bfoosh006

Just to be clear.. yes, I was referring to the heat in the gas tube.. I don't like the idea of trial and error on bending the gas tube. ...( YMMV ) For the sake of accuracy, the BCG should freely return to battery, the same way every time. And the PSA FF barrel nut has no splines to line up ( like a "normal barrel nut ) with the gas tube.

IMHO... while I could have bent the gas tube.. it may have worked or not... the amount of heat going through the gas tube is a lot, so I wanted the gas tube to be unaffected by any external forces, either from me or the barrel nut.

This is the new 18" SS upper.... The first image is with the OEM gas block loosened and pulled back so everyone can see how much the barrel nut was pushing the gas tube up, it would not freely enter the gas tube hole at all... as a matter of fact it took a fair bit of gentle pushing to allow it to go in. The second image is with it entered into the hole in the receiver... note how much it is flexed at the front of the gas block. Third photo shows the wear from the OEM install and me taking it on and off. Furth photo show the clearance now after grinding off material along the entire top... free movement and clearance. I will add... the gas tube was binding the BCG ( via the gas tube interaction ) the same way my first upper was. Again That binding will not help accuracy and function ( let alone longevity of parts ) at all. So if yours is like the first photo... fix it for your own good... I'd bet you'll be happy you did.

1187Shooter... you are very welcome !! All of the input on .308ar.com has helped dramatically when it comes to me understanding the "AR10" platform ! And I am glad to help as much as possible.

I received the SS Barreled Upper today from PSA...18" middie, FF, SS barrel, Nitrated BCG http://palmettostatearmory.com/psa-pa10-18-midlength-308-win-1-10-stainless-steel-15-m-lok-upper-with-bcg-and-ch-516445088.html Weight of just the upper, from the PSA is 5 1/3lbs I has the same gas tube binding issue the FF Barrel nut and the BCG... exactly the same. ( The barrel nut makes contact with the gas tube, forcing it in to the top The gas key is properly staked... just like the first. The charging handle lacks the raised "tab" at the front of it.. just like the first. The upper is also bone dry...no extra oil at all... a very slight amount of something on the BCG. Going to change the gas block to an SLR adjustable, grind down the barrel nut flat to allow free movement of the gas tube, oil it up, use a BCM Gunfighter "Brake" on this barrel and see how it shoots. I am hoping for better accuracy then the nitrated barrel has done, and will be reporting more info as I get it. Again, which ever upper shoots the worst, will receive the Criterion replacement barrel. ( I have high hopes for much better, consistent accuracy ) Photos of its OEM state will follow.

That is a great way to say it... Linda Blair.. Lol Another vote for SLR.

Gadzooks... if only my wife was as reasonable as you guys !!

Boot_Scraper.... Same here... the "budget" idea is long gone ... I was lying to myself anyway !! Accuracy is addictive.... you know what they say, "Only an accurate rifle is interesting." I knew I wouldn't be happy unless the rifle was "hopefully" as accurate as my SAI '96 M21... for a longer firing session.. soooooo.... I just hope no one puts a Krieger .308 barrel on sale during the "Labor Day" sales... or a Vortex scope.... or a.... ( PSA already had 168gr FGMM back on sale for $16 / 20rds, damn them ! ) Actually... the worse part was, realizing I have all the tools I need to build an AR15.... not an AR10 sized receiver...

Well.... I ordered up the "better" barrel today.... Criterion 18" Middie.... https://msrarms.com/collections/m-o-t-m/products/criterion-barrels-nitride-finish-stainless-steel-hybrid-contour-barrel-308-ar?variant=29092302337 As well as the Brownells version of the Geissele reaction rod and JP Upper vise blocks. After shooting again on last Sat. ... I couldn't bear the thought of shooting so much expensive ( compared to 5.56 ) .308, and accepting the PSA barrels accuracy level ( really , Lack of accuracy ). Criterion said the barrel should fit just fine, but did caution me about using the Nickel Boron Bolt... the reason being .. A. Quality, ... B. Since it is a coating, headspace could be excess as it possibly wears off / flakes off the locking lugs or bolt face. Interesting... I had never thought of that. Granted if the bolt was produced properly, it should be a-ok. For me... that is another reason to use a conv. bolt or a nitrated bolt... or at least one that is not a coating.

Very good data... and great shooting. Thank You for sharing.

1lb 7oz at least... so with the mount I imagine close to two lbs.... heavy to be sure, but it is FFP .. and that is what my tired old eyes like.

Old Sarge.. Currently I am using a Primary Arrms 4-14x44... IMHO it is a heck of a deal for a Front Focal plane scope. http://www.primaryarms.com/primary-arms-4-14x44mm-riflescope-acss-hud-dmr-308-223-reticle-pa4-14xffp308 The mount is just as good. I have numerous that I have been using for years.

Would you still have a link to your info? I'd like to look at it.

IMHO....IMR 3031... pretty sure it was used in the original FGMM... the red and white boxed stuff. The M1A guys certainly like it in the 16" M1A Scout... made tack drivers out of numerous Scouts over on M14Forum.com

Exactly !! Honestly, I have wanted a truck gun ( preferably the nitrated upper ) and while the accuracy is good... I really want better "general" accuracy. So which ever upper is the lesser will be the parts donor for the better barrel. My M21 and My Krieger barreled AR15 will shoot most all ammo "better" ( those barrels have made me an addict to accuracy ) ... they both have ammo they hate, but for the most part there is a general improvement in overall accuracy ... that is what I'd like with a better quality barrel. The issue with the M21 is it only holds great accuracy for about 150rds before the groups open up ( seems to be related to the gas piston and fouling )... a good cleaning will restore the accuracy, but the Krieger AR15 doesn't do that.... I am hoping the AR platform in .308 ( with a decent barrel and a little finessing.. trueing the receiver face and a properly headspaced bolt ) will yield the results I would like. At this point, I am strongly considering a 18" or 20"Criterion rifle length gas. The price is good and the reputation is very good.

This... I have a few 4-14 Illuminated FFP's w/ ACSS... Very nice for the money. The Illumination knob is stiff... but for a Under $300 Front focal Plane scope... I can live with it.

Just received an E-mail from Faxon... 25% off a Nitrated .308 BCG if you buy a clearance .308 barrel..... soooo.... if you are interested, you might phone them and see if you can add it to your order.

Again very impressive parts / rifle life. Taking care of your "tools" works !

Lol

Yes muzzle blast will be more then your 18".... I'm not sure how much, but trust your instincts, the .308 has a lot of volume of propellant gas.... the linear comp will help as much as possible. And as long as the barrels profile has as much mass as possible towards the receiver, it will be much more nimble / balanced feeling. As for the "fever" in respect for AR parts... it is .. well terminal... Lol I looked at the barrel, and it is a bargin.... ( A bargin is something you don't need , but is a hell of a deal... Lol ) Personally, I think you only live once... enjoy your hobby.... Buy it. And consider adding an adjustable gas block... works wonders IMHO.

So, I ordered another upper... in SS.. 18" ( one of the two will be a parts donor to my better barrel.....) between the 2, which ever is less accurate will receive the new barrel.

PSA Just introduced the PX10... which I can no longer find on their website... but Google shows links...

Impressive ! Did you ever change any parts ? And I assume you are reasonable when it comes to cleaning and lube ! Again .. impressive !!

I run the BCM Mod 4 ... but the extended charge latch might be slightly to long... it pokes into my gut when carrying it across my torso. So if you can look at some of the BCM models... you can decide which you prefer. I guess the same could be said for all the extended latch charging handles... lol