Will be replacing the stock 14" barrel on a Crossman 2289 Backpacker with a 24" barrel increase the velocity (fps)? And if so, by how much? Only mod so far is a steel breech, and brass barrel bands. I've asked in all of the Crossman Facebook groups, and haven't gotten an answer.
Crosman Velocity increase with a longer barrel?
- Thread starter Robg7734
- Start date
Derrick,
so nice we have specialists on here!
●
Is this 12fps per inch caliber related, or projectile weight related in any way?● The following conflict has been going on for several months now, all about an RTI 2 Performance .30cal.
The fuss is about the decision between the Compact with a 500mm barrel, and the Regular with a 600mm barrel:
• Dr. Jekyll in me tells me that a shorter gun is a better gun, just easier in so many situations.
• Then Mr. Hyde lashes out saying it is a bad idea to give up power while trying to drive 45 grainers.
• Dr. Jekyll runs out of arguments and hits Mr. Hyde with his umbrella.
• Mr Hyde ducks and steals Dr. Jekyll's hat, all the while arguing that a shorter gun is a louder gun, something that both don't want in their respective backyards.
Any light you can shed on this?I understand that by tuning the RTI (balanced valve) I can get more power, I can quiet it down, all that, but for the price of less shots. The piper has to be paid somehow — with loudness, less power, or less shots....
Why do I make my life so complicated?(Derrick, I don't expect you to answer that last question, even my psychiatrist is clueless.)
Matthias
PS: And I'm still hoping to find that RTI 2 rifle in the classifieds some day....
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the 12fps is a common guess but there is a but
every gun, pistol or rifle will have its own numbers
so, the 2289 uses a 1322 valve and the 14 inch barrel vs the 1322 barrel at 10.25 might be giving its best performance in factory dress, so gaining 120fps is more a hope then reality
when doing this it takes time and R&D work
one other thing the 12FPS is a number also used when cutting barrels down and much has been written on that and the number 12 seems to be the loss per inch of reduction
Mr. Hyde i guess runs the show as i stated the number 12 is more a guess then a fact
in spring rifles the barrel lengths are all over the place
an Air Arms Pro Sport has a 9.5 barrel, a Diana 350 has a 19.25 inch barrel, one reason is you could not cock the 350 with a 9.5 inch barrel but if you could, would you have the same fps in the same caliber at the same length who knows
there are too many factors besides barrel length
pellet fit is one of them
you look at RWS hobby pellets they are always slower than a little heavy pellet of a different brand
so, you see it is complicated
now the 1322 valve can be improved but that is above my pay scale
you could test different combinations for a very long time and never find perfect
every gun, pistol or rifle will have its own numbers
so, the 2289 uses a 1322 valve and the 14 inch barrel vs the 1322 barrel at 10.25 might be giving its best performance in factory dress, so gaining 120fps is more a hope then reality
when doing this it takes time and R&D work
one other thing the 12FPS is a number also used when cutting barrels down and much has been written on that and the number 12 seems to be the loss per inch of reduction
Mr. Hyde i guess runs the show as i stated the number 12 is more a guess then a fact
in spring rifles the barrel lengths are all over the place
an Air Arms Pro Sport has a 9.5 barrel, a Diana 350 has a 19.25 inch barrel, one reason is you could not cock the 350 with a 9.5 inch barrel but if you could, would you have the same fps in the same caliber at the same length who knows
there are too many factors besides barrel length
pellet fit is one of them
you look at RWS hobby pellets they are always slower than a little heavy pellet of a different brand
so, you see it is complicated
now the 1322 valve can be improved but that is above my pay scale
you could test different combinations for a very long time and never find perfect
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You have to factor in whether there’s enough air for you to realize the speed increase. What Marflow was hinting at above. And why people start modding valves with longer barrels.
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The valves were modded when I installed a flat top piston. Stronger hammer spring with guide, my transfer port bushing has been opened up with a .161" ream, to allow more exhaust airflow.
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Then somewhere on GTA is a thread with many of your answers. Believe he even tested the 24” barrel. Will see later if I can find it.
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Well, you’re the one that posted it like it was God’s truth. Where did you get that information?
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