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Just shoot it.

If it was designed and produced for the gas piston that is on it, it should be fine. If you have problems, then I might suggest getting rid of it.

I'm thinking that the issue that weapons converted from gas tube to gas piston is that the gas tube probably uses more gas since it has to maintain adequate pressure while expanding inside the tube. Short stroke gas pistons don't need to move as far so they should need less gas. Too much gas on the piston will produce excessively harsh forces on the rifle.

I'm not an expert on the subject, but this seems reasonable to me.

Any other opinions?
 

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Just shoot it.

If it was designed and produced for the gas piston that is on it, it should be fine. If you have problems, then I might suggest getting rid of it.

I'm thinking that the issue that weapons converted from gas tube to gas piston is that the gas tube probably uses more gas since it has to maintain adequate pressure while expanding inside the tube. Short stroke gas pistons don't need to move as far so they should need less gas. Too much gas on the piston will produce excessively harsh forces on the rifle.

I'm not an expert on the subject, but this seems reasonable to me.

Any other opinions?

I must be missing something here, because I don't recall seeing anything in the OP or the link that mentions a gas piston system, whether it be original or a conversion.

I think what the OP is getting at is he is hearing negative things about the carbine length gas tube systems being harder on the internals than mid length or rifle length systems. While this is true to some extent, the carbine length systems are tried and true.

Which length gas system is best for each one of us comes down to what type of usage the rifle will see. I ended up going with a mid-length simply because they have less recoil than the carbine and that was important to me due to back injury and 7.62NATO chamber. With the 5.56 rounds I'm not sure it really makes that much of a difference.
 

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I share the same logic with you, and judging from your "small" AR family you got going one; you probably know a thing or two about carbine gas systems.

And no I was not referring to the gas piston solution, that's something completely different.

I was just trying to ask whether or not one can change tubes to go from a carbine gas system to a middy; that's all.
Yes, you can change from a carbine gas to a midlength gas. It does require a gunsmith though. Unless you are fully capable of blocking off the first hole and tapping in another hole.

There is absolutely nothing wrong with the carbine gas system. They say that you have a less felt recoil w/ the longer gas systems, but between the carbine and the midlength, I don't notice much of a difference. As far as reliability goes, if it's built right and maintained properly, then more than likely it will last you and serve you for quite some time.
 

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I'm going to try to answer your questions as I come to them. My replies in red.

I keep hearing this all over the "internets"

"The carbine gas system is less reliable than a middy or rifle"

I honestly don't think the middy is a huge improvement. I'll go ahead and get that out of the way now. I don't think a middy is a terrible idea (I've heard worse anyway), but I think a lot of people and places like to make a lot of fluff about them for no apparent reason.

After all, a middy will have slightly less of a pressure curve in the system because there's less space between the gas port and the muzzle (that's really the only difference between them is gas port placement on the barrel anyway), so honestly I think the middy's will suffer from failures from not cleaning them before a carbine length will simply because they can't get as much pressure back to cycle it short of enlargening the gas port.

"you'll end up with a short stroking rifle"

Any gas fed gun can do that, but just because you have a carbine length tube doesn't mean it's going to.

"You need to upgrade the extractor"

That really doesn't hurt to do on any AR regardless of the gas system it uses, but the upgrade is a little piece of rubber and an extra tension spring and costs about a buck and a half for the little extra insurance and piece of mind. No biggy there. If that argument sways you to a middy over a carbine length, then I have a bridge you may want to buy. It goes over my ocean-front property in Oklahoma. It'd be a heckuva place to set up a toll booth. You'd make your money back in no time.;-)

"Recoil is too harsh on the internals"

It all depends. There are a lot of ways to slow the rate of the operating system if that bugs you. Adding heavier buffers, adjustable gas tubes, etc. If you use an A2 stock that really softens it up too.

etc... etc...

I could keep going...

I'm kinda glad you didn't. :lol:

I had a Bushy Dissy, bone stock, and it was a pleasure to shoot (Only shot 100 rounds) very light recoil and reliable.

However I managed to sell it (wasn't completely to my liking)

And I went ahead and pulled the trigger on this upper:

Now this upper has the carbine gas system and I'm now afraid I will run into issues with it.

Just because you've fell prey to all the hype. Middy's are actually a fairly new beast. They came about not as an improvement in the operating system, but because of the pressure curve in 18 inch barrels during the SPR project so they'd shoot reliably. And then someone had a brain fart to try that length gas system in a 16 inch barrel, so they had to convince everyone that it was a better system so they wouldn't starve. I would say a midlength is good, but depending on how they were made, I don't know that I would say one was any better than another if they're built right.

Could I switch gas tubes and morph it into a middy?:oops:

It would be easiest to swap to a midlength barrel than it would be to try to plug off the OEM gas port hole under the Front sight/gas block. Probably safer too. A .223 round has chamber pressures of about 58,500 psi, so I don't think I'd want to try to tap the .087ish" wire gauge gas port hole with a screw. That sounds like just asking for trouble.

Or should I stop worrying too much and just go and shoot the thing and see if I run into any issues?

Yes you should.

I have a box of 200 UMC Remington from Dicks, and then again I keep hearing these rounds are a little under loaded, not hot enough for a carbine gas system.

Remington UMC are crap in any gun, not just carbine length AR's. They're filthy, they're not accurate, they're not consistent, and there's a reason they're cheap.

