Sig M400 rebuild. . opinions pls?

[Pyromelana]

And thanks alot for the info on the firing pin. I was just thinking about having a pin thatwas stronger. Anyway, thanks again!

[Sasahara]

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

And thanks alot for the info on the firing pin. I was just thinking about having a pin thatwas stronger. Anyway, thanks again!

Ahhhhh gotcha! I couldnt figure out for the life of me what it was lol. Yeah, I can relate to that problem though. Once or twice I have went to slap my catch and did not send the bolt home.

And np on the firing pin link. You could always probably sell it off for some ammo $$. Looks like a nice build with good parts. Hope you enjoy it!

[Pyromelana]

Thanks! And yea, i just put it on armslist

[.46caliber]

I'm curious as to why you replaced a 1:7, carbine gas, FSB barrel with another 1:7, carbine gas, FSB barrel.

Sent from my Nexus 4 using Tapatalk

[Pyromelana]

The original sig barrel didnt have a F stamped fsb and sig doesn't list the barrel steel or whether or not its mp/hp. And ive seen so many conflicting reports on their barrels. Ive seen 4140, 41v50, button rifled, CHF ect, same with the bolt... Plus i wanted a hammer forged barrel. I just like to know exactly what i have. I guess im picky?

[Jwknutson17]

The original sig barrel didnt have a F stamped fsb and sig doesn't list the barrel steel or whether or not its mp/hp. And ive seen so many conflicting reports on their barrels. Ive seen 4140, 41v50, button rifled, CHF ect, same with the bolt... Plus i wanted a hammer forged barrel. I just like to know exactly what i have. I guess im picky?

I think he was referring to why didn't you get a mid length gas system barrel?

[Pyromelana]

Oh. That was a no brainer. I got that FN barrel for $50. It was "lightly used", said the store clerk here at ocala armory, but its hammer forged and double CL. Im aware of the benifits of a mid gas system but thiis was only $50.

[J4ggy]

Almost the same setup as my m400 except I went with the Charlie and ACS-L stock. My A2 front post is F stamped so that is odd that yours wasn't. If you want a battery assist lever that will work correctly on the rifle, check out tactical link's version. Placing the light at the 6 o'clock position would be preferable for me. What is the weight of the rifle. With the pro and a light, mine is coming in at 8lbs 8oz without a mag.

[Pyromelana]

The handguard on mine is the charlie rail. The charlie is quad and the delta i think is tubular with a small rail section on the bottom below the FSP (i think). And when sig first released the m400 it was a little different than the new ones, no f stamp fsp, commercial receiver ext. tube, and a few other small things. So you probably have a newer one. I actually dont have a scale to weigh it, but it feels quite a bit heavier than my 6920. If i had to guess...with no mag, probably 8.5-9.5 pounds. Which doesnt bother me at all. Some folks complain about a heavier AR (10LBS) for various reasons, which is understandable. But idk, for me its fine. I use a 5.11 plate carrier LBE with ar500 plates, (4) double mag pouches (holds 8 AR mags), a few other molle pouches for pistol mags etc. and a blackhawk backpack and i have no problem with a 9-10 lb rifle. But thats just me. Thanks for the battery assist advice. Im going to check it out for sure. What i REALLY want is a Geissele SSA-E fire control group. Just so expensive. Do you ever find yourself using the milled in QD sling mounts on the lower? Only thing that bothers me is when i havebthe MS4 sling configured to single point and plugged into the QD mounts sometimes i have a little trouble flipping the safety, kinda annoying. Also, does your barrel like lighter loads? (55gr and lower) The one that was on mine HATED light loads... freakin 3-4 inch groups at 50. With heavier bullets the groups got better...but not nearly as good as the FN barrel. Im rambling haha sorry. I like to talk guns but none of my friends are as enthusiastic as i am... so you have to deal with me haha...im so glad m4carbine.net exists

[J4ggy]

The stock trigger works well for me. I've been tempted in the past but I'm still working on techniques to improve my shooting skills. If I ever get to the point where the trigger is a limitation, I'll replace it then. I haven't had any issues with a single point interfering with the safety. As far as accuracy goes with the stock barrel, it's been accurate with loads that are 55-62 grains. I would take 3-4 inch groups at 50 yards, using an PRO, as acceptable if standing. If that's using a rest, maybe not. It's not a magnified optic.