- Thread starter Outlaw45
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Re: Adjustable gas blocks
Need isn't a term I would use, that's for sure. However, they can be nice to have. You can tune them for allowing the gun to run very smootly and not so harsh (carbine length gas system). Or, their other use is for suppressed rifles. You can also adjust it if your gun gets too dirty to pump more gas it. Best of luck!
Need isn't a term I would use, that's for sure. However, they can be nice to have. You can tune them for allowing the gun to run very smootly and not so harsh (carbine length gas system). Or, their other use is for suppressed rifles. You can also adjust it if your gun gets too dirty to pump more gas it. Best of luck!
Re: Adjustable gas blocks
Suppressor use or if you feel that the rifle is over gassed and hammering your brass + bolt (DPMS 308) , or you like your brass to land in a small pile 1-2 feet away from you.
Suppressor use or if you feel that the rifle is over gassed and hammering your brass + bolt (DPMS 308) , or you like your brass to land in a small pile 1-2 feet away from you.
Re: Adjustable gas blocks
Yep, big bore AR's are notoriously hard on the system. By being able to control the gas with an adj. block, you can ease the violent cycle and taylor your system to a specific load that works well in your rifle. Can come in handy on AR15's also. BTW, if you want to single cycle for some reason.....you can completely turn the gas block off. Good luck.
okie
Yep, big bore AR's are notoriously hard on the system. By being able to control the gas with an adj. block, you can ease the violent cycle and taylor your system to a specific load that works well in your rifle. Can come in handy on AR15's also. BTW, if you want to single cycle for some reason.....you can completely turn the gas block off. Good luck.
okie
Re: Adjustable gas blocks
Primarily for running a suppressor or lightened bolt carrier group, you shouldn't need one.
Primarily for running a suppressor or lightened bolt carrier group, you shouldn't need one.
Re: Adjustable gas blocks
They are very nice to have on a grendel. I wouldn't build one without it. Most grendels are over gassed so they come in handy.
They are very nice to have on a grendel. I wouldn't build one without it. Most grendels are over gassed so they come in handy.
Re: Adjustable gas blocks
Adjustable gas blocks can be problematic. Keep in mind they are generally not linear in operation. That is to say they can't be finely adjusted. They are either on or off. You would be better off building your rifle with quality known parts and tuning it to run with a single load. The idea that an adjustable gas block will give you the ability to tune the rifle to a wide range of ammunition choices and maintain reliability is questionable.
Adjustable gas blocks can be problematic. Keep in mind they are generally not linear in operation. That is to say they can't be finely adjusted. They are either on or off. You would be better off building your rifle with quality known parts and tuning it to run with a single load. The idea that an adjustable gas block will give you the ability to tune the rifle to a wide range of ammunition choices and maintain reliability is questionable.
Re: Adjustable gas blocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">Adjustable gas blocks can be problematic. Keep in mind they are generally not linear in operation. That is to say they can't be finely adjusted. They are either on or off. You would be better off building your rifle with quality known parts and tuning it to run with a single load. The idea that an adjustable gas block will give you the ability to tune the rifle to a wide range of ammunition choices and maintain reliability is questionable.</div></div>
So adjusting the set screw doesn't 'adjust' the gas depending on how far you turn in/out the screw?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">Adjustable gas blocks can be problematic. Keep in mind they are generally not linear in operation. That is to say they can't be finely adjusted. They are either on or off. You would be better off building your rifle with quality known parts and tuning it to run with a single load. The idea that an adjustable gas block will give you the ability to tune the rifle to a wide range of ammunition choices and maintain reliability is questionable.</div></div>
So adjusting the set screw doesn't 'adjust' the gas depending on how far you turn in/out the screw?
