How would you correct an over gassed AR ?

Metal god · November 29, 2018, 07:08 PM

I recently inherited my dads AR . It"s 16" mid length 223 Wylde from PSA with a standard carbine buffer and spring . It's always been over gassed since we put it together 3 years ago . It ejects the brass to the 1:30 position and today I tried a H1 buffer in it but that only changed the ejection to the 2:30 position . An H2 will likely fix the issue but is that the best way to fix the problem ?

For the most part my uppers and lowers are dedicated sets to each other but I do from time to time mix and match . All my personal AR's eject to the 4:00 position pretty much stacking the brass in little piles .

I can add the H2 buffer and just call his rifle a set not to be messed with because that lower with a H2 buffer will likely not work well with some of my other uppers . Or I can install an adjustable gas block on the upper allowing it to be gassed the same as the rest of my uppers .

What do you guys do who have multiple uppers and lowers that need proprietary items that allow them to operate best ? Do you dedicate each upper to a lower as sets or try to get them all gassed the same so mix and match is not an issue ?

kilotanker22 · November 29, 2018, 07:38 PM

I assume that your Gas Block is non adjustable?

ed308 · November 29, 2018, 08:19 PM

Mine have dedicated lowers. Adjustable should fix it.

Sharkbite · November 29, 2018, 08:21 PM

With mtpl uppers being switched onto a lower, the buffer is not the place to adjust stuff. Put an adj gas block on the upper and tune that.

Eazyeach · November 29, 2018, 08:27 PM

If my guns are reliable and accurate I could give a rip where they eject.

Fusion · November 29, 2018, 08:33 PM

Change the gas block out to an adjustable one.

zukiphile · November 29, 2018, 09:41 PM

Quote:

Originally Posted by Metal God

I can add the H2 buffer and just call his rifle a set not to be messed with because that lower with a H2 buffer will likely not work well with some of my other uppers .

Have you tried? I have H3 or 9mm 5+ ounce buffers in all of my carbines, and they all function with everything including Wolf and Tula.

https://palmettostatearmory.com/9mm-...ffer-assy.html

Sharkbite · November 29, 2018, 09:44 PM

Quote:

If my guns are reliable and accurate I could give a rip where they eject.

Over gassed is more then just ejection patterns. It also causes more recoil and accelerates wear

MarkCO · November 29, 2018, 10:08 PM

Changing buffers and springs is not fixing overgassing, just a band-aid.

If you reload, use a faster powder or drop the charge weight. Otherwise, the only way to do it is to reduce the amount of gas that goes into the gas key. That mostly means putting on an adjustable, or switchable gas block. That increases maintenance, some more that others. I use Superlative Arms gas blocks on the 3 I have that needed adjustable gas.

Metal god · November 30, 2018, 01:43 AM

Quote:

Changing buffers and springs is not fixing overgassing, just a band-aid.

That's a good point and one I knew but needed to hear again . I have a Seekins adjustable gas block on hand that does not have a home . I think I give it a try .

Bartholomew Roberts · November 30, 2018, 10:05 AM

By the way, they also make adjustable gas keys now as well.

MarkCO · November 30, 2018, 11:58 AM

Adjustable gas keys will tune the recoil impulse, but they do not correct all overgassing issues and run dirtier than controlling the gas at the block or port.

Metal god · November 30, 2018, 12:46 PM

Quote:

By the way, they also make adjustable gas keys now as well.

Quote:

Adjustable gas keys will tune the recoil impulse, but they do not correct all overgassing issues and run dirtier than controlling the gas at the block or port.

I thought you were kidding Bartholomew . I'm not even sure I see the benefit of such a thing , at least with out causing another problem . Which would be more gases being directed into the action in areas they were not intended to be ????

Am I wrong in assuming an adjustable gas key would need to bleed off the gas ? where does that bleed off to/at ?

Is there an actual good reason to have such a thing rather then fixing an issue the traditional ways ? I asked the question like that because I see no reason to even invent such a thing but leave open possibility there are fantastic uses for an adjustable gas key .

