SJG 253 Posted November 19, 2019 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? Quote Share this post Link to post Share on other sites
fatty 241 Posted November 19, 2019 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 Quote Share this post Link to post Share on other sites
Scorpio64 5,155 Posted November 19, 2019 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. Quote Share this post Link to post Share on other sites
SJG 253 Posted November 19, 2019 So what gas system would be the best on a 12. 5 556 other build? Quote Share this post Link to post Share on other sites
fatty 241 Posted November 19, 2019 My 12.5 is running on a carbine gas system, most likely for reliability. 1 Quote Share this post Link to post Share on other sites
Scorpio64 5,155 Posted November 19, 2019 I'd probably go with a middi. More real estate on a mid handguard. Quote Share this post Link to post Share on other sites
0Jeep4 87 Posted November 19, 2019 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. Quote Share this post Link to post Share on other sites
fatty 241 Posted November 19, 2019 Sounds interesting. Let us know how she shoots when it's finished Quote Share this post Link to post Share on other sites
0Jeep4 87 Posted November 20, 2019 @fatty will do once I get it together. Will probably post build sheet etc.. 2 Quote Share this post Link to post Share on other sites
RUTGERS95 890 Posted December 1, 2019 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 Quote Share this post Link to post Share on other sites
Shane45 807 Posted December 1, 2019 It is true that rifle setup is important and has an effect. But I can tell the difference in gas systems. Quote Share this post Link to post Share on other sites
0Jeep4 87 Posted December 1, 2019 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. Quote Share this post Link to post Share on other sites
RUTGERS95 890 Posted December 2, 2019 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:) Quote Share this post Link to post Share on other sites
raz-0 1,259 Posted December 2, 2019 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. Quote Share this post Link to post Share on other sites
RUTGERS95 890 Posted December 2, 2019 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 Quote Share this post Link to post Share on other sites
Shane45 807 Posted December 2, 2019 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. Quote Share this post Link to post Share on other sites
RUTGERS95 890 Posted December 2, 2019 JHC forget it. some of you really are retarded motherfkers. I say that nicely carry on Quote Share this post Link to post Share on other sites
Zeke 5,504 Posted December 2, 2019 Just now, RUTGERS95 said: JHC forget it. some of you really are retarded motherfkers. I say that nicely carry on Are you going to change back to myhatinthering ? Now? Quote Share this post Link to post Share on other sites
RUTGERS95 890 Posted December 2, 2019 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 Quote Share this post Link to post Share on other sites
Zeke 5,504 Posted December 2, 2019 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 Quote Share this post Link to post Share on other sites
raz-0 1,259 Posted December 2, 2019 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? Quote Share this post Link to post Share on other sites
0Jeep4 87 Posted December 2, 2019 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. Quote Share this post Link to post Share on other sites
Shane45 807 Posted December 2, 2019 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." Quote Share this post Link to post Share on other sites
Zeke 5,504 Posted December 2, 2019 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 Quote Share this post Link to post Share on other sites
raz-0 1,259 Posted December 2, 2019 buried in the military times link is the actual report https://partner-mco-archive.s3.amazonaws.com/client_files/1527866983.pdf Quote Share this post Link to post Share on other sites
Shane45 807 Posted December 2, 2019 2 minutes ago, Zeke said: You can be more creative then” stay in your lane “ jus sayen Yea but Im too so fist two kate did 4 that 1 Quote Share this post Link to post Share on other sites
rauchman 3 Posted October 24, 2020 I do find some difference in the different systems I have an older M&P15 w/ 16" (no muzzle device) w/ carbine and a Spikes 16" midlenth w/ Dynacomp. I find the carbine system cycles the bolt a little quicker and gets back on target a smidge quicker. However, I do think the Dynacomp is not the greatest. It has some significant flash and also pushes the barrel slightly down and find myself fighting it to get back to line of sight. I would guess a different muzzle device would help that. As far as recoil, I don't see much difference though. Also, the carbine setup will be more tolerant of all kinds of ammo, but it does stress the internals a bit more. Also, gas port size and buffer weight will matter in recoil characteristics Quote Share this post Link to post Share on other sites