308 AR extension (buffer tube) question / concern

[HRnightmare]

I bought a A2 extension tube because I am going to do the Magpul PRS.

the gun shop told me all I need is the A2 tube. He sold me a Stag arms one. he said castle nut and and end plate is not necessary. I can see why an end plate is not necessary but why not a castle nut?

there's also no divot cut out on the inside of the tube like a carbine ext tube has. So what holds the extension in place without allowing it to vibrate loose? am I missing something? Like I said I have built plenty of carbine AR15s but never these.

Sorry about playing 50 questions...new gun to me and I did not know it had differences between AR15 carbine's.

Any other surprises anyone might be able to think of?

Thanks

 

[henschman]

It doesn't vibrate loose because it has a stock screwed to it from the rear, holding the stock tight against the back of the receiver, and giving the receiver extension no room to "back out."

I hope you like the fixed stock setup. I've switched 2 of my rifles to the same using a MOE rifle stock, and am about to do another. I really like the improved cheek weld and recoil reduction. I don't understand the PRS at all though. The cheek riser is way too far to the rear to be of any use. Anyway, I hope you like it.

 

[HRnightmare]

thanks for the info and help.

I like the look of the PRS and have felt on on a dummy gun and liked it. Also I must admit, I am a "fan boy" of Magpul. All my AR's furniture is Magpul, any new AR and AK mag is Magpul. They just make great quality stuff for a good price. I am kicking around a few other options too but think I will end up with the PRS.

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This is going to be a slower moving project. I am just going to put it together when I can get the right pieces for the right price.

 

[henschman]

No prob... I like Magpul stocks a lot myself, and use them on all my ARs. You might want to look into the MOE rifle stock. It is a lot lighter than the PRS, and has a ton of internal storage. The only real reason to go with a PRS is if you need the adjustable comb and LOP. I already mentioned my issue with the adjustable comb, and when it comes to LOP I just bought the thicker butt pad to get where I want to be with the fixed MOE stock.