About to start another AR build…. Stay tuned

[Lumber_Jack]

Someone explain the low mass BCG to me. What's the purpose

[mikegideon]

Someone explain the low mass BCG to me. What's the purpose

 

Less mass flying around, less of the gun flying around. You can reduce the mass of the BCG and buffer, then tune it all with adjustable gas pressure. On top of that, he added a battlecomp. That thing is gonna stay on the target. With that trigger, it's set up for accurate rapid fire. Gonna be a helluva gun.

[Lumber_Jack]

Less mass flying around, less of the gun flying around. You can reduce the mass of the BCG and buffer, then tune it all with adjustable gas pressure. On top of that, he added a battlecomp. That thing is gonna stay on the target. With that trigger, it's set up for accurate rapid fire. Gonna be a helluva gun.

I wasn't sure how that affected the buffer and gas. Thanks.

[sigbrown1297]

I went from a 7.5" Noveske Diplomat SBR on my very first build so this thing should be much flatter shooting.

Edited December 10, 2013 by sigbrown1297

[mikegideon]

This thing is set up to be a 3 gun killer. Hope you're gonna do some of that

[sigbrown1297]

Something I've always wanted to get into but never have. I'm guessing they have certain regs on what you can use?

[mikegideon]

don't know. I just know you have the best 3 gun trigger on the planet, and a gun that's set up to exploit it. I think the regs are pretty loose

[sigbrown1297]

Yeah I was teetering between the SD-E and the SD-3G but didn't want a two-stage. I don't do much bench shooting either so I went with the SD-3G.

[mikegideon]

Yeah I was teetering between the SD-E and the SD-3G but didn't want a two-stage. I don't do much bench shooting either so I went with the SD-3G.

 

Two stage is the bomb on an AR. The 3G is a fast trigger, but not an accuracy one (outa Bill Geissele's mouth). What you're gonna have is a really kickass 3 gun rifle. I'm a big Geissele fan. I don't have any of the SD triggers, but have 2 SSA's, and SSA-E, and a High Speed Match. Best AR triggers you can buy IMO.

 

BTW: Bill also says it can be shot accurately with a learning curve, but its purpose is rapid fire

Edited December 10, 2013 by mikegideon

[sigbrown1297]

Two stage is the bomb on an AR. The 3G is a fast trigger, but not an accuracy one (outa Bill Geissele's mouth). What you're gonna have is a really kickass 3 gun rifle. I'm a big Geissele fan. I don't have any of the SD triggers, but have 2 SSA's, and SSA-E, and a High Speed Match. Best AR triggers you can buy IMO.

 

BTW: Bill also says it can be shot accurately with a learning curve, but its purpose is rapid fire

Yup, i just wanted a fast trigger.

[mikegideon]

Yup, i just wanted a fast trigger.

 

You're gonna have the most accurate mag dumps on the block. :) That BattleComp rocks too. I have one on my favorite carbine with an SSA-E and an Eotech.

Edited December 10, 2013 by mikegideon

[Luke E.]

More parts came in today. Upper/Lower should come in tomorrow

JP 14.5" .223 Wylde Chrome Lined Barrel 1:8 Twist Black Teflon Coating


Burris XTR 1-4-24 with FastFire III




JP Low Mas Bolt Carrier High Polish (this thing is a machined piece of artwork)




JP Enhanced Bolt (individually head-spaced to barrel)

If you were trying find your way to a great platform decked out in some of the best parts out there that when combined will net you a top notch competition rifle, sir you have arrived at your destination and you've done so in style!! That is gonna be one awesome competition rifle whether you ever decide to compete with it or not. You have made me drool a little.

[sigbrown1297]

Still waiting on the Upper/Lower.  Hopefully tomorrow.  In the meantime, I had some time to put the gas tube in to the block.  Little painters tape to protect the gas block, leatherman to hold and start the roll pin, and a hammer and 1/16 and 3/32 punches to drive the pin in.

 

[url=http://s19.photobucket.com/user/sigbrown1297/media/IMG_6495_zpsc51c3c95.jpg.html][/URL]

 

[url=http://s19.photobucket.com/user/sigbrown1297/media/IMG_6494_zps788c6a0e.jpg.html][/URL]

 

[url=http://s19.photobucket.com/user/sigbrown1297/media/IMG_6497_zpsf07cd975.jpg.html][/URL]

 

[url=http://s19.photobucket.com/user/sigbrown1297/media/IMG_6496_zpsceb7e7bc.jpg.html][/URL]

Edited December 11, 2013 by sigbrown1297

[Guest Phizzle99GST]

Dangit! you convinced me to order a JP low mass bolt for my 308 build! lol ordering the JPBC-4SPA soon...and maybe the Syrac adjustable gas block

Edited December 11, 2013 by Phizzle99GST

[sigbrown1297]

well i got the lower/upper in today.  The matched billet set is amazing. The fit between them is incredible with absolutely no play, even without the pins.  

