Newbie / Stupid FNG Question

[Machfiver]

I was an 11B from 79 to 87. Then I did 25 years in Naval Aviation. Been away from this stuff for a while. Here's the deal: trying to get a 5.56 SHTF rifle put together, completed using stuff I have around the house.

Here's what I've got-
Unfired, NIB SIG 556 SWAT
Unfired, NIB LWRC M6A2 in 6.8
Unfired, NIB HK M556A1 Upper
CMAGs for AR

Choice looks like trying to make the SIG work or putting the HK upper on the LWRC lower? Or just trying to get my hands on some reasonably priced 6.8 ammo?

Any issues with the HK upper on the LWRC lower?

I have a couple thousand of Federal XM855 and SSA 5.56 mm 77 gr OTM.

Thanks,

Machfiver

[kirkland]

That 6.8 LWRC lower may have a larger than standard magwell. I could be wrong but I seem to remember something about certain 6.8 PMags that were too big for a standard AR-15 only fitting in the LWRC. I would take that sig out and start running it through it's paces, if it proves to be reliable, I say go with that. It's a factory built rifle, so there's no question of "will this non standard upper work on this non standard lower" Sig is known to make quality stuff. Get that thing out to the range and burn through some mags.

[Stickman]

I would sell those Beta C mags off, and get a few decent AR lowers. Or at least one decent AR15 lower.

Beta C mags have never been known to be overly reliable. To give you an idea of how poorly they are looked on by some people, I turned away free ones that were NIB. They weren't even worth taking for trade IMHO.

The Magpul D60 mags are pretty solid if you need extended capacity, and the 40 round PMAGs are dirt cheap so you can free fire RPK style if you wish.

[MountainRaven]

That 6.8 LWRC lower may have a larger than standard magwell. I could be wrong but I seem to remember something about certain 6.8 PMags that were too big for a standard AR-15 only fitting in the LWRC. I would take that sig out and start running it through it's paces, if it proves to be reliable, I say go with that. It's a factory built rifle, so there's no question of "will this non standard upper work on this non standard lower" Sig is known to make quality stuff. Get that thing out to the range and burn through some mags.

Depends on which LWRC rifle it is.

If it's a Six-8, yes, there will be issues. If it's an M6A2 in 6.8mm SPC, there will be no issues.

I would say OP should just drop the HK upper on the M6A2 lower, assuming it's not a Six-8.

Better yet, I'd sell the SiG and buy an LMT, KAC, or BCM (or similar) lower and put the HK upper on that.

[Firefly]

Ditch the SIG, ditch the LWRC, track down a better lower for the HK upper. DX the CMAGS. Get Gen 3 Pmags.

6.8 is dead. 300 blk is a meme(I fell for it too, don’t feel bad). Easier said than done but like, try to find a 6920.

If nothing else get a decent stripped lower and just make a rifle out of the HK upper. I have a complete HK and it is a laser beam by AR standards just be aware that it will have more going on with the piston. It’s my 3rd favorite rifle. Keep barrel 16”. I wish A5s were a thing stateside because the HK magwell can get frustrating (not a problem if you use a normal lower)

With the upcharge money you can get hocking the bullshit guns and CMAGs you have on Barfcom; you can very easily come out with a legit stick plus some putaway cash

[georgeib]

^Meh. Ditch everything and get a standard DI rifle from a quality manufacturer. The HK is unnecessarily heavy for what it is.

Frankly, I like my Sig 556, but the unavailability of parts relegate it to a fun rifle role. For more serious work, I would definitely stick with something standard. BCM seems like the easy button.

[Firefly]

^Meh. Ditch everything and get a standard DI rifle from a quality manufacturer. The HK is unnecessarily heavy for what it is.

Frankly, I like my Sig 556, but the unavailability of parts relegate it to a fun rifle role. For more serious work, I would definitely stick with something standard. BCM seems like the easy button.

Newpers. My personal HK is pretty manageable with the bootlegged keymod rail and swapping to a slimmer stock. Would love a G rail. The wannabe SOPMOD stock holds it back.

I mean for what it is, you get your money’s worth. SPR accuracy and a trigger a frog hair less nice than a Geissele with a pretty ingenious bolt design.

It’s certainly Gucci but I like mine. Want the G rail though.

Do Not Get the Pic rails

An A7 configured HK is life goals.

https://i.pinimg.com/736x/11/9e/75/119e750bc04047cb9aca8b29eeb1c459.jpg

I sorta think it renders G rail moot. Geissele hates my money because they sure aren’t making 14.5 G rails no more and I really don’t put too much crap on my guns anyways (until I get off me arse and get nods)

[robbins290]

Having a sig 556 swat. I would sell that to fund the project and never look back. I fell for that years ago with sig, regretted buying mine after a class at the pro shop.

[Machfiver]

Thanks to all for the replies. I'm already getting a clue. So far, I've got the SIG 556 SWAT and CMAGs are not that great. Also, it seems that the LWRC M6A2 lower is just so-so, as well?