Speed increase from 500mm to 600mm ?

[Trucker3573]

Just curious what the approx speed increase would be going from a 500mm compact in my Maverick to a 600mm. Looking at shooting 33.95 pellets. Current tune with 500 mm is just over 900 with 25.39. Most videos I’ve seen the 33.95 are about 100 fps slower. My current setup should shoot them around 800 fps. Just curious how much the 600 mm would boost that with the same tune ?

 

[cfs916]

Around 35-40fps

 

[Long_Gun_Dallas]

Depends on tune. My guess would be 65fps give or take. But seriously depends on the tune. If it is extremely efficient for you barrel length you may pick up very little. If you tune is inefficient you may pick up a lot

 

[Vetmx]

When I shoot 34gr pellets out of my RTI, I swap to a 600mm barrel from the 500mm one. What the 500mm works to do, the 600mm just coasts to do it. I shot some 34’s out of my M3 compact and there was a considerable difference than when I tuned an Impact 600mm I sold with a 34gr tune. Basically a 500mm has to be on a slug tune compared to a 600mm that just has to be on a slightly hefty pellet tune. There will be 10 guys jump in and swear by their 500mm 34gr guns and tunes but when you start pushing heavier lead, barrel length is the key to keeping a friendly gun. Sounds like you already know it’s time to say when. Ole stubby is good if you keep it 28gr and lighter. Both of my 500mm Compacts, .22 and .25, have projectile weight limits.

 

[Larcat]

I'll guesstimate the speed increase at 10cm.

 

[JaceSpace1369]

Anytime I've swapped from 500 to 700 i get between a 100 and 110 gps increase. But that's with the pin probe and the humor transfer port also included. I assume that with the 600 to a 700 you may only see maybe a 25-35 fps increase. From what I have read the increase in fps is not linear. So the amount of fps increase will not be as great as going from 500mm to 600mm.

 

[yenniedn]

Around 35-40fps

^^^This...with my Impacts, a change from a 500mm barrel to a 600mm barrel resulted in an increase of 30-40fps with the JSB 25.4g pellets. I saw about the same 30fps gain going from a 250mm to a 350mm barrel in my Leshiy's as well.

 

[18.13]

45fps

 

[Trucker3573]

Thanks guys

 

[ladwict]

60fps would be quit a good guess

 

[Centercut]

Rule of thumb is 10 fps per inch...

 

[Jasonmc]

I agree with the rule of thumb...
Makes for a sweet shooting...good, smooth sounding rifle...
Sure you can squeeze a bit more but it's all about a good tune.. sometimes less is more

 

[bigHUN]

My project to investigate the tune and POI effects in between two lengths @ 100 meters...
JSB 34 gn MK2, I wanted to keep a speed of about 930,
I swap the .25x700 barrel to .25x600 and needed to pump up a Reg for about 30 bars to 155. Both same liner STX-A, huma large dual port and pellet probe, and btw the pellet probe is a limitation for proper dwell with shorter barrel.
Also I recorded a speed difference MK2 vs MK1, the later have stronger skirt ring and slower for 15 fps.
Just FYI.