bad barrel or other gremlins?...

[jc5420]

Kind of thought this would have been mentioned by now, but you need to check upper to lower fitment. With the Plum Crazy lower it is possible that either the fitment was bad to begin with or the rifle has been broke down enough to cause the lower to fit more loosely than it should. Upper to lower fitment can cause major issues with accuracy in an AR-15 platform. But as mentioned before check the barrel nut to unsure it is holding the barrel tight.

http://www.youtube.com/watch?v=IgaTzNLTRJI

He talks about fitment at 9:58 in the video.

My best advise would be if he is really wanting a scoped AR-15 rifle is to ditch that one and buy one of quality. Never anything with a polymer lower.

 

[uncle money bags]

Without inspecting the gun myself it is hard to make definitive diagnoses. At best, all that can be offered are recommendations as to the most likely cause.

having said that, I have a couple of questions.

1. what brand of ammo are you using?
2. what is the condition of the bore, throat, rifling and crown? if you can take good pics, all the better.

It is true, your friends rifle has several strikes against it in the quality department. This isn't a criticism, but a realistic assessment that needs to be taken into account so you can have an honest expectation of what the gun will do.

considering the groups are so dispersed, and that the gun is benched with a good stop on the hand guard and stock, you can disregard upper and lower fit as the issue as long as it isn't super excessive. It would maybe factor in if you were using a mag well hold, but even then it would not usually affect the shot like you describe at the distance you are talking about. Upper and lower fitment; to a degree, has no real bearing on accuracy until you start talking about sub of sub m.o.a.( moboost, correct me if this seems counter to what your experience is).

If your friend is determined to keep this gun and not just sell it or trade it away then...
Before your next outing I would suggest these things:

1. clean and inspect the chamber, throat, rifling and crown. Any obvious issues? If you can scope it, all the better.

2. Check the fit of the barrel to the upper. Optimally, you will want to remove the barrel and re torque to spec using grease on the threads. Don't do this dry. If this is a foreign procedure for you or you don't have the tools, find somebody who does. It isn't hard to do, but if you are not familiar with the platform its better to have some body who is do it for you. After you have seen it done once, you are probably golden doing it yourself in the future.

3. re mount the scope, using blue locktite, or an equivalent.

4. If you are satisfied that the barrel is right, the scope is right, and an honest assessment of your own abilities is right, it is time to shoot. Bring more than one weight of bullet for your test. You stated the barrel was a 1 in 9. you should be GTG up to 69 gr pills without issue. Depending on the length of the barrel you may get along fine with heavier but I wouldn't count on it. Probably best to stick with 55-69. I have had guns that would not print better than 5 or 6 inches with 55 gr rounds but could shoot flys with 77's. nothing wrong with the barrel, it just didnt like 55's, but made sweet, sweet love with heavy match loads. It shouldn't be necessary for you to use expensive match loads for acceptable accuracy if the gun is up to snuff. However, better quality factory ammo will be more consistent and give you better results. (Unless you happen to be a competent reloader, then all bets are off).

5. At first, forget about zeroing the gun as long as it hits paper at distance. Sacrilege, i know. You should be able to bore sight it to this degree of accuracy. To make it easier try this at 50 yards if you want, and then switch to your zero distance after you verify good groupings.
Pick a target point in the middle of the paper and give it a go for 5 to 10 rounds. if everything is tight and GTG you should have a decent grouping somewhere on the paper, (3 inches or less). If you dont, then you will be wasting ammo trying to zero. If you are satisfied with the grouping, go ahead and zero that puppy, I mean mutt. Then you can experiment with the other weight rounds, your zero should not change drastically, but you will see a difference in the size of your groups.

I hope this helps. Please let us know how things go.

 

[Hump66]

Does the scope mount span the upper and hand guard?

 

[swampratt]

You say you cleaned the barrel..
Did you use a copper remover..I am never surprised when someone brings a gun to me and states they just cleaned it.
I run some copper bore solvent through it and WOW..not cleaned at all..
Just brushing or bore snaking a barrel does not make it clean..

My .308 was shooting a tad larger groups than normal.. maybe 40-50 rounds through it with just a bore snake cleaning every few rounds , was a while since i really cleaned it..Copper was the culprit...rough savage barrels ...

And i have the 4-16x40 centerpoints on my .308 10fp and my 30-06.. tighter groups than my nikon buckmaster could muster up....Best was in the .3" for the .308 and best for the 30-06 has been in the .550" area
These have been dropped from 10 feet and kicked around and stomped on..never lost zero..Maybe i got lucky ..

 

[NikatKimber]

It *shouldn't*, but QC is important. What if the crown is bad? Build quality would be my first guess after optic and mounting though. It's far more likely that someone using bottom tier components might not put it together properly.

