Just done with my first AR-15 build in 6.5G!

[R2BRO]

So! I never built any gun before, this is a first time I made my own AR-15 from scratch...and it turned out to be a 6.5 Grendel!
Am I now legitimately accepted into a 6.5G club?

Here are the pics!!!



The parts were ordered from 22mods4all.com, the lower was 80% 7075, then I milled it out using the 5D Tactical in my garage! Then I took upper, lower, handguard to the cerakote guy living 10 mins away from my home and he coated it in tungsten for $145

Total: all the kit except lower: ~ $320, BCG ~ $70, Lower $40,
Then, instead of using milspec trigger included in the kit, I bougth short action Timney Targa 2 stage trigger for $190.
Total: 320+70+40+145+190=$765, for a 6.5G 20" complete rifle.
The scope was just taken from my another Colt AR, it is 6x Strike Eagle.

Below are some observations during a build:

• The safety was super stiff, I had to clip the small spring which goes inside pistol grip
• The GO gauge did not GO, but NOGO did not go either, and Hornady rounds chambered well
• Rifle was tested by me, I did 89 shots with 0 defects
• I inspected the brass, some of the brass turned out to be a little lightly scratched near the bottom ( a place where extractor grabs the brass), but not really bad. just a tiny bit. Any comments on that?
• To mount the scope, I attached the scope mount from Nikon, and I noticed that passing a mount from the handguard was super hard, I even had to oil that handguard's picattiny rail...why so? poor tolerances on that brand or what?
• The very first test with Hornady match ELD showed me just around 2" groups @ 100, its not great at all, however I was really hurrying cuz by the time i was all done the range was almost closing...so I ordered more ammo and will test more. Please write me what group you think is reasonable for such setup and barrel? (I think its beer creek arsenal barrel or BCA as someone pointed?)
• bought grendel magazine from 44mag.com, and they were horrible, I had to shave them off with dremel to make rounds come out nicely!

can you please comment on the observations regarding scratched brass and group size?
and maybe add anything else you think matters?

[Klem]

R2,

Nice build, and from an 80%, excellent work.

You might want to bring that forward ring back onto the upper receiver. Handguards are not solid enough to hold a scope repeatable (which is why cantilever mounts are made for AR's, so they sit on the upper and hold the scope over the handguard). The receiver is a more solid interface with the barrel.

As for the accuracy it depends also on how you held the gun at the time. Was it bench rested, or did you use a bipod? Rear bag or even prone unsupported. How many rounds in each group? Windy day? Are you a good shot? All this makes a big difference. No offence but all your parts are budget and you get what you pay for in this industry, generally.

There's some tape stuck on the lower you might want to peel off (only kidding!).

[drykilned]

R2, i also built what most call a low budget gun and the major problem i had/have appears to be a common problem which is feeding from the mag. Still working on that. At first my handloads (factory ammo unavailable here) were not accurate with some groups at 4-5 inches at 100yds from bench with bipods and rear bag supported. I am old, but i can still shoot, so i knew it was not me. I kept experimenting with the loads and i finally came up with sub-moa groups at 100yds with the same bullet that was giving me the worst groups when i started, but with less powder and of course slightly less velocity. I am now shooting the 123sst at 2415fps which is all i need for deer/hogs under 300 yds. I did not start with 80% as mine was already inletted. My barrel is the bca 18" stainless 5r 1:8. I used the anderson upper receiver and lower receiver with the anderson lower parts kit and jp springs. I also substituted spikes battle trigger group for the anderson trigger group. Handguard is a budget keymod free float. Carbine length gas tube with mini gas block and budget m4 style collapsible stock. Bcg is brownells as it was all that was available at the time! On mine, the accuracy gets better as i passed 80 rounds. Keep shooting and maybe try different loads for the right one. My most accurate load was not usable as velocity was too low, that was 140 grain speer, so had to get lighter, more streamlined bullet.

[1Shot]

