Sythetic Flashpup Adventure Started

[Rallyshark]

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.

Yep!  The factory barrels are already threaded 1/2-20, so easy peasy .

[Chilihead]

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.

Yep!  The factory barrels are already threaded 1/2-20, so easy peasy .

Well dang, learn something new every day on this site. Thanks to both of you.

I just ordered a DonnyFL Sumo to try on the Pup.

[Thane]

In .22 the factory QE moderator does fairly good up through 34FPE.

In .25 not so much, just shot a string @ 52FPE and my ears are still ringing.

Seeing the segmented Huma moderator on Donny's rig has me envious.

[Rallyshark]

In .22 the factory QE moderator does fairly good up through 34FPE.

In .25 not so much, just shot a string @ 52FPE and my ears are still ringing.

Seeing the segmented Huma moderator on Donny's rig has me envious.

It will look more at home after sleeve the barrel with CF!  I'm just trying to decide, if I want to re-barrel it or not first.  I can't get any of my many different HP ammo to work well in it.  It does great with some of the non-hp ammo.  I think the bore on mine may be a bit oversized.  I'm debating if I want to try my luck with another Hatsan barrel, or just go ahead and get a LW unchoked barrel machined for it.  If I go LW, I'll probably go ahead and make it a 20-21". 

[Rallyshark]

I made some progress with the HS adjustment on the SFP today!  It is a really simple solution, but it works well and is super easy to adjust now.  I basically tapped the metal plug that screws into the rear of the breech, the one the HS rests in. 

I put the factory HS adjustment to minimum and locked down the little grub screw, so it will never have to move again.  Then I tapped the plug at the rear for 8mm x 1.25 threads.  I got the appropriate 8mm x 1.25 grub screw that fits that thread, and ground down the tip to make a little protrusion to fit inside the spring.  That 8mm grub screw is the exact same size as the hole in the plug, so the spring will fit perfectly and move freely.  It just so happens that the center of that plug lines up with the top screw of one of the butt pad adjustment plates.  I drilled that out to have direct access to the new grub screw in the plug, and simply added a screw to the side of the original to hold that plate in place.  I lost my side to side adjustment in the butt pad, but I like it dead center anyway, so no loss there.  That plate is covered up by the up/down adjustable plate, and I still have my height adjustment. 

Now, I simply remove the single 5mm allen that holds the butt pad in place(the one you loosen for vertical adjustment), and I can adjust the HS with a 4mm allen.  I don't have to remove the stock, or monkey with that little grub screw in the hammer anymore!  I imagine this mod would be even easier on a wood Flashpup!  I did wrap the new grub screw in teflon tape so it wouldn't want to move.  This is SO MUCH BETTER than the factory way of adjusting the HS   I have some pictures below to show the modified plug/HS rest. 

[RedDirtDog]

I made some progress with the HS adjustment on the SFP today!  It is a really simple solution, but it works well and is super easy to adjust now.  I basically tapped the metal plug that screws into the rear of the breech, the one the HS rests in. 

I put the factory HS adjustment to minimum and locked down the little grub screw, so it will never have to move again.  Then I tapped the plug at the rear for 8mm x 1.25 threads.  I got the appropriate 8mm x 1.25 grub screw that fits that thread, and ground down the tip to make a little protrusion to fit inside the spring.  That 8mm grub screw is the exact same size as the hole in the plug, so the spring will fit perfectly and move freely.  It just so happens that the center of that plug lines up with the top screw of one of the butt pad adjustment plates.  I drilled that out to have direct access to the new grub screw in the plug, and simply added a screw to the side of the original to hold that plate in place.  I lost my side to side adjustment in the butt pad, but I like it dead center anyway, so no loss there.  That plate is covered up by the up/down adjustable plate, and I still have my height adjustment. 

Now, I simply remove the single 5mm allen that holds the butt pad in place(the one you loosen for vertical adjustment), and I can adjust the HS with a 4mm allen.  I don't have to remove the stock, or monkey with that little grub screw in the hammer anymore!  I imagine this mod would be even easier on a wood Flashpup!  I did wrap the new grub screw in teflon tape so it wouldn't want to move.  This is SO MUCH BETTER than the factory way of adjusting the HS   I have some pictures below to show the modified plug/HS rest.

Very nice design!! simple too. wish i could do something for the flash lol. I'll do this to my flashpup when i get it, but im waiting for a refurb or a good deal.

