New member and build with initial issues. Advise and input welcome

[JT303]

Hello all, I have been building AR15 for a while now and just completed my first DPMS Aero 308 build.  Mostly Aero/Ballistic advantage parts (upper/lower M5).

First time to range for barrel break in resulted in failures to cycle or lock back on single round. Loading multiple rounds also resulted in base over boat failures and jams.

Single round fired ejection occurs but is very weak at 3 o'clock.

Gas system is SA adj confirmed at full open (18 clicks).

20 rounds so far and consistently the same malfunctions. 

After reading the forums several times over, I am going to first try a carbine length M5 buffer from Aero instead of the Breek arms rifle length combo. The reason is I believe is that the buffer itself was gouged by the spring (See pic). I believe that the rifle length tube and spring may be out of spec as I did measure them several times (see below). Breek arms charging handle as well. 

I also ordered a JP SCS-10K and odin works AR10 buffer (carbine) to play with on the cycling. If it runs correctly, great. If not, I will the try to open the gas port. 

I believe that the gas port is correct size, but will measure and confirm if the buffer issue doesn't fix cycling.

It should be noted that the barrel is a BA bull barrel with a Apollo Max ultradyne muzzle break. Very minimal recoil with this comp which makes me think that has something to do with the cycling/timing and gas pressure. 

I know I will need to shoot it several times more (as 98 recommends maybe up to 200 rds) for sealing of ports etc. Just looking for some advise on the buffer/carbine combo swap and if anyone has experienced similar issues with Breek arms. Also, any tips on opening up gas port after next test fire too. 

 

1.       Aero M5 Lower/Aero Upper

2.       Buffer weight 5.44 oz

3.       Buffer Length 5.269 inches

4.       Extension Buffer Tube Internal depth 9 23/32nd inches

5.       Breek arms Rifle length buffer and tube/spring combo

Coil is 12 11/16ths depth, 35 coils, gray in color

6.       Rifle Length gas system Bought in kit from Ballistic advantage special

7.       Gas tube length=Rifle 

8.       Photo looking directly thru magwell

9.       Photo of bolt face

10.   BCG Clearance and bolt stop

11.   Gas journal and gas port diameter .936 gas block SA adjustable. Gas port to be measured if weights correct issue

12.   Photo of description of malfunction and issue fail to lock back on last round or cycle properly.

13.   Extra photos

Thanks !

JT

 

 

[shooterrex]

Take the gas block off and measure the gas port first.

You only change one thing at a time. Unless your buffer spring is totally wack the rifle length recoil system should work.

Quit throwing parts and money at the problem till you figure out what the problem is.

[Armed Eye Doc]

I second the need to measure the gas port first.  It costs nothing to check it.  There are far more potential issues with carbine buffer systems than rifle systems.

[jim3326]

Start by closing the gas block a couple clicks at a time. You're letting all the pressure off at full open.

[98Z5V]

6 hours ago, JT303 said:

After reading the forums several times over, I am going to first try a carbine length M5 buffer from Aero instead of the Breek arms rifle length combo.

Don't do that.  Just don't.

4 hours ago, shooterrex said:

Take the gas block off and measure the gas port first.

You only change one thing at a time. Unless your buffer spring is totally wack the rifle length recoil system should work.

Quit throwing parts and money at the problem till you figure out what the problem is.

^^^  Yep, what he said.

4 hours ago, Armed Eye Doc said:

I second the need to measure the gas port first.  It costs nothing to check it.  There are far more potential issues with carbine buffer systems than rifle systems.

^^^  Yep, he's right, too.

4 hours ago, jim3326 said:

Start by closing the gas block a couple clicks at a time. You're letting all the pressure off at full open.

^^^  Nope.  You run an adjustable gas port WIDE OPEN when you're running a new gun build.  The reason is simple  - you start closing that adjustable port down, and down, and down  - and it doesn't ever get any better.  Because the gas port is too small to begin with.  Undersized.  You just wasted a bunch of ammo, playing with clicks on a fancy gas block.

Adjustable gas blocks can only do one thing - reduce the amount of gas pressure going back to the BCG gas key.  They can NEVER increase the amount of gas pressure necessary to operate the platform, when the gas port is too small in the first place.