I would go to Primaryarms.com and get one of their cantilever scope mounts that will allow you to mount your scope on the receiver and not the handguard. They are just as good as the higher priced name brands but much cheaper. As far as the accuracy of your BCA barrel time and rounds down it will tell. I know it was a typo but you may have hit the nail on the head. "Beer" Creek Arsenal, It is Bear Creek Arsenal but with some of the stuff they are letting out of their place it seems that quality control may have been in the BEER a little too much. The BCA barrel I ended up with after having to send one back because every shot was a flier is a stainless straight flute 5R 20". It took between 60 and 70 rounds down it to get it to start grouping decent. I have a handload with the 120 Sierra Pro Hunter and 28.5 grs IMR 8208, Hornady case, CCI BR-4 COAL 2.260 and I use a medium Lee Factory Crimp that shoots 1" 5 shots at 100 yards. I have two Grendel's with different barrels and neither likes the Hornady 123 SST bullet in factory or so far with any hand load. I have not shot any ELD yet. I just got into the Grendel's this past Feb. by getting a complete BCA upper but as said it was a shotgun not a rifle. After the time it took to send it back to the factory and get it back I decided to build me a REAL rifle. Found a deal on stripped Anderson lowers $52 out the door. Got most everything else from joeboboutdoors.com. Used a Anderson upper Oden Works 18" Stainless barrel package which contained CBG, gas block and tube $438.99. I got a STNGR PVVR handguard from STNGR.USA for $124.99 shipped. It shoots. Sub MOA with most loads and one so far half MOA. I still have a lot of load work up and shooting to do yet with both. I really did not totally keep up with the total cost of my build but it was around $1000. I decided that I have worked hard all my life and done without and scrimped and now that I have my house paid for and owe nobody nothing it is time to live a little and get some toys to play with while I still have the health to do it. I like the way that you started this thread using the word "FIRST" build. These things have a habit of multiplying. Good luck and good shooting.

[BluntForceTrauma]

Diggin' that tungsten color!

[VASCAR2]

I have a set of the Nikon scope rings like the OP used with the Strike Eagle. These rings were very difficult to move on my upper rail. I know the Cerokote would have to make the rings harder/tighter to move on the rail. At my age with a 6 power scope I figure I’d be the limiting factor in getting good groups. With Hornady 123 grain SST and 6X scope I’d be lucky to consistently shoot 1.5” groups at 100 yards.

[Bigs28]

You have plenty of room on that front ring to slide it back on the scope so it's on the upper receiver.

[R2BRO]

Alright guys, thanks for comments, I came back with some updates. Now I have additional questions and need help.

Well, first of all, I did follow recommendations and bought a single mount and installed it only on the upper, below is a picture (that little thing on the handguard is just a rail for case catching bag holder), I also decided to put rather cheap but 16x-44 scope on it from covenant cabela's:


Now here are the issues which I need help with:

1. After first 89 rounds without problem, I started having feeding issues on the next 100 rounds; specifically, I load for example 5-6 rounds in my ASC steel Grendel magazine, and after 2nd or 3rd round the next round is stuck at around 45 degrees before the chamber, and also its body is bent by a bolt moved forward. What could be the source of this problem?
   Couple comments about magazine: when I bought 2 of those steel ASC mags and decided to dry run them manually by hand with dummy rounds, I noticed that sometimes the rounds get stuck, or for example something like this happens:
   
   In the above picture, that was a dummy round with bullet inserted to have proper overall COL but not crimped, what happened is the round was stuck and bullet was pushed all the way in. So I saw that the magazine does not work and it really sucks even during a dry run. As a result, I decided to shave it up with dremel. After I shaved it up with dremel, I could nicely push out the round even with my finger (same thing I can easily do with my plastic Lancer mags for 556). After I shaved it up with dremel, I took it previous weekend to a range where I shot 89 first rounds with 0 errors. But now, with same shaved magazine, and nothing changed in the gun (instead of correcting issue with scope mount) I start having issues of 3rd or 4th round being stuck as described above. Can you tell me what could be problem? Below are pics of the original magazine (left) and shaved off magazine (right) with dremel which was used in shooting:
   
   
   Ok, so what is going on with magazines and that feeding problem? Can you guys recommend me a high quality magazine to buy? what do you use? I want this time to buy a really high quality magazine because I feel that these mags are shit.
2. Next, what is the proper buffer spring parameters for 20" 6.5G build? Can you tell me proper length which needs to be used for this build?
3. Next is, what size/weight of buffer I need to use for this 20" 6.5G build? Again, I just used whatever came with kit, but that kit was a cheapass kit so now Im not sure if all parts were "proper" parts.
4. Another problem I have is, after the last round fired, the bolt rolls all the way forward. Could it be magazine/buffer spring/buffer related as well?
5. and of course problem described previously, the brass is kinda shaved off on the bottom, picture is attached:
   
   so what is going on with the brass?
6. another problem which is still there is around 2"-1.5" (at best" group sizes @ 100. But...this problem now is kinda minor, because first I need to fix the ones above, then I'll get back to precision shooting.
   

so any ideas?

[R2BRO]

here is a picture of the bolt after around 190 shots:

[R2BRO]

one more short detail, the orientation of case ejection is around 3 to 3:30PM.

