Just looking to hear some ideas from guys on what makes a gas gun really accurate. Do you think it just comes down to a good barrel and bolt fit? A good trigger and glass helps. By accurate I'm talking sub moa. Any thoughts on piston vs. gas?
What makes a gas gun accurate?
- Thread starter rkgsmith
- Start date
Re: What makes a gas gun accurate?
barrel and trigger, fuck everything else as long as its free float and its got a good barrel that headspaces and a good trigger the thing will shoot.
barrel and trigger, fuck everything else as long as its free float and its got a good barrel that headspaces and a good trigger the thing will shoot.
Re: What makes a gas gun accurate?
My question is WHY isn't a PISTON actuated bolt semi-auto rifle as accurate as a direct gas impingement rifle such as the original Armalite/M16 rifles use??
An example is the JP .308 rifle, which Remington Defense uses for its RSASS version. And there's the LMT .308 that the Brits bought for their designated marksman rifle. Both are direct gas impingement, not piston actuated.
My question is WHY isn't a PISTON actuated bolt semi-auto rifle as accurate as a direct gas impingement rifle such as the original Armalite/M16 rifles use??
An example is the JP .308 rifle, which Remington Defense uses for its RSASS version. And there's the LMT .308 that the Brits bought for their designated marksman rifle. Both are direct gas impingement, not piston actuated.
Re: What makes a gas gun accurate?
Good barrel, good bolt with a good fit to the barrel/extension, an upper that is on the tighter side of spec so that there isn't an over abundance of slop in the bolt carrier area, a bolt area that is true with no high spots, a good fit between the barrel extension and receiver and a square receiver face.
Every AR I've built using this formula has shot sub MOA consistently with good ammunition and kept on doing it even after the barrel got hot. If I pay attention while shooting, I can usually (we all have our bad days) shoot two dot drill sheets consisting of 25 half inch targets each and keep a vast majority of the hits at least getting a piece of the 1/2" circle.
Getting an AR to shoot sub MOA is no great feat; but I believe that getting an AR to do it and keep on doing it after things start to heat up requires that things be as true as you can make them so that uneven stressed aren't applied as heat builds up and metal starts to expand a tad bit.
Of course, I could be totally full of crap and just been lucky with my builds.
Good barrel, good bolt with a good fit to the barrel/extension, an upper that is on the tighter side of spec so that there isn't an over abundance of slop in the bolt carrier area, a bolt area that is true with no high spots, a good fit between the barrel extension and receiver and a square receiver face.
Every AR I've built using this formula has shot sub MOA consistently with good ammunition and kept on doing it even after the barrel got hot. If I pay attention while shooting, I can usually (we all have our bad days) shoot two dot drill sheets consisting of 25 half inch targets each and keep a vast majority of the hits at least getting a piece of the 1/2" circle.
Getting an AR to shoot sub MOA is no great feat; but I believe that getting an AR to do it and keep on doing it after things start to heat up requires that things be as true as you can make them so that uneven stressed aren't applied as heat builds up and metal starts to expand a tad bit.
Of course, I could be totally full of crap and just been lucky with my builds.
Re: What makes a gas gun accurate?
My thoughts on the piston is that it is putting downward force on the barrel while the bullet is inside, that's why a piston isn't as accurate. Ya I know you POF guys are going to tell me how accurate your rifle is yada yada yada I know.
My thoughts on the piston is that it is putting downward force on the barrel while the bullet is inside, that's why a piston isn't as accurate. Ya I know you POF guys are going to tell me how accurate your rifle is yada yada yada I know.
Re: What makes a gas gun accurate?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Captain Moroni</div><div class="ubbcode-body">My thoughts on the piston is that it is putting downward force on the barrel while the bullet is inside, that's why a piston isn't as accurate. Ya I know you POF guys are going to tell me how accurate your rifle is yada yada yada I know. </div></div>
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Captain Moroni</div><div class="ubbcode-body">My thoughts on the piston is that it is putting downward force on the barrel while the bullet is inside, that's why a piston isn't as accurate. Ya I know you POF guys are going to tell me how accurate your rifle is yada yada yada I know. </div></div>
Re: What makes a gas gun accurate?