 

 

However, when doing a test fit, i learned to my disappointment that the Geissele SMR rail will NOT work with the Mega Billet upper.  The locking tabs of the rail slides over the upper and there is too much material in the billet upper to fit.  F*CK!!!!   What to do….  I don't want to use another upper so my other two options are to find a machine shop that can machine out the excess material or use a different rail.

Edited December 12, 2013 by sigbrown1297

[mikegideon]

I wouldn't machine the receiver

[Lumber_Jack]

[quote name="mikegideon" post="1077490" timestamp="1386810756"]I wouldn't machine the receiver[/quote] Me either. I'd get a different rail Edited December 12, 2013 by Lumber_Jack

[sigbrown1297]

the mock up looks amazing.  That rail is so sexy and made well.  So disappointed… :(

 

I've got the lower completed, but now i gotta figure out what I'm gonna do.  

 

If I machine the lower, i wouldn't have to remove much and the machined part would be covered up.  I don't think i can machine the rail.  There very little material on those locking tabs.

 

I'll put up some pics later

Edited December 12, 2013 by sigbrown1297

[sigbrown1297]

If anyone knows a good machine shop that can do a small job like this, let me know.

[mikegideon]

Kick this around in your head. Since the rifle is gonna be such a fast shooter, think about adding the JP dissipator to the barrel and use their handguard. It's gonna change the look of the gun, but it will probably work better

[mikegideon]

If anyone knows a good machine shop that can do a small job like this, let me know.

 

How much machining would have to be done? You don't want to bite into the structural integrity of the receiver. I would change receivers first

[sigbrown1297]

How much machining would have to be done? You don't want to bite into the structural integrity of the receiver. I would change receivers first

Very very little.  it may only need to be one on one side.

[Lumber_Jack]

[quote name="sigbrown1297" post="1077507" timestamp="1386812111"]Very very little. it may only need to be one on one side.[/quote] Can you mock it up and take a pic. I'm having a hard time picturing what needs to be removed. You'll have to have it refinished after grinding on the upper

[sigbrown1297]

Yeah. I'll get some pics up. Gotta upload them to photobucket first. But before that, I'm going to try to relieve my frustration by stuffing myself with some Mexican food first.

[sigbrown1297]

The upper and rail is mated, but this is without the barrel nut.

[url=http://s19.photobucket.com/user/sigbrown1297/media/ar15/IMG_0205_zps6ff24cf4.jpg.html][/URL]

 

Another shot of the upper and rail without the barrel nut.  

[url=http://s19.photobucket.com/user/sigbrown1297/media/ar15/IMG_0204_zps25966c31.jpg.html][/URL]

 

​Pic of the locking tabs that slide over the upper.

[url=http://s19.photobucket.com/user/sigbrown1297/media/ar15/IMG_0203_zps902e5d08.jpg.html][/URL]

 

[url=http://s19.photobucket.com/user/sigbrown1297/media/ar15/IMG_0200_zpsa2474363.jpg.html][/URL]

 

 

Upper and rail with the barrel nut installed.  You can see that the upper has too much material to slide under the locking tabs.  there is about a 1/2inch gap between the upper and rail since the rail cannot mate up against the upper.

[url=http://s19.photobucket.com/user/sigbrown1297/media/ar15/IMG_0199_zpsc074dd67.jpg.html][/URL]

 

Another shot showing the No Go.  Its just hitting the lower corner of the upper.

[url=http://s19.photobucket.com/user/sigbrown1297/media/ar15/IMG_0198_zpsc44a02da.jpg.html][/URL]

 

 

​Gap between the upper and rail.

[url=http://s19.photobucket.com/user/sigbrown1297/media/ar15/IMG_0195_zps351764ef.jpg.html][/URL]

 

Bottom view showing the gap.

[url=http://s19.photobucket.com/user/sigbrown1297/media/ar15/IMG_0193_zpsab3100b7.jpg.html][/URL]

Edited December 12, 2013 by sigbrown1297