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Recoil Impulse Comparison Carbine v Midlength

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All things being equal will the recoil impulse be greater with a carbine length or mid-length gas system?

How do these compare for different length barrels?

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from my own limited experience, the longer the gas system or barrel, the recoil impulse gets softer - granted you're comparing with the same muzzle device.

 

to be honest, the difference is not that great... it's just a 223/556 at the end of the day.  if you were comparing .308 or larger, then I think the differences could be felt more especially with varying muzzle devices

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Mid-length will be softer than carbine, rifle length will be even softer.  Carbine recoil is negligible, it's only like 3.2#  and there's not a huge difference between gas ststems, but a difference none the less.

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   I just picked up a kak 12.5 middy for the same type of build. I’m waiting for Black Friday to gather the rest of the parts. I’ll let you know how it works out and or I’m always down to meet up for a range day. 

From what I’m gathering from third party info is that the carbine gas system is more reliable, the 12.5 mid was allegedly built to run completely suppressed. I have read people have had no issues with a normal gasblock, but I’m probably going to throw an adjustable on just in case. 

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14 hours ago, RUTGERS95 said:

no one could possibly feel the difference all things being equal, it's a placebo effect

the way the rifle is set up will have far greater impact on felt recoil

   I’m more worried about reliable function in the 12.5 mid length. That’s why I’m throwing a SA adj gas block on it. 

 I do agree that balance definitely means way more, but controlling unnecessary gases and movement definitely helps. 

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crane would disagree with anyone saying they can feel the difference all things being equal.  An interesting side note to the middy vs carbine length felt recoil crowd is that they'll yammer away about softer shooting only to find that they are actually allowing more gas through with greater recoil impulse due to barrel manufacturers opening up the holes to insure reliable operation across a wide spectrum of ammo.  but I digress....

 

agree 0Jeep4, reliability is key so I'd check the port diameter before worrying about the adj block.  I'd call Colt and find out what size they use on their short barrels if you can't find it on the i net:)

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On 11/30/2019 at 11:58 PM, RUTGERS95 said:

no one could possibly feel the difference all things being equal, it's a placebo effect

the way the rifle is set up will have far greater impact on felt recoil

1) You can definitely feel the difference. 

2) You are right about the rifle setup being of greater significance. 

 

18 hours ago, Shane45 said:

It is true that rifle setup is important and has an effect. But I can tell the difference in gas systems.

Same here. 

 

12 hours ago, RUTGERS95 said:

crane would disagree with anyone saying they can feel the difference all things being equal.  An interesting side note to the middy vs carbine length felt recoil crowd is that they'll yammer away about softer shooting only to find that they are actually allowing more gas through with greater recoil impulse due to barrel manufacturers opening up the holes to insure reliable operation across a wide spectrum of ammo.  but I digress....

 

agree 0Jeep4, reliability is key so I'd check the port diameter before worrying about the adj block.  I'd call Colt and find out what size they use on their short barrels if you can't find it on the i net:)

who's this crane person and why would they be the arbiter of how a rifle feels?  

The carbine length gas system, is pulling gas  at a really high pressure, and especially in a 16" barrel, you are getting a fairly long dose of this high pressure gas. It may be less pronounced on shorter barrels.

So for example, I have a lower that uses a carbine length buffer. Put my carbine length gas system 16" upper on it and you can really feel the the buffer and bcg bottoming out hard. Put one of my mid-length uppers on it, and it gets much better. Shooting it with a red dot, you can definitely see the difference quite a bit. 

That being said, setup matters. If I swap in one of my lowers with a rifle length buffer, the difference in feel between the two uppers is minimal as the added reciprocating mass tames the impulse a lot. Also not all manufacturers open up the gas port to keep whiny customers who don't know how to make a gun run from annoying them and making warranty claims. Which is still part of the overall setup. 

 

 

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3 hours ago, raz-0 said:

1) You can definitely feel the difference. 

2) You are right about the rifle setup being of greater significance. 

 

Same here. 

 

who's this crane person and why would they be the arbiter of how a rifle feels?  

The carbine length gas system, is pulling gas  at a really high pressure, and especially in a 16" barrel, you are getting a fairly long dose of this high pressure gas. It may be less pronounced on shorter barrels.

So for example, I have a lower that uses a carbine length buffer. Put my carbine length gas system 16" upper on it and you can really feel the the buffer and bcg bottoming out hard. Put one of my mid-length uppers on it, and it gets much better. Shooting it with a red dot, you can definitely see the difference quite a bit. 