That right there is the reason you run them wide open, testing a new gun build.  Always, Wide Open...

6 hours ago, JT303 said:

20 rounds so far and consistently the same malfunctions. 

This isn't even enough rounds through the gun to create a carbon seal around the gas block-to-barrel, or the gas block-to-gas tube.  You need alot more rounds through this thing to be able to tell if it's running right.  And, you need ALOT OF LUBE...  I don't know if you took those pics before you shot it (don't think so), but that thing is bone-fucking-dry. 

[jim3326]

1 hour ago, 98Z5V said:

Don't do that.  Just don't.

^^^  Yep, what he said.

^^^  Yep, he's right, too.

^^^  Nope.  You run an adjustable gas port WIDE OPEN when you're running a new gun build.  The reason is simple  - you start closing that adjustable port down, and down, and down  - and it doesn't ever get any better.  Because the gas port is too small to begin with.  Undersized.  You just wasted a bunch of ammo, playing with clicks on a fancy gas block.

Adjustable gas blocks can only do one thing - reduce the amount of gas pressure going back to the BCG gas key.  They can NEVER increase the amount of gas pressure necessary to operate the platform, when the gas port is too small in the first place.

That right there is the reason you run them wide open, testing a new gun build.  Always, Wide Open...

This isn't even enough rounds through the gun to create a carbon seal around the gas block-to-barrel, or the gas block-to-gas tube.  You need alot more rounds through this thing to be able to tell if it's running right.  And, you need ALOT OF LUBE...  I don't know if you took those pics before you shot it (don't think so), but that thing is bone-fucking-dry. 

That's my bad, thought he said the port was.093. Coffee hadn't kicked in yet.

[JT303]

13 hours ago, 98Z5V said:

Don't do that.  Just don't.

^^^  Yep, what he said.

^^^  Yep, he's right, too.

^^^  Nope.  You run an adjustable gas port WIDE OPEN when you're running a new gun build.  The reason is simple  - you start closing that adjustable port down, and down, and down  - and it doesn't ever get any better.  Because the gas port is too small to begin with.  Undersized.  You just wasted a bunch of ammo, playing with clicks on a fancy gas block.

Adjustable gas blocks can only do one thing - reduce the amount of gas pressure going back to the BCG gas key.  They can NEVER increase the amount of gas pressure necessary to operate the platform, when the gas port is too small in the first place.

That right there is the reason you run them wide open, testing a new gun build.  Always, Wide Open...

This isn't even enough rounds through the gun to create a carbon seal around the gas block-to-barrel, or the gas block-to-gas tube.  You need alot more rounds through this thing to be able to tell if it's running right.  And, you need ALOT OF LUBE...  I don't know if you took those pics before you shot it (don't think so), but that thing is bone-fucking-dry. 

 

[JT303]

Awesome advise 98 and all. All things have been pointing me to the gas port size. I should have taken that measurement BEFORE I installed it but I had faith BA was going to port the barrel correctly. I have also cleaned and wiped the parts down before taking these photos. I will take your advise and run it much more wet going forward. I grabbed a set of small HSS mm drill bits to measure the port and will try to get that number back to everyone.

Yes, I do agree that I am throwing money at parts I probably don't need, but that also gives me more parts for another build. (LOL) 😁

Gotcha all on wide open gas block. (The reason I got one was eventually, I may go suppressed and wanted that flexibility in the future) one day.

Any advise on the bad knicks on the buffer? I dont think those gashes and the tube/spring sizing is right.   

 

I only have a small dremel sized drill press so if I need to open the port up any advise on the drilling part? Just do it with hand electric or ? I know, nice and slow.....

Recommendations for best port size based on 20" BA Bull barrel SS approx 6.5" from gas port to muzzle (Not including comp) ?

Saw in other posts suggested .093 to .096 for 20" but just checking.

 

Thanks

 

JT

 

 

[JT303]

18 hours ago, Armed Eye Doc said:

I second the need to measure the gas port first.  It costs nothing to check it.  There are far more potential issues with carbine buffer systems than rifle systems.

