I Know someone has tested this
- Thread starter LeeS.
- Start date
I'm with you on that a friend was wanting to take his side charging AR and do that with the gas block because he was told it would be a precision gun then I told him he was full of s*** so I did a little bit of research couldn't really find anything every once in awhile you'd see something on a form about it so I figured I'd ask people who do long range precision shooting like on who wants to be A millionaire I asked the experts.
Observations On The Velocities Obtained From A Direct Impingement Gas System AR-15
Compared To A “Single Shot” AR-15
Compared To A “Single Shot” AR-15
I conducted a simple test that consisted of a comparison of the velocities obtained from an AR-15 using the direct impingement gas system with a standard sized gas block, to that of the same barrel with no gas system at all; that is, I completely clamped-off the gas port, turning the AR-15 into a "single-shot" rifle.
The ammunition used in this test was hand-loaded 69 grain Sierra MatchKings. I fired three 10-shot strings of this ammunition in a row over an Oehler 35-P chronograph, with proof-screen technology. The center screen of the chronograph was positioned 21 feet from the muzzle. The test vehicle was a 16” barreled AR-15 with a carbine-length direct impingement gas system and a standard sized (0.75”) Larue Tactical low-profile gas block.
After firing the three 10-shot strings from the upper using the direct impingement system, I let the barrel cool and then removed the gas tube. Next, I removed the low profile gas block from the barrel, flipped it 180 degrees and reinstalled it on the barrel, thereby completely clamping off the gas port on the barrel. This gave me a single-shot AR-15 in which I had to manually load and eject each round using the charging handle, thus giving me the means to determine the amount of velocity that is lost due to the auto-loading function of the direct impingement gas system of the AR-15.
Following the same procedure as previously used, I fired three 10-shot strings of the same hand-loaded 69 grain Sierra MatchKings over the Oehler 35-P chronograph positioned 21 feet from the muzzle using the single-shot AR-15. The results are show in the table below.
As you can see in the table below, there was a small (but statistically significant) difference of 23 FPS between the grand averages of the velocities from the direct impingement gas system and the single-shot (gas port clamped-off) system.
Atmospheric Conditions
Temperature- 63 degrees F
Humidity - 34%
Barometric pressure – 30.20
Elevation - 960 feet above sea level
Skies – sunny, Jupiter aligned with Mars
...
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Molons post shows the lack of any meaningful velocity gains. Your ammo could easily have ES and SD figures that are larger then the differnece.
As for improved precision... there are ( IMHO ) far better ways to possibly increase your precision then monkeying around with your GB / gas port. ( No offense intended. )
Making sure there is zero contact between a free float tube ( or anything mounted around the gas block ) and the gas block is a start.
As for improved precision... there are ( IMHO ) far better ways to possibly increase your precision then monkeying around with your GB / gas port. ( No offense intended. )
Making sure there is zero contact between a free float tube ( or anything mounted around the gas block ) and the gas block is a start.
IMHO... that shouldn't matter ( YMMV )... the ultimate goal is to get all the various parts consistently going back into battery the same way every time.
So both a heavy and LtWt reciprocated bolt mass can work very well. I tend to use a heavy setup very well.
Make sure the gas tube isn't binding at the gas key, and isn't touching the upper at all ( at the entrance hole on the upper and at the barrel nut. )
And all the other typical tricks. Free floated barrel, decent trigger makes it easier, shim / loctite in the barrel after lapping the upper receiver face, snug upper to lower fit.... etc ( ammo )
By turning off the gas you simplify the system and reduce the number of factors that the shooter has to manage. This might result in more consistent groups, depending on the build and tune of the particular gun.
(If the gasser is set up for precision (longer gas systems, smart reciprocating mass, gas tuned for load, load timed for barrel) I would expect to see less 'improvement'.)
(I would also expect to see less 'improvement' if the shooter knows how to run a precision gasser really well, regardless of the build.)
(If the gasser is set up for precision (longer gas systems, smart reciprocating mass, gas tuned for load, load timed for barrel) I would expect to see less 'improvement'.)
(I would also expect to see less 'improvement' if the shooter knows how to run a precision gasser really well, regardless of the build.)