Re: Adjustable gas blocks
http://www.brownells.com/.aspx/pid=7592/Product/AR-15-M16-ADJUSTABLE-GAS-BLOCK
http://www.shootingillustrated.com/index.php/23788/syrac-ordnance-adjustable-low-pro-gas-block/
http://www.spikestactical.com/new/z/spik...crew-p-738.html
http://www.rainierarms.com/?page=shop/detail&product_id=3183
I dont know much about them but it sounds like the manufacturers made them to tune the gas system. The ones I've seen either had several positions to choose from or could be set anywhere from closed to wide open or anywhere in between.
okie
http://www.brownells.com/.aspx/pid=7592/Product/AR-15-M16-ADJUSTABLE-GAS-BLOCK
http://www.shootingillustrated.com/index.php/23788/syrac-ordnance-adjustable-low-pro-gas-block/
http://www.spikestactical.com/new/z/spik...crew-p-738.html
http://www.rainierarms.com/?page=shop/detail&product_id=3183
I dont know much about them but it sounds like the manufacturers made them to tune the gas system. The ones I've seen either had several positions to choose from or could be set anywhere from closed to wide open or anywhere in between.
okie
Re: Adjustable gas blocks
Some have the 3 position, on - 1/2 off - off
Most are a screw type that you can adjust from, off - full open
Some have the 3 position, on - 1/2 off - off
Most are a screw type that you can adjust from, off - full open
Re: Adjustable gas blocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: smschulz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">Adjustable gas blocks can be problematic. Keep in mind they are generally not linear in operation. That is to say they can't be finely adjusted. They are either on or off. You would be better off building your rifle with quality known parts and tuning it to run with a single load. The idea that an adjustable gas block will give you the ability to tune the rifle to a wide range of ammunition choices and maintain reliability is questionable.</div></div>
So adjusting the set screw doesn't 'adjust' the gas depending on how far you turn in/out the screw? </div></div>
They don't have finite adjustment capability. Like I said it's more of an on/off switch. The gas port is the volume control. The adjustment on the gas block is more of a timing adjustment. It interrupts the flow of gas and the time it takes for the gas system to charge.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: smschulz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">Adjustable gas blocks can be problematic. Keep in mind they are generally not linear in operation. That is to say they can't be finely adjusted. They are either on or off. You would be better off building your rifle with quality known parts and tuning it to run with a single load. The idea that an adjustable gas block will give you the ability to tune the rifle to a wide range of ammunition choices and maintain reliability is questionable.</div></div>
So adjusting the set screw doesn't 'adjust' the gas depending on how far you turn in/out the screw?
They don't have finite adjustment capability. Like I said it's more of an on/off switch. The gas port is the volume control. The adjustment on the gas block is more of a timing adjustment. It interrupts the flow of gas and the time it takes for the gas system to charge.
Re: Adjustable gas blocks
this is a cheaper way to go if you don't have a bull barrel, will need a hole to adjust it
http://www.midwayusa.com/product/2979396319/mgi-adjustable-gas-tube-ar-15
this is a cheaper way to go if you don't have a bull barrel, will need a hole to adjust it
http://www.midwayusa.com/product/2979396319/mgi-adjustable-gas-tube-ar-15
Re: Adjustable gas blocks
Well for my intended use I want to find a load that is accurate and reliable in the gun. That's it. If Iowa ever gets suppressors legalized then I'll have the suppressor issue to deal with but that's a ways off.
Well for my intended use I want to find a load that is accurate and reliable in the gun. That's it. If Iowa ever gets suppressors legalized then I'll have the suppressor issue to deal with but that's a ways off.
