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98Z5V

98's 12.5" Sig Barrel .308 Win Pistol

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Physically got it together last weekend, still waiting on the custom gas tube from White Oak Armament.  Good news on that front, too - you hop on their website, put the custom gas tube in the cart, and explain your needed details in the comments section.  Don't have to call in and speak to John anymore - you state it, he'll build it, and if you gave him bad numbers...   ...then that's on you.

https://www.whiteoakarmament.com/shop/upper-parts-248/gas-tubes/white-oak-custom-gas-tube.html

Parts breakdown:

Aero Precision M5 upper and lower.

Sig 716 12.5" gas postion-spec'd barrel,  0.750" gas block journal.

KAK 0.750" set-screw lo-pro gas block, 15/16" OAL, front to back.

SB SBA3 brace, which comes with the AR15 carbine extension, 7.000" internal depth.  This necessitated breaking out my other custom 2.500" buffer that I brewed up for the .260 Rem, and it's 5.7oz.  Put in a Sprinco Orange spring.

Aero M5 lower parts kit (minimal) and upper parts kit. Battle Arms Development single-sided safety.  MagPul K2 grip.  Aero Precision's BRAND NEW 2-Stage Nickle Boron trigger setup.  Here's the trigger:

https://www.aeroprecisionusa.com/2-stage-nickel-boron-trigger

aprh101659c-schmid-2-stage-trigger.jpg

Gun Pusher John had one, so I said "Fuk it, I'll try it out..."  :thumbup:  Dry-fire only right now, but it's not bad.  It's not a LaRue MBT2S, but it's not bad.  Time will tell if it gets alot smoother with use, but the LaRue is smooth before you ever shoot it.  More coming on that trigger.

Strike Industries, ARCH-EL .308 charging handle.  The "EL" is the Extended Latch one. 

Wilson Combat 10" TRIM Rail. 

A cheap, unknown version of a BE Meyers 4-prong flash hider.  I don't know where or when I got this.  It was in the parts box.  It'll stay, or it'll go.  Shooting it at night will tell the tale.

ToolCraft nitrided .308AR BCG, of course.

That's it, for now.  It sits, until the gas tube comes in.  I'll pick up a set of Danial Defense fixed iron sights, and a PA red dot for it.  I'll probably get bored and paint this bitch next weekend.

Here she is:

P1080677.thumb.JPG.ee8084b572af834d92804cc91730a19d.JPG

P1080678.thumb.JPG.2f53150f23426ed5ddde738e7faf9a21.JPG

P1080679.thumb.JPG.bad0b8998a78095f5953e91f07ff2af2.JPG

P1080680.thumb.JPG.06be42ebd913807cf1e7ee1599aa0f3b.JPG

 

Edited by 98Z5V

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41 minutes ago, Robocop1051 said:

Sorry I’m not there to pop her cherry for you. 
 

 

You popped the 13.5" build.  Want me to save this one?  I'll wait, but you better hurry...   :thumbup:

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54 minutes ago, RedRiverII said:

Nice!!  You must have some parts box,  something like that POD box on the other thread?  It's probably a shipping container!

I have some pretty crazy shiit laying around, man - no kidding.  I'm shocked at what I find sometimes...   :lmao:

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14 hours ago, 98Z5V said:

I have some pretty crazy shiit laying around, man - no kidding.  I'm shocked at what I find sometimes...   :lmao:

^^^^^Nothing but the truth right there.

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Looks pretty nice so far!

I hope yours runs better than mine! So far I have blown up a Palmetto adjustable gas block (seriously, broke it into 3 pieces) and broke the extractor in that Wilson BCG! After the catastrophic failure of the Palmetto gas block I got one of these;

https://www.seekinsprecision.com/select-adjustable-gas-block-876.html

I was out at the range tuning it when the damn Wilson extractor took a schit! I can understand why he quit selling those BCG's I've had extraction problems with mine from day one. I just put a JP extractor in it and will take it out tomorrow and try it.

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Looks good. My 1st one took a while to get the gas adjusted correctly. It runs good now but took about 150 rnds to get to that point. Think I have the second one about adjusted right. 1failure to eject in the last 40 rnds.

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If I run into gas port problems and a lack of gas (I'm pretty certain that's gonna happen), then you guys know that I'll dive headlong into this and fix it fast.  I'm thinking of taking it out the first time just for a runability test, WITHOUT the handguard on there.  With Drill.  With bits.  One long hot range session, and sort this bastard out right then.  If I have the gas tube in this week, then it'll be out there this coming weekend - sights on it or not.  Just function testing and sorting.

If the gas tube doesn't come in this week - then it's getting painted this coming weekend.  Desert Tiger Stripe. 

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@98Z5VI just got back from the range and that JP extractor worked like a champ! No failures to extract & eject whatsoever. That Seekins adjustable gas block is awesome once you get it set. Flip it to the left and shoot suppressed and flip it to the right and shoot unsuppressed with lock open after last round on both settings. The brass lands at 3:00 suppressed and 4:00 unsuppressed both about 8 feet away.

