I need...

[Jholdbrooks]

Probably just predator hunting and paper shooting.

I have a M400 upper and a spikes hellbreaker lower

Did you get the M400 that was on sale? I got one and my Spikes Enhanced Lower will be in Tuesday along with my BCM BCG, I also got a raptor charging in the other day for this also.
And to top her off I’m going with a vortex strike Eagle in a cantilever mount

 

[Wallace's]

Come on Wallace's ... you mentioned everyone but JP. Good list by the way.

No JP. Since the upper is complete according to OP, I see nothing else to recommend from them for this application. After seeing they literally suggest you use a quarter to drop on your receiver extension to make up for tolerance stacking to make their SCS fit properly in some assemblies, I lost all interest. I have seen very good results from their barrel/bolt combos though.

 

[Wallace's]

I am all for advice but part of the fun of building an AR is researching the things you want that fit your exact use case. You should be able to say, "I chose this because...." for nearly every part on the gun, not because someone told you to. You will then end up with a weapon system that is perfectly tailored for Tyler and not anyone else.

While I agree with this, many times people get steered in the wrong direction like what GV is doing when new to AR's. Sometimes it helps to have some recommendations to start with that aren't gimmick/junk items like anything from Strike Industries, ACME, Wish/Jet.com, Guntec....etc...

 

[Tylerls1]

Did you get the M400 that was on sale? I got one and my Spikes Enhanced Lower will be in Tuesday along with my BCM BCG, I also got a raptor charging in the other day for this also.
And to top her off I’m going with a vortex strike Eagle in a cantilever mount

Yes i did

 

[Wallace's]

I didn't see your post. I usually use cmmg lower builders kit. It contains just the pins, springs, mag release and bolt catch and safety and doesn't have a fire control group. I learned in my high performance engine building that there are only a few spring manufacturers in the US. The pins can't be all that different. I usually use a different trigger so I don't need one in the kit any way. I do have a seekins bolt catch I can sell you for cheap. I actually have a lot of lower parts if you interested.
For the bolt carrier group I use a DD for my 6.8 builds. They are 200 bucks but worth it. For 5.56 I like to use a nickle boron, WMD, Fail Zero, or any of the high line gun vendors are a good choice it just depends on how much you want to spend. Core15 makes a great BCG.
For a trigger I like the ALG ACT trigger with reduced power springs. It gives about a 4 lb. pull which is good for home defense and just general shooting. If you are going all out target performance then you might want a drop in unit or an adjustable one. I use JP enterprises and adjust it myself.
I like the Raptor ambi charging handles. Expensive but comfortable to use and look nice. BCM is also a good choice.
I like the Spikes H2 buffer adj. stock kit. I always use a little heavier buffer to soften the blow. I have never had a problem with a build whether it be a carbine, mid length or rifle length with that kit. It's 90 bucks but it has a coating on the inside of the tube and the buffer has media in it that quiets the weight bearings inside. The are just balls, usually three with two the same weight an one heavier one in the middle.
If you want to splurge on some of the lower parts you can discard or save the mag release and bolt catch and opt for the billet ones. They are more refined and a better finish. The also goes for the safety. You can opt for a ambi safety. There are plenty to choose from. I just used a short throw ( means it only goes to a 45 degree angle when in the fire position instead of all the way to a 90 degree angle. It doesn't point all the way up to the little bullet engraving). I used a stainless one and it feels so smooth. I can't remember which manufacture but I will check and let you know. You can really feel the difference between the one I used and a mil spec unit. I just feels so much more fluid and easier to operate.
For a grip I like to use the Houge over molded grip or the Magpul MOE+. They both have a rubber coating and feel real comfortable. The Houge has finger grooves and the Magpul is just has a straight front. Either one is a gives me a better purchase on the grip.
The forward assist is something you will hardly ever use so a milspec is ok. I used a Radian Raw Titanium since I went with all Titanium parts on my lower and upper for this build. You can get all Titanium parts with a black finish but I warn you I went overboard with that on this current build and spent a small fortune on that crap. It looks cool but not cool enough for what I spent. That sh*t is high dollar. I think I have at least 350 or more dollars on all the external lower parts and the upper dust cover and forward assist. Just to give you an example the dust cover and forward assist was 120 bucks. It's light and strong and looks cool enough but I don't recommend it. Just for sake of what I spent. I kicked myself in the teeth on this build. I do like the take down pins I bought though. They are extended and have a little raised button to pull them out easier.
If there is anything I left out let me know. You can text me for quicker info @ 404-437-9592.
Seekins and Rainier Arms have a good selection to choose from but if you find something you like on Rainier look at a few other places. They carry real good parts but sometime they are a bit over priced on some items. Rainier Arms does carry some of the best barrels I have ever used. They are costly but worth the money on paper.
You have my number feel free to call are text for any info that I left out. I have used one of every thing there is to be had except for PSA I don't use them for nothing. Except if they ever get the FN HF barrels back in stock. If I choose to go with that type of barrel. I am right in the middle of building a billet 6.8 and upgrading a 1911 right now so I am still shopping myself. We can go through it together if you like.