MarkCO · November 30, 2018, 01:07 PM

The primary use for an adjustable gas key is competition. You run your hoser load which is 55s at 2600 to 2800 fps. Nice and soft and flat, tuned to go fast and not overgassed so the adjustable gas key is not bleeding off much of anything. Then with the 69 to 77 grain load at 2800 to 2900 fps, the excess gas is dumped (yes into the action) but the gun behaves and recoils substantially similar to the hoser load. So unless you are running mostly a short range low powered load with some longer range precision loads like is done in 3Gun, there is absolutely no benefit to an adjustable gas key. I keep 3 or 4 3Gun ARs running with close to 20K through them annually and still won't use the adjustable gas key. But shooting PRS as well, I focus on the long range a lot more and I don't see any benefit in them for how I shoot.

Most avid 3Gunners are, over the next month or two, stockpiling ammo and rebuilding their guns. Run 10K and rebarrel, some go with a new bolt, and replace all the wear parts.

Bartholomew Roberts · November 30, 2018, 01:15 PM

Well, technically, your bolt is already adjusting gas pressure by blowing the excess gas out the two holes in the side of the carrier once the gas rings are pushed back far enough.

So, the adjustable gas key isn’t directing more gas into your upper. It is directing the same amount of gas and diverting some of it through the gas tube cloverleaf and the rest through the ejection port.

If you take the view that most fouling in the AR systen is related to the bolt unlocking early with residual pressure still in the bore, then anything that delays the unlocking will reduce fouling; and bleeding off gas before it enters the expansion chamber in the carrier will delay unlocking.

An adjustable gas key is also easier to retrofit then pulling off a gas block or swapping to a barrel with the correct port size/no erosion for your use (which is what all the other solutions, including adjustable gas blocks, are patching).

If you’ve got an adjustable gas block handy and you are comfortable swapping them out, I’d go that route. But for the guy who doesn’t want to dremel off his pinned front sight base, the adjustable gas key gives you options.

On my personal rifles, I just increase buffer weight; but I’m not swapping uppers and lowers around either.

imashooter · November 30, 2018, 05:15 PM

Typical suggestions to include heavier buffer. On a PSA, which ever is cheapest and easiest; the buffer.

300 wsm hunter · December 1, 2018, 10:20 AM

have you noticed any copper fouling in or around your bcg?
i'd be concerned about the size of your gas hole in the barrel. i've found the larger the hole the more over gassed and you will see alot of copper stuck in the gas block.

Wyosmith · December 1, 2018, 10:56 AM

One thing that can help is to go to the heaviest recoil spring and heaviest buffer you can get. This will not fix a grossly over-sized port, but when you are about 20-25 percent over-gasses it works very well and also help with brass life. Brass life is not a consideration if you don't reload your own ammo however.

Metal god · December 1, 2018, 11:29 AM

I do reload and although I have a lot of brass . Brass life is still something I want to extend .

The rifle is new to me so I don't know if it's getting more copper fouling . I've not shot it enough . In fact I only have about 100rds if that through it since I got it a couple months ago . I'm going to put the Seekins gas block on it this weekend and shoot on the tenth .

On a side note :

Quote:

That mostly means putting on an adjustable, or switchable gas block. That increases maintenance, some more that others.

I was going to ask sometime soon here at TFL how often any of you clean your gas tubes and how would you do that . The carbon build up you get on the back end of your bolt needs to be scraped off , at least mine do . A wire brush and solvent doesn't do anything for me . That leads me to think there must be carbon building up in the gas tube and block . What's the best way to clean that out ?

300 wsm hunter · December 1, 2018, 11:50 AM

i pull mine apart and put it in my ultra sonic cleaner with berrymans carb and parts cleaner

MarkCO · December 1, 2018, 12:15 PM

Quote:

Originally Posted by Metal god

I was going to ask sometime soon here at TFL how often any of you clean your gas tubes and how would you do that . The carbon build up you get on the back end of your bolt needs to be scraped off , at least mine do . A wire brush and solvent doesn't do anything for me . That leads me to think there must be carbon building up in the gas tube and block . What's the best way to clean that out ?

At about 2K, I take the BCG apart and put it in the ultrasonic with Lucas BS/US Cleaner. Gunslick Pro foaming down the gas tube until I see it come into the bore, then fill the bore with it. 30 minutes later, flush out with contact cleaner, blow out with compressed air, reassemble BCG, lube with Lucas Extreme Duty...good for another 2K. It will go longer this way, but I know I won't have any failures on this schedule.

I have a few with Melonite or QPQ bolts and barrels, and that is a wipe down at 1K and keep on going until about 10K when I do the above.

