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Discussion Starter · #1 · (Edited)
OK, so I have been lurking here for a couple of years, and have decided to build an upper to get both my AR's to 6.8 . . . once is a REC-7 already in 6.8, and the other a fairly decent Bushmaster I want to build the upper for (and which has already seen the awful stock trigger replaced with a Geissele).

So, a couple of things I am pretty much set on:

This will be a piston operated upper . . .
I really like the Mega Arms MKM receivers . . .

Looking for more than a standard 16" barrel - want this to be more of a target gun, but still be capable of taking a can at some point.

Looking at ARP, they have a 20" rifle length Triad 3D stainless mid-weight barrel that looks interesting . . . looks pretty much the same as their target barrels except for being threaded.

So, if I use that barrel, the Syrac rifle length piston system, and the Mega MKM either rifle length (or extended rifle length) receiver, would you expect any problems?

And if so what? (And no, I don't want this to become a piston vs. DI war) . . . having one of each, both have been reliable, but I prefer the piston . . . yeah, that's just me . . .

Any issues with the Syrac piston system vs. others? I see Mega now listing one that I think is based on the Adams parts, but looks like it has a rail etc. as part of it, and I was more hoping to get the gas block to sit *under* the hardguard on the Mega . . . looks like it's close, but should fit . . . if anyone has tried this and had it *NOT* work, please let me know - I don't want to get $$$ into this, and find out it won't fit!

I want to use a quick attach flash arrestor/suppressor mount - any thoughts? I know Barrett has tuned the REC-7 for the SureFire can, IIRC, and I'd like to be able to exchange it . . . not set on that can, but that would at least give one that should not give me grief (hopefully) . . .

Thoughts on the Mega stuff, other than being a bit expensive? And any other barrels that might be better suited than the above?

And has anyone build this basic setup, and any tips/tweaks/issues in getting it reliable?

Thanks in advance,

- Tim
 

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Since I and new to building AR's I chose to go with a simple basic build still collecting the pieces actually but I started with a PSA complete lower and the rest is ARP. From H I bought one of his 18" Triad barrels with a target crown a Aero receiver that he trued up on the lathe and one of his Super bolts and one of his carriers and a 12" Aero floating handguard up front Haven't figured out what I want to do about sights yet.

Sounds like if you go ahead with your plans as listed it should be pretty awesome build.

Mark
 

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OK, so I have been lurking here for a couple of years, and have decided to build an upper to get both my AR's to 6.8 . . . once is a REC-7 already in 6.8, and the other a fairly decent Bushmaster I want to build the upper for (and which has already seen the awful stock trigger replaced with a Geissele).

So, a couple of things I am pretty much set on:

This will be a piston operated upper . . .
I really like the Mega Arms MKM receivers . . .

Looking for more than a standard 16" barrel - want this to be more of a target gun, but still be capable of taking a can at some point.

Looking at ARP, they have a 20" rifle length Triad 3D stainless mid-weight barrel that looks interesting . . . looks pretty much the same as their target barrels except for being threaded.

So, if I use that barrel, the Syrac rifle length piston system, and the Mega MKM either rifle length (or extended rifle length) receiver, would you expect any problems?

And if so what? (And no, I don't want this to become a piston vs. DI war) . . . having one of each, both have been reliable, but I prefer the piston . . . yeah, that's just me . . .

Any issues with the Syrac piston system vs. others? I see Mega now listing one that I think is based on the Adams parts, but looks like it has a rail etc. as part of it, and I was more hoping to get the gas block to sit *under* the hardguard on the Mega . . . looks like it's close, but should fit . . . if anyone has tried this and had it *NOT* work, please let me know - I don't want to get $$$ into this, and find out it won't fit!

I want to use a quick attach flash arrestor/suppressor mount - any thoughts? I know Barrett has tuned the REC-7 for the SureFire can, IIRC, and I'd like to be able to exchange it . . . not set on that can, but that would at least give one that should not give me grief (hopefully) . . .

Thoughts on the Mega stuff, other than being a bit expensive? And any other barrels that might be better suited than the above?

And has anyone build this basic setup, and any tips/tweaks/issues in getting it reliable?

Thanks in advance,

- Tim
"Looking at ARP, they have a 20" rifle length Triad 3D stainless mid-weight barrel that looks interesting . . . looks pretty much the same as their target barrels except for being threaded."