Re: What makes a gas gun accurate?
The barrel, trigger, shooter.
Re: What makes a gas gun accurate?
The barrel, trigger, shooter.
Re: What makes a gas gun accurate?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">From what I know, the gas guns are built to much looser tolerances to allow the mechanicals to function reliably in motion.</div></div>
Yeah, they are, but there is the spec range and having a rifle that is on the tighter side of spec range rather than the more sloppy side is more conducive to accuracy.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">From what I know, the gas guns are built to much looser tolerances to allow the mechanicals to function reliably in motion.</div></div>
Yeah, they are, but there is the spec range and having a rifle that is on the tighter side of spec range rather than the more sloppy side is more conducive to accuracy.
Re: What makes a gas gun accurate?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kentucky Jelly</div><div class="ubbcode-body">Re: What makes a gas gun accurate?
The barrel, trigger, shooter. </div></div>
that is it... seriously i have seen some cheap as lowers used with a cheap plastic free float tube with a good barrel and a decent trigger and the damn guns shoot, it is not rocket science.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kentucky Jelly</div><div class="ubbcode-body">Re: What makes a gas gun accurate?
The barrel, trigger, shooter. </div></div>
that is it... seriously i have seen some cheap as lowers used with a cheap plastic free float tube with a good barrel and a decent trigger and the damn guns shoot, it is not rocket science.
Re: What makes a gas gun accurate?
I have 2 subMOA, actually sub .5 MOA piston driven 308s...
And those were shot by a .gov group for accuracy and they beat out a bunch of the bigger name direct impingement rifles where cold, the agent shot a stone cold 3/8th inch group.
I have 2 subMOA, actually sub .5 MOA piston driven 308s...
And those were shot by a .gov group for accuracy and they beat out a bunch of the bigger name direct impingement rifles where cold, the agent shot a stone cold 3/8th inch group.
Re: What makes a gas gun accurate?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Broker</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Captain Moroni</div><div class="ubbcode-body"> Ya I know you POF guys are going to tell me how accurate your rifle is yada yada yada I know. </div></div>
</div></div>
Damn right!
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Broker</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Captain Moroni</div><div class="ubbcode-body"> Ya I know you POF guys are going to tell me how accurate your rifle is yada yada yada I know. </div></div>
Damn right!
Re: What makes a gas gun accurate?
Ammo & chamber are high on my list besides trigger, barrel, optics and shooter .... and shooting conditions .... and size of the target .... and distance .... and whether someone is shooting back at you.
Maybe something else.
Ammo & chamber are high on my list besides trigger, barrel, optics and shooter .... and shooting conditions .... and size of the target .... and distance .... and whether someone is shooting back at you.
Maybe something else.
Re: What makes a gas gun accurate?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I have 2 subMOA, actually sub .5 MOA piston driven 308s...
And those were shot by a .gov group for accuracy and they beat out a bunch of the bigger name direct impingement rifles where cold, the agent shot a stone cold 3/8th inch group. </div></div>
POF and ??
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I have 2 subMOA, actually sub .5 MOA piston driven 308s...
And those were shot by a .gov group for accuracy and they beat out a bunch of the bigger name direct impingement rifles where cold, the agent shot a stone cold 3/8th inch group. </div></div>
POF and ??
Re: What makes a gas gun accurate?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BigJoe</div><div class="ubbcode-body">barrel and trigger, fuck everything else as long as its free float and its got a good barrel that headspaces and a good trigger the thing will shoot. </div></div>
+1 also, a wise man once taught me to pay attention to how the gas tube makes contact with the gas key on the carrier. there should be little to no friction. i.e. bend it until you get no resistance when the bolt locks and unlocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BigJoe</div><div class="ubbcode-body">barrel and trigger, fuck everything else as long as its free float and its got a good barrel that headspaces and a good trigger the thing will shoot. </div></div>
+1 also, a wise man once taught me to pay attention to how the gas tube makes contact with the gas key on the carrier. there should be little to no friction. i.e. bend it until you get no resistance when the bolt locks and unlocks
Re: What makes a gas gun accurate?
