survivalshop

You can also chuck the bolt up & sand the tail with 600 grit paper to polish it. (or by hand, like buffing it ) Just the tail below the gas rings. Some of the fitment issues may be the coating on the bolt. It will be easier to clean & collect less fouling ,because its has a smooth surface.

Measurements of the two upper receivers I have ,both measured from the face of the bbl. extention to the outer surface of the receiver. DPMS -- ---7.867 " SIDefence--7.899 " That's not much difference & could be a lot of reasons for that small of a one. Now, as said ,I would look into a lot of other things ,if the upper measured about the same as mine , because mine work . We know this rifle is using a Fulton Armory BCG , so its DPMS & probably not out of spec's , because FA sold it . If the measurements of the barrel extension face to the back surface of the upper are close to mine( hell , all you have to do is insert the BCG & see if it protrudes from the end of the upper ) & of course the bolt, head spaces correctly , the only thing left is the Buffer retaining pin hole in the lower receiver. That would be a manufactures defect.

I am not a fan of extended rails , just something else to come loose or have alignment problems . A one piece mount with a 20 MOA would be a much better alternative . Not saying it won't work ,just anther thing that can screw up a long shot .

Ok , some Photo's & measurements of the two mag catches . They are both the same as far as them being a rectangle .0296" long & 0.245" wide , the difference is thickness or depth of the pad that goes into the mag recess to hold it in . M16 pad --0.155" AR10 pad - 0.170" There is also ,on the leading edge of the M16 pad , a slightly beveled portion , but the AR10 is squared off & has no bevel . Must be to help the mag. be inserted. If you can't see it in the photo ,I can post a larger one . As you can see in the photo's the AR10 threaded rod for the button is longer , AR10--1.092" M16---1.133" I also measured the thickness of the arms of the mag catch them self's & the difference is very small ,0.1015" for the AR10 & 0.103" for the M16 catch. I installed the AR10 catch & the Pmag does seem tighter & cycled some dummy rds. & it worked ,but actually firing the rifle, will tell if it works or not & I have laid out three brand new Pmags ,in the wrap er , to test. If its going to screw up ,it will do it on a brand new untested mag.

I have a Shot gun news , the Treasury edition , it has an article from a GunSmith in Arizona ,named Phil Arrington, where he's rebuilding a M4 Colt for a Sniper going to Afghanistan . Even though its for a 5.56 , we all know ARs , for the most part are all the same . The article was written in 2010. I will put forth some of his wisdom for us to ponder & discuss. Now that makes sense , I never thought of it making much of a difference. Does that mean that if a front sight was installed with the taper pins , is it already deformed some what or will the barrel stress back after the pins are removed. Some thing to think about .

An easy way to find that out , would be to measure the distance from the BBL. extension to the upper rear or the upper receiver. With BCG removed ,you should be able to have a clear path to measure . I don't have a precision instrument to go past six " (no laughing ) I will bring one home from work tomorrow . I did take a measurement with a good tape measure & both my SIDefence & DPMS upper are both 7 13/16 . I would like to see something more precise.

Sound advice form someone who builds there rifles around that little pin. <laughs>

Looks like the same bbl. I have on mine . Nice light wt., shooten bbl. Is that a carbine gas system ? Nothing wrong with putting a Can on a 16" bbl.. Might be an advantage on what bullets will function through it with out playing around with gas ,buffer & such. Yes , stubby rd. for sure , but when you shoot it , you will get to like it .

Went to the range for 100 yrd testing of the 135 gr. MK bullets & some interesting things popped up . One ,it was far too hot & humid , even @ 0830 to do anything . The sweat was rolling down into my eyes after setting up the Chrono & targets. Note to self , do this kind of testing when cooler out . I was using Rem. ACC 300 BLK cases & some cut down once fired LC brass. The LC got a 20 fps more than the Rem. same load , same bullet same primer ,loaded on a Dillon 550B. Rem. ACC 300 BLK brass AVG. VOL.- 2034 ES-------- 39 SD-------- 16 LC cut down & formed AVG.VOL.- 2054 ES-------- 31 SD-------- 9 The LC cases being thicker, must of course, have something to do with this . The LC also had a much tighter 10 shot group , which of course, may be because the faster speed, may also be a better grouping combo . Hard to say with out more testing. Now here's a strange one . I always lose a couple Rem.ACC 300BLK brass , every time I shoot . No idea where they go . The Rem. brass goes about two to three feet behind me @ about the 5 0clock poss.. I search for them for a long time in every direction ,but I always lose a couple . This time six. The LC brass on the other hand are all in a neat pile to the right of me @ about 330 poss.. This may also have something to to do with the slightly heaver brass , not sure . No pressure signs on any of the loads , they look perfect.

My AR 10 catch was shipped yesterday ,so If no one else gets a photo comparison , I will , with measurements.

Man, all I have is a Armilite AR 10 mag. catch on order.

I ordered a Armilite mag catch today , so we will see . I will be happy if it works . I will take another set of measurements when I install it .

Nice brake if you plan to use a Can , but if some one is not going to use one , the money for one, to me, seems wasted . You can always buy a Suppressor for it later though, if its on there.

Well said .

He has a lot of info to soak in to make a decision . We all know how that goes . The BBL. is a very important component of a build & there sure is a lot choices out there now . Not like ,when I built my first AR 308.

Nice job !

All barrels are crowned in some way ,threaded or not. Look closer next time you have your muzzle device off . His bbl. is crowned all the way out to the full bbl. dia.. Most are just crowned at the bore opening.

Just because its expensive , doesn't mean it will out shoot other barrels . All this fancy stuff , fluted, wraped ,heat sink barrels , just don't impress me . And I have heard & seen it all ,before. Sorry ,JMHO.

My Wilson BBL. is the light weight ,the heavy fluted was out of stock when I ordered this one & she shoots real good & this complete rifle is very light .

Got my pin(s) yesterday . I only needed one that wasn't with my my lower & asked for a part # to order an extra ( I like extra pins around ) , well they sent me two , cool , a happy customer .

Sounds like a mid length or in between or is that the way it is with the removable ? Try these.http://www.midwestindustriesinc.com/index.cfm

I think I posted that along with a photo of the comparison of springs , a while back, But good info reminder for all to know . I thought at first I wasn't going to get that spring in my Carbine receiver extention , but it went in & works fine.

The shorter Smiths Enterprises brake works well on my 16" Wilson bbl.. They make a longer one , I like the short one . I got it from Brownells.

Not sure what you mean by risers, but you have a DPMS type of AR 308 & there is a section just for Bushmaster below some where , you answer may be there . This will probably be moved down there. & welcome to the AR 308 family & here, of course.

18 " too short ,why ? For hunting you would think a lighter shorter bbl. would be the ticket . Unless real long range would be the goal. Interested in the out come of range session @ 400 yrds.