Let me clarify. I would think lower receiver quality shouldn't affect accuracy.

Of course lower quality, ie, poor quality, can affect accuracy.

Make a little more sense that way?

 

[Tyson C.]

Scope mount and rings properly tightened?

yes. on all three tried scopes

I suspect you don't have the 1-9 you suspect? Is it engraved on the barrel?

it is engraved on the barrel. i want to shoot a hotter round...curiosity.

http://www.youtube.com/watch?v=IgaTzNLTRJI

QUOTE]

fixing to watch this all now...

Without inspecting the gun myself it is hard to make definitive diagnoses. At best, all that can be offered are recommendations as to the most likely cause.

I hope this helps. Please let us know how things go.

thanks for all the advice. i can get some pics....maybe...

i will have to say that i put my palm to my head on your theory of sighting in. never thought about aiming at a point of intrest just shooting at paper and see how it groups then start. thanks, normally i just jump in on zeroing. what i usually do--- i have a full sheet of plywood 4'x8' and lay it long ways @100yrds. i staple 2pcs of poster board side by side and put target paper up in the middle of them. that way i have about 4' of a good idea of seeing where it might hit left to right, or a little high. shoot, measure, adjust. usually about 3-4rounds is all i need to get a zero....not all the time but most commonly, i do bore sight when i can, usually starting at 50yrd and work from there back.

Does the scope mount span the upper and hand guard?

i am assuming?? you are asking about the "bite" (span) around the rail...yes good bite. funny story about that: i have had a guy come out and let me sight in his sons rifle...he then told me "i can do mine i don't need any help", "not a prob" i said. he gets set up on the bench gives a good father to son speech about him being a great shooter, knowing all this great stuff, etc... fired off round #1 from a 30-06 and the back of the scope rings/base came off. i helped him out with my extra rings i had around..... and kept my laughter on the inside....lol

i really appreciate everyones help on this and don't worry i have someone to turn to that has handle a lot more AR's than i have. its just good to get ideas of knowing how to approach things. i love learning this type of stuff so thanks for all the info and advice.

on another note i'm not sure how long it will be in my possession, i relay this info to him and he is leaning towards a whole new gun..lol.

 

[Tyson C.]

You say you cleaned the barrel..
Did you use a copper remover..I am never surprised when someone brings a gun to me and states they just cleaned it.
I run some copper bore solvent through it and WOW..not cleaned at all..
Just brushing or bore snaking a barrel does not make it clean..

My .308 was shooting a tad larger groups than normal.. maybe 40-50 rounds through it with just a bore snake cleaning every few rounds , was a while since i really cleaned it..Copper was the culprit...rough savage barrels ...

And i have the 4-16x40 centerpoints on my .308 10fp and my 30-06.. tighter groups than my nikon buckmaster could muster up....Best was in the .3" for the .308 and best for the 30-06 has been in the .550" area
These have been dropped from 10 feet and kicked around and stomped on..never lost zero..Maybe i got lucky ..

i use Hoppes Bore cleaning #9 and bench rest #9 copper cleaner..is that ok?

i agree on the scopes. some friends of mine run CP scopes and have had great luck. after seeing how the gun is reacting i would say that the first scope (Center Point) was fine. i will say that i bought a new Bushnell DOA 600 for my .223 (replaced the Bushnell it came with)....just wasn't as clear as my first Bushnell. the DOA just didn't gather light all that well and both were same 44mm and it also had this fish bowl view to it, no matter the power, drove me nuts. i ended up trading the DOA back in for a Nikon BDC and WOW what a difference. i do however still use my orginal Bushnell as a spotting scope @ 100yrds for others that come out and shoot. it has seen its fair share of "being used and abused" and its still a great scope. i just needed a quicker reference for distance shooting, when a yote is on the run, hince the BDC i have now.

thanks for the help and info..

 

[Glocktogo]

Let me clarify. I would think lower receiver quality shouldn't affect accuracy.

Of course lower quality, ie, poor quality, can affect accuracy.

Make a little more sense that way?

Yea. Lower itself should have the least amou nt of bearing on accuracy, if any at all.

 

[swampratt]

sounds like cleaning is possibly not an issue..although i hear the #9 benchrest needs a 6-12 hour soak time.
Hope you get it figured out..

My 10fp shoots 4" groups with winchester ammo, like they are all fliers.. My 30-30 liked the rem and winchester ammo from the 1980's, but the stuff i got in 2009 would not hit 8x11 paper at 100 yards. hand loads got it back to 1.5" -1.75" at 100 yards.

could be that gun just does not like that ammo.

 

[Hump66]

I guess span was the wrong term. If you're using rings, is one on the upper receiver and the other on the handguard? Or if using amount does it cross over the joint of the upper and HG?