survivalshop

Ya , that plate locks the receiver extension in place ,aliened with the lower receiver . There's a tab to alien it with the receiver extension & it has a dimple on it to alien the stock assembly with the lower receiver . Then the castle nut is a lock nut , to keep it tight & aliened. And we all know that, that plate is also used to hold the disassemble pin, spring & detent, in , on most AR rifles.

This is from the POF sight, not sure if it helps.

NP3 coated 7075.

Head space is set when the barrel extension is attached & after it is tested ,its (barrel assembly ) put in a jig to bore the properly aliened gas port in the barrel . There may be some barrel ID. honing if needed after. Think of the barrel extension as the receiver or action of a bolt action rifle . They are fitted the same way . Its just the AR type rifles were designed to just be screwed together & have the proper tolerances. It still requires the proper tools to do it properly .

I just ordered this today . Its the first time I've seen them for sale . At the POF sight , all they sell is the monolithic type . NP3 upper. It will at least match my POF Gen. III lower , even though its black . Might look pretty cool . My barrel will not be here till Monday . Was supposed to be here today , I see the tracker says Monday now . Hay, no problem building just an upper . Nice way to get several rifles with reduced cost . That's whats good about the AR platform , versatility.

Is it this small ?

Kreiger Criterion by Fulton Armory , not sure there 18" is the twist rate ya want , but you get them on one of there sales & its a very good deal. There barrels I have shoot better than I ever will. Just another one to concider.

I would stick to a 308 carbine buffer & spring,with a collapsible receiver extension or a 308 rifle buffer & spring with rifle receiver extention. Also milspec & commercial receiver extensions have different out side tube dimensions.

The muzzle device should not make a difference as long as its for a .30 cal., choose what you like. Have you seen the choices of uppers made here in Florida ? , Spikes,Tactical Machine , Florida Arms , just to name a few . I will have no problem getting a good one , just which one. I'm not building just an upper assembly , I'm building a whole rifle. Although ,just having an upper to put on one of my AR's would be fine . I have extra lowers laying around I can use ,so why not a dedicated rifle in 300blk. I have a complete spare , new , milspec , M16 BCG to go in there also. I've had it for twenty years or more.

My barrel shipped & all I need is to chose an upper . Still deciding on that one . I think it might be easier to buy the brass & dies right now than the ammo. Some thing I won't worry about till I order the hand guard (Vtac mid length) Can't wait to start load development . We can compare data & target groups.

Send your bolt & barrel to the barrel manufacturer for proper fitting . I haven't seen one wrong yet.( if properly assembled) I check HS any way.

With modern barrel materials & manufacturing , it makes no difference of what the difference in chamber pressures are . The difference is in the chambers , with the 7.62x51 having a longer lead to the rifling . The 308 chamber is considered by some as a match chamber . You can shoot one or the other in ether chamber with modern rifles or barrels ,with out problems. One may shoot a particular round of ammunition better than the other ,but I see no difference, I will shoot 308 in a 7.62 chamber or 7.62 in a 308 chamber. We are talking about 308 AR's, The match ammo most are shooting , do you think is 7.62 or 308 . I think most of your AR 308 barrels are chambered in 308 any way ,unless you specifically ask for the 7.62 chamber dimensions. Now when you get into .223/5.56 things are a little different .

Specific twist rate for a specific purpose built rifle . I see nothing wrong with that , at all . I think we have just scraped the tip of the iceburg as far as what this new cartridge will do & with what . Most of the loading is based off of the 300 fireball from what I've heard or at least the case spec's . There will be more loadings with this cartridge in the near future . Just look at to .30 cal bullet selection out there . I think you will see a lot more coming out of this cartridge & I can't wait to test some loads with different configurations out of my build . I too don't intend to put a suppressor on , but you never know .

I just got my first Chronograph for Christmas & I've been reloading for over thirty years. It is a great tool for working up loads . Don't know why I didn't get one sooner . Just keep an eye on your brass & primers , they tell most of the story when you get close to max pressures. You are doing good to start at the lower end of the data ,because all chambers are different & one load for one may not be ok in another .

The only place I have seen that kind of damage is on the internet forums & yours is the second one . That is NOT normal .

HBAR, heavy barrel, AR. What ever twist rate you choose , there will be a lot of factors the contribute to its down range accuracy. The shooter . How the rifle is put together, including what is used for the trigger system, barrel . Ammo, including what bullet . Optics, if you want to hit something that small out to the end of the 308 envelope. If you intend to hit an apple @ 800 yrds. , you might be at that all day, just to do it . It can be done ,but a lot of things have to come together to accomplish it . I think that , with a good barrel , ammo , trigger , & of course the shooter , any of the 16",18" 20 " or 24 " barrels will work . What you have to think about is , if you are going for long range , well that will be a specifically built rifle for that purpose . CQB is another specific built rifle . To get some thing between the two , you will have to make sacrifices. one way or the other . A good scope for long range is going to be , BIG , not really a good thing for CQB. If you are getting my meaning here.

A son of a long time friend of mine , played for the Packers & I'm Happy for there family . ( # 57 , Matt Wilhelm ) On a side note , I lived in the Cleveland area most of my life & we all hate the "Steel pukes" & glade they took a dump. Also worth mentioning is Clay Mathews father( also Clay ) played for the browns for most of his career. And if that's not enough , I won $250 on a football square. That would not have happened if the pukes had won , well maybe ! <laughs>

Yep , 1-8 . I have not heard of that barrel manufacturer, but that doesn't mean much , there are are a lot of good manufacturers out there that don't make it to the gun magazines or forums.

Be carefull with WC846 , not all lots are the same . I use WC 846 for all my 223 & 308 , make sure you start with reduced loads . My batch is not compatible normal loading data comparisons . Be it BLC2 or others. I had to come up with my own loading data with trial & error. Most if not all reloading manuals have data on WW 748, if you have a chronograph , you can work up loads for milspec velocities.

Barrel twist rate is a matter of choice , what do you want to do with this type ,length barrel ? 1-10 is std & has been used for all sorts of 30 cal. rifles . they have 1-11.some thing , 1-12 is out there also . Most of the other than 1-10 are for heaver bullets & super long range or suppressor systems . 20",18",16" , well the longer barrel will give you more velocity for longer range , but don't count out the shorter barrels , they just lose some velocity at longer ranges . Look up in General section , I believe , there is a thread on shorter barrels. Imschur , just started a build thread in here some where , to help you build your rifle .

I think its the ejector you need to remove , to eliminate its spring pressure on the HS gage , as to not give false readings. Some of the older or milspec head space gages , you had to remove both the ejector & extractor , but most the new ones have an extractor grove in them .

I ordered a 16" light weight from Wilson on Friday . I have a POF billet Lower to use. Its marked ,Multical , so that works . Now what upper to match the POF . Should I go Billet ? I'm going to try to keep the upper manufacturer from here in Florida. I have a lot of choices & help the economy here in my state . No offence to any other state.

You would need a full custom barrel made for that twist. Use your search engine to bring up barrel manufactures for AR's & a bunch will come up . Email or call them what you want & most will even tell you who to go to for that twist.

Depends on what type of scope you put on there . Some don't interfere with the standard AR type charging handle & some do . Fulton Armory is one manufacturer that make a side charging upper & components for it . There are others. Stocks & cheek weld have a lot to do with the scope mount . I always get the stock type I want, than the scope . You can adjust minor , if not all scope heights for proper sighting with the rings or mount you put on .

Sun Devil billet upper is one of the top ones on my list to mate my 300blk bbl. on. Its a good thing to have more competition out there , it brings prices down.