I had a AR-15 upper that needed each round to be single loaded into the chamber, instead of from the mag, to achieve 1 MOA accuracy. Load the chamber from the mag the groups open up to about 1.5 MOA.
Is this usual? Can the scratches the bullet receives from being loaded from the mag affect the accuracy that much?This message has been edited. Last edited by: chino101,
That is unusual. The bullet shouldn't be getting scratched loading from a magazine. How it would make a difference loading single rounds is puzzling.
I'd be curious what other factors were at play, whether the bullet is magazine fed or hand fed shouldn't get you a half minute, or really any significant change in accuracy. Many ARs are 1moa out of the box, the platform is inherently accurate.
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what is the make and model of the rifle/barrel?
What ammo are you using?
I had a rifle which was very accurate if I tugged on my left earlobe before pulling the trigger.
Some days, it's just not worth the effort of chewing through the leather straps.
It was a LWRC Piston Upper with a 16" barrel. The ammo used was IMI 77gr match and Norma 77gr match.
I never thought about single loading an AR by dropping a round in the chamber and closing the bolt with the forward assist, but got curious when I notice an AR was marketed with two accuracy specifications; loading from the mag and single loading.
When I tried single loading, I noticed the accuracy improvement.
Some AR-15 competitions favor the long and heavy bullets -- those weighing 80 grains or more. These long bullets must be single loaded, as they are too long for most magazines. I haven't shot such ammo.
When I began shooting ARs, I questioned why I had so many "flyers". I read about issues with the first and last rounds from mags. So when shooting for groups of five, I'd load at least 7 rounds, toss the first round into another target, then put 2-6 into my target of choice. It didn't seem to make any difference.
I bought a Bob Sled single loading device. I actually shot worse with the Bob Sled -- I suspect because I was getting out of position behind the rifle, then not consistently getting back into position after each reload. Although I do feel there might be something about the accuracy of the first round in a magazine, I can't shoot well enough to see a statistically significant difference.
As my fundamentals of marksmanship have improved behind an AR, my "flyers" have decreased. My guns haven't become any more accurate over time. In fact the steadily increasing volume on the barrels decreases their accuracy. IMO the difference of how we shoot an AR from one target to the next, or even from one shot to the next, is due to our inconsistencies in technique. ARs are hard to shoot as a precision weapon.
Last week I was trying to determine if the 16" Wilson barrel was toast on one upper, or if I was shooting like dog doo. At 440 yards I could only achieve vertical impacts of 2 to 3.25 MOA with various ammo that had traditional shot well. I replaced the Wilson upper with a 14.5" piston 1.7 twist LWRC. I soon found out the Wilson barrel was toast.
With the LWRC I put 8 rounds in 3-3/8" vertical (3/4 MOA) using Hornady 55 ZMax -- ammo that shot 2-1/4 MOA in the Wilson. I put 10 rounds in the magazine, but the first 2 rounds were off the steel target due to my mis-dialing elevation. I then put five new rounds in magazine, shot at paper at 50 yards and produced a .3" cloverleaf.
Bottom line -- I don't see any accuracy issues with shooting my LWRC (or any upper/rifle) while feeding ammo from a magazine.
If individually loading into the chamber, does the rifle still cycle, i.e. does the bolt blow apart for case extraction?
I don't recall ever having my bolt "blow apart".
However, all of my ARs fire, cycle, extract, and lock back on an empty mag (or cycle the next round of a loaded mag) -- when rounds have been individually loaded. Without fail.
Perhaps the bullet seats better in the chamber single loading it?
I'd have to agree that the problem is more likely a result of different shooting technique single loaded vs semi-auto. It's pretty easy to find out if autoloading is doing anything to the bullet though. Just load 2 rounds fire one, eject the 2nd and check it over!!
Remember, this is all supposed to be for fun...................
I haven't heard an complaints on that rifle/ammo combo before.
When you say single load, am I correct in assuming that you have 1 round in the magazine and release the bolt from the locked position and then pushing the Forward Assist?
Not a 15, but my 716's both noticeably score copper bullet jackets when autoloaded.
I'm sure the same thing is possible in a 15 with certain bullets/mag combos, particularly the long match types. Tips may also drag in some mags.
Single loading would remove those possibilities.
Having properly fitted ramps will too.....
Remember, this is all supposed to be for fun...................
Pistols are known to throw the first round hand cycled into the action to a different spot on target than those cycled by the force of recoil ( probably only noticeable when fired from a ransom rest) so it would not be a surprise semi auto rifles would show the same tendency and perhaps more so due to the inherent accuracy a rifle has. The slow fire phases of long range matches require single
Loading and benchrest guns are usually single shots so perhaps there is something to this
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I was thinking the same thing. I have thousands of rounds through match grade AR's and have never seen an accuracy difference between magazine fed and single round loading.
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Sounds like one takes time knowing you only have one round to kill with vs I have 5 rounds to hit the target. Slow down, breath, squeeze the trigger and make your dime size group. Most ARs unless make by a butcher can do it. Chris
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Maybe there is a heat and thus time dependency. With single loading the bolt is locked open longer, air flows through the barrel, and it takes you longer to load each round and re-establish a proper shooting position. Hence more time to cool down between shots.
With magazine feeding the bolt only opens momentarily to cycle the action, and your shooting rate is only limited by your trigger finger, so you have a faster heat up rate.
Possibly there are some heat related stresses in the upper that are diminished with a longer time between firing. Just a thought...
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Sure...I was referring to the way direct impingement works. Exhaust gas is tapped into the receiver to blow the bolt apart for case extraction and rechambering. Saying the bolt blows back is only half correct, since half of it moves forward.
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More specifically, by single loading, I have the bolt locked open, insert a round into the chamber until it seats, then lower the bolt on the the round, and finally locked the bolt in place using the forward assist.
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