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18" barrel with rifle legth DI?


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Hey guys,

Took a while off from firearms....  Needed to buy a new car so had to recoup financially before getting back into firearm building.  So I have an unfinished 308 project that I'd like to work on over the winter.  The next part I need is the barrel.  I really would like an 18" rifle length DI setup.  Only found two so far.  One is from Aero Precision but it's a heavy contour style.  Criterion barrels has one but (1018S-HYR-N) which is spec'd exactly how I want it but I have to call them?  Just wanted to make sure I'm not missing any other options out there?  If not, I guess I'll call Criterion.....


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There is X Caliber but you should do some reading here and a Google search before you buy. They get good marks from the bolt gun crowd but didn't seem real up on The 308AR. In there defense I asked for an unusual configuration, 16 inch with rifle length gas. I did get a 1.2 MOA 5 shot,100yard group yesterday. 

Edited by jtallen83
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I'd love a 16" because this build is going to be a "more maneuverable" build.  I thought about it, but I have some concerns about the 16" rifle config.  About a year ago I built an SBR.  One of the concerns when building an SBR when using really short barrels is lack of dwell time.  

Dwell time is the time between the bullet passing the gas port and exiting the muzzle.  The longer the duell time, the more reliable your firearm will be (cycling).  My concern with a 16" barrel with a rifle gas system is the lack of dwell.  If I were to go with a 16" barrel, i'm thinking a mid length would offer more reliability.  Is my logic right??? 

Edited by BadBoyBilly
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Once I got the gas port the right size and a spring issue worked out I've been through 12 different types of ammo, most cheaper stuff, and all is functioning well. These guys showed me you can get the dwell time needed on a 16 inch rifle gas barrel to be reliable. .1005 in. was the magic number for my gas port, might have gotten by a tad smaller now that parts have broken in but like you expressed, reliability was my biggest concern. 

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 I can tell you, you will not see much difference in Grouping . I've been testing different Bullet configuration & powders in the 16" & 20 " Criterion Barrels & the 20" does have a slight edge , probably better for a long range rifle , but 200 yards , there is not much difference  between the two .

After the Holidays , I will have input & target results of the 20" HB ,18 " & 16"HB , Criterion Barrels with 155 gr. Bullets ( Hornady A Max & Nolser Match ) 



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