New to the Big Boy Rifle

[Primeh1alpha]

New member from the poorly labeled Free State of Maryland, have learned quite a bit about building my .308 rifles just from the posts I have been reading. My first one was a total failure, all the problems listed I seemed to find. So now I am working on an Aero Precision build with mostly M5 parts, upper 18" rifle length gas with a listed .0890 gas port and the adjustable block. Used the recommended orange spring in the aero carbine tube, but may have gone too far with the KVP AR10 SS buffer that all said and done was about 5.7oz. As of yet have not fired this version, so I am hoping for the best. I like to shoot outdoor ranges and just not a fan of the indoor shooting, so waiting for better weather. Hope that it goes well. My BCA is still a work in progress. Have been following the "waterboarding" to the letter (I hope)

[Shotcaller6]

The Cavalry is saddling up and headed your way shortly...

[98Z5V]

4 hours ago, Primeh1alpha said:

18" rifle length gas with a listed .0890 gas port and the adjustable block. Used the recommended orange spring in the aero carbine tube, but may have gone too far with the KVP AR10 SS buffer that all said and done was about 5.7oz.

Welcome aboard  - I think you're gonna be fine with the recoil system.  The listed gas port diameter is damn close.  All of these are slightly different, and I've seen 18" rifle gas .308s with 0.750" journal diameters need a gas port diameter up to 0.096" before. Start that adjustable gas block wide open, when you do start lighting it up.

You're on a great track with it, man - stay the course, see what it does like that, with the parts you have now.  

[shooterrex]

Welcome from Ky.  Lube the BCG dripping wet to start.

[Magwa]

Welcome from the Rez sounds like it will be a great rifle I love Areo's barrels

[Rsquared]

Welcome aboard from another citizen of the peoples republic of Marylandstan.

[sagebrush]

welcome from Oregon

[Primeh1alpha]

Thanks everyone for the warm welcome. I have already purchased my Ace Hardware drill bits just because you may never know. Forgot to mention that I had purchased 2 Toolcraft Nickel Boron BCG's. When my rifles were shooting they seemed to be doing their job just fine. What I found after going through all the information here was almost always  too short gas tube, wrong buffer and spring, crappy BCG, etc. (all from BCA rifle). Broke the buffer retainer off, carbine tube was too short by about 1/8". I have fixed all those issues just waiting to get back outside and give it a go again.

[shooterrex]

In the bottom pic your scope mount is backwards.

On further review looks like the other mount is backwards too.

Edited February 1, 2024 by shooterrex

[98Z5V]

^^^  Yep, what Rex said.  Flip that mount around.

[Magwa]

10 hours ago, 98Z5V said:

^^^  Yep, what Rex said.  Flip that mount around.

rgr that taper to the front

[Primeh1alpha]

And that is why I joined this group, did not even know that was a thing. Thank you all for pointing it out. The sad thing is that I read what little instructions came with the darn things.

[Primeh1alpha]

Sorry that I am old and slow, so finally took the M5 build to the range and once again 98Z5V was spot on. Just couldn’t get enough gas though it took lock back on empty mag, didn’t even make it to cycling a magazine. I took the adjustable block off and machined it to .096, dropped the buffer to 5.1 oz. When I get off my you know what, get back to range and try, try,try again. Thanks again for the knowledge.

[Armed Eye Doc]

1 minute ago, Primeh1alpha said:

Sorry that I am old and slow, so finally took the M5 build to the range and once again 98Z5V was spot on. Just couldn’t get enough gas though it took lock back on empty mag, didn’t even make it to cycling a magazine. I took the adjustable block off and machined it to .096, dropped the buffer to 5.1 oz. When I get off my you know what, get back to range and try, try,try again. Thanks again for the knowledge.

I look forward to the summer update. 

[Primeh1alpha]

The gentle reminder to not be so slow has sparked me back to the range. I am glad to report that all of the advice and help has yielded me a very functional rifle. No more tuning was needed. Fired 7.62 and 308 from various manufacturers with no failures. I was more than impressed, didn’t even realize just how much a little machining could do. I am very grateful to everyone who helped me. Thank you all very much. The next one will be DPMS upper and M5 lower that was a salvage.

[98Z5V]

3 hours ago, Primeh1alpha said:

The next one will be DPMS upper and M5 lower that was a salvage.

Those two platforms work well together.  Well, depending on that term "salvage..."