[Randy99CL]

The pic of the brass is screaming "Extremely High Pressures."

Did you say you bought the BCA 20" barrel? Specifically the 20" melonited straight-fluted 5R barrel?
Some of those barrels (mine included, purchased Oct '17) have very short leads and normal factory ammo seats with the bullet pushed hard into the rifling. Hence the high pressures.
They sent me 3 test-fired cases with my upper and they show signs of excessive pressure, but not as bad as those in your pic.

Is your barrel one of those BCAs?

[R2BRO]

First I decided to use barrel which came with the kit "Bear Creek Arsenal 20 Inch 6.5 Grendel Heavy Barrel Barrel 1:8 Twist 5/8x24 tpi Threaded for muzzle"
Then after build was complete, I noticed that my GO gauge does not lock the bolt, so I did not use this barrel and used the following barrel bought online from this link:

https://www.classicfirearms.com/ar-barrel-20-nitrided-6-5-grendel-heavy

The funny thing is, after I installed the barrel from above link, the GO gauge did not close again... (but neither did NOGO gauge close the bolt), so I just decided to test it and start shooting, and that is the barrel I am shooting with now, the one linked above.

[VASCAR2]

One thing I would do is the ejector mod described in the link.

http://bulletin.accurateshooter.com/2014/08/ar-ejector-mod-for-improved-reliability-with-larger-cartridges/

There have been numerous issues with ASC mags. With the ASC mags I recommend you take them apart and clean the interior mag body and spring. Inspect the follower for excess molding and see if the follower moves freely in the mag body.

On new 6.5 Grendel mags I load the magazine to capacity and let them set loaded. Most 6.5 Grendel mags have very stiff mag springs. Leaving the mags loaded can help the springs wear in. Some people use dry lube on the interior of the mag.

I usually don’t lube the inside of my mags because lube can accumulate gunk. My ASC mags came new with a sticky substance on the inside and cleaning helped. I had one 24 round ASC mag where it had one feed lip bent to low. The mag would feed from one side but not the other. The mag was not letting the nose of the bullet to rise enough to feed. The AR-15 mags feed from each stack inside the mag well. For example my faulty mag failed to feed from the left side non ejection port side. Once I tweaked the feed lip of the faulty 24 round mag it has not failed to feed.

Trimming the front of the mag body can help but it can’t hurt to bend the feed lips up a little to allow the cartridge nose to rise a little sooner. Go with slight amount of change as many times it doesn’t take a lot change.

I suggest you do the ejector mod first to see if that helps. Also make sure the ejector moves freely in the bolt. Brass shavings can get in the ejector channel which can cause failure to feed. The ejector has to be depressed to allow a cartridge to go into battery.

If the ejector mod fails to solve your problem I’d try to tweek the mag feed lips.

The ASC mags which are the same size as a 20 round 223/5.56 mag are known not to function reliablely when loaded to full capacity of 14 rounds. Alexander Arms specified a curved mag body which ASC never intoduced. AA never sold the 14 round mags as they couldn’t guarantee reliability. At one time AA sold rebranded C Products and ASC mags. AA now sell E-Lander 6.5 Grendel mags.


The last mags I’ve purchased have been E-Lander. The mag springs are very stiff when new but otherwise I’ve had very good results with E-Lander 6.5 Grendel mags.

[VASCAR2]

The barrel you bought from Classic firearms is most likely from Bear Creek Arsenal. Like Randy99 mentioned the Nitride/Melonite barrels from BCA have been released with a short chambers lately. I’d color the bullet on a factory cartridge with a black marker and drop it in the chamber. With the bolt carrier out of the upper if you raise the muzzle the factory cartridge should fall out of the chamber. If you have to push the cartridge out with a cleaning rod you probably have a short chamber. Look at the bullet you can probably see where the bullet is into the lands.

If the cartridge does fall out of the chamber and the colored nose does not have any black rubbed off I’d inspect the chamber. The chamber could be very dirty or have a rough finish. Some times residue is left in the barrel and chamber from the Nitride/Melonite process. It’s hard to see if the sides of the spent brass has marks from a rough chamber.

With a 20” barrel you can use a carbine length buffer tube, carbine spring and carbine buffer. If you have a short chamber the bolt carrier might be out running the ability of the mag to feed a new cartridge. Generally over gassed guns will kick the brass out to 1-2 O’Clock. Over gassed and under gassed can exhibit some of the same failures. If you have an H-2 buffer you could try that. I suspect you might be dealing with multiple issues.

[R2BRO]

So short chamber is causing high pressure as well as the GO gauge not locking the bolt, is it correct?