What made you guys pick the Synpup over the wood? Im still leaning towards the wood cuz I like traditional wood stocks but my woodflash has a few scraches and dings already from using tree's as a rest when shooting lol

[Thane]

I started with a refurb wood FlashPup in .22.  Turned up with an incredibly accurate barrel and it was very easy to hit my desired tune of 24 shots JSB 18.1 at 920FPS w/o a regulator.

Followed up a new SynFlashPup .25(even more accurate) from AirGunDepot last week during a deep discount ($10 over refurb price) and have been tweeking on it since.

I like the mono breach block design over the AT44 extruded aluminum breach on tube layout. Flashes have great economy in the arrangement of parts, simple hammer, no anti-double feed parts, removed sliding magazine axel bolt.  I'm a simplicity guy, hate electric adjustable car seats, headlights on gimbals,... These FlashPups appeal to that.

The SynFlashPup has more features (primarily a very good adjustable butt up down left and right) and is a bit more refined like anodized metal port dust plug vs. plastic dowel. If wood is your thing definitely go wood.

If I could only have one it would be the SynFlashPup, but in .22 (in .25 the QE moderator is inadequate).

[Thane]

... I lost my side to side adjustment in the butt pad, but I like it dead center anyway, so no loss there.

I relocated the same butt screw, and counter bored it to retain side to side adjustment which is better than I expected. Just have to return to center for hammer spring adjustments.

Really like what you did, simple operation and if you lose the original hammers spring grub screw you could fit a longer spring netting more power while maintaining free flight clearance.

Last night I removed the spring spacer, put a heavier gauge and longer spring in letting some more FPE out without leaning on the valve pin.
Polished the Pellet probe, bolt and hammer rounding sharp edges, polished the bolt catch and replaced bolt probe port with a turned MDS one. No gains in power, just smoothed the string and operation. Cocking is much improved, no grinding,  smooth predictable operation.

I did run the bore scope and noticed the bolt probe appears to be short, not setting the pellet entirely into the lands. The lead goes half a pellet length beyond the port. Seems to me the pellet should be entirely engage with the probe, but doesn't seem to affect groups. Maybe the probe is less of an obstruction? Either way I'm shooting a comparison string, hand setting pellets into the lands, see what's what.

[Rallyshark]

I made some progress with the HS adjustment on the SFP today!  It is a really simple solution, but it works well and is super easy to adjust now.  I basically tapped the metal plug that screws into the rear of the breech, the one the HS rests in. 

I put the factory HS adjustment to minimum and locked down the little grub screw, so it will never have to move again.  Then I tapped the plug at the rear for 8mm x 1.25 threads.  I got the appropriate 8mm x 1.25 grub screw that fits that thread, and ground down the tip to make a little protrusion to fit inside the spring.  That 8mm grub screw is the exact same size as the hole in the plug, so the spring will fit perfectly and move freely.  It just so happens that the center of that plug lines up with the top screw of one of the butt pad adjustment plates.  I drilled that out to have direct access to the new grub screw in the plug, and simply added a screw to the side of the original to hold that plate in place.  I lost my side to side adjustment in the butt pad, but I like it dead center anyway, so no loss there.  That plate is covered up by the up/down adjustable plate, and I still have my height adjustment. 

Now, I simply remove the single 5mm allen that holds the butt pad in place(the one you loosen for vertical adjustment), and I can adjust the HS with a 4mm allen.  I don't have to remove the stock, or monkey with that little grub screw in the hammer anymore!  I imagine this mod would be even easier on a wood Flashpup!  I did wrap the new grub screw in teflon tape so it wouldn't want to move.  This is SO MUCH BETTER than the factory way of adjusting the HS   I have some pictures below to show the modified plug/HS rest.

Very nice design!! simple too. wish i could do something for the flash lol. I'll do this to my flashpup when i get it, but im waiting for a refurb or a good deal.

What made you guys pick the Synpup over the wood? Im still leaning towards the wood cuz I like traditional wood stocks but my woodflash has a few scraches and dings already from using tree's as a rest when shooting lol

I still haven't figured out a solution for my regular Flash on the HS front   The only solution I have in my head is to do the same thing, but with a permanently attached "wheel" of some sort that I just turn.  I would have do a cutout in the stock, and it really doesn't seem worth the effort or potential failure(of the stock modification) on that gun.  At least the regular Flash doesn't have the trigger linkage to deal with when out of the stock.

I picked the SFP over the WFP due to the butt pad adjustment mostly, and the bolt design myself.  Actually, I may end up modifying the bolt on SFP at some point.  If they put the adjustable butt pad on the WFP, I'd probably go that route.