Re: Adjustable gas blocks
Ok... The JP Entetprise adjustable gas block has a set screw that adjusts the gas. You can close it off, open it wide open, or anywhere inbetween the two. It workes very well supressed & unsupressed with the grendel. The JP block is NOT like a switch block, where you have 3 settings. On the JP block you just turn the screw as much as needed. Hope this helps
Ok... The JP Entetprise adjustable gas block has a set screw that adjusts the gas. You can close it off, open it wide open, or anywhere inbetween the two. It workes very well supressed & unsupressed with the grendel. The JP block is NOT like a switch block, where you have 3 settings. On the JP block you just turn the screw as much as needed. Hope this helps
Re: Adjustable gas blocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: smschulz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">Adjustable gas blocks can be problematic. Keep in mind they are generally not linear in operation. That is to say they can't be finely adjusted. They are either on or off. You would be better off building your rifle with quality known parts and tuning it to run with a single load. The idea that an adjustable gas block will give you the ability to tune the rifle to a wide range of ammunition choices and maintain reliability is questionable.</div></div>
So adjusting the set screw doesn't 'adjust' the gas depending on how far you turn in/out the screw? </div></div>
They don't have finite adjustment capability. Like I said it's more of an on/off switch. The gas port is the volume control. The adjustment on the gas block is more of a timing adjustment. It interrupts the flow of gas and the time it takes for the gas system to charge. </div></div>Maybe, maybe not. It depends on what model you're talking about. There are basically two types: Gas blocks that have a couple of preset options and gas blocks that have a set screw that can be very finely adjusted. I have the JP adjustable gas block with the set screw on a DPMS LR-308 that can be finely adjusted in anticipation of the arrival of my suppressor. I anticipate being able to tune my rifle to 100% reliability without too much (if any) blow-back and gentle recoil for a .308 all while saving the action from a beating.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: smschulz</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">Adjustable gas blocks can be problematic. Keep in mind they are generally not linear in operation. That is to say they can't be finely adjusted. They are either on or off. You would be better off building your rifle with quality known parts and tuning it to run with a single load. The idea that an adjustable gas block will give you the ability to tune the rifle to a wide range of ammunition choices and maintain reliability is questionable.</div></div>
So adjusting the set screw doesn't 'adjust' the gas depending on how far you turn in/out the screw?
They don't have finite adjustment capability. Like I said it's more of an on/off switch. The gas port is the volume control. The adjustment on the gas block is more of a timing adjustment. It interrupts the flow of gas and the time it takes for the gas system to charge. </div></div>Maybe, maybe not. It depends on what model you're talking about. There are basically two types: Gas blocks that have a couple of preset options and gas blocks that have a set screw that can be very finely adjusted. I have the JP adjustable gas block with the set screw on a DPMS LR-308 that can be finely adjusted in anticipation of the arrival of my suppressor. I anticipate being able to tune my rifle to 100% reliability without too much (if any) blow-back and gentle recoil for a .308 all while saving the action from a beating.
Re: Adjustable gas blocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LocoGringo</div><div class="ubbcode-body">Maybe, maybe not. It depends on what model you're talking about. There are basically two types: Gas blocks that have a couple of preset options and gas blocks that have a set screw <span style="text-decoration: underline">that can be very finely adjusted</span>. I have the JP adjustable gas block with the set screw on a DPMS LR-308 that can be finely adjusted in anticipation of the arrival of my suppressor. I anticipate being able to tune my rifle to 100% reliability without too much (if any) blow-back and gentle recoil for a .308 all while saving the action from a beating.</div></div>
My experience with JP gas blocks is diametrically opposed to yours. Several years ago I used a shot clock to measure cyclic rate change after changing screw position on a CTR-02. Once the screw was adjusted out to the point the rifle would complete the cycle of operation, there was no increase in cyclic rate after it was opened further. Hence my assertion that it is either on or off. I'd love to see you document the ability of ANY adjustable gas system to be finitely adjusted.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LocoGringo</div><div class="ubbcode-body">Maybe, maybe not. It depends on what model you're talking about. There are basically two types: Gas blocks that have a couple of preset options and gas blocks that have a set screw <span style="text-decoration: underline">that can be very finely adjusted</span>. I have the JP adjustable gas block with the set screw on a DPMS LR-308 that can be finely adjusted in anticipation of the arrival of my suppressor. I anticipate being able to tune my rifle to 100% reliability without too much (if any) blow-back and gentle recoil for a .308 all while saving the action from a beating.</div></div>
My experience with JP gas blocks is diametrically opposed to yours. Several years ago I used a shot clock to measure cyclic rate change after changing screw position on a CTR-02. Once the screw was adjusted out to the point the rifle would complete the cycle of operation, there was no increase in cyclic rate after it was opened further. Hence my assertion that it is either on or off. I'd love to see you document the ability of ANY adjustable gas system to be finitely adjusted.
