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Ported Gas Plug

Availability: In stock


Quick Overview

Our custom made gas plug has a tuned port which increases the starting volume of the gas cylinder causing the peak gas pressures in the gas cylinder to drop by over 30%.
Click images to enlarge

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[CMP Service Bulletin for the M1, 1903,1903A3]

Please note that the Ported gas plug ONLY deals with pressures in the gas cylinder and is not a device intended to lower chamber pressures of the rifle.  Please follow any recommendations set forth by the CMP and verify the headspace on your rifle is also in spec.

Our custom gas plug has been designed to lower peak gas cylinder pressures in your M1 Garand. Our gas plug has a tuned port that delays the operating rod for several microseconds and lowers the peak gas cylinder pressure by over 30%! Unlike a vented gas plug, ours requires no adjustments and is ready to use right away. The gas plug can be installed using a standard 1/4 socket driver!

Our ported gas plug does NOT vent gas like a vented gas plug. The secret is the hollowed out area in the base of the plug which increases the initial volume of the gas cylinder. By increasing the volume, the peak pressures are reduced without the need to vent the gas.

Customer QuestionsQ: Will the ported gas plug work with normal M2 Ball Ammunition? A: Absolutely! The ported gas plug will work with all M2 ball ammunition types made. 

Q: Will the gas plug work with low pressure loads? A: This is a harder question to answer without knowing the load being used. If there is enough gas pressure to cycle the rifle with a normal gas plug, then the ported plug should operate correctly. If the load being tested is marginal, the ported plug may not cycle the rifle reliably.

Q: The product mentions the potential for increased accuracy. Can you explain that? A: Accuracy in it's most basic form is the ability of the rifle to remain unchanged from shot to shot. The M1 has several factors inherent in its design that can cause the rifle to move or shift slightly from shot to shot. Forces acting on the barrel can change between shots. If this occurs then the accuracy potential is degraded. The ported gas plug does two things. The first is to delay motion of the op-rod for a few microseconds. (delays the forces applied to gas piston). This helps keep the system more static until the bullet has left the barrel. The second is to reduce how hard the op-rod is forced rearward. This reduces the natural flexing and bending the operating rod experiences and helps the rifle return to the same state between shots. Recall that accuracy potential is a result of the sum of all the factors acting on the rifle. The gas plug will not make a 5 MOA rifle a 1 MOA rifle.

Q: Will the gas plug work with a gas system that is worn out? A: The gas plug is designed to work with an M1 Rifle that has a gas system that is in spec. That is to say, not worn beyond the normal reject levels. That would be a gas piston with a diameter between 0.5250" and 0.5260" and a gas cylinder that is between 0.5280" and 0.5320". The operating rod spring should also be in spec and not worn excessively and the rifle properly lubricated.

Q: Can I use the ported gas plug on a Tanker or a M1 Garand with a short barrel? A: The ported gas plug is designed to work with a standard length M1 Garand Rifle. A Tanker or short barreled M1 moves the gas port closer to the chamber and results in port pressures that are many times higher then a M1 Garand was ever designed to operate with. The ported design is not suitable for use in this application.

Q: Can I use a bayonet with this gas plug?
A: The ported gas plug is NOT designed to accept a bayonet with a lug that inserts into the gas plug. The lugs on the bayonet are larger in diameter then the 1/4" cutout on the gas plug and will not allow the bayonet to be fully seated.

Q: What causes an Op-Rod to get bent? A: There are three factors that can result in damage to the Op-Rod. The first is high pressure in the gas cylinder. The second is binding of the Op-Rod, and the third is poor lubrication. If any two of the these three conditions is present then damage is possible. If the op-rod is binding then the operating rod will flex and bend when cycling until the bind is overcome. This causes the operating rod to flex and damage is possible. Our ported gas plug reduces the peak pressures in the gas cylinder, which in turn reduces the peak forces acting on the operating rod. Always check your M1 for binding by performing the [Tilt Test].