If you want a. 223 bolt gun just build it,
its recoil management, you don’t have the system moving so you can be a crappy shooter with the gas system off, its a single pulse like a bolt gun. In a semi you have to know how to shoot and follow through because it matters, you add to the movement.
people will yell the bullet is gone before the bolt opens, sure, but not before the system starts moving. The gas moves 5x faster so the bolt carrier starts to unlock before the bullet is gone. You really want to see it, add more barrel after the gas block, you’ll shoot worse, make it a 308 and things really change.
it’s just the semi vs bolt action argument, part of why semis are not supposed to be as accurate. But today with the right driver, if you’re not shooting a quality semi sub 1/2 MOA it’s you not them.
buy a tuner before you flip the block or take a class
its recoil management, you don’t have the system moving so you can be a crappy shooter with the gas system off, its a single pulse like a bolt gun. In a semi you have to know how to shoot and follow through because it matters, you add to the movement.
people will yell the bullet is gone before the bolt opens, sure, but not before the system starts moving. The gas moves 5x faster so the bolt carrier starts to unlock before the bullet is gone. You really want to see it, add more barrel after the gas block, you’ll shoot worse, make it a 308 and things really change.
it’s just the semi vs bolt action argument, part of why semis are not supposed to be as accurate. But today with the right driver, if you’re not shooting a quality semi sub 1/2 MOA it’s you not them.
buy a tuner before you flip the block or take a class
if that is really what he wants to do then he should invest in a Noveske Switchblock or another gas system with an Off position or a bolt gun.
Dont try to turn a Cat into a dog.
POF makes it
sofrep.com
POF-USA ReVolt Bolt-Action Rifle: First Impressions
The ReVolt gives the AR shooter options where laws or hunting regulations restrict the type of rifle you can own.
sofrep.com
I’ve done it. You can also rotate the gas block slightly to partially cover the gas port to adjust the amount of gas in the system, kind of a poor mans adjustable gas block. Very easy to do, but a tiny rotation can cause a big change in gas flow.
The “problem” with covering the gas port all the way is that it builds up layers of copper and carbon, which you can’t get out unless you remove the block and really work on it. I used a hole punch.
The “problem” with covering the gas port all the way is that it builds up layers of copper and carbon, which you can’t get out unless you remove the block and really work on it. I used a hole punch.
what kind of gains would this guy expect from stopping the gun from cycling? from 1.5 moa to <1 moa?
is he aware that some bolt guns shoot for shit?
i think some gas guns are "meant to be accurate" but i guess that depends on the gun and what your definition of accurate would be.
primarily they are designed to shoot a lot of rounds quickly, and accuracy is limited by the primary function, as frank explained.
these are 3 round and 7 round strings semi fast fire (<5 seconds for 7 shots) from my first trip with a tripod to the range, .308 btw.
it seems fairly accurate for a gas gun with a newb behind it, taking advantage of the primary function.
i am sort of bulldogging the rifle in the tripod, which i am loading with my off hand.
by that i mean this isn't using the resting or natural poa of the rifle sitting in the tripod.
the natural poa is the top of red diamond, and i am pushing the poa down and holding it, so recovery is almost instant.
is he aware that some bolt guns shoot for shit?
i think some gas guns are "meant to be accurate" but i guess that depends on the gun and what your definition of accurate would be.
primarily they are designed to shoot a lot of rounds quickly, and accuracy is limited by the primary function, as frank explained.
these are 3 round and 7 round strings semi fast fire (<5 seconds for 7 shots) from my first trip with a tripod to the range, .308 btw.
it seems fairly accurate for a gas gun with a newb behind it, taking advantage of the primary function.
i am sort of bulldogging the rifle in the tripod, which i am loading with my off hand.
by that i mean this isn't using the resting or natural poa of the rifle sitting in the tripod.
the natural poa is the top of red diamond, and i am pushing the poa down and holding it, so recovery is almost instant.
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I would like to know what keeps an AR Gasser from being an 'ACCURATE' rifle.
It wasn't designed that way just doesn't cut it.
