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Okay,
I am not trying to open up a whole can of worms here, I am totally in the dark on what makes one AR (Grendel), more accurate than another? I know barrel quality is paramount, albeit a voodoo art, but more than that, what must be done to assure an accurate rifle?
The reason I am asking, is that I have a Grendel, with a suspect Liberty barrel, and I am trying to formulate my best course of action to get an accurate rifle in my hands. I guess I should define "accurate"..............sub-MOA. My Grendel was put together by ??, so I am in the dark there, but with the option of sending it to Precision Arms, to get the chamber checked, I am wondering what else he might do to get me where I want to go?
Sorry for the "book" post
Redraider
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11-30-2014, 11:00 PM
(This post was last modified: 11-30-2014, 11:21 PM by pds.)
Red,
There are several factors beside the barrel quality that will determine if a rifle is sub-moa capable. Quality of ammo being used and shooter ability being just two of those factors. Having shot benchrest for over 10 years I can personally say that if a shooter can't read the wind and other range conditions the best built rifle will not be sub-moa at all times. Please don't take this as a question of your shooting ability. That is not my intent. :-)
pds
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For absolute mechanical accuracy it starts with a square upper receiver face to seat the barrel extension against, bedding the barrel extension in the receiver, having a free floated barrel, making sure the gas tube is centered and does not rub against one side or the other of the gas key when the bolt carrier group moves forward, and a good trigger. The quality barrel is important also. If you use the google search in the pinned subjects at the top of this discussion board you will find many threads with good information. Billet upper receivers are stiffer and suppose to help with accuracy also. These things just apply to the mechanical accuracy the rifle is capable of. Shooter ability is a whole other topic.
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If that liberty barrel is an early one with the short throat ,you will have to reload for it .I have one that is very accurate but I have to seat the bullets deeper into the case than Hornady does on there factory ammo . I believe from memory its .030 OAL less but not sure with out checking . Besides all the other things mentioned by others above ,if you got this rifle used ,you might give the barrel a good cleaning and see how that works .
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I currently have two ar's that shoot sub-caliber groups with hand loads, and a third which makes even tulammo shoot at 1 moa. All have had the upper receiver trued, one barrel was bedded (because the fit was not as tight as the other two) and all have had their gas systems carefully aligned and BCG's checked for interference. As Joseph5 says, mechanical accuracy begins with straight, stiff barrel to receiver fit and, from there, goes on to the smoothness of the moving parts.
Some additional gains can be made by fine tuning various components (ejector polishing, lug lapping, etc.), but this is the domain of the "last 2-5%" .
Once your weapon is mechanically sound, a quality mount is needed to keep your optic rigid and true. Rings or one piece mount, they need to be free of any movement and should not introduce any uneven pressure on the scope tube.
Ammunition is very much a component of an accurate weapon. Factory ammo is, well, factory. Some rifles can shoot it quite well, but most will agree that hand loading unleashes almost very rifles potential. Since you've already got the barrel, it's up to you to discover what ammunition it likes the most. If it is a liberty barrel, you should investigate whether or not it has a compound throat or is one of the GII throated barrels. This will determine seating depth, which will help you select the bullets to load.
.02
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I also want to add that I am by no measure an expert, everything I have learned about accurate AR's and how to assemble one I have learned here on this site. I started with a Lilja barrel and a square reciever and I was able to take the knowledge I acquired here and assemble a sub MOA shooter (as long as I do my part) on my first try. There is an incredable amount of experience and knowledge here that is freely shared with anyone willing to search for it.
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One other thing that his helpful beside physicals skills involved in shooting is a good predictable, repeatable trigger pull. There is a reason after market quality triggers are more expensive than mil spec. Knowing how your going to employ your Liberty barreled Grendel will help you decide which might be the best type of trigger to buy (single stage, two stage, weight ect.).
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Quote:The reason I am asking, is that I have a Grendel, with a suspect Liberty barrel, and I am trying to formulate my best course of action to get an accurate rifle in my hands. I guess I should define "accurate"..............sub-MOA. My Grendel was put together by ??, so I am in the dark there, but with the option of sending it to Precision Arms, to get the chamber checked, I am wondering what else he might do to get me where I want to go?
