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Posted: 8/13/2010 8:37:41 PM EDT
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::::Update 8-14 new Range report I finished a SPRish build with a 1/7in 18in barrel from WOA. I've shot about 150 rounds and cleaned it a few times.  Today I shot for some groups at 100 yards off a bench with sand bag rests. I used Prvi Match 69 and 75 grain. I have a 3x ACOG with a 2MOA dot. I was shooting at a Black dot about 3.5 inches. I was able to center the ACOG dot perfectly inside the Black dot. Theoretically with this set up I should be able to get MOA if I do my part. Well I shot the Prvi 75gr and the wind was ~5mph.  The Prvi 69gr was shot in 5-10mph variable wind.  Sorry that the text is sideways, The targets are aligned properly though. Some might blame the ammo but Molon's thread makes it appear that Prvi match is pretty good stuff. http://www.ar15.com/forums/topic.html?b=3&f=16&t=491816 I'm sure I installed the Handguard correctly and my gas tube is aligned properly with my BCG gas key. ACOG is tight on the receiver. Could the flash hider be causing this? What else aside from me could be the issue? Maybe I need to buy some 75gr TAP but I choke at paying 1$ a round for 223 ammo. My reloading stuff is 400 miles away too. Edit to add: -RRA 2 stage trigger -Resting on crushed Corn kernel filled bag Update 8-14 Range report |
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First I would try some better optics if you're looking at achieving MOA accuracy. Second, I would try 3 or 4 other types of ammo (BH Match, Fiocchi Match, Corbon 69gr & 77gr, Hornady Match). Then if you aren't able to shoot MOA or better I think there is a problem.
-Cody |
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I really don't mean any offense, but have you in fact ever shot a MOA or sub MOA group with any rifle before? I'm not trying to be condescending, just asking. Shooting small groups isn't as easy as it looks and requires a good amount of trigger control. I know that you feel that you are keeping the dot centered, but odds are that you aren't. You are using an ACOG, which was never intended to do what you are doing with it. What trigger are you running? A stock type of trigger? Maybe your rifle doesn't like the Prvi ammo. I know that mine isn't particularly fond of it.
When you test the capabilities of equipment, it's always good to have lots of magnification (assuming good glass), a very good trigger, good ammo and great trigger control. My rifle can shoot .5-.75" five shot groups, when I'm shooting good and I'm running a 10X scope and a Geiselle trigger. If you want to test what your rifle can do, I'd throw at least a 3-9X on top of it, get a box of black hills 77gr ammo and, if you don't have it, a good trigger. I'm not suggesting that you absolutely can't shoot a tight group with an ACOG. I'm not looking to get flamed, but for the average shooter, an ACOG isn't the best piece of equipment for shooting groups. |
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Quoted: First I would try some better optics if you're looking at achieving MOA accuracy. Second, I would try 3 or 4 other types of ammo (BH Match, Fiocchi Match, Corbon 69gr & 77gr, Hornady Match). Then if you aren't able to shoot MOA or better I think there is a problem. -Cody I don't have any spare 1" mounts for spare scopes unfortunately. I guess I could go buy some. I do need to get some new ammo, unfortunitly anything I get has to be internet ordered so I cannot easily go down to the gun store. I'll order some TAP and BH soon. Quoted: I really don't mean any offense, but have you in fact ever shot a MOA or sub MOA group with any rifle before? I'm not trying to be condescending, just asking. Shooting small groups isn't as easy as it looks and requires a good amount of trigger control. I know that you feel that you are keeping the dot centered, but odds are that you aren't. You are using an ACOG, which was never intended to do what you are doing with it. What trigger are you running? A stock type of trigger? Maybe your rifle doesn't like the Prvi ammo. I know that mine isn't particularly fond of it. When you test the capabilities of equipment, it's always good to have lots of magnification (assuming good glass), a very good trigger, good ammo and great trigger control. My rifle can shoot .5-.75" five shot groups, when I'm shooting good and I'm running a 10X scope and a Geiselle trigger. If you want to test what your rifle can do, I'd throw at least a 3-9X on top of it, get a box of black hills 77gr ammo and, if you don't have it, a good trigger. I'm not suggesting