What physical parameters cause AR Gassers to be less accurate than a bolt gun?
What physical parameters cause a No-Gas AR to be less accurate than a bolt gun?
Note that most of the replies will be for things that Don't Matter.
What things do people/gunsmith's do to make a bolt gun 'Accurate'?
Start by excluding the big one, lock time and the human, who knows how each part in an AR causes shots to go off?
If you have a Friend that wants to make his one and only upper into a No-Gas upper, tell him to get another.
Make one a fast running house clearing shorty and play make believe gunsmith with the other.
Stickage with No-gas is an issue but does it affect accuracy?
I can shoot an AR to under 1 MOA @ 100, less than 1.5 MOA @ 600.
Just imagine the awards I could get with a bolt gun
It wasn't designed that way just doesn't cut it.
What physical parameters cause AR Gassers to be less accurate than a bolt gun?
What physical parameters cause a No-Gas AR to be less accurate than a bolt gun?
Note that most of the replies will be for things that Don't Matter.
What things do people/gunsmith's do to make a bolt gun 'Accurate'?
Start by excluding the big one, lock time and the human, who knows how each part in an AR causes shots to go off?
If you have a Friend that wants to make his one and only upper into a No-Gas upper, tell him to get another.
Make one a fast running house clearing shorty and play make believe gunsmith with the other.
Stickage with No-gas is an issue but does it affect accuracy?
I can shoot an AR to under 1 MOA @ 100, less than 1.5 MOA @ 600.
Just imagine the awards I could get with a bolt gun
Stickage with No-gas is an issue but does it affect accuracy?
I can shoot an AR to under 1 MOA @ 100, less than 1.5 MOA @ 600.
Just imagine the awards I could get with a bolt gun
With my handloads in my nothing special AR 15 coyote rifle, I easily shoot under 3/4 moa .
Thanks for the answer.
I assume that's a gasser. What barrel length, what did you do to make it so darn accurate?
Things you would normally do to a gasser, like non contact free float, or low SD, ES ammo, should be a given with either operating system. DI, Piston, No-Gas. Why one and not the other?
Cats and Dogs?
Here's a bunch of 1MOA or less 3/5 shot groups (a few .5 MOA) with a No-Gas AR. The top row is a set of 3 shots then followed by another after scope adjustment.
And a cherry picked 40 rounds, 1.5 MOA @ 600 (because of a couple 9's )
Anyone with a bolt gun could easily do better.
I assume that's a gasser. What barrel length, what did you do to make it so darn accurate?
Things you would normally do to a gasser, like non contact free float, or low SD, ES ammo, should be a given with either operating system. DI, Piston, No-Gas. Why one and not the other?
Cats and Dogs?
Here's a bunch of 1MOA or less 3/5 shot groups (a few .5 MOA) with a No-Gas AR. The top row is a set of 3 shots then followed by another after scope adjustment.
And a cherry picked 40 rounds, 1.5 MOA @ 600 (because of a couple 9's
)Anyone with a bolt gun could easily do better.
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I agree on the good barrel, but a good gas system? or NO gas system?
What makes yours more accurate than others without gas?
The thread is about Removing, turning off, or not having a gas system and will it be more accurate.
I added the WHY, or maybe WHY NOT.
What makes yours more accurate than others without gas?
The thread is about Removing, turning off, or not having a gas system and will it be more accurate.
I added the WHY, or maybe WHY NOT.
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in a bolt gun, the bolt locks up behind the cartridge.
in a gas gun, nothing keeps the gun from cycling except the expansion of the case in the chamber. it isn't "locked up" like a bolt gun.
this is going to introduce some variation that doesn't exist in a bolt gun.
I know a lot of gunsmithing goes into bolt prep of a good bolt gun.
Doesn't case expansion work the same with a bolt gun and a No gas AR?
Without gas pushing the carrier back isn't the BOLT in an AR locked up on the extension?
I'm not a gunsmith, just a old shooter that likes to shoot paper.
Doesn't case expansion work the same with a bolt gun and a No gas AR?
Without gas pushing the carrier back isn't the BOLT in an AR locked up on the extension?