Re: Adjustable gas blocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">
My experience with JP gas blocks is diametrically opposed to yours. Several years ago I used a shot clock to measure cyclic rate change after changing screw position on a CTR-02. Once the screw was adjusted out to the point the rifle would complete the cycle of operation, there was no increase in cyclic rate after it was opened further. Hence my assertion that it is either on or off. I'd love to see you document the ability of ANY adjustable gas system to be finitely adjusted. </div></div>
You'd have to have a high-speed camera to test the cycle speed scientifically.
JP blocks are infinitely adjustable and very useful in certain specialty applications like competition rifles, wildcat rounds, suppressed guns, etc.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">
My experience with JP gas blocks is diametrically opposed to yours. Several years ago I used a shot clock to measure cyclic rate change after changing screw position on a CTR-02. Once the screw was adjusted out to the point the rifle would complete the cycle of operation, there was no increase in cyclic rate after it was opened further. Hence my assertion that it is either on or off. I'd love to see you document the ability of ANY adjustable gas system to be finitely adjusted. </div></div>
You'd have to have a high-speed camera to test the cycle speed scientifically.
JP blocks are infinitely adjustable and very useful in certain specialty applications like competition rifles, wildcat rounds, suppressed guns, etc.
Re: Adjustable gas blocks
? wonder why my stock DPMS .260 use to throw brass 6ft at 2:00, and now with JP it throws it 3ft at 4:00 & seems to leave less of an ejector mark.
? wonder why my stock DPMS .260 use to throw brass 6ft at 2:00, and now with JP it throws it 3ft at 4:00 & seems to leave less of an ejector mark.
Re: Adjustable gas blocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: boomfab</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">
My experience with JP gas blocks is diametrically opposed to yours. Several years ago I used a shot clock to measure cyclic rate change after changing screw position on a CTR-02. Once the screw was adjusted out to the point the rifle would complete the cycle of operation, there was no increase in cyclic rate after it was opened further. Hence my assertion that it is either on or off. I'd love to see you document the ability of ANY adjustable gas system to be finitely adjusted. </div></div>
You'd have to have a high-speed camera to test the cycle speed scientifically.
<span style="text-decoration: underline">JP blocks are infinitely adjustable</span> and very useful in certain specialty applications like competition rifles, wildcat rounds, suppressed guns, etc.
</div></div>
OK. Nothing left to discuss...
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: boomfab</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">
My experience with JP gas blocks is diametrically opposed to yours. Several years ago I used a shot clock to measure cyclic rate change after changing screw position on a CTR-02. Once the screw was adjusted out to the point the rifle would complete the cycle of operation, there was no increase in cyclic rate after it was opened further. Hence my assertion that it is either on or off. I'd love to see you document the ability of ANY adjustable gas system to be finitely adjusted. </div></div>
You'd have to have a high-speed camera to test the cycle speed scientifically.
<span style="text-decoration: underline">JP blocks are infinitely adjustable</span> and very useful in certain specialty applications like competition rifles, wildcat rounds, suppressed guns, etc.
</div></div>
OK. Nothing left to discuss...
Re: Adjustable gas blocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">
OK. Nothing left to discuss... </div></div>
It has a SCREW for adjustment.
Infinite settings.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">
OK. Nothing left to discuss... </div></div>
It has a SCREW for adjustment.
Infinite settings.
Re: Adjustable gas blocks
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: boomfab</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">
OK. Nothing left to discuss... </div></div>
<span style="text-decoration: underline">It has a SCREW</span> for adjustment.
Infinite settings.
</div></div>
No shit...
Been around for awhile. You aren't telling me anything new.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: boomfab</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BallistaOne</div><div class="ubbcode-body">
OK. Nothing left to discuss... </div></div>
<span style="text-decoration: underline">It has a SCREW</span> for adjustment.
Infinite settings.
</div></div>
No shit...
Been around for awhile. You aren't telling me anything new.
