Ejection between 1 and 3

[Navistar82]

Finally got around to shooting my new 308 build. Upper is a 16" m5e1 with a ballistic advantage barrel, midlength gas system, non adjustable low profile gas block, an H3 carbine buffer and a JP enterprise custom centerless ground and polished operating spring.

Each shell consistently ejected between 1 as 3 o'clock. Without messing with an adjustable gas block can i go up to an H4 buffer to help it eject in the proper spot?

 

Thanks 

[Navistar82]

...or am i backwards and need a lighter buffer? 

[Robocop1051]

You're correct. More weight in the buffer will slow the cyclic rate down, and bring the ejection back towards the 3-4 o'clock. Upgrade to an Armalite spring while you're at it. 

[Navistar82]

Which armalite spring specifically and should i try it first and keep my buffer or do both? 

Thanks

[Robocop1051]

Actually, scrap the AR10 spring. I didn't read you already had a JP spring. 

[Navistar82]

So go with an H4 buffer? 

[Robocop1051]

Or heavier!

i have a 17" rifle length system that just hums with a 10 oz tungsten buffer and a Tubbs flat wire spring. 

[survivalshop]

Adjust the Gas block .  I personally don't have an issue with ejection on a new build , well, maybe unless they eject forward in front of the rifle . Get a higher round cost & see where they go , could also be the Ammo .

Edited June 26, 2017 by survivalshop

[Navistar82]

14 hours ago, survivalshop said:

Adjust the Gas block .  I personally don't have an issue with ejection on a new build , well, maybe unless they eject forward in front of the rifle . Get a higher round cost & see where they go , could also be the Ammo .

I don't have an adjustable gas block.

[mineralman55]

If it is reliable and has no functioning problems, leave it alone. Several of my ARs throw the empties to 1-2 o'clock. As long as you're getting consistent and repeatable function, and the accuracy is good, should be no problems.

[Navistar82]

it functions fine but I don't want excessive wear and tear if it can be fixed with a heavier buffer or an adjustable gas block.  Right now accuracy is terrible, 2"-3" groups at 100.  But I've been told AR 308's don't like 150gr bullets in a 1:10 twist, so I guess I'll try 165's or something in that range.

[survivalshop]

7 hours ago, Navistar82 said:

I don't have an adjustable gas block.

Sorry I misunderstood , I thought you already had one & didn't want to adjust .

 The ejection pattern is not fool proof way of showing a semi auto firearms health or function properties , in relation to wear & tear .  With a new Build it will change with round count .  There could be several reasons why the rifle is printing 2-3" groups & may have nothing to do with Bullet weight .

[Navistar82]

How many rounds need to be fired before i address the ejection and accuracy issues? 

Thanks

[survivalshop]

 The accuracy issue , the first thing I would do is run a Copper Solvent through the Barrel to start with a clean slate , so to speak & it will take 40-60 rounds to re-season the barrel , you can try different factory ammo or reloads & see how they shoot to do this .  The 1-10 twist rate should handle most bullet weights , its why most .30 cal. rifles have this twist rate .

   If you can't get the Barrel to shoot well , close to MOA at 100 yards ( after re-seasoning ), I would contact the Barrel Manufacturer & inform them you are not satisfied with the Barrels performance .

 Also make sure all components are correct & those that should be tight , are tight , Barrel , Scope & Mount /Rings etc . What Chamber is in the Barrel , 7.62x 51 , 308 or some kind of hybrid ? 
 
 Was Head Space Checked ? 

Muzzle Devise ( Brake ) ?  if so , make sure its not interfering with Bullet Travel . Taking the Muzzle Device off & test firing with the same ammo that was tested for grouping , sometimes is the only way to see if the MD is an issue .

[Navistar82]

Ive already cleaned the barrel with copper solvent, but havent shot it again. It is a 1:10 twist and i was shooting 150gr factory loads and handloads. Everything is tight that needs to be, i double checked before, during and after shooting, It's chambered for 308.

As for headspace, i dont know how to check it. I bought it as a complete upper from aero precision. How does one check it?

It does have a hellfire muzzle break on it. Ill take it off next go around.

Thanks

[shepp]

29 minutes ago, Navistar82 said:

Ive already cleaned the barrel with copper solvent, but havent shot it again. It is a 1:10 twist and i was shooting 150gr factory loads and handloads. Everything is tight that needs to be, i double checked before, during and after shooting, It's chambered for 308.

