noob from IL

[wwlefty]

hello everyone, i'm new to this site but not forums in general. i've been lurking on this site since i got the urge to "upgrade" to a 308 platform. i purchased a sun devil mfg. stripped upper/lower set and about 10 months ago as a "just in case" measure and finally got serious about the build late summer this year. i just wanted to start out with a big thank you for the wealth of info this site contains. i feel confident you guys have saved me money and, more importantly, a lot of time and hassle (the buffer info alone has been invaluable.) currently i have the upper assembled (by a competent builder) using a black hole weaponry 24' barrel, troy trx 13.8" battle rail, BCM Vltor charging handle and a CMMG BCG.

i'm wondering if i made a mistake in my selection of the sun devil platform as i started the LPK install today using the guide on the site. things went smoothly until i ran into an issue that must be fairly exclusive to the sun devil lower. they actually use a bolt catch roll pin instead of a screw. my concern is that i purchased a CMMG LPK (38CA61A minus the trigger group and grip) to assemble the lower and i'm concerned that the roll pin will be too sloppy inside the bolt catch as it has a larger hole to accomidate the screw. what is my best option, should i go ahead and assemble it "as is"? an AR15 bolt catch would probably have the proper size hole but would it hold up to the larger bolt? any advise about this issue or about another part of the build is appreciated. i included a link to my photobucket page with a pic of the lower

http://i1035.photobucket.com/albums/a438/woller1/heads%20studs%20and%20gaskets/IMG_20131214_165806_714.jpg

http://i1035.photobucket.com/albums/a438/woller1/heads%20studs%20and%20gaskets/IMG_20131213_132716_130.jpg

Edited December 15, 2013 by wwlefty

[unforgiven]

Welcome from Indiana brother wwlefty.Looks like you got a badass motor goin on.How about tappin the hole for a larger screw?? Bolt catches on .308 seem to have more meat on them vs. 5.56. <dontknow>

[planeflyer21]

Welcome from Arizona wwlefty!

[wwlefty]

Welcome from Indiana brother wwlefty.Looks like you got a badass motor goin on.How about tappin the hole for a larger screw?? Bolt catches on .308 seem to have more meat on them vs. 5.56. <dontknow>

thanks for the welcome and the complements on "ironmax" unforgiven, what part of Indiana are you from? i forgot that i had a PSA LPK downstairs so i took a look at it and the bolt catch in there was definitely not an option. i like your idea about drilling/tapping for the screw. anyone have an idea how big to drill the reciever and the thread size/pitch on the bolt catch screw?

[unforgiven]

I'm in Griffith  not far from the state line.Where's Villa Grove? You got a hole already just a matter of getting a set screw to hold bolt catch snug but not to tight.

[wwlefty]

i'm in east central IL., just about 20 miles south of Champaign-Urbana which is where the University of IL is located. if i'm not going to drill the hole bigger and tap it to use the set screw that came with the LPK why can't i just use the roll pin that came with the receiver? my main concern is the bolt catch hole is slightly oversized for the roll pin so just using a set screw that will fit the current hole would be the same effect wouldn't it?

[unforgiven]

I misunderstood bro I thought roll pin was to small.Try it see what happens.

[Dane Armory]

Welcome from AZ !

My GF is from Rockford and my stepdad was born in your neck of the woods.

I am familar with Sun Devil lowers. Buy a bolt catch like the Armalite Ar10 or the DPMS lr308 version with is larger than the standard ar15 bolt catch. Also go to a hardware store to find a threaded bolt/screw to fit you hole in the receiver. Drilling and tapping in that area is a super PITA , would NOT recemend doing that at all , way to easy to F@$k up. Order the part and wait if you have to.

[wwlefty]

let me start by saying thanks for everyone's advise, i appretiate the help. i guess i wasn't very clear about things, the LPK i have is for a 308AR so the bolt catch is the correct part. I decided to try to install it with the roll pin that sun devil supplied with the lower but after a "mock up" removal i determined there is no way the pin can be removed without a ton of difficulty even though sun devil did attempt to machine a relief for install/removal of the pin in the receiver. i decided to take dane's advice and use a screw to hold it in place but no luck at the hardware store and my buddy at the local machine shop has been working out of town on a job for the past two weeks so looks like i won't get the issue resolved until after the holidays (she's so close too!) but in the mean time here are some updated photos

[Rsquared]

That's lookin good lefty. I'm a fan of those Troy rails. They're pretty light-weight. Got one of those on one of my 10 carbine's. They're nice rails.

[wwlefty]

thanks Rsquared, I really dig it too, definitely worth the money. another question...if I may. my flash suppressor arrived today and I didn't realize it is completely round with no machined flat spots for a wrench and a crush washer also came with it. when I mocked it up it was about 260-270* off and without the ability to put a wrench on it I don't see how I can get it lined up. I did some searching and there was some mention of pre-crushing the crush washer...is this a good idea or is there a better way out there?

Edited December 27, 2013 by wwlefty

[Rsquared]

Hmm. Odd. No flat spots huh? I'd say try a strap wrench.