FX Boss .30 cal to .257 cal. Possible??

[jimreed1948]

Since the FX Boss has more regulater power than the Royale 500 and it has a side power adjuster, is it possible to change the barrel to a TJ's .257?

[oldpro]

Anything is possible with enough $$$$ LOL

[Tofazfou]

Like Oldpro said, its possible for sure.

But what the gains are gonna be........who knows.  Dont think anyone has done 1 or at least, i've never read about it.  Thats a reg'd gun made for efficiency of shooting pellets which are pushed pretty easy.  Especially down a smooth twist bore.  But add a fully rifled barrel and cast bullets and i'm sure its gonna take some good valving to push it down the barrel with any power.

Wish i had some CONCRETE FACTS for ya.  Good luck

[Unclebuck1234]

Are you saying the Boss has a side wheel adjuster? Because I have a Boss and there isn't one.

[rkr]

Can you find short enough bullets in .257 to fit Boss's magazine (assuming you sleeve it to .257)?

[rintafile]

Edit: oops..I read and understand it wrong so this post is worthless. Sorry. Moderators could whip this one a way

[oldgoat]

Jim, I got one of the first 5, 30 cal. Boss air guns that AOA got in.  I bought it with the intensions of making a .257 slug shooter out of it using my cast 55 grain .257" slugs.

I used a 28" long TJ's .257" barrel.

I threw a ton of money at the "dang" thing and FINALLY got it to shoot my 55 grain slugs at, IIRC, around 750 fps.

I ordered a 25 cal cocking handle and probe assembly, had to have a brass thimble made for it that threaded onto the barrel, made a heavier hammer, tried heavier springs, tried running the gun without the regulator.  I also drilled out the transfer port and tried an Altaros regulator. 

I did finally get the gun into the 750 fps range BUT; that was without a regulator and each successive shot would be a little bit slower. 

I came to the conclusion that the breech block is maxed out when shooting a 30 cal pellet.  The breech block was designed for a 22 cal pellet originally.  It just can't flow enough air to push a 55 grain .257" slug out of a TJ's barrel at anything over 750 fps. The air valve is way too small and I didn't think that there was enough "meat" in the block to have a larger valve fitted.  Also, the high pressure air has to make 5, 90 degree turns to make it from the air bottle to the barrel bore.

I spent a lot of time trying to get it to work, ended up putting it back stock and taking an $800 beating on the gun.

Friends don't let friends buy FX air guns!  LOL!

[jimreed1948]

Jim, I got one of the first 5, 30 cal. Boss air guns that AOA got in.  I bought it with the intensions of making a .257 slug shooter out of it using my cast 55 grain .257" slugs.

I used a 28" long TJ's .257" barrel.

I threw a ton of money at the "dang" thing and FINALLY got it to shoot my 55 grain slugs at, IIRC, around 750 fps.

I ordered a 25 cal cocking handle and probe assembly, had to have a brass thimble made for it that threaded onto the barrel, made a heavier hammer, tried heavier springs, tried running the gun without the regulator.  I also drilled out the transfer port and tried an Altaros regulator. 

I did finally get the gun into the 750 fps range BUT; that was without a regulator and each successive shot would be a little bit slower. 

I came to the conclusion that the breech block is maxed out when shooting a 30 cal pellet.  The breech block was designed for a 22 cal pellet originally.  It just can't flow enough air to push a 55 grain .257" slug out of a TJ's barrel at anything over 750 fps. The air valve is way too small and I didn't think that there was enough "meat" in the block to have a larger valve fitted.  Also, the high pressure air has to make 5, 90 degree turns to make it from the air bottle to the barrel bore.

I spent a lot of time trying to get it to work, ended up putting it back stock and taking an $800 beating on the gun.

Friends don't let friends buy FX air guns!  LOL!

Thank you very much for this response.  This is the information I was looking for.  Sooooooo, Air Force here I come.

[Tofazfou]

Jim, I got one of the first 5, 30 cal. Boss air guns that AOA got in.  I bought it with the intensions of making a .257 slug shooter out of it using my cast 55 grain .257" slugs.

I used a 28" long TJ's .257" barrel.

I threw a ton of money at the "dang" thing and FINALLY got it to shoot my 55 grain slugs at, IIRC, around 750 fps.

I ordered a 25 cal cocking handle and probe assembly, had to have a brass thimble made for it that threaded onto the barrel, made a heavier hammer, tried heavier springs, tried running the gun without the regulator.  I also drilled out the transfer port and tried an Altaros regulator. 

I did finally get the gun into the 750 fps range BUT; that was without a regulator and each successive shot would be a little bit slower. 

I came to the conclusion that the breech block is maxed out when shooting a 30 cal pellet.  The breech block was designed for a 22 cal pellet originally.  It just can't flow enough air to push a 55 grain .257" slug out of a TJ's barrel at anything over 750 fps. The air valve is way too small and I didn't think that there was enough "meat" in the block to have a larger valve fitted.  Also, the high pressure air has to make 5, 90 degree turns to make it from the air bottle to the barrel bore.

I spent a lot of time trying to get it to work, ended up putting it back stock and taking an $800 beating on the gun.

Friends don't let friends buy FX air guns!  LOL!

Whats up OG?

Wow, 5-90 degree turns?  Talking about ruining efficiency.  In the Elevator Trade, our rule of thumb for hydraulic fluid and piping is no more than 360 degrees.  I did not know this about the BOSS.

[KnifeMaker]

Howdy OG! Sounds more like an F-1 track than a decent air passage. LOL!

Knife

[QVTom]

European makers don't believe in plenums or slugs.  Their designs are based on the elegance of the monoblock which does not easily lend itself to efficient porting.

Tom

[Bill G]

180* of turns are bad enough.....5 turns, if they are all 90*, is 1 1/4 X around the block before any work gets done.  I guess that would be OK if there was a sufficient plenum at the base of the bullet waiting to do the deed and the plenum was being fed by the 5 turns of porting. 

[rsterne]

My tankers have four 90* turns.... two between the tank and/or regulator and the plenum (not counting the turns inside the regulator) and two between the plenum and the bore (not counting the air snaking around the poppet).... Mind you the one in the valve is more like 60* plus 30*.... If the ports are big enough the air can make a lot of turns without much loss.... My .257 Hayabusa reaches 190 FPE at 3000 psi with a 28" barrel....

Bob

[Bill G]

Bob, are all those turns at ambient pressure?  I suppose no since you wrote about the reg too.  I guess if some of those turns are under pressure, they act as part of the plenum, after the reg.  anything at ambient pressure is dead space.  we knowdDead space is not good.

Bill

[rsterne]

Typical setup, like a Crosman.... a 90* turn in the valve and another in the barrel (both at atmospheric pressure until you pull the trigger, then at operating pressure).... The other two are at the inlet end of the plenum, so have no effect on airflow, of course....

Bb