I think this thing is humming now!:thumbup:

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4 hours ago, 392heminut said:

I think this thing is humming now!:thumbup:

SAH-WEEET, BROTHER!!!   :banana:

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So, I took the gas block back off tonight to check everything out.  For those that have this barrel, I went with one of the smallest set-screw 0.750" gas blocks that I could find, and it's a KAK low profile block, purchased from Primary Arms. OAL on the block is 15/16" long. That worked for what I wanted, which was to keep both set screws on the 0.750" portion of that barrel - those with the barrel know what I'm talking about, due to the gas-piston-designed gas port location.  I dimpled both set screw witness marks, for future.  Once the White Oak gas tube comes in, it's a shooter.

Gas port diameter in my barrel is 0.070".  We'll see if that works, but my dwell time on this barrel is 3.500".

For those that bought these SIG 716 barrels, and haven't built the guns yet - measure, measure, measure.  The only place you'll be able to purchase a gas tube will be from White Oak.  Once mine comes in, I'll confirm, but I triple-measured this thing with the barrel installed, then ordered a gas tube that's 11.000" long, AR-10 bend.  Once it gets here, during the install, I'll get all the pics in here.  I know when Jim was building his up, we talked in detail about gas tube length for this combination - and he ended up with an 11.000" gas tube measurement.  I don't know why other people are reporting gas tube lengths that are different from that, other than just maybe, gas ports were drilled in all kinds of different locations on these barrels.  Jim had one of the first, and I've got one of the last, out of that batch of 500 that CDNN had.  Weird that we came up with the same number - but there are other numbers out there, too.  All I can say is - measure, measure, measure.

Edited by 98Z5V

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I ought to start one of mine while we're talking this stuff once more.  I did order a gas tube from WOA 11 1/4" IIRC,  when you needed to explain why you wanted the length you asked for.   

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4 minutes ago, RedRiverII said:

I ought to start one of mine while we're talking this stuff once more.  I did order a gas tube from WOA 11 1/4" IIRC,  when you needed to explain why you wanted the length you asked for.   

I torqued my barrel down in the upper, and got a measurement of 10.400" from the center of the gas port to the center of the cam pin cutout.  Every gas tube made is another 0.600" longer, from the center of the gas port in the gas tube, to the end of the gas tube.  That gave me 11.000" on the money for the perfect gas tube.  We'll see how perfect I got that, once the tube gets here. 

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After seeing a comment that heminut made about extractors. I looked at the extractors on the Brownells bcg's. There is a mark where they are running into the pin sig put in the barrel extension. I ordered a different extractor and it's almost 10 thousandths thinner than the ones I had in the guns. I am still having problems w/gun number 2 not always going into battery and leaving emptys in the receiver sometimes. I didn't get any pictures when I had it apart sorry. If the new extractor still hits that pin I'll pull the thing apart and knock the pin out.

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5 minutes ago, shooterrex said:

If the new extractor still hits that pin I'll pull the thing apart and knock the pin out.

I blew that pin out as soon as I received my barrel. Gone. Knock that pin towards the INSIDE of the chamber. Outwards, IN.  Hit that fucker hard, too.

Brownell's BCGs are ToolCraft BCGs.  :thumbup:

Edited by 98Z5V

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On 5/5/2020 at 5:27 PM, 392heminut said:

@98Z5VI just got back from the range and that JP extractor worked like a champ! No failures to extract & eject whatsoever. That Seekins adjustable gas block is awesome once you get it set. Flip it to the left and shoot suppressed and flip it to the right and shoot unsuppressed with lock open after last round on both settings. The brass lands at 3:00 suppressed and 4:00 unsuppressed both about 8 feet away.

I think this thing is humming now!:thumbup:

I had ejection problems with build #2. I changed the extractor yesterday. The new one is about 10 thousandths thinner. It doesn't hit the pin sig put in the extension. Thanks for the idea. 75 rnds downrange today and no problems at all.

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9 minutes ago, shooterrex said:

I had ejection problems with build #2. I changed the extractor yesterday. The new one is about 10 thousandths thinner. It doesn't hit the pin sig put in the extension. Thanks for the idea. 75 rnds downrange today and no problems at all.

The Secret Ingredient in these barrel builds is to... punch that pin out and get rid of it.  That was a Sig thing, to cure a problem that didn't even exist in the first place... 

You had to search around for an extractor that would work with it - punch it out, run a standard extractor, zero issues.

Edited by 98Z5V

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On 5/12/2020 at 10:53 PM, 98Z5V said:

The Secret Ingredient in these barrel builds is to... punch that pin out and get rid of it.  That was a Sig thing, to cure a problem that didn't even exist in the first place... 

You had to search around for an extractor that would work with it - punch it out, run a standard extractor, zero issues.

I am going to give that a try, I had issues at first that I attributed to deformed brass around the rim area, fit in case gauge but really tight and near impossible to eject said rounds live. I have 50 or so rounds that way I've culled out, when I get a chance I'll punch the pin and cycle a few. 

Edited by Albroswift

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