[Rallyshark]

I started with a refurb wood FlashPup in .22.  Turned up with an incredibly accurate barrel and it was very easy to hit my desired tune of 24 shots JSB 18.1 at 920FPS w/o a regulator.

Followed up a new SynFlashPup .25(even more accurate) from AirGunDepot last week during a deep discount ($10 over refurb price) and have been tweeking on it since.

I like the mono breach block design over the AT44 extruded aluminum breach on tube layout. Flashes have great economy in the arrangement of parts, simple hammer, no anti-double feed parts, removed sliding magazine axel bolt.  I'm a simplicity guy, hate electric adjustable car seats, headlights on gimbals,... These FlashPups appeal to that.

The SynFlashPup has more features (primarily a very good adjustable butt up down left and right) and is a bit more refined like anodized metal port dust plug vs. plastic dowel. If wood is your thing definitely go wood.

If I could only have one it would be the SynFlashPup, but in .22 (in .25 the QE moderator is inadequate).

... I lost my side to side adjustment in the butt pad, but I like it dead center anyway, so no loss there.

I relocated the same butt screw, and counter bored it to retain side to side adjustment which is better than I expected. Just have to return to center for hammer spring adjustments.

Really like what you did, simple operation and if you lose the original hammers spring grub screw you could fit a longer spring netting more power while maintaining free flight clearance.

Last night I removed the spring spacer, put a heavier gauge and longer spring in letting some more FPE out without leaning on the valve pin.
Polished the Pellet probe, bolt and hammer rounding sharp edges, polished the bolt catch and replaced bolt probe port with a turned MDS one. No gains in power, just smoothed the string and operation. Cocking is much improved, no grinding,  smooth predictable operation.

I did run the bore scope and noticed the bolt probe appears to be short, not setting the pellet entirely into the lands. The lead goes half a pellet length beyond the port. Seems to me the pellet should be entirely engage with the probe, but doesn't seem to affect groups. Maybe the probe is less of an obstruction? Either way I'm shooting a comparison string, hand setting pellets into the lands, see what's what.

Thane, I like the whole Flash series for the reasons you mentioned.  They are super simple, easy to work on, and have less reasons to fail.  The weight is certainly a plus too!  You did a nice job polishing the parts there.  I would have gone a similar route on the side to side adjustment screws, but I didn't really see the need, since I like it dead center.  I also like removing one screw and just adjusting.  I wouldn't worry at all about the probe not pushing the pellet into the lands.  As long as you're clearing the barrel port, that is the most important part.  If you're shooting heavier ammo, or longer ammo, you'll appreciate that it doesn't push it into the lands.  Otherwise, loading would become a chore I think. 

I'm still trying to decide what I want to do with the barrel.  It is super accurate with some pellets, but none of those are pellets I would use for normal critters, only for the high power/high penetration needs.  I use HP pellets of some variety for most of my hunting, but this barrel doesn't like any of them.  It comes down to this particular barrel having a bit larger than average bore I think.  I'm on the fence about trying another barrel from Hatsan, or getting another barrel machined for it.  Obviously, another Hatsan barrel would be way less expensive, but the idea of a longer barrel opens up easier power, so I don't know,lol.

[Thane]

Made a second MDS Nylon pellet probe guide doubling the length to address racking on the wood FlashPup with-out all the other bolt polishing.
Increased the closing force a bit, but significantly reduced the ragged feel of the steel on steel pellet probe. Channel is not needed.

The pellet probe, bolt and bolt's hammer catch have been the main culprits for rough cocking on both my FlashPups.

[Rallyshark]

Made a second MDS Nylon pellet probe guide doubling the length to address racking on the wood FlashPup with-out all the other bolt polishing.
Increased the closing force a bit, but significantly reduced the ragged feel of the steel on steel pellet probe. Channel is not needed.

The pellet probe, bolt and bolt's hammer catch have been the main culprits for rough cocking on both my FlashPups.

Nice!  I was considering doing the same thing with PEEK on my gun.  I just got my hands on a mini lathe in need of a little attention.  Once I get it working, I just may give that a go with the PEEK  

[Thane]

I have a 1.25" dia slug of PVX PEEK, carbon and PTFE impregnated, used for bearings.

I am too cheap to turn it down to under 1/2" and leave most of it in my chip tray.

[Rallyshark]

I have a 1.25" dia slug of PVX PEEK, carbon and PTFE impregnated, used for bearings.