As for headspace, i dont know how to check it. I bought it as a complete upper from aero precision. How does one check it?

It does have a hellfire muzzle break on it. Ill take it off next go around.

Thanks

If it was complete head spacing was most likely checked by manufacturer I wouldn't suspect muzzle device in that case either maybe? Shoot it more see what happens then like SS said if your not happy contact the manufacture 

[98Z5V]

15 hours ago, mineralman55 said:

If it is reliable and has no functioning problems, leave it alone. Several of my ARs throw the empties to 1-2 o'clock. As long as you're getting consistent and repeatable function, and the accuracy is good, should be no problems.

This is my philosophy, as well.  I don't care where the brass goes, as long as it gets out of my rifle, and the next round chambers.  If your BCG is going too fast (which will tear up parts in the long run), then you'll have malfunctions related to that. If you're not having malfunctions, then the BCG is doing what it's supposed to be doing, as far as speed goes.  It's a "range," not an exact speed.  You chase some ghosts trying to find a "perfect ejection pattern" in these things.  You'll also spend alot of money on parts that you don't need (adjustable gas blocks, for one), and you'll have a pile of parts left over that will build a perfectly functioning "next" rifle. 

I've seen that pie chart, that shows ejection patterns - that's all based off AR15 stuff.  Sure the Large Frame ARs are the bigger brother, but they're not totally identical.

 

I wouldn't worry where the brass is landing, in a clock position - just that the rifle functions, and the brass is getting out, and the next round is chambering. 

[survivalshop]

  Well said 98.

  One thing you have to know is most Barrel/Rifle manufacturers don't Guarantee their Barrels to shoot MOA . Try the different ammo testing & bullet weights to see what the Barrel likes .

[Navistar82]

Out of the 70 i shot the other day there wasn't any malfunctions. I've already contacted Aero as they guarantee their barrels to shoot moa, but they use 147gr match grade bullets. They said to shoot it 50 more times and if it doesn't tighten up to get back with them. Im going to try some ammo in the 165-168 range and see how that goes.

[Doodle]

2 hours ago, Navistar82 said:

Out of the 70 i shot the other day there wasn't any malfunctions. I've already contacted Aero as they guarantee their barrels to shoot moa, but they use 147gr match grade bullets. They said to shoot it 50 more times and if it doesn't tighten up to get back with them. Im going to try some ammo in the 165-168 range and see how that goes.

I was only shooting military 147-150 gr ball ammo, then I came here.  After several recommendations of match ammo, I finally gave it a try (168 Sierra match kings by Federal).  I will echo the wisdom shared with me --- match ammo is that much better.  I bet your gun will shoot 1 moa with match grade ammo.  

[Navistar82]

Downside to that for me is my rifle will be a deer hunting rifle first, paper puncher second. Match grade bullets aren't geared towards hunting. 

[Doodle]

5 minutes ago, Navistar82 said:

Downside to that for me is my rifle will be a deer hunting rifle first, paper puncher second. Match grade bullets aren't geared towards hunting. 

There seems to be a lot of options between 165-180 gr in hunting ammo.  I'd certainly try those.  

I'd like to try these:  http://www.federalpremium.com/ammunition/rifle/caliber/308-win/vital-shok-sierra-gameking-boat-tail-sp/p308c

and compare them to the 168 gr. SMKBTHP, which have impressed me.  

[Navistar82]

Im going to some sporting goods stores at lunch to see what they have. We have a gander mountain in town...so...might catch a deal. 

[shepp]

 

[survivalshop]

 Try some 150 gr. Hornady SST's , I load for several hunters down here & all of them use the Hornady SST's in various calibers .( Remington Bolt gun) ,139 gr. SST in 7mm08 , ( Remington Bolt Gun ) 150 gr. SST in 308 & two Browning BAR's  30'06 with the 150 gr. SST . I load all of them using IMR 4064 Powder & all will print under MOA @ 100 yards , but I had to test each rifle & combos of Powder Charges & COL to get there .

   Brownings only Guarantee 2-21/2" MOA from the factory , after trying various factory loads , thats about all you will get , hand loading the Hornady's made a very big difference , with some groups having some Bullets into the same hole .  The Hornady SST is a very good shooter & judging on how many Deer /Hogs they get every year , seems to work .