Before spending serious money on sending it to a smith, see about having another (more experienced) shooter give it a go. See about trying different ammo.
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Thanks for the inputs, especially Joseph5, call me anal, but, when I stumbled on to the Grendel, I WANTED a Grendel! I was definitely disappointed when all this "different" chamber crap started up, and since I know so little about the AR, I think I will ultimately send it to Precision to at least get the chamber checked, if it IS a Grendel chamber ........okay, if it is not, but is someone else's best adaptation of the Grendel chamber..........I WANT it corrected. So, while it is there, I might as well have Mark do any of the other things that should be done to get the most accurate rifle I can have. Now this brings in the question of NOT fixing the non-Grendel chamber(if that is what I have), and upgrading to a top tier barrel.........questions, questions, questions!
For all the shooter ability folks here, I am not concerned with that, we are talking "accurate rifle" as I first stated, I appreciate all the responses, but lets limit this thread to the rifle only and what can be done to assure it's quality first
Thanks all
Redraider
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Redraider Wrote:Thanks for the inputs, especially Joseph5, call me anal, but, when I stumbled on to the Grendel, I WANTED a Grendel! I was definitely disappointed when all this "different" chamber crap started up, and since I know so little about the AR, I think I will ultimately send it to Precision to at least get the chamber checked, if it IS a Grendel chamber ........okay, if it is not, but is someone else's best adaptation of the Grendel chamber..........I WANT it corrected. So, while it is there, I might as well have Mark do any of the other things that should be done to get the most accurate rifle I can have. Now this brings in the question of NOT fixing the non-Grendel chamber(if that is what I have), and upgrading to a top tier barrel.........questions, questions, questions!
For all the shooter ability folks here, I am not concerned with that, we are talking "accurate rifle" as I first stated, I appreciate all the responses, but lets limit this thread to the rifle only and what can be done to assure it's quality first
Thanks all
Redraider
Do yourself a favor and get Mark to install a good barrel on your rifle. Liberty barrels, like any off name barrel, do not represent the higher end of the barrel business.
Mark will true up the receiver if it needs it. He will also test fire it for group so you will know its capabilities and that it actually functions.
Next would be a decent trigger. Then decent sights.
That is about it.
LR1955
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One thing for sure PF will give it the once over twice. Both my rifles came from there and both are the most accurate rifles I have owned, any will get it where the barrel is pointing but the two I have seem to make it effortless (along with the scope deal, that does not hurt)  !! BANG BANG!!
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I already have a Geissele super match trigger, and this one will be my scoped rifle. So basically, it is have the Liberty fixed, if needed, or upgrade!
Thanks again
Redraider
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LR1955 Wrote:Do yourself a favor and get Mark to install a good barrel on your rifle. Liberty barrels, like any off name barrel, do not represent the higher end of the barrel business.
Mark will true up the receiver if it needs it. He will also test fire it for group so you will know its capabilities and that it actually functions.
Next would be a decent trigger. Then decent sights.
That is about it.
LR1955
Red,
This by far is the best advice and route for you to go. PF will test fire a group and let you know.
pds
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The first, last and only thing the bullet touches is the barrel.
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jurassic Wrote:The first, last and only thing the bullet touches is the barrel.
Great quote AND so true...
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Redraider
I have one of the Liberty/Bolt combos from this past fall, I believe it is a Grendel II. I could care less as it is still called a Grendel at least, looks like a duck, quacks like a duck etc etc. This thing will shoot some scary accurate groups. It has accounted for several one hole three shot groups, even five shot groups are almost unbelievable. Couldn't be happier with it. I didn't know Liberty barrels could shoot this good. Hope you get what you want.
Steve........
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You will, or can save a ton of money reworking your rifle youself and just asking questions here dumb or not we will answer because honestly there is no dumb question when messing with firearms, its just dumb not to ask.
Most of us built ours ourselves... no need to waste money there...
If you really want a shooter starting with a quality barrel is probably your first best bet. Then slowly upgrade as needed...
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