I was unaware that carbine stocks were more troublesome than Rifle lengths on the 308 platform. My intention was also use this lower and swap the upper out with a 6.5 CM in the future. Hoping that one lower works with others is a money saver. 🙂 

[JT303]

Its all fun and games until you strip a gas block screw. Dang it. Now gotta get some more tools. Will advise my port size after I get that bugger off. 

 

[98Z5V]

13 hours ago, JT303 said:

I only have a small dremel sized drill press so if I need to open the port up any advise on the drilling part? Just do it with hand electric or ? I know, nice and slow....

Electric hand drill is perfectly fine, and easy to do.  The pilot hole is already right there, just follow it.  Slow speed, light pressure on the drill, and just let the bit eat - let the bit do it's work, it will, in short order.  If it makes you nervous, shove a 1/4" wooden dowel down the barrel first, for protection of the other side of the barrel.  If it's light pressure on the drill, and slow speed, that won't happen anyway, but it's an insurance policy against "BUCK FEVER!" and just going after it!... 

13 hours ago, JT303 said:

Recommendations for best port size based on 20" BA Bull barrel SS approx 6.5" from gas port to muzzle (Not including comp) ?

Saw in other posts suggested .093 to .096 for 20" but just checking.

If you're running a 20" barrel with a rifle gas system, .308 Win caliber, and a 0.750" gas block journal size - that's perfect information.  0.093"~0.096" is exactly where you'll need to land, with a proper recoil system, and that barrel configuration. 

HOWEVER...   You are running a barrel with a 0.936" gas block diameter.  You need to target your gas port size right around 0.085", a few thou to either side should be okay.  Call it 0.083"~0.087". 

[JT303]

10 hours ago, 98Z5V said:

Electric hand drill is perfectly fine, and easy to do.  The pilot hole is already right there, just follow it.  Slow speed, light pressure on the drill, and just let the bit eat - let the bit do it's work, it will, in short order.  If it makes you nervous, shove a 1/4" wooden dowel down the barrel first, for protection of the other side of the barrel.  If it's light pressure on the drill, and slow speed, that won't happen anyway, but it's an insurance policy against "BUCK FEVER!" and just going after it!... 

If you're running a 20" barrel with a rifle gas system, .308 Win caliber, and a 0.750" gas block journal size - that's perfect information.  0.093"~0.096" is exactly where you'll need to land, with a proper recoil system, and that barrel configuration. 

HOWEVER...   You are running a barrel with a 0.936" gas block diameter.  You need to target your gas port size right around 0.085", a few thou to either side should be okay.  Call it 0.083"~0.087". 

Yes, I have a 0.936" gas block diameter. As soon as I can get this messed up Allen gas screw out I will let you know what the current port size is. getting an extractor tool tomorrow and some uncure fluid. 

[shooterrex]

A left handed drill bit will get the messed up set screw out .

[JT303]

21 hours ago, shooterrex said:

A left handed drill bit will get the messed up set screw out .

Yeah, I ordered a little extraction set which is basically the same thing. I should have just went and bought that to begin with, but I was trying not to strip it too badly or mess up the threads, but I wound up stripping it that anyway. Threads still okay. Tried smacking and JB welding a torx head and gonna try that with uncure fluid. If not, its getting drilled out. I have always hated little allen head screws. Wish someone would come up with something better.  

[JT303]

Success. JB weld a T15 torx head and some overnight Uncure debonder did the trick.

The carbon on the gas port is perfectly centered (sorry bad pics)

Measurement I did the best i could. 

I came up with it currently just a little loose using a 2.0 mm bit.

The 2.35 bit does NOT fit.

I also used a caliper and came up 2.12mm

So by my math, if I should open it up to 2.2mm to make it .086 per recommendation by 98. (IT IS A .093 size BULL Barrel).

Gonna try and find a 2.2mm cobalt bit right?

 

 

 

 

 

    

 

 

[JT303]

On 4/2/2023 at 1:59 PM, shooterrex said:

Take the gas block off and measure the gas port first.

You only change one thing at a time. Unless your buffer spring is totally wack the rifle length recoil system should work.