That being said, setup matters. If I swap in one of my lowers with a rifle length buffer, the difference in feel between the two uppers is minimal as the added reciprocating mass tames the impulse a lot. Also not all manufacturers open up the gas port to keep whiny customers who don't know how to make a gun run from annoying them and making warranty claims. Which is still part of the overall setup. 

 

 

no you can't, all things being equal as we're talking microfractions of dwell time.  Even the parts wear/tear is of immaterial concern when measured by crane given CORRECT gas hole sizing.  This is like 2012 type stuff.  Hell, companies have even stopped marketing it as such lol

google placebo effect

google navy crane testing

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Well...Im not sure what you mean by "all things being equal" These are systems. So Im not going to take one system and introduce 1 single change. The changes need to match the system.  What do mean by parts wear/tear is of immaterial concern? There is no way a Mk18 is going to have the service life of a KAC SR16. Its probably not even 10% of the service life. Shoot a 6920 next to a SR15, both with the same brake. You will feel a difference and you can see it on paper in the form of spread when doing hammers.

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2 minutes ago, Zeke said:

Are you going to change back to myhatinthering ? Now?

it's my alter ego but neither are as retarded as this lot!  lol

seriously however, the lack of fundamental understanding of firearms systems that have been around for 50+ years is staggering

 

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3 minutes ago, RUTGERS95 said:

it's my alter ego but neither are as retarded as this lot!  lol

seriously however, the lack of fundamental understanding of firearms systems that have been around for 50+ years is staggering

 

I dunno. @Shane45 knows his shit. Not gonna lie 

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1 hour ago, RUTGERS95 said:

no you can't, all things being equal as we're talking microfractions of dwell time.  Even the parts wear/tear is of immaterial concern when measured by crane given CORRECT gas hole sizing.  This is like 2012 type stuff.  Hell, companies have even stopped marketing it as such lol

google placebo effect

google navy crane testing

Did you read the report? The bolt speed in unsuppressed fire was  22.3% less. That's a minimum 12.5 Oz mass moving roughly 75% of the sites of a carbine system. You notice it. 

Not to mention it had less broken parts and less wear. Does metal experience the placebo effect?

 

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   I’ll check the port size tomorrow, I’m not sure Colt ever made a mid gas on a short barrel.

   The KAC barrel I have isn’t too common of a configuration. (12.5 mid length gas) I’m just experimenting on this build hoping for the best, figured adjustable gas block was a good idea. I’v built ARs before but am definitely still a novice. 

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This is what came up for me... which means Rutgers95 needs to get back in his fucking lane, in a nice way.

 

http://soldiersystems.net/2018/05/14/nswc-crane-carbine-mid-length-gas-system-testing-shows-increased-performance/

https://www.militarytimes.com/news/your-military/2018/06/01/this-detailed-report-shows-which-m4-rifle-design-works-the-best/

"Conclusion

Although testing to 34,000 rounds isn’t yet complete, the conclusion is simple. Use of a mid-gas system significantly extends the life of the overall weapon system. It also offers increased performance over a carbine-length gas system."

 

"Using a mid-length gas system on an M4A1 carbine extends the life of the weapon system and increases the weapon’s performance over a carbine-length gas system, according to a detailed study by Naval Surface Warfare Center — Crane, obtained by Military Times through a Freedom of Information Act request......

.....This study may not come as a complete shock to civilian shooting aficionados and U.S. special operations forces who customize their M4 variants, but it does offer data to back up what those communities have believed for some time."

 

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11 minutes ago, Shane45 said:

This is what came up for me... which means Rutgers95 needs to get back in his fucking lane, in a nice way.

 

http://soldiersystems.net/2018/05/14/nswc-crane-carbine-mid-length-gas-system-testing-shows-increased-performance/

https://www.militarytimes.com/news/your-military/2018/06/01/this-detailed-report-shows-which-m4-rifle-design-works-the-best/

"Conclusion

Although testing to 34,000 rounds isn’t yet complete, the conclusion is simple. Use of a mid-gas system significantly extends the life of the overall weapon system. It also offers increased performance over a carbine-length gas system."

 

"Using a mid-length gas system on an M4A1 carbine extends the life of the weapon system and increases the weapon’s performance over a carbine-length gas system, according to a detailed study by Naval Surface Warfare Center — Crane, obtained by Military Times through a Freedom of Information Act request......

.....This study may not come as a complete shock to civilian shooting aficionados and U.S. special operations forces who customize their M4 variants, but it does offer data to back up what those communities have believed for some time."

 

You can be more creative then” stay in your lane “ 

jus sayen 

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