The effect of the ported gas plug design is shown below.empty chamber         (Click image for full view)
    Custom Made in the USA

[Installation Instructions]


Customer Reviews

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EXCELLENT Review by Mac
Very impressed with the quality and functionality. So simple but totally effective. Absolutely recommended.

Very prompt and secure shipping. (Posted on 7/3/2020)
6 Years, Going Strong Review by Trevor
I bought my ported Gas Plug 6 years ago. I was trying to figure out a way to use more commercial ammo, without worrying about bending my op-rod. I was looking at adjustable gas plugs when I came across this one. I watched the video and looked at the extensive research done with a lot of different ammo and I was convinced that this was the way to go for me. I knew that I was going to do mostly plinking with my M1, which means I was also going to be buying some of the cheaper ammo out there. I didnt want to worry about bending my Op-Rod because I put something other than GI loaded ammo in the gun. I will say that in 6 years I have never had a problem, and trust me I am crazy about checking the wear on my gun.

If you are looking for peace of mind when it comes to undue stress on your M1 then this is hands down the gas plug for you. (Posted on 3/14/2020)
Why not Review by Richard
I ordered 2 of these to protect the operating system on both my M1's. just shot a match last weekend with one of mine. and worked flawless. I liked the concept better than getting an adjustable plug for them. (Posted on 6/10/2019)
Great Review by Gregg
Year #2 still not a hiccup the only issue is you recommend to tighten it to tight. I told a friend who purchased one. Any made it way to tight.. Any way we fixed it in my shop. I ordered another rifle when I get it I will order another. Thanks. (Posted on 5/5/2019)
functions flawlessly Review by Josh
Bought this to run Remington core-lokt. Functioned exactly ad advertised, zero malfunctions. I would very much recommend it. The only thing that would make it better would be if it were compatible with the M3A1 combination tool. (Posted on 12/13/2018)
Great product Review by Infantry327
I installed the new gas plug the day before shooting and was using Remington 150gr core lok and my M1 performed flawlessly. After much research and reading it was not a hard decision to give my rifle a little extra protection and flexibility in ammo use. (Posted on 10/7/2018)
Ported Gas Plug Review by Patrick
Bought two ported gas plugs. One for regular Garand 30-06 and one for my tanker .308.
Both work great. I was having a problem with the tanker ejecting the spent rounds into my shoulder. Changed op spring and hammer spring with no difference. Bought and installed
The ported gas plug and it now ejects at About three o'clock. For me, it works in a tanker.
Thanks. (Posted on 8/23/2017)
Worked great in my .308 Garand. Review by Ozzy
Worked like a charm in my .308 (7.62x51) NM Garand. Tightened up my groupings at 200 yd using PPU FMJ BT 145gr 7.62x51 M80 ammo. Can't wait to try it in a match and with other ammo. (Posted on 5/13/2017)
Great idea great product Review by Gregg
Had mine over a year now. Great product . I've had my rifle more than 25 year's now when they were not so popular. But I always kept it clean and well greased. I used to buy bag's of 100 surplus round's for $20.00 good old days. Was in the service 28 years so i
didn't do much recreational shooting after 9/11 we were busy retired in 2008. Got back into shooting and got this computer and learned about certain ammo found this plug and nu worries. I still try to stay within the boundaries. But it's good to know I can shoot reloads to modern ammo with out issues well worth the money (Posted on 5/6/2017)
so far so good Review by David
So i've tried twice now to share my videos on here of my trials using this, so far, amazing product. I am a "youtuber" or at least trying to be one. I have attempted to put on video my ammo testing with this product. As my summary says: so far, so good. I haven't noticed any damage on my rifle so far and it seems to function fine. For any that are curious my youtube page name is Gunlover82. Search for the ammo testing. So far this is a great product and appears to work as advertised. Buy one and try for yourself! (Posted on 5/26/2016)

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