I'm not a gunsmith, just a old shooter that likes to shoot paper.
Never claimed to be more accurate than a bolt gun, but if I had to speculate, I think it’s plausible to be as accurate as a bolt gun with a gasser.
In a gas gun? A softer gas system allows for better follow up. We all know fundamentals are key and any improvement in the mechanics of the gun can assist in making sure your fundamentals are consistent.
I’m up to the challenge however, as I will be running my gas 14.5 ar in the Missouri MOST rifle series next year. I was told that it wouldn’t work by some folks because of the mechanics of the gun, however I found that with my setup, my follow through is on par with the 20 pound bolt guns. It’s the contrarian in me haha.
That looks like a whole big bunch of fun
huntslongrange.com
The MoST Series | Hunt's Long Range
Missouri Steel Tactical Series (MoST) Long range tactical matches are alive and well in Missouri, and it is time to step up your game for the second year of a friendly and fast-paced competition series….the Missouri Steel … Read More
huntslongrange.com
nothing is locked behind the cartridge in a gas gun like a bolt or lever gun.
yes the cartridge expands in the chamber of both, but the gas gun can let the cartridge slip back a tiny bit before the brass expands enough to stop it, and since every cartridge can have small differences in dimension, even this would not be consistent.
while this slip can happen in a bolt, there is a limit that is fixed (assuming the same case dimensions).
add possibility of a slightly larger chamber for reliable feeding in a gas gun and you have another source of "slop".
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Yes, but I'm willing to bet it's a lot looser lockup than a bolt gun. You need a little "slop" in the system to account for carbon buildup or any other junk that may get in the action.
there is only the spring. you don't have to unlock anything to pull the bolt back on a gas gun. for all intents and purposes, the only thing that keeps the gun from cycling immediately from the pressure in the barrel is the expansion of the case. this is why timing of the gas is important.
Wrong. the BOLT absolutely rotates and locks into the barrel extension. It's not just a spring holding everything in place. The bolt CARRIER has to start moving rearward either from gas from the gas system or manually using the charging handle before the cam pin in the bolt carrier rotates the bolt to unlock it.
A primary contributor to accuracy differences between an AR-15 and a bolt gun is the swinging hammer mass.
In a bolt gun, pre-ignition firing pin travel and drag in the bolt is a factor.
In an AR-15, the mass of the hammer swinging also pushes on the spring into the lower, which pushes on the receiver set away from the mass of the hammer.
Reduced mass hammers are known to fail if not made to the most exacting controls, which is why LaRue does what they do with the MBT-2S from S7 tool steel.
Tom Beckstrand wrote a great article about all of this with actual testing using a laser to show the difference in POI from POA when the trigger breaks using several different triggers.
In a bolt gun, pre-ignition firing pin travel and drag in the bolt is a factor.
In an AR-15, the mass of the hammer swinging also pushes on the spring into the lower, which pushes on the receiver set away from the mass of the hammer.
Reduced mass hammers are known to fail if not made to the most exacting controls, which is why LaRue does what they do with the MBT-2S from S7 tool steel.
Tom Beckstrand wrote a great article about all of this with actual testing using a laser to show the difference in POI from POA when the trigger breaks using several different triggers.
just putting a 10lb sandbag on top of your rifle would probably make a gas gun more accurate.
Good sturdy free float bolted to a short block.
What is the UPPER limit for weight in a competition rifle?
What is the LOWER limit for weight in a competition rifle?
See, still no consensus on how an AR operates
If the lugs don't hold the bolt in place, never ever have broken lugs again
The Recoil spring pushes forward on the Bolt Carrier, not to resist firing forces but to hold the bolt in full battery rotation. Too much firing force without gas or piston to push the carrier back and unlock the bolt and lugs fail. This channel guides the bolt into the open position. Carrier forward, bolt locked in with only a couple thou clearance with the case head. Move the carrier to the rear (gas, piston, or by hand) and the bolt lugs unlock.
As far as 'extra clearance' a straight pull AR doesn't need a lot of clearance.
(maybe a thou or two extra in the neck to chamber to help with stickage).
Not much gas or carbon gets into the action of a NO-Gas AR.