10-96 · December 1, 2018, 12:40 PM

It was probably considered cheating, but on one rifle I thought was over-gassing I just used a bore scope to watch the holes and I eased the gas block forward slightly. I only "off-centered" the holes by maybe 1/8 to 1/4 of the hole width, but it was enough.

ed308 · December 1, 2018, 01:01 PM

I was going to ask sometime soon here at TFL how often any of you clean your gas tubes and how would you do that.

I've got some ARs that are almost 30 years old and I've never cleaned the gas tube in any of my ARs.

Mobuck · December 1, 2018, 03:12 PM

Personally, I've not seen an over-gassed mid-length 16". Guess I'm missing something.

jugornot · December 1, 2018, 04:53 PM

My DPMS was wildly overgassed and tearing up brass to the point it wouldn't go in shell holder. An adjustable gas block solved all the problems.

November 29, 2018, 07:08 PM	#1
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,876	How would you correct an over gassed AR ? I recently inherited my dads AR . It"s 16" mid length 223 Wylde from PSA with a standard carbine buffer and spring . It's always been over gassed since we put it together 3 years ago . It ejects the brass to the 1:30 position and today I tried a H1 buffer in it but that only changed the ejection to the 2:30 position . An H2 will likely fix the issue but is that the best way to fix the problem ? For the most part my uppers and lowers are dedicated sets to each other but I do from time to time mix and match . All my personal AR's eject to the 4:00 position pretty much stacking the brass in little piles . I can add the H2 buffer and just call his rifle a set not to be messed with because that lower with a H2 buffer will likely not work well with some of my other uppers . Or I can install an adjustable gas block on the upper allowing it to be gassed the same as the rest of my uppers . What do you guys do who have multiple uppers and lowers that need proprietary items that allow them to operate best ? Do you dedicate each upper to a lower as sets or try to get them all gassed the same so mix and match is not an issue ? __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

November 29, 2018, 10:08 PM	#9
MarkCO Senior Member Join Date: October 21, 1998 Location: Colorado, USA Posts: 4,308	Changing buffers and springs is not fixing overgassing, just a band-aid. If you reload, use a faster powder or drop the charge weight. Otherwise, the only way to do it is to reduce the amount of gas that goes into the gas key. That mostly means putting on an adjustable, or switchable gas block. That increases maintenance, some more that others. I use Superlative Arms gas blocks on the 3 I have that needed adjustable gas. __________________ Good Shooting, MarkCO www.CarbonArms.us

November 30, 2018, 11:58 AM	#12
MarkCO Senior Member Join Date: October 21, 1998 Location: Colorado, USA Posts: 4,308	Adjustable gas keys will tune the recoil impulse, but they do not correct all overgassing issues and run dirtier than controlling the gas at the block or port. __________________ Good Shooting, MarkCO www.CarbonArms.us

November 30, 2018, 01:07 PM	#14
MarkCO Senior Member Join Date: October 21, 1998 Location: Colorado, USA Posts: 4,308	The primary use for an adjustable gas key is competition. You run your hoser load which is 55s at 2600 to 2800 fps. Nice and soft and flat, tuned to go fast and not overgassed so the adjustable gas key is not bleeding off much of anything. Then with the 69 to 77 grain load at 2800 to 2900 fps, the excess gas is dumped (yes into the action) but the gun behaves and recoils substantially similar to the hoser load. So unless you are running mostly a short range low powered load with some longer range precision loads like is done in 3Gun, there is absolutely no benefit to an adjustable gas key. I keep 3 or 4 3Gun ARs running with close to 20K through them annually and still won't use the adjustable gas key. But shooting PRS as well, I focus on the long range a lot more and I don't see any benefit in them for how I shoot. Most avid 3Gunners are, over the next month or two, stockpiling ammo and rebuilding their guns. Run 10K and rebarrel, some go with a new bolt, and replace all the wear parts. __________________ Good Shooting, MarkCO www.CarbonArms.us

December 1, 2018, 12:40 PM	#22
10-96 Senior Member Join Date: October 19, 2005 Location: Tx Panhandle Territory Posts: 4,159	It was probably considered cheating, but on one rifle I thought was over-gassing I just used a bore scope to watch the holes and I eased the gas block forward slightly. I only "off-centered" the holes by maybe 1/8 to 1/4 of the hole width, but it was enough. __________________ Rednecks... Keeping the woods critter-free since March 2, 1836. (TX Independence Day) I suspect a thing or two... because I've seen a thing or two.