I am too cheap to turn it down to under 1/2" and leave most of it in my chip tray.

LOL, we all have our breaking points   It will be a bit, before I get around to possibly making a new probe guide.  It looks like I'm probably gonna go ahead do a LW Polygon barrel for the Flash, and see where it gets me.  It will probably take me a few days to get that done, then I'll do some testing with some of the newer NSA slugs in it.  It should be interesting and informative, if nothing else... 

[UCChris]

I have a 1.25" dia slug of PVX PEEK, carbon and PTFE impregnated, used for bearings.

I am too cheap to turn it down to under 1/2" and leave most of it in my chip tray.

LOL, we all have our breaking points   It will be a bit, before I get around to possibly making a new probe guide.  It looks like I'm probably gonna go ahead do a LW Polygon barrel for the Flash, and see where it gets me.  It will probably take me a few days to get that done, then I'll do some testing with some of the newer NSA slugs in it.  It should be interesting and informative, if nothing else...

Are you going to put a longer barrel on it, or stay factory length?

[Rallyshark]

I'll probably go a little longer than factory, but not much.  I'm thinking around 20" right now.  I acquired a LW polygon from a friend that was going to get one machined for one of his guns, and it never got finished.  I'm not sure how much I'll have to work with, depending on how much machining was already done.  I won't know that until I get the barrel in my hands to do some measurements.  Judging from the pics I saw, I should have at least 20" to work with...

[Rallyshark]

I have an update on the barrel front.  It turns out that barrel I got from a friend is a standard rifled/choked LW barrel.  I machined it to fit, and ended up with about a 20.5" barrel.  This barrel has a very tight bore, so slugs are pretty much out of the question.  Just for kicks, I cranked up the HS and it hit 1024fps with the Monsters, so that extra 3" added about 20fps.  I think it would have been a bit more on a barrel that doesn't have as tight of a bore.  I went a little too far on the barrel port, so there are some loading issues with the smaller pellets.  That's okay though, because this was literally the first barrel I've ever done.  I did get the o-ring groove right at least, haha. 

I haven't even bothered to test accuracy yet, because I don't think I'm done with it.  Given the tight bore, I won't be using this barrel for high power stuff, so I've decided I'm going to change it.  The good thing about the SFP is the shorter cylinder, which means I can make the barrel shorter.  I'm going to re-do this LW barrel to remedy the port situation and make it a shorty.  I can go shorter with it, than I could on the other Flash variants.  I'm gonna make it a 15.5" me thinks   That would make the gun a little over 27" with the 5" LDC, and it would still only be around 31" with the full length LDC.  The weight loss won't hurt either.  That will make it an excellent little woods walker!  This should be fun...

Oh the higher power front, I'm not done there.  I ordered an FX slug liner that I will sleeve and adapt to the SFP.  If I can pull that off, I should have a little pup with some serious juice.  I can add length without the weight penalty, since I'll be adding multiple CF sleeves.  I'm thinking I'll go 24" and see what the little devil can do with some slugs.  To be continued! 

[Rallyshark]

I just finished up with my shorty barrel today.  I gotta let the CF sleeve set, then I'll get it in the gun tomorrow or Thursday for some testing.  The picture is a little deceiving, because of the phone camera, but it is exactly 15 3/8" long.  You can only do a barrel this short on a Sythetic Flashpup, because it has the shorter steel cylinder.  It's so darn cute, haha 

[Thane]

Looks great!

Did you cut the threads on your lathe? or used a die?

[Rallyshark]

Looks great!

Did you cut the threads on your lathe? or used a die?

I got the barrel from someone that was going to put it on a gun they sold, so the threads were already cut(lucky me).  I just had to chop it and re-do the breech end completely.  I used a mini lathe.  I've got the gearing to thread it, but I haven't had to yet.  That will change on the next barrel though.  It is super short with the shorter Huma LDC on it at 27", and it is still only 31.5" with the long Huma on there   It is insanely quiet with the full length LDC, and still easily backyard friendly with the short one. 

I'm waiting on some black derlin to machine an insert to fit around the barrel at the front scope rail support, so not finished yet.  I didn't really test for accuracy, because it was getting dark, but it shot about a dime size group with the cheap crosman domes at 30 yards.  Between the barrel insert I gotta make, and a couple other little things, it should be a little tack driver with this barrel and pellets.  Believe it or not, the little monster can still make 50fpe with that 15" barrel,lol!