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I have never installed or removed a barrel from a AR before and finally got one in 6.5 Grendel. It is a 24" AA Overwatch that I'd like to shed some weight on. I am looking to have the barrel fluted. I have read horror a story or two about people damaging there uppers during the R&I process. I have a AR vice block that the upper pins into but I have also seen the wrap around vice blocks, What is the best/safest way to do this?
I know this is childs play to most here and I wouldn't mind jumping right in on a M4 upper but really don't want to F-up my factory AA upper or hinder its accuracy.
My rifle also has the carbon fiber hand guard that I will have to access from the rear of the barrel nut.
I am showing my ignorance here and do appreciate any positive and constructive advice or help. Thanks.
Don't use the upper receiver insert with cross pins to try to remove that barrel. It will likely crack your lugs, since your barrel is bedded with Blue loc-tite, and needs to be prepped with penetrating oil in the barrel nut area, set overnight, then torqued off with an armorer's wrench.
The heat you need can be generated from a blow dryer or heat gun, and doesn't need to be anything crazy like from a torch. You could also bake the upper on low temp, like 180-200F.
What kind of accuracy are you getting right now?
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Another thing to consider is fluting will probably not shed that much weight and you may want to consider just getting another barrel and building another upper I think there are still a few barrels available in the liberty group buy
Punctuation is for the weak....
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LRRPF52 Wrote:What kind of accuracy are you getting right now?
I have only had time to do a rough site-in, But the best 50 yard group was one ragged hole. I also didn't want to shoot up much ammo with the horrific stock trigger. I just put a 3lb drop in Timney last night.
mongoosesnipe Wrote:Another thing to consider is fluting will probably not shed that much weight and you may want to consider just getting another barrel and building another upper I think there are still a few barrels available in the liberty group buy
I have considered this route too, I'd really like to keep this rifle all original but shed a few OZ's. It looks like I could cut 8-10 oz by fluting.
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Yes, the fluting drops more weight than you think. I have an 18" Fluted and a 16" non fluted and the 18" is oz's less than the 16". I have the data at home but got my scale the other day to start the comparison chart. You could shed a lot of weight off a 24" barrel for sure....
As far as your accuracy, crap with a 24" barrel you should be half way to the target with that barrel. My 24" Stoner is getting 1" to 1.5" groups at 200 yards but heavy as hell. I was going to cut it down to 20" but just got my Lilja AR740 (20") so not sure what I'll be doing with it now...
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I got an AR740 and a 311 in the Lilja buy, both fluted. The AR740 wieghs in at 2.06lb and the 311 weighs in at 1.94lb. Lilja's EDs list them NOT fluted at 2.43lbs-AR740 and 2.25lbs-311.
So you're looking at a 15%-20% weight savings, maybe more.
"Those who sacrifice liberty for security, deserve neither." Benjamin Franklin
Won't fluting after the barrel is made effect accuracy??? I've though about this a couple of times and have been turned off to the idea by reading about it.
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PigOPs Wrote:Won't fluting after the barrel is made effect accuracy??? I've though about this a couple of times and have been turned off to the idea by reading about it.
I have researched this quite a bit. I have yet to find any creditable source to say properly milled fluting will change accuracy ANY. I talked with a few smiths who do this and of coarse they said none done in their shop(s) have decreased accuracy. Some suggested better groups after fluting, Something about changing of the harmonics.
I am all for actual factual info that says it will hurt group size, That would change my game plan for sure.
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PigOPs Wrote:Likewise, if I hear factual info stating the opposite I would be in to have mine done... Come on experts, weigh in!
Will it change the accuracy of loads you've established for that barrel? Quite possibly (change in harmonics). Will it diminish the accuracy of the barrel in general if milled correctly? The research I've done says no. If you see accuracy change afterwards, try reworking your loads.
"Those who sacrifice liberty for security, deserve neither." Benjamin Franklin
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I don't what all barrel manufactures do but a lot of them, fluting is the last step, then polishing and engraving. Of course if coated that is next so whether they do it or you should not matter.
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cory Wrote:I got an AR740 and a 311 in the Lilja buy, both fluted. The AR740 wieghs in at 2.06lb and the 311 weighs in at 1.94lb. Lilja's EDs list them NOT fluted at 2.43lbs-AR740 and 2.25lbs-311.
So you're looking at a 15%-20% weight savings, maybe more.
Liberty 18" Fluted- 1lb 14oz
Liberty 18" NON-Fluted- don't have one right now apart to weigh
Liberty 16" NON Fluted- 2lb 1oz
Brownells 18" with .755" behind the GB 2lb 1.6oz
Lilja AR740 20" with .742 behind the GB 2lb 3.1oz
Not sure how to calculate Cory's AR740 with .06 oz, but about 3 oz's less with fluting
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01-29-2014, 10:40 PM
(This post was last modified: 01-29-2014, 10:44 PM by cory.)
It's not .06ozs it's .o6 lbs, which converts to 1oz.
Huh Lilja's website lists the AR740 at 2.6lbs or 2lbs 9.6ozs. I guess that would make since with a large bore being removed. duh
"Those who sacrifice liberty for security, deserve neither." Benjamin Franklin
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afew ounces for all this fuss. im out. carry on.
I think you would be much better leaving a factory built AA upper alone and building another one.
