real low, and you could shoot all day,lol! 

[anti-squirrel]

I like Turkenstein.  Yessirree.

The thought of a Flash with a big tube, regulator, and lower-speed tune focused on the 15-to-16 FPE range would be incredibly appealing as a backyard pesting tool.  Though- despite being bottle-fed, I love the lines on the Predator, too.  And I dig the Vectis, too.

[Rallyshark]

I like Turkenstein.  Yessirree.

The thought of a Flash with a big tube, regulator, and lower-speed tune focused on the 15-to-16 FPE range would be incredibly appealing as a backyard pesting tool.  Though- despite being bottle-fed, I love the lines on the Predator, too.  And I dig the Vectis, too.

At that power level, you could get a ton of shots with the BT cylinder installed!  I managed to get 56 shots regulated at that power level with the factory 165 cc cylinder and factory barrel.  I did do the "cobra" mod to the valve spring to get there though.  I've since removed the "cobra" mod in favor of power.  Read below, the Turkenstein is going to be nuts!

I just got part way done with the new Flashpup Wood.  I did all the porting, changed the HS out, and installed a PEEK valve seat.  I found a little room for improvement with the hole in the valve lining up with the transfer, and ported the valve accordingly.  Finally, I moved the 23.8" poly barrel over from the regular Flash, and shot a few over the chrony to make sure all the bits are working.  It is gonna be a little monster of a .177    As I always do, I cranked the HS just to see what it had for the fun of it.  I put some 24 grain griffin slugs in the single shot tray, and she peaked at 990 fps on the second shot!  That's right, the little Flash .177 hit 52 fpe        The first shot was 985, then 990, then 979.  I stopped after that and lowered the HS down to a more sane 925 fps for when I do some testing on target. 

That was with the factory air cylinder.  I left it sitting to make sure the valve is going to hold air, because the PEEK seat was a TIGHT fit in the valve.  So much so that it shaved a sliver of the o-ring off when I banged it home    I know, kinda sketchy...  I'm not super worried about it, since I know there was just no more room for o-ring left with how tight it fit.  It is still holding right now, but we'll see where it is tomorrow.  Worse case, I'll have to dig that seat out and make another one.  The machining on this gun isn't as good as the Synthetic Flashpup I got, but I cleaned most of that stuff up.  Regardless, the gun should be able to do a solid 20 shot power tune in the 45 fpe range with the BT cylinder installed.  It picked up a couple fpe just by getting that valve aligned with the transfer better.  The hole in the valve from the factory doesn't line up perfectly, so I had to open it up "manually" with a carbide bit(as opposed to just drilling the hole out larger). 

If any of you guys are going to open up the valve hole, spin the valve around(without the o-rings installed) 180 degrees, and see if it lines up with the middle hole that the larger grub screw holding the valve goes in.  That will tell you if it is lining up with the transfer.  That's all I have for now guys, but more to come soon.  I just had to update you folks the power the little Turkenstein is making

[moorepower]

How accurate are the slugs out of the puppy?

[Rallyshark]

The NSA 21 grain and 18 grain have proven to be very accurate out of the unchoked poly barrel. Small targets at 100+ yards were pretty easy, and they buck the wind very well!   I just got some griffin 23/24 grain in yesterday, but I haven't got to test them yet. I hope to try them this weekend, if the weather allows.

[anti-squirrel]

50+ FPE in .177....  Jiminy Cricket!   That's insane- and conversely, that energy level out of that tube a super-low-power level will be a pellet-tin-emptying tune.

I know most folks like tuning for power, but I'm especially fond of lower tunes to get the most out of wadcutters. I'm keeping my eye on this thread.

[moorepower]

The NSA 21 grain and 18 grain have proven to be very accurate out of the unchoked poly barrel. Small targets at 100+ yards were pretty easy, and they buck the wind very well!   I just got some griffin 23/24 grain in yesterday, but I haven't got to test them yet. I hope to try them this weekend, if the weather allows.

Thanks! Very good news!

[Rallyshark]

50+ FPE in .177....  Jiminy Cricket!   That's insane- and conversely, that energy level out of that tube a super-low-power level will be a pellet-tin-emptying tune.

I know most folks like tuning for power, but I'm especially fond of lower tunes to get the most out of wadcutters. I'm keeping my eye on this thread.

It can be made to do just about any tune you want!  It is mostly a matter of spending a little time on them, with not much in parts cost  

The NSA 21 grain and 18 grain have proven to be very accurate out of the unchoked poly barrel. Small targets at 100+ yards were pretty easy, and they buck the wind very well!   I just got some griffin 23/24 grain in yesterday, but I haven't got to test them yet. I hope to try them this weekend, if the weather allows.

Thanks! Very good news!

Yes it is.  I was so dang happy when I finally found a barrel that likes the .177 slugs!  I don't mean does okay, but actually shoots really well with them.  The combo of power/low noise/long range effectiveness/penetration offered by this combo is pretty awesome in my book.