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Old September 22, 2021, 07:36 AM   #1
Runs With Fire
Join Date: March 19, 2018
Location: Ensley Center, MI
Posts: 82
Too Fast for a Carbine Length gas system?

I'm running a 16 inch barrel .223 with a 55 grain bullet going averaging 3,190 fps. That's rifle length velocity so is that pushing the limits on my gas system, or is the almost 200 fps hotter than average still just fine?
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Old September 22, 2021, 01:36 PM   #2
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Originally Posted by Runs With Fire View Post
I'm running a 16 inch barrel .223 with a 55 grain bullet
Got it

going averaging 3,190 fps.
factory ammo or hand loads? If factory what ammo?
did you chronograph it, or are you going off what a box stated?
While possible I find it highly unlikely that you are getting those velocities out of a 16in barrel unless you are hand loading over max.

That's rifle length velocity so is that pushing the limits on my gas system, or is the almost 200 fps hotter than average still just fine?
What do you mean by "pushing the limits on your gas system" the gas system runs off the gas pressure from the cartridge. the speed of the bullet is mostly irrelevant. there is dwell time to consider, the time after the bullet has passed the gas block, but before it has left the barrel which allows the gas to enter the gas block and operate the system. however even with a mid length gas system, 200 fps is not going to make it leave the barrel too soon. there are people who push light 45g varmint bullets in the 3500fps plus range with no issues.

in short, even if you are actually running 3190fps, which I find very unlikely, it should run just fine.
I don't believe in "range fodder" that is why I reload.

Last edited by Shadow9mm; September 22, 2021 at 03:54 PM.
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Old October 3, 2021, 02:45 AM   #3
Metal god
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16" carbine length gas is always WAY over gassed so yes you are pushing the gas system hard . Stiffer spring , heavier buffer will help that a lot and there's always an adjustable gas block if need be .

What powder are you using ?

CAUTION: The following post (or a page linked to) includes or discusses loading data not covered by currently published sources of tested data for this cartridge (QuickLOAD or Gordon's Reloading Tool data is not professionally tested). USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.

26.5gr of H-335 pushing a 55gr FMJ-BT got me 3100+fps from a 16" barrel . With out looking at my notes I can't say exactly but it was over 3100fps , I want to say 3124-ish . Slightly slower powder might get you in the upper 3100's . I remember this load for a couple reasons , 1) I was surprised I had no pressure signs but stopped there anyways . 2) I ran a second test load work up using mag primers to see what the difference was . The averages were about the same but the mag primers produced much higher ES/SD's then the standard primers . All the above is from memory of the testing 7+ years ago . If you'll are lucky I'll get off my butt and actually look at my notes at some point haha

FWIW 25.5gr of H-335 gets my over 3000fps with a 55gr bullet from a 16" barrel .
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Last edited by Metal god; October 3, 2021 at 02:50 AM.
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