dubya

Very informative. I was thinking along the same lines as Alan while reading the first page, I'm glad that was explained better. Now what do you do if you have short headspace, other than reaming out the chamber? My 308 Rainier Match barrel is a hair short, wont quite close on a 1.630 Clymer GO guage but chambers multiple different 168gr 308 rounds showing Sharpie marker wear on the ogive from touching the lands but nothing I can feel with my fingernail on the bullet itself.

Yes, I believe that may be. This is my response in a similar thread I have going on the other forum. So this is kind of interesting. I went shooting on Sunday and didnt bring my new 308 because my buddy said the 224 Valkyrie upper I built for him was having all sorts of feeding and extraction issues and I wanted to get that running for him (I cleaned the chamber and lubed the BCG and it ran perfect ). One of the other guns my friend brought was his somewhat new 18" PSA PA10 308. We put about 120 rounds of factory fresh Federal 308 ammo through it, on top of the 40 he shot in that gun previously. It ran nearly perfect with surprisingly decent accuracy. The only malfunctions were a spent case not being ejected quick enough before the next round tried to feed, that happened twice. I didn't notice any over pressure signs or blown primers in the spent brass, although I didn't check every single case either. When we left he asked if I would store the rifles he brought until he and his family closed on their new house and settled in. No problem. Once I was home I took both mine and his ARs apart to clean and decided to check the headspace of his PA10 as well as my 308 with his bolt. His PSA BCG is nearly identical to my Toolcraft BCG. The only difference between the bolts and carriers is mine (Toolcraft) has a O-ring extractor and his (unbranded PSA) doesn't. Using his bolt in my gun I could get it to close more than my bolt on the GO guage but still not fully. Then, I checked the headspace of his factory assembled PA10 upper with both his bolt and mine. Both failed to close on the GO guage. I'm not exactly sure what to take away from this but his PA10 now has nearly 200 rounds of 308 through it and it failed a 1.630 GO guage. I'm going to shoot mine the next time we hit the range.

They use PTG guages

I did email Rainier a few days ago but haven't gotten a response yet. Since I cant sleep tonight I decided to see if a spent 308 case would chamber. I tried a couple I randomly picked out of a bag of brass I've been saving and they could have been shot out of my old PA10 or one of my buddies 308s. Either way, none would chamber. My forward assist doesnt work in the M5 upper so I also tried letting the bolt slam home, it still didnt chamber and I had to mortar it out. Guess I'll be giving Rainier a call on Monday. The gun chambers factory 308 ammo but fails on a Clymer 1.630 GO guage. Now I wish I had bought the Faxon pencil barrel like I originally planned.

Well, there's no sending this one back. I already cerakoted the barrel black

This is my thread regarding the headspace of my 308 on ARFCOM if anyone cares to check it out. https://www.ar15.com/forums/AR-15/What-if-my-headspace-is-off-/121-738596/

It's a Rainier Arms Match barrel and it has a modified 308 chamber proprietary to Rainier. From my understanding its similar to 223 Wylde, it's not 308 or 762 NATO but is supposed to shoot either. The ammo is brand new factory 308 ammo

The gun is all assembled, just needs an optic now. I think.... I borrowed a set of Clymer 308 Match headspace guages 1.630 GO & 1.634 NO GO. Stripped the bolt and the NO GO doesn't chamber, great. Try the GO guage and it also doesnt chamber but the bolt does turn a bit, just not enough to lock. I painted two different factory 308 rounds with a sharpie. First was Hornady Black 168gr Amax and the other was Norma Match 168gr SMK. Both chamber just fine but extraction is a tad sticky with the Hornady (no mortaring or anything). The bullets look to be touching the lands just the slightest bit, it removed the sharpie lightly but there isnt anything I can feel with my fingernail on the bullet. I chambered these rounds with the mag inserted and letting the BCG slam home. This is a Rainier Arms Match barrel and Toolcraft 308 Nitride BCG. Apparently Rainier has a modified 308 chamber. Would I be pushing my luck if I went ahead and fired this gun? I've recently talked to a member on ARFCOM that is experiencing nearly the exact same thing i am with his new 308 build using a Rainier barrel.

If you look at a picture of the LMT 308 CH it has these two "ears" that stick down from the bottom of the handle. The ears hit the receiver and stops the CH from fully closing. At first I hand filed until it worked but it looked crappy so I sanded it smooth on my belt sander, refinished the bottom with black ceramic paint and all is good now. It essentially looks like a standard charging handle with an extended latch now

Just a heads up to anyone considering the LMT charging handle. It does NOT work with DPMS pattern receiver sets without modification. I got mine to work but it took the work of a belt sander and can of cerakote to fix.

Yeah, I wouldn't put any heavier grease like that in for lube, especially on a new build that needs breaking in. Clean that stuff out and run it wet with a good oil.

http://i.imgur.com/EXjEPZf.jpg

Aero just had the M5E1 builders set which included the upper, lower and a Quantum handguard on sale for $299. If you are a first time buyer from their site there is a coupon to take an additional 10% off your entire order and I believe free shipping. I think it's out of stock now though.