that you absolutely can't shoot a tight group with an ACOG. I'm not looking to get flamed, but for the average shooter, an ACOG isn't the best piece of equipment for shooting groups. I have shot MOA groups at 100 yards with other guns. But it's mostly with reloaded ammo so that gives me a leg up. I know that ACOG is not the best target optic but I'm curious what I can do with it and I want to find the best ammo for this combo. This set up should be capable of at least 1-1.5 inch groups at 100 yards with good ammo. Heck I can shoot 10 round 3.75 inch groups at 100 yards with Prvi M193 with a 2 MOA Aimpoint. And if you remember Molon's post about Prvi M183 he was averaging 3.5 inch groups. Quoted: What were you resting it on? Jeans bags filled with semi-crushed corn kernels. Front is completely rested and stock is resting on my hand which is on a bag. Quoted: Are you concentrating on your trigger control? Do you have a 2-stage trigger? A lot of the time that could be the problem. I have a RRA 2 stage in it. I'm getting the rifle lined up and make sure that I can close my eyes for 5 seconds and the sights don't move. Then I slowly break the trigger so it surprises me. I was shooting at about 4-5pm facing almost directly West so could have the sun caused some bad mirage or something? |
First off, awesome new build and congrats
Now to the business of hand, As nice as Acogs are, they are not anything I would every want to do any kinda of bench work with or if I did, I would not be expecting stunning results. I personally believe you need a magnified piece of glass in the range of 8-10x, and any bench shooter will most likely believe that is really to underpowered. As far shooting groups goes...I really need two things to be present on a gun for me to be effective and precise with it...one is a solid, no play buttstock with a repeatable and great cheekweld....your m4 stock is lacking a bit imho for your desired applications. The second is a quality match 2 stage trigger with a significantly reduced pull, and although the RRA's can feel great and be a solid, quality trigger its just not the best one for precision shooting. Ammo selection: It takes me numerous range trips along with 5-6 diff. types of ammo ranging from 55gr. hornady vmax to 68gr. BH's match HP. all the way up to 75gr. TAP T2 and BH's mk 262 before I have a clue as to what my barrel likes to eat best. Bottom line is it takes a minute to put enough diff. types of ammo in a new barrel before anybody can know what round is the go to load. Lastly the precision AR is the most skilled and hardest to perfect within the world of ARs, and you cannot expect to take a brand new rifle to the range the first time with accuracy from the bench the intended purpose and expect to see awesome stuff on the paper. It will take you some time to refine that awesome looking build of yours and your own ability to shoot with it. You should stay positive about it and think of this as the starting place and now work your way forward through time on actual gun as well as refining the actual build's specs to serve precision applications the best. |
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Quoted: First off, awesome new build and congrats Now to the business of hand, As nice as Acogs are, they are not anything I would every want to do any kinda of bench work with or if I did, I would not be expecting stunning results. I personally believe you need a magnified piece of glass in the range of 8-10x, and any bench shooter will most likely believe that is really to underpowered. As far shooting groups goes...I really need two things to be present on a gun for me to be effective and precise with it...one is a solid, no play buttstock with a repeatable and great cheekweld....your m4 stock is lacking a bit imho for your desired applications. The second is a quality match 2 stage trigger with a significantly reduced pull, and although the RRA's can feel great and be a solid, quality trigger its just not the best one for precision shooting. Ammo selection: It takes me numerous range trips along with 5-6 diff. types of ammo ranging from 55gr. hornady vmax to 68gr. BH's match HP. all the way up to 75gr. TAP T2 and BH's mk 262 before I have a clue as to what my barrel likes to eat best. Bottom line is it takes a minute to put enough diff. types of ammo in a new barrel before anybody can know what round is the go to load. Lastly the precision AR is the most skilled and hardest to perfect within the world of ARs, and you cannot expect to take a brand new rifle to the range the first time with accuracy from the bench the intended purpose and expect to see awesome stuff on the paper. It will take you some time to refine that awesome looking build of yours and your own ability to shoot with it. You should stay positive about it and think of this as the starting place and now work your way forward through time on actual gun as well as refining the actual build's specs to serve precision applications the best. Thanks for the reply bud. I must defend the stock by saying that it's definitely not permanent, I'm waiting around for a used URB or similar to snatch up.  