It ain't running fast, pew, pew, pew
And the cases come out COOL.
Head space of about 0.002" bolt or straight pull AR should be enough.
Something about bumping shoulders for a slow firing rifle compared to a rapid firing rifle.
Anyone use a single load sled?
What is the UPPER limit for weight in a competition rifle?
What is the LOWER limit for weight in a competition rifle?
See, still no consensus on how an AR operates
If the lugs don't hold the bolt in place, never ever have broken lugs again
The Recoil spring pushes forward on the Bolt Carrier, not to resist firing forces but to hold the bolt in full battery rotation. Too much firing force without gas or piston to push the carrier back and unlock the bolt and lugs fail. This channel guides the bolt into the open position. Carrier forward, bolt locked in with only a couple thou clearance with the case head. Move the carrier to the rear (gas, piston, or by hand) and the bolt lugs unlock.
As far as 'extra clearance' a straight pull AR doesn't need a lot of clearance.
(maybe a thou or two extra in the neck to chamber to help with stickage).
Not much gas or carbon gets into the action of a NO-Gas AR.
It ain't running fast, pew, pew, pew
And the cases come out COOL.
Head space of about 0.002" bolt or straight pull AR should be enough.
Something about bumping shoulders for a slow firing rifle compared to a rapid firing rifle.
Anyone use a single load sled?
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So to OP you got some good answers.
Either get a good precision AR sorted & Learn to drive it or buy a bolt gun!
You can somewhat overcome mag length restrictions with a modified mag allowing 2.36 COAL
Side note: I really with PRI or someone made a steel mag to fit LWRC's 6.8 receivers. You'd be able to get about 2.38 or more without cutting anything.
How about a K-31 straight pull bolt gun????
The AR bolt is locked if it is fully in battery............no gas = no unlock. All actual recoil happens with bolt locked. Secondary impulses are BCG reciprocating movement. When you pull it rearward you are manually rotating the bolt to unlock via the cam pin, sim. to a straight pull bolt gun.
The amount of brass play is same as bolt gun & completely dependent on head space. if it's .005 then typically the brass will be .005 off the bolt face when chambered. This is due to the stiff ass ejector spring shoving the brass to the head space datum point (same as a bolt gun with spring ejector). Yes the brass locks to the chamber when fired just like a bolt gun & it will/can extrude the base back to the bolt face. = Don't bump shoulders back further then necessary for reliable feeding for your application.
The above is why checking and having proper head space matters in an accurate gasser. Also why checking and obtaining proper firing pin protrusion matters.
For mechanical accuracy potential (not reliability) here is my list prioritized most important to least:
It's really incredible just how well a gasser can shoot. My home built 80% DPMS 308 is a hammer with factory FGMM or Nosler 168 or 175. No load development.......no BS, well under 1 moa with good factory ammo.
When you take a step back and compare to a bolt gun. it really is incredible the performance these gasser's are delivering, assuming you can shoot one well.
Gasser = 8-12lbs & often not well balanced depending lrg or sml frame vs. Precision bolt gun typically 12 - 22lbs balanced in front of mag
Gasser barrel length 18-22" vs. Precision bolt gun 24-28"
Gasser stock ergo's, such as check weld etc are a compromise vs. most precision bolt guns.
Gasser recoil impulses are multiple vs. 1 for bolt gun.
Gasser trigger pull is typically heavier (My DPMS with Geissele SSA-E is 3.5lbs) vs bolt gun 6oz - 1.5lbs
Here is a direct field comparison @ 547 yards, where all the above differences are at play.
I shoot ever so slightly better with the bolt gun that has a better bipod, it's heavier, less recoil from 6.5C 130, better brake, longer barrel, 1.5lb trigger, & cheek riser.
I could see trace with the bolt gun, but not the DPMS. I do think it's possible, but I'm just not there yet. Maybe after Franks class in PA next year.
18" DPMS 308 set up.
Previously this DPMS shot no better then 2.5 MOA with a Bergara 18" mid gas barrel.
The only time 1 tried single feeding was with the Bergara barrel trying to sort accuracy & reliability issues.
