I am a self taught AR platform garage gunsmith. I would like to be able to enlarge gas ports on AR15 and AR/308 barrels, but I don't know how it is done. Could someone please explain how it is done?
Gunsmithing How do I open up a gas port on an ar type barrel?
- Thread starter Robe
- Start date
Re: How do I open up a gas port on an ar type barrel?
Drill bits seem to be good for making holes, but there's a little science behind gas port hole sizes. I've only opened one gas port, but it was done with a drill bit and didn't seem to hurt anything.
Drill bits seem to be good for making holes, but there's a little science behind gas port hole sizes. I've only opened one gas port, but it was done with a drill bit and didn't seem to hurt anything.
Re: How do I open up a gas port on an ar type barrel?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Recoil</div><div class="ubbcode-body">A reamer would make a nicer whole. msc direct sells just about any size you want. </div></div>
The reamer is your best bet.You use them dead slow with lots of oil and don't let the cutting action stall on feeding,go slow metal don't grow back.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Recoil</div><div class="ubbcode-body">A reamer would make a nicer whole. msc direct sells just about any size you want. </div></div>
The reamer is your best bet.You use them dead slow with lots of oil and don't let the cutting action stall on feeding,go slow metal don't grow back.
Re: How do I open up a gas port on an ar type barrel?
+1 on the reamer. MSC is a good source.
+1 on the reamer. MSC is a good source.
Re: How do I open up a gas port on an ar type barrel?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: P.A.R.</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Recoil</div><div class="ubbcode-body">A reamer would make a nicer whole. msc direct sells just about any size you want. </div></div>
The reamer is your best bet.You use them dead slow with lots of oil and don't let the cutting action stall on feeding,go slow metal don't grow back. </div></div>
Only way I have ever done it. Make sure not to open to much, start small and work up if needed.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: P.A.R.</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Recoil</div><div class="ubbcode-body">A reamer would make a nicer whole. msc direct sells just about any size you want. </div></div>
The reamer is your best bet.You use them dead slow with lots of oil and don't let the cutting action stall on feeding,go slow metal don't grow back. </div></div>
Only way I have ever done it. Make sure not to open to much, start small and work up if needed.
Re: How do I open up a gas port on an ar type barrel?
My guess is that the AR10 gas ports are already too large.
My guess is that the AR10 gas ports are already too large.
Re: How do I open up a gas port on an ar type barrel?
An adjustable gas block has worked for just about any issues I have seen.
An adjustable gas block has worked for just about any issues I have seen.
Re: How do I open up a gas port on an ar type barrel?
be prepared for accelerated wear on your bolt lugs.
be prepared for accelerated wear on your bolt lugs.
Re: How do I open up a gas port on an ar type barrel?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Stangfish</div><div class="ubbcode-body">be prepared for accelerated wear on your bolt lugs. </div></div>
Unless it is short stroking or not the right size in the first place, it happens more than people would think.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Stangfish</div><div class="ubbcode-body">be prepared for accelerated wear on your bolt lugs. </div></div>
Unless it is short stroking or not the right size in the first place, it happens more than people would think.
Re: How do I open up a gas port on an ar type barrel?
AR-10 gas ports are already too large.... be prepared for accelerated wear on bolt lugs? Not really applicable to my question.
The problem I am trying to fix is low gas pressure in an AR-15. The bolt/carrier will travel back enough to extract the brass from the chamber and eject the brass, but it does not travel far enough rearward to be able to strip the next round from the magazine and load it. I need to enlarge the gas port. I am tired of paying shipping charges to someone for this work and want to learn how to do it myself.
I have received several emails with helpful info and I appreciate the info on reamers and MSC Direct. I found the tools I needed at MSC.
AR-10 gas ports are already too large.... be prepared for accelerated wear on bolt lugs? Not really applicable to my question.
The problem I am trying to fix is low gas pressure in an AR-15. The bolt/carrier will travel back enough to extract the brass from the chamber and eject the brass, but it does not travel far enough rearward to be able to strip the next round from the magazine and load it. I need to enlarge the gas port. I am tired of paying shipping charges to someone for this work and want to learn how to do it myself.
I have received several emails with helpful info and I appreciate the info on reamers and MSC Direct. I found the tools I needed at MSC.
Re: How do I open up a gas port on an ar type barrel?
Not saying that this is your problem but, too large of a gas port hole will cause the bolt carrier group to cycle too hard and fast causing simular feeding problems. Before you enlarge the hole check the hole diameter with pin gauges. The gas port sizes should be close to the following;
308:
Rifle Length gas system 20"-24" barrel length .089"-.094"
Carbine length Gas System 16" .079"-.081"
When I cut my DPMS LR308 to 20" the gas port became too large. In order for my rifle to cycle 100% when fully suppressed the Adj Gas Block I installed only required 1/4 turn out from being off. The gas port hole size in my rifle is .096"
Not saying that this is your problem but, too large of a gas port hole will cause the bolt carrier group to cycle too hard and fast causing simular feeding problems. Before you enlarge the hole check the hole diameter with pin gauges. The gas port sizes should be close to the following;
308:
Rifle Length gas system 20"-24" barrel length .089"-.094"
Carbine length Gas System 16" .079"-.081"
When I cut my DPMS LR308 to 20" the gas port became too large. In order for my rifle to cycle 100% when fully suppressed the Adj Gas Block I installed only required 1/4 turn out from being off. The gas port hole size in my rifle is .096"
Re: How do I open up a gas port on an ar type barrel?
I already posted it was an AR-15, but any info is good.
I already posted it was an AR-15, but any info is good.
Re: How do I open up a gas port on an ar type barrel?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Robe</div><div class="ubbcode-body">I already posted it was an AR-15, but any info is good. </div></div>
Hmmm.....
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Robe</div><div class="ubbcode-body">I would like to be able to enlarge gas ports on AR15 and AR/308 barrels </div></div>
Guess that is why you're getting input on AR10/.308 too?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Robe</div><div class="ubbcode-body">I already posted it was an AR-15, but any info is good. </div></div>
Hmmm.....
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Robe</div><div class="ubbcode-body">I would like to be able to enlarge gas ports on AR15 and AR/308 barrels </div></div>
Guess that is why you're getting input on AR10/.308 too?
