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Posted

Hi Eveyone

Ok so i figured out that my 8" SBR in 338fed was over gassed..and i turned the gas selector 3/4 way to the close position and now my AR10 is shooting much smoother and kicking the brass at a 4 oclock direction..I did another chronograph test after i did this and i am gaining about 100fps faster at 2310fps out of my barrel using the same 185gr American Eagle. The weather today was cooler than before ..temps were around 87F. Any thoughts? I made a video to record the results from today but i have not yet uploaded it..

 

 

 

IMG_0371.JPG

Posted (edited)

Tune your gun to run, good ejection pattern and no FTF's or FTE is more important than velocity of projectiles .

Never really had any failure to eject or feeding problems with it since i built it..but if yo take a look at this video ..I am ejecting brass in the 1 oclock direction showing an indication of the gun being overgassed.. After turning the gas down 3/4 way to close ..I am now ejecting Brass at a 4 oclock direction which is perfect and the gun is not over gassed.. But i discovered while doing this my bullet velocity increased to about 100fps faster than my previous testing..

 

Edited by jeanclaudesegal
Posted (edited)

It makes sense.... Less gas going through the BCG = more gas down the tube, behind the proj... the path of least resistance and all that scientific crap.

Better cycling and better projectile performance = win/win.

Edited by Robocop1051
Posted

 The theory is sound , but far too many variables to say for sure that ,that's why the increase in Velocity . I find it odd that you can get that velocity increase from an 8" bbl., a longer barrel maybe ,just  maybe .

Posted

If you miss'em on the first shot the muzzle blast should be enough to stun'em till the second round hits! That is a bad a$$ rifle!

thanx.. Im still experimenting with it.. I am awaiting some subsonic 230gr loads for further testing using my buddies sound suppressor.. I am very curious to see how quiet it can get :)

Posted

 The theory is sound , but far too many variables to say for sure that ,that's why the increase in Velocity . I find it odd that you can get that velocity increase from an 8" bbl., a longer barrel maybe ,just  maybe .

I dunno..But you saw both videos from my previous testing ...one with the gas port opened almost all the way and the other 3/4 way closed..and the velocity results were different ..Im not too sure about the whole sound thing

Posted (edited)

On the day you got that video, it would have been very beneficial to shoot the gasport wide open, and again 3/4 closed, and compared those results.  Instead, your comparing data from different shooting days, and those days have different weather data. 

 

"The theory is sound."

 

I dunno..But you saw both videos from my previous testing ...one with the gas port opened almost all the way and the other 3/4 way closed..and the velocity results were different ..Im not too sure about the whole sound thing

I'm not sure you understood what he's saying - he's not saying that sound is the theory...  he's telling you that your theory of closing the gasport seems solid...

Edited by 98Z5V
Posted

Good call. That would be an easy test next time. Record all info same day. Would be cool just to see how it plays out.   

Posted (edited)

On the day you got that video, it would have been very beneficial to shoot the gasport wide open, and again 3/4 closed, and compared those results.  Instead, your comparing data from different shooting days, and those days have different weather data. 

 

I'm not sure you understood what he's saying - he's not saying that sound is the theory...  he's telling you that your theory of closing the gasport seems solid...

whoops.. my bad ..lol ..Weather was a factor. but this time it was cooler ..

Edited by jeanclaudesegal

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