Now that both accuracy & reliability is 100% there is simply no chance in hell I would even consider turning the gas off!!
Only small changes will be made going forward such as a precision armament 4 port brake.
I can now just focus on improving my driving skills.
First 10 rounds out of new proof 18" rifle gas 1/11.25T 308 barrel & new MK 5 scope. Break in was Hoppe's #9 clean before going to range.
rounds 41-45 zero check with FGMM 175
Having finally gotten the DPMS sorted I entered and shot my first ever match recently. The Geissele Gas Gun Challenge in PA.
Heavy tac. div.
They say confidence in your rifle is very important when competing & after finally doing it I completely agree. I knew my gun was capable of any precision required & would run 100%.
I did very well on the precision shots & finished mid field of 50. The match was a blast & there were a lot of very good shooters.
Stage 3 was I think they called him Bob (pictured below). A bad guy with a K-bar blade dangling from 1 hand @255yards (about 3 moa tall x 1/2 moa wide).
You start standing with the gun on ground aimed towards target, 1 round in chamber & on safe. On go you have 5 seconds to drop down and shoot the K bar. Ding Fuck yeah! + 5
The mover absolutely kicked my ass. Only hit it once & only got off like 6 of 10 possible. It was moving at a pretty good clip @ 300. One of the biggest mistakes I made (hindsight) was having the magnification set to high @ like 8x. Every shot I lost that fucker in my sight picture and had to go hunting for it. Something to work on this winter rapid transitions @ lower mag.
The last stage was a double hostage @600 yards 2 x 2/3 IPSC hostages staggered 1 in front of the other (no space between) with about 6" bad guy head only between their heads.
Hit a hostage -10, bad guy +10, Throw the shot or somehow miss everything = 0
Start prone 1 in chamber, on safe, the whole squad. They randomly call a name & you have 2 seconds to come off safe and fire. Steady rain with light wind to 4:00 & I was first name called. Killed that M F er Hell yeah!
I would stand in line for this!
Cant wait for next year!
- Gain 20-25 fps
- Ability to load longer then mag length
- Easier to drive without secondary impulse from BCG reciprocation.
Either get a good precision AR sorted & Learn to drive it or buy a bolt gun!
You can somewhat overcome mag length restrictions with a modified mag allowing 2.36 COAL
Side note: I really with PRI or someone made a steel mag to fit LWRC's 6.8 receivers. You'd be able to get about 2.38 or more without cutting anything.
How about a K-31 straight pull bolt gun????
The AR bolt is locked if it is fully in battery............no gas = no unlock. All actual recoil happens with bolt locked. Secondary impulses are BCG reciprocating movement. When you pull it rearward you are manually rotating the bolt to unlock via the cam pin, sim. to a straight pull bolt gun.
The amount of brass play is same as bolt gun & completely dependent on head space. if it's .005 then typically the brass will be .005 off the bolt face when chambered. This is due to the stiff ass ejector spring shoving the brass to the head space datum point (same as a bolt gun with spring ejector). Yes the brass locks to the chamber when fired just like a bolt gun & it will/can extrude the base back to the bolt face. = Don't bump shoulders back further then necessary for reliable feeding for your application.
The above is why checking and having proper head space matters in an accurate gasser. Also why checking and obtaining proper firing pin protrusion matters.
For mechanical accuracy potential (not reliability) here is my list prioritized most important to least:
- Barrel quality + correct profile + chamber (Proof, Craddock, White Oak, etc) some are capable and some are not.
- Head spaced bolt close to min for accuracy with factory ammo. Loose HS can be compensated for if hand loading brass already fire formed in the chamber.
- Free float barrel
- Feed ramp geometry blended deburred to ensure your not damaging projectiles when chambering
- barrel nut torque value
- Ensure hammer is square to firing pin when struck (should be perpendicular or 90 and not offset to side)
- Trigger system has different checks & characteristics depending on cartridge system or traditional hammer/trigger. Ensure no bind, side play, or vertical play.
- Ensure buffer is loaded against bolt (not buffer retainer) when locked (you'd be surprised how many aren't).
