Sig M400 rebuild. . opinions pls?

[Pyromelana]

Started as stock M400, ive owned 2 AR's in the past (Windham era Bushmaster and a 6920) however i never altered them. So these are my upgrades to this Sig M400. Feedback please? Positive or negitive, just wondering if im on point.
Sig M400 E
-Replaced barrel with a FN CHF CL 1:7
-Replaced FSP with F stamped FSP
-Troy Ind. Charlie freefloat rail with FSP cutout
-Surefire and Magpul ladders (BLK, OD, FOL)
-Streamlight TRL-1 HL
-Magpul AFG2 (OD)
-Aimpoint PRO
-Replaced the AR15 BCG with Centurion F.A. BCG
-Replaced firing pin with Titanium pin
-Added H buffer
-Samson flip up rear BUIS
-Magpul MOE+ grip
-Magpul STR stock
-Magpul trigger guard (OD)
-Magpul MS-4 gen2 dual QD sling (OD)
Last thing i want is a Geissele SSA FCG.
Im a nub, i know. Just want opinions as I dont have any shooting friends besides my wife.

[Jwknutson17]

Nice work. I like those lower receivers with the Ambi mag release and the QD sockets built in. Does that M400 model have the adjustment pin inside the lower to keep the upper tight. I have a lower from a 516 and curious if yours was the same.

I like the upgrades. Looks a whole lot nicer. And probably runs a lot better also. Do you like the TLR HL where you have it at the 6? The few rail after FSB I had, I would mount it on the 12 after the FSB to give the shadow at the 6. You prefer it at the 6?

[Jwknutson17]

Also, what length barrel and hand guard?

[Pyromelana]

Thank you! Yes, it has the "wobble/play" tensioner. I actually prefer the TLR-1 on my pistol lol. But on the rifle its easier for me to actuate the light at the 6. And since the rail goes out so far the shadow is extremely minimal. I have an Elzetta with mount on the way in the mail so ill be using that instead, and put the streamlight back on my m&p. And yes, it runs smoother with the f.a. bcg and h buffer. Originally it had an ar15 bcg with carbine buffer. And the barrel is great too. Went from 2 moa at 100 to just under 1moa. Thatd be the freefloat rail and better barrel i guess. Anyway thanks again!

[Pyromelana]

Its a 16.1" and the troy handguard is 13"... i love the extra space past the fsb.

[Pyromelana]

minimal shadow if any

[nate89]

I think you did very well. I prefer the pinned FSP as well.

[Pyromelana]

I think you did very well. I prefer the pinned FSP as well.

Thank you. And i agree, love the FSP.

[Sasahara]

Nice rebuild! Not a fan of the TLR-1 at the 6 and the titanium firing pin though. Quick question though, what exactly is on the bolt catch?



A quick read on titanium firing pins
https://www.m4carbine.net/showthread...um-firing-pins
Quite a few knowledgeable people cite the drawbacks of these.

[Pyromelana]

Oh wow, im switching it back lol. I figured "titanium = stronger" . That THING, lol, on the bolt catch.. is a brownells version of a battery assist lever like magpuls BAD lever. However, it wouldn't work with the ambi mag release on the lower, so i cut it in half, and put it on upside down i like to slap the button instead of pressing it and it gives me alot more of a target when i slap the bolt catch and reduces the chance of missing it if i happen to cup my hand at all..., its ugly as hell but works for me