CMMG supplies low grade LPK's IMHO. Like the use of non standard FCG (I have also seen Spikes use these), only 1 groove on each pin(you night get some like that, you may not). The problem lies in the fact that only one pin has a notch for the J spring in the hammer, and the other only one notch for the hammer spring to rest in. If you mix them, you run into a pin walk situation.

FailZero uses cheap taiwan YFS fasteners on their BCG's which do not have the correct profile or serrations to be retained by proper staking (which they are not known for). Additionally, NiBx has been proven to cause more issues than its worth. Coating thickness variation as well as the inherit poor surface structure lends itself to be less than a stellar alternative to traditional parkerized BCG's...

Spikes ST-T2 buffers are snake oil and have been proven to mitigate bolt bounce the same as a standard steel weight carbine buffer. Junk....just use a BCM H2. Also, "softening the blow" is a by product of using a heavier buffer to compensate for an overgassed rifle, like most 16" carbine gas rifles are.

Dont discount a forward assist. Forward Controls makes a low profile version that helps to keep you from snagging your finger nail while hand cycling. Sounds stupid, but its one of those things you dont notice until you have one.

 

[KERTWOOD]

No JP. Since the upper is complete according to OP, I see nothing else to recommend from them for this application. After seeing they literally suggest you use a quarter to drop on your receiver extension to make up for tolerance stacking to make their SCS fit properly in some assemblies, I lost all interest. I have seen very good results from their barrel/bolt combos though.

Agreed on BCG and barrels, as that was what I was pretty much refering to.. But, lets not forget they have a ultra reliable set up for the 9mm AR (speaking from experience). I know that's not what the OP is looking for, but I just wanted to add JP to the quality lineup you mentioned.

And the quarter method is new to me. Not saying it isn't true but do you care to share a bit of info on the matter for curiousity sake? I'm pretty big on their AR BCG and 9mm Bolt/SCS.

 

[Wallace's]

Since someone commented about the "why" vs a list of ****ty parts, here...

BCG: All of the below selection use the corect C158 bolt material and individually HP/MPI every bolt. They also use the correct extractor spring (without that stupid O-ring) and use correct fasteners and properly stake their gas keys. They are possibly the best value, quality BCG's on the market. I suggest these over any LMOS or gimmicky coating that may alter the function of your rifle negatively if you do not know what components to select.

BCM
SOLGW
Sionics

LPK: These kits simply have proper basic components. If you want aftermarket safeties, bolt catches or trigger gaurds. Look at Forward Controls for their ambi-mag releases and bolt catches. Small company, but quality, well thought out designs which offer great ergonomic improvements over mil-spec shaped parts. My favorite trigger guard is KAC's (Knights Armament). Perfect shape and doesn't look like something off a storm trooper blaster. Safeties can be sound at Battle Arms Development. They offer regular 90 degree ambi and short throw selection. Choose to your liking. They make very high quality parts.