- Upper to lower receiver fit. I like em tight with zero rattle. AR15 accushim for vertical play http://www.wheeldiamond.com/ar15accushim.htm & Triggershims.com for the front pivot pin. https://triggershims.com/ar_15_shims.php
- Gas system length = longer is better i.e. 18" - 20" = Rifle length - +1" / 22" = Rifle +2"
- Gas system, yes it is a system and each part must compliment one another to prevent sharp impulses (buffer hits back of tube), early unlocking (gun twists while bullet is still in bore), & bolt bounce.
It's really incredible just how well a gasser can shoot. My home built 80% DPMS 308 is a hammer with factory FGMM or Nosler 168 or 175. No load development.......no BS, well under 1 moa with good factory ammo.
When you take a step back and compare to a bolt gun. it really is incredible the performance these gasser's are delivering, assuming you can shoot one well.
Gasser = 8-12lbs & often not well balanced depending lrg or sml frame vs. Precision bolt gun typically 12 - 22lbs balanced in front of mag
Gasser barrel length 18-22" vs. Precision bolt gun 24-28"
Gasser stock ergo's, such as check weld etc are a compromise vs. most precision bolt guns.
Gasser recoil impulses are multiple vs. 1 for bolt gun.
Gasser trigger pull is typically heavier (My DPMS with Geissele SSA-E is 3.5lbs) vs bolt gun 6oz - 1.5lbs
Here is a direct field comparison @ 547 yards, where all the above differences are at play.
I shoot ever so slightly better with the bolt gun that has a better bipod, it's heavier, less recoil from 6.5C 130, better brake, longer barrel, 1.5lb trigger, & cheek riser.
I could see trace with the bolt gun, but not the DPMS. I do think it's possible, but I'm just not there yet. Maybe after Franks class in PA next year.
18" DPMS 308 set up.
Previously this DPMS shot no better then 2.5 MOA with a Bergara 18" mid gas barrel.
The only time 1 tried single feeding was with the Bergara barrel trying to sort accuracy & reliability issues.
Now that both accuracy & reliability is 100% there is simply no chance in hell I would even consider turning the gas off!!
Only small changes will be made going forward such as a precision armament 4 port brake.
I can now just focus on improving my driving skills.
First 10 rounds out of new proof 18" rifle gas 1/11.25T 308 barrel & new MK 5 scope. Break in was Hoppe's #9 clean before going to range.
rounds 41-45 zero check with FGMM 175
Having finally gotten the DPMS sorted I entered and shot my first ever match recently. The Geissele Gas Gun Challenge in PA.
Heavy tac. div.
They say confidence in your rifle is very important when competing & after finally doing it I completely agree. I knew my gun was capable of any precision required & would run 100%.
I did very well on the precision shots & finished mid field of 50. The match was a blast & there were a lot of very good shooters.
Stage 3 was I think they called him Bob (pictured below). A bad guy with a K-bar blade dangling from 1 hand @255yards (about 3 moa tall x 1/2 moa wide).
You start standing with the gun on ground aimed towards target, 1 round in chamber & on safe. On go you have 5 seconds to drop down and shoot the K bar. Ding Fuck yeah! + 5
The mover absolutely kicked my ass. Only hit it once & only got off like 6 of 10 possible. It was moving at a pretty good clip @ 300. One of the biggest mistakes I made (hindsight) was having the magnification set to high @ like 8x. Every shot I lost that fucker in my sight picture and had to go hunting for it. Something to work on this winter rapid transitions @ lower mag.
The last stage was a double hostage @600 yards 2 x 2/3 IPSC hostages staggered 1 in front of the other (no space between) with about 6" bad guy head only between their heads.
Hit a hostage -10, bad guy +10, Throw the shot or somehow miss everything = 0
Start prone 1 in chamber, on safe, the whole squad. They randomly call a name & you have 2 seconds to come off safe and fire. Steady rain with light wind to 4:00 & I was first name called. Killed that M F er Hell yeah!
I would stand in line for this!
Cant wait for next year!
In that case you'll be abusing parts. Accuracy will suffer! Beat the hell out of brass, bolt, rings, & extractor.
It may run well in a mud puddle though
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