lablover

89 thou Rifle length

I'm pretty anal about my reloading. COL is 2.800 and I F/L resize lake City brass. I'm going to grab a box of factory ammo again today and give it a go. I'm also going to bring the fixed gas block I had on it originally and never had any issues. After I built it with the fixed gas block and it worked flawless....I changed 2 things. Added Magpul PRS stock and changed gas block to a Syrac adjustable block. It's gotta be one of those 2 things. My reloads functioned fine with the fixed gas block. I'm at a loss....The Syrac is wide open as well

Did not but I can. What should it be

Plan B It wasn't the gas block alignment. I tried the reloads again and no bolt lock back. Fed 168 GM and no probe...hmmmmm Is 41.7 gr of 4064 that freakin light? 175 Match Kings Damn, what a bummer. I will say every once in awhile it would lock back. Grrrrrrrrrrrrrr

On the fixed block the hole is way bigger than the hole in the barrel. The Syrac, not so much

Pretty excited. I'm almost sure I just figured it out. I took the Syrac gas block off and measured the distance from the hole to the edge of the gas block that goes against the barrel shoulder... If you remember I said I pushed the block all the way against the barrel shoulder...Big mistake. the hole was .035 off So, that being said I was not dead center hole for hole on the barrel and block. I have to think .035 off would make a huge difference in the way the block functioned..or in this case didn't. Cant wait to try her out again...I have no doubt that was the issue

I will say I had lube on the bolt but it wasn't like dripping wet. Makes me ill to buy a box of ammo these dye when reloading is a but cheaper. I'll give that a try however.

Something I need to check is when I installed the new Syrac gas block I seated it all the way agaist the slope of the barrel. I have a feeling I need to measure how far back the whole is in the block then measure how far back the hole is from the barrel shoulder. Why do I know this is the issue...LOL Still all ears.

Bolt won't lock back on last round So first let me start by saying new build was working great with the Federal Factory ammo. The first 20 shots went great without any issues. I used factory ammo to be on the safe side. I also shot some of my reloads after the box of factory and she ran like a champ. So, being I couldn't leave well enough alone. I decided to change out the fixed gas block and A2 stock. I installed a Syrac Gen 2 adjustable gas block and a Magpul PRS stock. Keep in mind I did not change the spring that I got with the DPMS Stock, buffer, spring Buffe tube kit from DPMS for 308. Anywho. I loaded the following loads new loads so I was starting low and worked up. Clean BCG and Rifle First load was with the Syrac gas blocked closed half way. Load was as follows First load was..... 40.5 Gr IMR 4064 175 gr SMK all single loaded all fired and bolt locked back on each round. Pretty happy so went to the next load 41.0 gr IMR 4064 175ge SMK First shot..bolt locks back but not all the way back. I figured I was on the raged edge with the gas block so opened up a few click. Every shot after that no bolt lock back.....grrrrrr Decided to open the block up all the way and fire the next groups 41.7 gr 4064 175 ge smk. Bolt wont lock back. Had the rifle on the bags so I even tried it off the bags..No lock back. Here are my questions. Is this just a break in issue? Are my loads ...wimppy. I even tried some Ball LC ammo and it locked back but once it failed too Tried a different Mag...Worked fine but one didn't lock back I thought when I first did the build with the fixed gas block all went great with the Fed gold medal match and no issues at all. I did not try to load more than one round until I get this figured out. I'm gonna take the Syrac block off and make sure I have everything ligned up correct. I did use a different gas tube with the Syrac too..Not sure that matters. Not even sure the MAgpul PRS can be an issue because with the A2 stock it worked fine with the spring/buffer I have. All ears guys. Lookin for some suggestions. I will say the 41.0 gr load was a hammer..Stuck all 5 shots in one single ragged hole at 100. Mega Arms Megalithic upper and lower (set) Mega Arms 20" Barrel BCM GAs Block..Fixed.....Now Syrac gen 2 Adj. Surefire SFMB-762 Muzzle Break LMT BCG and Bolt Vortex Viper pst 6-24 FFP ADM 20 MOA rings and Base set Giesslee 2 stage Match trigger Not sure what I might of forgot? Thanks for listening Joe

Longer hand guard is not an option..Its all Monolthic...OR Megalithic. It aint gonna grow...LOL I'm fine with it really.

CRAP! Ijust realized that low pro gas block exposed out front like that might not be a good idea......Any suggestions for a adj. a bit more heavy duty. Now I know why everyone likes 18" barrels...LOL

Is it ok to "NOT" rockset or locktite the gas block or muzzle break before I know its good to go. I haven't even shot it yet and already am debating going with an adjustable block...LMAO

