Semi-auto Precision

redshooter

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This is a typical group from my Rifle, well not really...usually it's three in the cluster, but overall size pretty much always MOA, or less for five shots.

y4m2jpE6hlCOWHTiyiZnKDNgcBIfNyAuxJ3u5qvl5vpZYmdi-79SFy8WusrGo8hkh5ZgYd9iw9MT-JRJTrjlaaaMv6sDCTx54vdl3tF2NU0zrmP8aRNDSXz53qofrU7lwEd0wX0yqYpZh98pf8iIG8aTMX85IwX97IcZdRl-JhEQVcnw2vJbUX_74rDI_NJPzrki-RClEhbCBny0cHcJlYoXQ


I did a brief search for a thread dedicated to Semi-auto Precision, but it appears there are none.

Any advice as to how to improve lock time, etc., etc., etc. would be most appreciated.
 
Much harder to get a semi auto, AR, to run with a precision bolt gun, but you can get pretty close, if you are willing to spend a few extra bucks and approach it like a custom bolt rifle build.
I have a Stag 10, in 6.5 Creedmoor, that is pretty much custom from one end to the other, built by the fabulous guys at Insite Arms, that is easily sub MOA, but it also cost close to the same as a high end bolt gun, as well. Krieger barrel, Triggertech Diamond trigger, JP internals and capture spring, adjustable gas block, LRA Bipod, ATACR scope. Shoot it at our range here out to 875 yards, and is sub MOA with handloads, but it’s an expensive exercise and I have lots of experience with shooting ARs, as they are not quite the same to shoot as a bolt gun too.
Have also owned a JP LRP-07, and it was also close to sub MOA but it is also a 6K rifle to buy off the shelf.
So it can be done, and is extremely satisfying, but there is a significant cost involved too. Not many 1500$ AR10s or AR15s, with 7lb triggers and a Chrome moly barrel, will ever be close to MOA with factory Ammo, and we’re never designed to be tack drivers. Precision ARs are either expensive boutique brands, or pricier builds from the ground up. In my experience anyways.
 
Even if the semi auto rifle is capable of shooting accurately, it's much more difficult for the shooter. Semi autos exploit weaknesses in your fundamentals more so then bolt guns do, they are much less forgiving to shoot.
 
Any advantage to changing my hammer to improve lock time?


Was the low shot the last shot with the bolt held open?

All of them were, my first attempt at eliminating inconsistency, all shots were loaded and fired from a magazine one at a time. Have you ever used a Bob Sled, I'd like to grab one, esp. for trying 80+ gr projectiles. Hahaha, I told Barney a few years back that I wanted to bring my AR to an F Class match...I was actually serious.

joehunt said:
What are you shooting?

AR-15 (mixed parts) with a 20" Colt 1 in 7 HBAR Barrel, Geissele G2S Trigger, 75gr Hronady HPBT, 24.5 gr RL-15.

y4mGvqB46vTHTwmzWgAB3C7wUcvdcvmv--EqkJXB354qBSJlYX9K3D6ZQ9UU2cJf9zEK7Y_nfoZ3LKxHKV88xThEbE-J7p0mEIY-MF8wnmkXwgP9wi3eGo-OV3m2s5eiH9jN7kdxg8g8ylbSdiCB_VUW7pAYuVuezPLo-thTRfcO4gki6GrIku7_j5ioOCv4SjQqoQwg_bBbZ251xdMd5J9Ng


kthomas said:
Even if the semi auto rifle is capable of shooting accurately, it's much more difficult for the shooter. Semi autos exploit weaknesses in your fundamentals more so then bolt guns do, they are much less forgiving to shoot.

This is part of what I had in mind with my query. Is there an approach to mitigate lock time etc. through hold etc.
 
Last edited:
Any advantage to changing my hammer to improve lock time?

All of them were, my first attempt at eliminating inconsistency, all shots were loaded and fired from a magazine one at a time. Have you ever used a Bob Sled, I'd like to grab one, esp. for trying 80+ gr projectiles. Hahaha, I told Barney a few years back that I wanted to bring my AR to an F Class match...I was actually serious.