I guess the next step for me is trying some new ammo, I'll get some TAP, BH, and some Hornady Vmax (Hang on! Thanks for reminding me, I have 20 rounds of 60gr VMax TAP loaded in a mag that I completely forget about). There's no denying that I need more practice, unfortunately come Monday I'm leaving my rural location and heading down to PHX until December so I probably wont be able to do any decent AR shooting more than once or twice in the next four months. I'll be heading to the range in about 12 hours so I'll take some prvi 69 and 75 grain and work on my fundamentals more and see if I can improve over today's performance. I'll also shoot a group of the recently discovered 60gr VMax. I kinda want to prove that I can shoot 8-10 rounds 1.25-1.5 inch groups with my set up. I like a challenge. But Once I get the opportunity I will throw on a 3-9x to take that variable out of the equation. As an aside, I shot a 5 round 1.18" group yesterday when I was zeroing in the rifle using the Prvi 75gr. |
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Quoted:
I really don't mean any offense, but have you in fact ever shot a MOA or sub MOA group with any rifle before? I'm not trying to be condescending, just asking. Shooting small groups isn't as easy as it looks and requires a good amount of trigger control. I thought eveyone on the Internetz could shoot sub-MOA groups? Seems like everyone here says they can shoot an apple off their wife's head from 300 yards with a 20mph cross breeze. |
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If everything is tight and you did your part.
Then its the AMMO. I had good results with 69gr SMK or 77gr SMK Federal or Black Hills ( I get better groups with Black Hills Blue 77gr SMK than I do with Black Hills Blue 75gr in 3 different ar15`s ) 3.5-10x scope Use a REAL Sand Bag Good luck For combat shooting your GTG |
Okay i took everything out again today and shot some more groups. Wind was 5-10mph and blew from my 3 to 7 o'clock All 8 round groups. (I know they're not 10 round groups but I'm cheap)I made the black part of the target an inch bigger to maybe help me. Prvi 69gr. Maybe I was concentrating to much lining up left to right so that might be a cause of the vertical stringing. Or maybe the powder charge is really varying.  Prvi 75gr. This was the last group shot so I was a little antsy and eye sore.  Now some 60gr TAP 223. Not bad.  Second group with 60gr TAP 223. That "flier" happened because someone next to me shot off a small cannon while I was almost breaking the shot and I flinched like a little girl.  So it appears that my rifle likes 60gr TAP a lot better than the Prvi. Or the lots of Prvi I got were worse. So more ammo brands are needed obviously. |
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To shoot well from a bench you need bags front and rear, Protecktor brand rear bags are inexpensive and work very well. You should have your rifle aligned perfectly on target while it sits resting in the bags.
Try Black Hills 68's or 69's or 75's or 77's. Try Federal Gold Medal Match 69's, 77's or 52's/53's if they make them. PRVI's ammo isn't match grade, despite the bullet weights. In my experience every .223 rifle, regardless of twist rate or barrel length, will shoot 52/53 grain match bullets better than most anything else you try to feed it. Using these light weight match bullets will reveal your barrels accuracy potential. I have several WOA 18" barrels with the rifle length gas system and am very happy with their performance. My standard loads are Hornady 68's or Sierra 69's moving around 2730 to 2770 from a 20" barrel. 24.5 grains of Varget or RE-15 with a SMK will usually get you good groups. 2.250" OAL. |
| It appears that you are vertically stringing your groups. This is not the barrel, nor A2 flash hider. Practice. Use a more precise optic. Horizontally, your groups are good, for the optic you are using. Accuracy rests with the three B's: barrel, bullet, brass...in that order. I think your groups are good, shooting the equipment you have. |
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