Quit throwing parts and money at the problem till you figure out what the problem is.

Got a measurement of 2.12mm (.0827) approx. (See pix below in thread).

I am really not far off from 98 port recommendation for .0936 sized barrel.

Got some 2.2mm bits ordered to give it a bit more opening. (I have a 2.35mm bit just in case I need more)

I still think the spring and buffer are too much, but Im going with everyone's consensus for the combined expertise to increase gas first. 

Thanks! 

 

[JT303]

On 4/4/2023 at 12:27 PM, shooterrex said:

A left handed drill bit will get the messed up set screw out .

That was my next step, and the JB welded T15 did the trick. The extractor set has been on my wish list for a while anyway. 

Gonna go get some HF left bits for future use. Hey for $8.50 cant go wrong if it saves me time in the future.

[98Z5V]

Just dump the metric shiit and use numbered drill bits.

This is the same chart I always use for reference, all the time, so I always stay consistent.

https://littlemachineshop.com/Reference/NumberDrillSize.php

[NF1E]

Listed to this guy, he's the bee's knees of this type of rifle.  Whatta Hobby!

[JT303]

11 hours ago, 98Z5V said:

Just dump the metric shiit and use numbered drill bits.

This is the same chart I always use for reference, all the time, so I always stay consistent.

https://littlemachineshop.com/Reference/NumberDrillSize.php

Thanks 98 !!

Sweet site ! That makes it easy and stay consistent too.  

I was searching for a nice set and couldn't find anything decent out there nearby. Wound up just ordering 2.2mm (pk of 5) for 10$ on amazon. Will be here Sat and will get it opened up a notch. Probably will order that set next week too. Cant have enough extra tools/bits for future builds. 🙂

98. You should teach some online courses or YouTube some stuff. I'm not Mr. internet but I'm sure your experience and knowledge would help many out there with future builds. Great info !    

[JT303]

11 hours ago, 98Z5V said:

Just dump the metric shiit and use numbered drill bits.

This is the same chart I always use for reference, all the time, so I always stay consistent.

https://littlemachineshop.com/Reference/NumberDrillSize.php

The bits from there are actually manufactured near me. go figure...........(but they charge more at the source, thanks IL😂🙃) I am so moving out of here.

 

[JT303]

6 hours ago, NF1E said:

Listed to this guy, he's the bee's knees of this type of rifle.  Whatta Hobby!

I noticed in your aero build that you used a Aero rifle length tube. I have a Breek arms Rifle length spring and buffer. My coils measured kind of long and the buffer is 5.4oz. 

I am curious as to what your buffer spring length, # of coils and inside depth of the tube is? 

Also, if you have any nasty gouges in your buffer as I posted in this thread?

I'm gonna be drilling my gas port a bit tomorrow and out to the range next week for test fire. Pretty sure I need a bit more gas with the current set up but also have a feeling my spring is too strong still. I took a chance on a good deal with Breek arms on the buffer tube set, but they are supposedly up to spec. 

Anyway, thanks again brother from another branch. Stay safe

 

    

[NF1E]

Didn't pay much attention, or don't remember coils or buffer weight other that they were what was recommended. I do remember that I needed to close my agb half way because it was overgased and has run great with all ammos tried from 110gn to 175 without a hickup since.

[shooterrex]

From your pics the gas block doesn't have enough carbon to seal yet.

The pic of your gouged buffer isn't showing up. It shows a broken link on my end.

These guns take some breaking in to get everything working. Your probably looking at 100-200 rounds. Maybe less maybe more.

[JT303]

18 hours ago, shooterrex said:

From your pics the gas block doesn't have enough carbon to seal yet.

The pic of your gouged buffer isn't showing up. It shows a broken link on my end.

These guns take some breaking in to get everything working. Your probably looking at 100-200 rounds. Maybe less maybe more.

Yes, Gas block had only seen 20rnd for barrel break in. Now that I took it off, I will need many more.

Let me know if you can see this attached pic. Its gouged where the end of the spring meets the center of the buffer stop ring. The damage aligns with the spring.

To me, that is saying its too much force in spring compression.   

No other damage on the lower receiver or bolt carrier is observed.