Actually the rigidity, straightness and fit of the barrel into the upper also matters. Lots of potentialy good shooting ar's won't because of how the barrel nut is installed or how it fits. Just like a bolt rifle consentricity and perfection help. otherwise all of the above is also tru to bolt guns and we all know there is more to it than just a good headspace.
Most tight shooting ar's never will because of the shooter. They are a different animal to drive well
Actually the rigidity, straightness and fit of the barrel into the upper also matters. Lots of potentialy good shooting ar's won't because of how the barrel nut is installed or how it fits. Just like a bolt rifle consentricity and perfection help. otherwise all of the above is also tru to bolt guns and we all know there is more to it than just a good headspace.
Most tight shooting ar's never will because of the shooter. They are a different animal to drive well
Re: What makes a gas gun accurate?
Did a range day at Central Virginia Tactical in the Spring "Precision shooting with imprecise components," shooting steel out to 750 yds with 16 inch AR carbines, factory M855 ammo and an XPS-2 holosight. Really. Try a 11x17 inch plate (1/4 the surface area of a full size torso), 5 hits in a row. I never thought this kind of accuracy would be possible and I was using a home-brewed DPMS upper/lower with standard trigger group components and a suppressor. Two other guys were out that day, and many others have done the same course.
The most accurate, reliable, precise component was the ammunition, I thought, but I also tried some home-brewed M193 rounds, surplus powder, resized bullets and range brass, CCI primers, made hit after hit on 400 yd targets, maybe 1 out of 3 on the 700 rd plate.
Wrote it up on marylandshooters.com, here:
http://www.mdshooters.com/showthread.php?t=74747
YMMV
Did a range day at Central Virginia Tactical in the Spring "Precision shooting with imprecise components," shooting steel out to 750 yds with 16 inch AR carbines, factory M855 ammo and an XPS-2 holosight. Really. Try a 11x17 inch plate (1/4 the surface area of a full size torso), 5 hits in a row. I never thought this kind of accuracy would be possible and I was using a home-brewed DPMS upper/lower with standard trigger group components and a suppressor. Two other guys were out that day, and many others have done the same course.
The most accurate, reliable, precise component was the ammunition, I thought, but I also tried some home-brewed M193 rounds, surplus powder, resized bullets and range brass, CCI primers, made hit after hit on 400 yd targets, maybe 1 out of 3 on the 700 rd plate.
Wrote it up on marylandshooters.com, here:
http://www.mdshooters.com/showthread.php?t=74747
YMMV
Re: What makes a gas gun accurate?
AXEMAN,
What is this GAP you speak of? And who is George?
Can they make an AK shoot as good as Red Jacket?
JK, have a great day!
AXEMAN,
What is this GAP you speak of? And who is George?
Can they make an AK shoot as good as Red Jacket?
JK, have a great day!
Re: What makes a gas gun accurate?
If you want the best Precision upper made, Call Wes at MSTN. Precision uppers start at $1600, but they have built some 10.5" uppers that make my Custom 700s look factory. I believe stated earlier, in an AR, Lap your upper receivers face, (good stiff upper) if you like 1 stage triggers, a JP, or a Timney, 2 stage only Geissele DMR, and a Noveske (Pac-Nor) barrel.
If you want the best Precision upper made, Call Wes at MSTN. Precision uppers start at $1600, but they have built some 10.5" uppers that make my Custom 700s look factory. I believe stated earlier, in an AR, Lap your upper receivers face, (good stiff upper) if you like 1 stage triggers, a JP, or a Timney, 2 stage only Geissele DMR, and a Noveske (Pac-Nor) barrel.