November 29, 2018, 07:38 PM	#2
kilotanker22 Senior Member Join Date: October 14, 2012 Location: North Central, PA Posts: 2,117	I assume that your Gas Block is non adjustable?

November 29, 2018, 08:19 PM	#3
ed308 Senior Member Join Date: November 5, 2016 Location: DFW, TX Posts: 1,147	Mine have dedicated lowers. Adjustable should fix it.

November 29, 2018, 08:21 PM	#4
Sharkbite Senior Member Join Date: November 4, 2013 Location: Western slope of Colorado Posts: 3,679	With mtpl uppers being switched onto a lower, the buffer is not the place to adjust stuff. Put an adj gas block on the upper and tune that.

November 29, 2018, 08:27 PM	#5
Eazyeach Senior Member Join Date: January 14, 2014 Posts: 706	If my guns are reliable and accurate I could give a rip where they eject.

November 29, 2018, 08:33 PM	#6
Fusion Senior Member Join Date: August 13, 2010 Posts: 429	Change the gas block out to an adjustable one.

November 30, 2018, 10:05 AM	#11
Bartholomew Roberts member Join Date: June 12, 2000 Location: Texas and Oklahoma area Posts: 8,462	By the way, they also make adjustable gas keys now as well.

November 30, 2018, 01:15 PM	#15
Bartholomew Roberts member Join Date: June 12, 2000 Location: Texas and Oklahoma area Posts: 8,462	Well, technically, your bolt is already adjusting gas pressure by blowing the excess gas out the two holes in the side of the carrier once the gas rings are pushed back far enough. So, the adjustable gas key isn’t directing more gas into your upper. It is directing the same amount of gas and diverting some of it through the gas tube cloverleaf and the rest through the ejection port. If you take the view that most fouling in the AR systen is related to the bolt unlocking early with residual pressure still in the bore, then anything that delays the unlocking will reduce fouling; and bleeding off gas before it enters the expansion chamber in the carrier will delay unlocking. An adjustable gas key is also easier to retrofit then pulling off a gas block or swapping to a barrel with the correct port size/no erosion for your use (which is what all the other solutions, including adjustable gas blocks, are patching). If you’ve got an adjustable gas block handy and you are comfortable swapping them out, I’d go that route. But for the guy who doesn’t want to dremel off his pinned front sight base, the adjustable gas key gives you options. On my personal rifles, I just increase buffer weight; but I’m not swapping uppers and lowers around either.

November 30, 2018, 05:15 PM	#16
imashooter Senior Member Join Date: December 28, 2013 Location: Alabama Posts: 395	Typical suggestions to include heavier buffer. On a PSA, which ever is cheapest and easiest; the buffer.

December 1, 2018, 10:20 AM	#17
300 wsm hunter Member Join Date: November 19, 2018 Posts: 19	have you noticed any copper fouling in or around your bcg? i'd be concerned about the size of your gas hole in the barrel. i've found the larger the hole the more over gassed and you will see alot of copper stuck in the gas block.

December 1, 2018, 10:56 AM	#18
Wyosmith Senior Member Join Date: December 29, 2010 Location: Shoshoni Wyoming Posts: 2,713	One thing that can help is to go to the heaviest recoil spring and heaviest buffer you can get. This will not fix a grossly over-sized port, but when you are about 20-25 percent over-gasses it works very well and also help with brass life. Brass life is not a consideration if you don't reload your own ammo however.

December 1, 2018, 11:50 AM	#20
300 wsm hunter Member Join Date: November 19, 2018 Posts: 19	i pull mine apart and put it in my ultra sonic cleaner with berrymans carb and parts cleaner

December 1, 2018, 01:01 PM	#23
ed308 Senior Member Join Date: November 5, 2016 Location: DFW, TX Posts: 1,147	I was going to ask sometime soon here at TFL how often any of you clean your gas tubes and how would you do that. I've got some ARs that are almost 30 years old and I've never cleaned the gas tube in any of my ARs. Last edited by ed308; December 2, 2018 at 12:47 PM.

December 1, 2018, 03:12 PM	#24
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	Personally, I've not seen an over-gassed mid-length 16". Guess I'm missing something.

December 1, 2018, 04:53 PM	#25
jugornot Senior Member Join Date: September 20, 2017 Posts: 197	My DPMS was wildly overgassed and tearing up brass to the point it wouldn't go in shell holder. An adjustable gas block solved all the problems.