Colt through G&R tactical
ALG/Geissele
Sionics

FCG: Subject to user preference. I normally steer away from FCG's that cater to 3-gun type preferences as I like a "wall" before break on my FCG's for general use carbines. Also, triggers like Elffman and alike can be adjusted so light that you get inconsistent primer strikes which is a bummer on the range or at a match, so be careful in what you choose and try and find a shop with examples you can manipulate before you use. Lastly, many "cartridge" type FCG require use of anti-walk/roation pins which require a tool to remove. This becomes a hassle if you get an obstruction like a blown primer in the lower and cannot use a projectiile tip to remove the FCG pins... to each their own though. Again, YMMV>


Utility type FCG with a nicer definitive "wall" and crisp break.

Geissele SSA
G2S (Same as SSA sans some QC checks, lack of J spring -> uses an external type, and laser etching)
SD-C (flat trigger bow)

Precision, lighter pull and generally "faster" feeling.

SSA-E
SD-E (same as SSAE but with flat trigger bow)

Receiver Extension: I like the LMT because, although a tad more expensive than some others, for a traditional RE, they are 7075 AL, have 3 drainage holes, are dry filmed coated inside, plus fit nearly any mil-spec stock great. Their tubes seem to have a more consistent OD than other. Plus, they are a gray color, which nicely contrast the regular plain black ano of most other offerings. Your alternative is the Vltor A5 system, but that can come later on as its an entirely different way to approach the buffer system of the AR.

LMT

Stock: My preference for the perfect cheekweld, plus it has snack storage. Who wouldn't want that???

B5 Enhanced SOPMOD
Money no restriction, LMT SOPMOD

Take down pins: Small and subtle change, but you will wish all your AR's had them after you get a set, low profile but a tad longer and undercut/knurled to make manipulating them MUCH nicer than plain take down pins.

Battle Arms Development EPS

Grip: Find what works for you. I like shorter LOP's on carbines, so I tend to choose more vertical grips which I prefer in that arrangement.

To each their own:

B5, MIAD, K2, etc....

Buffer and spring: Given its a Sig, I doubt the gas port is properly sized (I could be wrong), but most carbine gas, 16" rifles are more rough from overgassing. An H2 weight buffer (like what the Colt SOCOMS shipped with) help manage some of that overgassing. The SpringCo spring is made of chrome silicon wirestock and is practically a lifetime service part. The added rate also helps deal with the over gassed carbine gas, 16" bbl systems.

H2 BCM

SpringCo red spring

Charging Handles: Again, preference but you will find the BCM Mod4 a VERY common and rightfully, a great suggestion. The new Geissele option are nice as well. Radian makes a good charging handle, but I like the BCM/Geissele enough that I dont care to add a 3rd brand to the mix.

BCM Mod4

Geissele SCH or Airborne.

I like the Mod4 as its pretty much the prefect size to manipulate and clear an optic, but not so large as to snag. The airborn sized Geissele is a little closer to the Mod 4 latch size, but given Geissele latch shape, I prefer the std Super Charging Handle. YMMV....

 

[Porter Rockwell]

For a grip I like to use the Houge over molded grip or the Magpul MOE+. They both have a rubber coating and feel real comfortable. The Houge has finger grooves and the Magpul is just has a straight front. Either one is a gives me a better purchase on the grip.

X2 on the Magpul MOE+ like that grip a lot. I also prefer Ergo grip over hot hogue...but it’s all personal preference, I do prefer the rubber grip feeling, works wells for me in all weather conditions.

 

[Porter Rockwell]

Wallace's offers solid advice.

 

[KERTWOOD]

Since someone comment about the "why" vs a list of ****ty parts,

Now you've been here long enough to know we have S****y parts cheerleaders.