AR-15 (mixed parts) with a 20" Colt 1 in 7 HBAR Barrel, Geissele G2S Trigger, 75gr Hronady HPBT, 24.5 gr RL-15.

y4mGvqB46vTHTwmzWgAB3C7wUcvdcvmv--EqkJXB354qBSJlYX9K3D6ZQ9UU2cJf9zEK7Y_nfoZ3LKxHKV88xThEbE-J7p0mEIY-MF8wnmkXwgP9wi3eGo-OV3m2s5eiH9jN7kdxg8g8ylbSdiCB_VUW7pAYuVuezPLo-thTRfcO4gki6GrIku7_j5ioOCv4SjQqoQwg_bBbZ251xdMd5J9Ng


This is part of what I had in mind with my query. Is there an approach to mitigate lock time etc. through hold etc.

Send me a pm or email. I have a few experiments to try if you are curious. I have mucked with ARs a bit and building a knowledge base of cause and effect. There are definitely some weak areas in the platform but also alot of strengths. Working through the various tweaks to see where consistency can be gained.... or lost.

IMG_1925.jpg

An accurate AR is definitely possible... Pic of customer"s BCL with a McGowen match barrel in 6.5 CM. Reloads and just doing a function check. Only group shot on paper cause I figured, " good enough"

IMG_2973.jpg

And that last shot 'low' has come up often enough to ask the question why???? 5rds were nice and tight at 175yds... last shot dropped low. Rds mag fed

Jerry
 

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I will bite :)

Why last round dropped?

My guess is inconsistency in applying the fundamentals. Last shot the bolt carrier isn't traveling forward, and that difference in the mass not traveling forward exploits your weakness in shooting fundamentals in a different way then the BCG mass moving forward.

Shouldn't make a difference if you are perfect at applying the fundamentals 100% of the time, but no one does :)

Semi-autos are not as near as forgiving as bolt guns, a lot more going on with them. Part of the reason why you never see semi-autos shoot as well and consistently as good as a good bolt gun.
 
My guess is inconsistency in applying the fundamentals. Last shot the bolt carrier isn't traveling forward, and that difference in the mass not traveling forward exploits your weakness in shooting fundamentals in a different way then the BCG mass moving forward.

Shouldn't make a difference if you are perfect at applying the fundamentals 100% of the time, but no one does :)

Semi-autos are not as near as forgiving as bolt guns, a lot more going on with them. Part of the reason why you never see semi-autos shoot as well and consistently as good as a good bolt gun.

That makes sense! But why down? As in why the last round with bolt open lands below the group?
 
Gas guns are easy to run for me the key is shooting as free recoil as I can. In all positions.

Won me a PRS match with it.

And I never noticed the last round out of the group. The bullet is long gone before the bolt even starts to move
 
Really unsure where the myth that semis are harder to shoot vs a bolt came from but I haven't found it to be the case. I have shot a number that were very poorly put together and speced. They shot inconsistently, loud, and far more recoil then desired... but that is not a fault of the basic design and operation.

NOTE: USGI spec triggers are horrid.... there are many wonderful solutions to replace. There is no need to run an AR with a crappy trigger. I have gone with a Timney TARGA 2 stage short first stage... quite the improvement.

Like any precision rifle, there are areas that need to be speced properly. With the massive range of manfs in the AR world, mixing and matching can lead to a variety of tolerance stacking problems or just a mismatch of function. Some parts don't work as well as their marketing suggests. Some parts are just used in the wrong way.

Feed it ammo not well suited to the system and all sorts of inconsistencies arise.

A DI AR has some very nice features that can help it shoot easier vs a bolt. You just have to understand how to work with its operation.. not against it.

I quick review of my rifle looking for obvious issues proved nothing had broken. I did find a problem area and will see if that was the root of the issue next time I go out.

Jerry
 
Yet you never see semi-autos shoot as good as a good shooting bolt guns. A really good shooting semi-auto shoots about as good as an average modern day bolt gun.

People are very happy if they can get their semi-autos shooting consistently 1/2 MOA. Usually on average a decent one shoots 3/4 - 1 MOA.

Semi-autos are definitely harder to drive consistently, but mechanically they there is a lot more moving parts which makes them a more difficult system to get shooting well.

I've yet to see evidence of a semi-auto shooting as good as a really good bolt gun.
 
Op. Try a different bolt carrier (just carrier, not bolt) if you have one or know someone who has one. See if there is any difference.
 
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