Switching RRA NM Upper from A2 to A3

This may belong in the ar15 build section, but I'm sure someone here can answer. I've got a complete NM A2 upper that I want to scope, and not have to use chin weld. Can I switch the receiver from RRA A2 to PSA A3 and still have the same level of accuacy. Also will my rear NM sights fit into a stripped RRA NM carry handle so I can still shoot service rifle later or are they specific to the carry handle.

Thanks
Rob

I should start by saying that I have not done what you are trying to do. I have been doing a lot of research on AR's though, and will offer my 2 cents.

First, the upper receiver as a component has very little to do with overall accuracy. If the take down and pivot pin fit snug and the barrel torques on you won't need to worry. Even if the upper isn't snug to the lower, the sight alignment will always be the same in relation to the barrel.

Rear sights are rear sights. The old one should fit in a carry handle, as long as it has the same thread pitch. I'm not sure if the rear aperture will be at the exactly same height over the bore, but once you are sighted back in it won't matter.

I recommend that you pick up one of the books on building an AR15. They have decent pics and take you step-by-step through every part of disassembly and reassembly of an AR.

You'll have less range of elevation with a A3.

I wouldn't

Please explain? Doesn't the A3 carry handle just swap out the regular sights and take the NM sights? If there is a difference between A2 travel and A3 travel, is it enough to stop one from getting to 600 yards?

The A3 uppers have been just as good as the A2 uppers as far as I can tell. If the OP changes to an A3 upper, with all other things being equal, he should not find himself limited in service rifle, no?

If mounting an occasional scope while being able to change back to a carry handle for SR is the OP's goal, that has been done for many years without issues.

thanks , that's what I needed to know.

Rob

Look at the rear sight.

fixed A2 is 300/800
removable A3 is 300/600

So, yes, you give up elevation. The fixed sight has more room to adjust.

I'll stick to A2 for service rifle. I see no advantage of going to the flattop.

You can get a carry handle that doesn't give up elevation, just not a stock one.

Where?

White Oak made mine. I thought they were all like that.

I still think the advantage is being able to slap a scope on the rig to determine load development and to see if the shooter is having an off day or if the rig is the issue.

I am switching to A3 uppers from now on for this reason.

There's no real need to do load development on an AR-15. It's been done.

There's no real need to do load development on an AR-15. It's been done.[/quote]

WOW, I didn't know.
So I can use the same load for a CL,CM or a SS 1/12", 1/9", 1/8 "or 1/7" Barrel.
SWeet I'll have to try that. Does the same hold true for my 24" and 26" Match Rifles, with extended gas tubes?

Well, yes and no. What works for some guys will come close for others. Batch variations do exist and when you can take most of the human out of the loop you can find things like that much quicker.
Even if the recipe is fairly well common, the loading process introduces issues which are specific to the user. I am not trying to sell flat top versus carry handle one way or the other. But I have found using a scope on there very valuable from time to time.

Good info. I didn't know that.

For me, I do not want removable sights on my service rifle.

I'm paraphrasing Konrad Powers. If your SERVICE RIFLE can't shoot with any of the standard loads, it's either the rifle or you.

For that matter, the AMU doesn't do "load development" for SR. Certainly not tuned to a particular rifle. They do shooter development instead.

I'm kinda new to the AR thing but in regards to rear sight bases, I believe the A2 match base threaded shank is longer than the detach carry handle version, hence it has more elevation travel. I have seen where people fit the A2 base to a carry handle but you have to mill a relief hole in the flattop upper so that the sight will go all the way down. I think you could also cut out the bottom of the roll pin slot to let the base travel up a little more, just be mindful that you could unscrew the sight out of the handle if you lose track of clicks.

That's what Armalite does with their NM AR-10s and flat top NM AR-15s.

Marty

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