IMHO, skip this and stick with 18" mid gas. 20" rifle can be finicky with function and bullets used. You honestly don't gain much with that extra 2" except to add weight. You have more to lose than to gain.

I just noted you're considering a piston system. You probably won't have issues as above with that.
 

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i have 6 mega uppers and lowers in my personal stash, great quality and everything fits just like it is supposed to. with the 20" barrel i'd go the extended rifle length rail, i did on a 6.8 and 5.56. mine are DI with syrac adj blocks, call mega and they'll tell you if it will fit or not
 

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If this is to be a target gun, DI makes more sense than a piston. Less reciprocating mass means better practical accuracy.
 

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Discussion Starter · #6 ·
Well, if anyone is interested, good progress has been made.

Final inventory is thus:

20" ARP stainless Triad barrel
ARP SMP comp
ARP NiB super bolt
Mega MKM extended rifle length upper
Geisselle charging handle
Superlative Arms piston setup

The main change has been from the Syrac to Superlative. I had heard good things about Superlative, and frankly, when I contacted Mega about clearances and such on the MKM, they also recommended it.
Service has been great (Can't say I have heard that about Syrac, but no 1st hand experience there). I ordered, and they called within 24 hours to let me know when to expect it, and what was going on that caused a 3 week delay. That delay has been dead on and held, and the parts are arriving on schedule. Tony has been great to work with, and is installing the kit for me in exchange for the chance to get some dimensions and such off the Mega and to make sure that all fits as he expects, and will also test fire and tune . . . . Not something that I think they will offer in general, but I'm certainly "feeling the love" on this one!

More info when I get it back and have a chance to test . . .
 

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Well, if anyone is interested, good progress has been made.

Final inventory is thus:

20" ARP stainless Triad barrel
ARP SMP comp
ARP NiB super bolt
Mega MKM extended rifle length upper
Geisselle charging handle
Superlative Arms piston setup

The main change has been from the Syrac to Superlative. I had heard good things about Superlative, and frankly, when I contacted Mega about clearances and such on the MKM, they also recommended it.
Service has been great (Can't say I have heard that about Syrac, but no 1st hand experience there). I ordered, and they called within 24 hours to let me know when to expect it, and what was going on that caused a 3 week delay. That delay has been dead on and held, and the parts are arriving on schedule. Tony has been great to work with, and is installing the kit for me in exchange for the chance to get some dimensions and such off the Mega and to make sure that all fits as he expects, and will also test fire and tune . . . . Not something that I think they will offer in general, but I'm certainly "feeling the love" on this one!

More info when I get it back and have a chance to test . . .
Nice report. I have a superlative block on my 22in Triad.
 

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Discussion Starter · #8 ·
OK, quick update if anyone cares . . .

The upper is still at Superlative Arms . . . Tony is having a few issues with reliability on the piston as initially built, and is doing some development of redesigned parts for 300BO and 6.8 based on it, and hopefully will see it soon.

I finally managed to get a lower, so this has become a full build, not just an upper:

Mega 3H Ambi billet lower
Geissele High Speed DMR trigger
Magpul PRS stock
Ergo target grip.
Ambi safety selector (don't remember whose . . .)
DPMS buffer, spring, and tube . . .

Oh, and the upper grew a scope - Leupold 6.5-20x50mm FFP Mark 4 Mil/Mil . . .

Should be fun when everything ends up in the same place!

And definitely not the low (inexpensive) road, but should perform well . . .
 

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OK, quick update if anyone cares . . .

The upper is still at Superlative Arms . . . Tony is having a few issues with reliability on the piston as initially built, and is doing some development of redesigned parts for 300BO and 6.8 based on it, and hopefully will see it soon.

I finally managed to get a lower, so this has become a full build, not just an upper:

Mega 3H Ambi billet lower
Geissele High Speed DMR trigger
Magpul PRS stock
Ergo target grip.
Ambi safety selector (don't remember whose . . .)
DPMS buffer, spring, and tube . . .

Oh, and the upper grew a scope - Leupold 6.5-20x50mm FFP Mark 4 Mil/Mil . . .

Should be fun when everything ends up in the same place!

And definitely not the low (inexpensive) road, but should perform well . . .
those megas are great lowers, and you're stuffing it full of nice parts. thumbs up!
 
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