My First Build That didn't take long at all. Not much different then 223 build......... I went to the local gun shop where I got everything to swap out the gas block. I brought everything with me and asked the owner..."I don't suppose you have any headspace gauges" Sure do he says...Woooohooooo. Got the barrel headspaced on the spot and she's good to go. That being said it gave me the OK to start the build...Then finish it..LOL. I think I may have had one screw up but won't know until I get to the range......I think my gas block dipole I did was a skosh off. There is 2 set screws so I only rippled the barrel for only one of the screws just in case I screwed it up. Anywho pics below and I have a few questions. 1. Why am I freakin about shooting it now..Little paranoid. Not sure why? I need to double check everything. 2. I really need som e lube on this bad boy. Pulling on that charging handle that springs sounds rough big time. And, it aint the easiest to pull back...Big bolt..not 223 right! 3. I have a surefire break that is also a mount for the can......Someday....... No way I want to rock set that thing on yet until I know the gas block is all well and everything else is golden. I'd hate to have rock set that thing in and then have to change the gas block or something. Can I just torque the break as well as the gas block down for the first several range sessions? 4. Any function checks I should worry about? Please, any reminders or things I need to keep an eye open for. New 308 build for me so I'm not so shire about it all. Anywho, here are the pics...the stock is a temp until I can get a Magpul PRS Mega Arms Megalithic upper and lower (set) Mega Arms 20" Barrel BCM GAs Block..Fixed Surefire SFMB-762 Muzzle Break LMT BCG and Bolt Vortex Viper pst 6-24 FFP ADM 20 MOA rings and Base set Giesslee 2 stage Match trigger Not sure what I might of forgot? Like I said, I was shocked it all went together pretty well. I will say the 65 lbs of torque made my butt pucker....and I had to do it 3 times...Set, loosen, Set, loosen Set....Fuggin sweating my a$$ off the whole time. Yes, I used a home made jig that I made and love but damn that was scary...

It's done...New post to follow :)

I'm all over it now...Thanks a bunch

Oh hell yea I like it!!!!! LMFAO.

SWEET! Thanks a bunch

Nope All Mega Arms and LMT I'm so confused about this whole a r10 308...etc What would one call a Mega Arms Megalithic receiver set and Mega barrel and LMT bCG etc etc etc....I gotta learn the diff so I don't feel like a A$$

Oh hell yea thats good news. I will say that I am concerned it had carbon on it and was supposed to be new. I wonder if they test fired it or the shop owner rugged around with it in a build? Going fixed gas block too... :)

I'll just bring the set back and get the spring and buffer and I'm all set. Oh hell, not like I won't need them for another build either right...LOL. Yea, I was tinkling of putting on the seek ins and just run it wide open. Part of me is half tempted to machine a little notch in the barrel but sort of afraid if that would screw the barrel. Any word on that bolt barrel combo? Is that a decent BCG and bolt

Yea, good point but I bought the whole set and it was like 100 bucks..I already have all of it here and if what I have is GTG then why buy more of the same I guess. I was just curious if the tube and spring are th same as 223 tube and spring.

First off lets hope I don't break the "Rule" LOL First post and I searched and tried to find an answer. But seeing that I'm so freakin new to AR10 308 builds..I'm clueless So, I bought the Mega Arms Megalthic Upper and Lower set. This thing is bad a$$ The local place I bought it had pretty much everything I needed. And when I say bought, I did some custom sign work for them and payed me with parts so I'm pretty happy. Anywho..the receiver I mentioned above. A LMT BCG. That thing was pricey and he said it would work with the Mega Arms 20" Barrel as well as the receiver etc. Is this correct. I'm a little confused on what BCG to use with what. I've built several 223 AR's and its not this complicated. Next few hurdles or questions. He gave me a DPMS A2 stock with buffer tube, spring and buffer. Ok, to me that buffer tube looks like any ole A2 AR-15 buffer tube in rifle length. Am I right, reason I ask is it may save me a few bucks to trade it back for other goodies. I know the buffer is different but what about the spring and tube. Seekins adj gas block. First, do I really need an adj gas block? Only reason I ask is it's a rifle length gas system. I have no issues using it but I'm in the less it moves and screws the less can go wrong. The bad thing about the seekins is the brass hold down screw that locks the other adj screw is in the back of the block and hits right up against the barrel contour. So, almost impossible to lock down. I'll try to post a pic at the end if I can. Thats kind of why I was thinking fixed gas block. Your call guys, I'm all ears. I'd like to eventually put a PRS stock on it because I've got the length of pull of a firkin gorilla...LOL And with the new PST Vortex I'm gonna set on top it seems to set up pretty high. need to order a few headspace gauges and I assume this LMT bolt is gonna be a biatch to tear down so I can get the 2 ejectors out to headspace...Ughhhhhh BTW, do they test bolts before they ship. This thing had carbon in it and I was like..Ummm did I just get someone else's problem? All I can think of right now, I can't really do a thing until the gauges come in. Thought I had enough lower parts but missing a few things. Gonna put the Giessle 165.00 2 stage in it for now..Good solid trigger with no adjustment. Your site rocks Guys. Tons of awesome info and looks to be not too many uptight folks...Awesome. Look forward to hearing about the above EDIT..forgot the pic Thanks a ton in advance

Looks like you all have a great site here. I plan on doing some serious reading as I just found myself with a bunch of new AR10 parts to put together for my first (i'm sure not last" 308 Hopefully I won't have to ask too many newb questions. You guys seem to be pretty organized here. Look forward to Forum Joe