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My first build has hit a glitch.


gadget228

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After lurking for  several months and following some of the builds going on here I come up with the following parts list to build my own LR-308, I have bought everything but the bolt carrier, two more long weeks before I can afford to get it. This gun has two purposes , I want something that I can target shoot up to 300-500 yards and my better half wants something that she can hunt with.

 

Aero M5 upper with forward assist and door already installed.

 

Vltor BCM Gunfighter charging handle large.

 

Aero stripped lower.

 

Aero lower parts kit.

 

Geissele SSA-E trigger.

 

JP Enterprises Silent Capture Recoil spring.

 

DPMS carbine length buffer tube.

 

Mako Recoil Reducing stock.

 

Magpul pistol grip.

 

Syrac Adjustable Clamp-on gas block.

 

JP Enterprises Enhanced Bolt.

 

JP Enterprises Bolt Carrier  ( yet to buy )

 

Troy Industries Claymore Muzzle brake.

 

Fortis Switch Rail 14"

 

And lastly the barrel, First I got the Rainier Select , 20 inch model in black and when I test fitted It was too long for my needs, I called Ranier and they let swap it out for a Match 16 inch barrel in stainless and this is where the glitch comes in,

 

When I test fitted the Rainier Select barrel I also mounted the Fortis rail and they fit together with barely a seam between the back of the rail and the front of the upper receiver, With the Rainier Match barrel there is a .1.40 mm gap between the two, I checked and checked and the only thing I can come up with is the flange on the barrel extension is thicker on the match barrel than it was on the select.

 

The Match flange is roughly 3.42mm thick, any chance a member here has a Select barrel and can post the thickness of it ?  I really don't like the look of this gap and just want to get rid of it

 

 

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The Match flange is roughly 3.42mm thick, any chance a member here has a Select barrel and can post the thickness of it ?  I really don't like the look of this gap and just want to get rid of it

 

I have one.  Give me a few days to get to this.  Work sucks, and I don't remember $hit after the next day's work.  Shoot me a PM about it, and I'll remember much more quicklier. 

 

Real word.  "Quicklier."  i decided.  <thumbsup>

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  How about some photo's . The Barrel nut flange on the Barrel Extension could be thicker , if that is what you are referring to , that's keeping the hand guard away from the Upper Receiver . I think most have a slight gap , how much from Hand Guard Manufacturer to another , is up to them .

 

 Also make sure the flange is seated all the way against the Upper receiver & the adaptor or Barrel nut is seated also . We had one here not too long ago that had the same problem & the flange was not seating all the way up to the Upper receiver & is what caused his issue .

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Unfortunately the flange/receiver/barrel nut all fit flush so the only thing left has to be the thickness of the barrel flange, if I want to get rid of the gap I'm going to have the flange thickness turned down on the muzzle side so the barrel nut will fit lower, question is how much can be taken out without risking a failure.

 

The flange on the Rainier Select barrel was just about right so reducing the flange to match it should be safe, 98Z5V has a barrel that should be the same as I had so when I get the thickness from him I'll have a better ideal on my next move. I've put a lot of time and money in this build and I want it to look right.

Edited by gadget228
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Strange issue. Id think they were the same. Need to be very carefull with that flange though. Hair too much off and you wont be able to torque it down. I have the same barrel and tried to check it out last night, but my stupid wrench doesnt fit the PRI barrel nut.

That gap would bug me too.

Edited by blue109
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  I don't at this time have any Barrels not attached to something , which is odd around here , so I can't help you out .

 

  Photo's of your hand guard set up, still would be nice . The stuff we have seen here , wouldn't surprise me one bit if the flange's were not the same .

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Unfortunately the flange/receiver/barrel nut all fit flush so the only thing left has to be the thickness of the barrel flange, if I want to get rid of the gap I'm going to have the flange thickness turned down on the muzzle side so the barrel nut will fit lower, question is how much can be taken out without risking a failure.

 

The flange on the Rainier Select barrel was just about right so reducing the flange to match it should be safe, 98Z5V has a barrel that should be the same as I had so when I get the thickness from him I'll have a better ideal on my next move. I've put a lot of time and money in this build and I want it to look right.

 

 

 Interesting , I still would like to see some photo's or it didn't happen  <laughs>

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Sorry that I haven't got back sooner been busy the last few days but here is where I'm at now.

 

Following your suggestions I double checked and the barrel pin is fully seated so I took the barrel, nut and upper receiver to a local machine shop and he came up with these measurements,

 

Flange thickness was at 0.142

 

Gap between rail and upper receiver was .050 ( not sure if I have this right, it's supposed to mean 50 thousands )

 

He turned the flange down to 0.121, I didn't want to go anymore that this, too worried that it would weaken the flange.

 

I forgot to bring the rail with me when I went and picked up the barrel so I don't have a measurement of the new gap yet but will get to it later today, also working on before and after pics of the gap and will post them soon.

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You had a gap of .005, and you removed .02

Sounds like gap should be gone. I don't know if I would've even noticed a 5-thou gap. Good eye!

Personally, I would've looked into modifying the less expensive (and much less likely to kaboom) handguard. I hope your method worked.

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I can't find a way to upload or link photo's thru photobucket, I have tried to use the gallery to upload directly from computer but can't find anyway of uploading them, In a post using the image button gives me a box to load URL's but when I insert the link and click the OK button it doesn't do anything, it won't let me cancel either, I have to use the back button or close the page to get out of it.

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  • 2 weeks later...

Success... ^-^

 

Finally got my last part and tried it out last Tuesday, I have to admit I was nervous about firing that first shot, this was my first build and all the info to do it was taken from this site and youtube video's so I was 95% sure I had done it right but to be on the safe side I took a heavy wooden bench and sit it in the backyard and fired the gun from a mount while I crouched under the bench using a string to pull the trigger.

 

My better half and her dad stood about 30 feet behind the gun and said even with the mount it jumped back about six inches but everything looked normal, I only put one round in it and with the adjustable gas block set at half open ( 2 1/2 turns ) it did lock open, Next shot I turned the block down a half of a turn and it locked again, I did this again till the block was open just one turn and on the second shot it failed to eject the shell so I opened it a half turn, the next five shots all cleared, unfortunately it started to rain so that's all I was able to do.

 

All the parts I bought were to reduce recoil as much as possible so how well that works I can't say, the only guns that I have to compare it to would be a AK-47 and a 30-30 lever action and it kicks as hard as both of those do, Do want to add that the ammo I was using is the ZQ-1 that you get from your local wallyworld.

 

Gun weighs in with no scope or magazine at 8 pounds and 4 ounces and with scope push's it up to 10 pounds and 8 1/2 ounces.

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