I've refused to use them in anything I own since I popped 2 primers out of the same box in my old SKS. There's a lot of bad press about those Ultra Made Cheap bullets. I'd rather shoot wolf over them.


So as you can tell I got the BRD fever and didnt do much homework.

Any input is much appreciated!
:?
 

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short stroking is a potential problem with all rifles its just more noticeable with the CAR system,

an upgraded extractor its a .02 rubber O-ring that sells for like $1 that goes over the extractor spring.

Recoil can be reduced with a heavier buffer

its likely that you will not shoot it enough to wear out many of the parts its not like its going to wear them out in anytime soon. most bolts are good for around 15K rounds a car may be 12k compared to the cost of ammo the difference is minute at .40 cents a round you will spend more than $6k on ammo a new bolt is less than $100

any problems that you may encounter with a CAR can fairly easily be resolve for cheap which is fine for me as i prefer the CAR over the Middy Or rifle length.
 

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I have 2 m4 carbines and they both shoot fine. I wouldn't change a thing as far as their gas systems go.
 

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I chose my mid-length Rock River Arms LAR-15 for the following reasons:

1. Narrows down the vast array of makers and models. Not everyone makes a middy.

2. Longer sight radius. When you get into your 40's you will find that your near focus starts to wane. The extra distance to the front sight makes a difference.

3. Better asthetics. For a civilian 16" barrel, the midlength grip is better proportioned. I can easily spot my AR from a rack of carbines and service length rifles. I like that it is different.

4. Longer hand guards. When shooting with a bracing sling at the range, the extra length affords a better hold and better control than a carbine.

5. Better gas pressures. Whether this really makes a difference in recoil or wear is debatable. It is not the primary reason I went midlength, but it is a theoretical side benefit.

Would I convert a carbine to middy? No.
Are all my current AR's midlength? Yes.
Will my future AR's be midlength? Yes.
 

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I didnt notice a difference in recoil b/t my middly and carbine. My carbine weighs more tho because of the UBR buttstock and other accessories, not sure if that affected it.
 

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I keep hearing this all over the "internets"
(snip)
Any input is much appreciated!
:?
Congratulations on not trusting everything you read by keyboard commandos. One good question to ask when anyone has a problem with an AR: Is it a factory built rifle that is still stock, or is it a home built or modified weapon?

If the carbine system sucked so bad, why are so many sold? We can't all be that stupid, can we?

Instead of being concerned with un- or over-educated opinions on the internet, go shoot one. Talk to people that really own a carbine system. Have you seen any threads here or elsewhere that jump out and say "Hey, that carbine system is unreliable because this happened to me..."

I own a carbine system rifle, as do many others that I know, and we have no problems with it. Maybe someday I'll buy a stronger recoil spring, but I really see no need to do so.
 

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The CMMG carbine uppers are great. They function just fine with various types of ammo and I doubt that you will have any problems with it. I only own one carbine upper at the moment having switched over to mid-length systems on many others, but having used the carbine gas systems on numerous rifles for 20 years...what you have read about the carbine gas system not being reliable, not working properly, not...well, you get the idea...is nonsense. Do I like the middy better...yes. Is there anything wrong with the function/operation of the carbine system...NO.

The carbine gas system is still in service around the world today and works just fine.

Now get to shootin!!! :)
 

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I use the heavy buffer in carbines, and make sure that the extractor has the heavy-duty setup as well with black insert and/or o-ring, stiff spring, etc depending on configuration (I've tested three different extractor setups on three bolts and all worked fine). There is no way you could use a longer gas system in mine, btw :twisted:

Zero issues.
 

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For the O-ring just go to the hardware store and get a #60 ring. Buy several.

I have rifles, carbines, mid-length's, and one dissy that I just got done building. They all work, and work fine.
 

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Ok ... now I am confused with all this "middy" and carbine length talk. My AR has a 16" barrel that even the Bushmaster website calls a carbine. So is my AR a mid length or a carbine?

This thread has me second guesing my interest in sending it in for a retro fit to a piston system.
 

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Ok ... now I am confused with all this "middy" and carbine length talk. My AR has a 16" barrel that even the Bushmaster website calls a carbine. So is my AR a mid length or a carbine?

This thread has me second guesing my interest in sending it in for a retro fit to a piston system.
Your barrel length is what makes it a carbine...not the gas system. A 16" barrel with a mid-length gas system is still a carbine by nature.

The length of the barrel does not necessarily correspondence with the length of the gas system, (i.e. - where the gas port holes are drilled into the barrel and the gas block is placed on the barrel). Mostly, 16" barrels are equipped with the carbine-length gas system, however, some people elect to have a slightly longer (mid-length) gas system on their 16" barrels which reduces wear/tear on the rifle, reduces the recoil impulse, and gives you a slightly longer sight radius than the carbine-length gas system.

On your Bushmaster...unless you ordered a mid-length gas system when you bought it...you have a carbine length gas system.
 

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Ok ... now I am confused with all this "middy" and carbine length talk. My AR has a 16" barrel that even the Bushmaster website calls a carbine. So is my AR a mid length or a carbine?

This thread has me second guesing my interest in sending it in for a retro fit to a piston system.
barrel length is the same, but on the midlength the gas system, front sight post are moved up a couple inches. Midlength has lower pressures due to some extra volume of the tube. Due to lower pressures its easier on the BCG and supposedly less recoil. Recoilwise I didnt notice a difference b/t my midlength and carbine. I prefer teh midlength due to its more proportioned looks and everyone had a carbine so I felt like a non conformist.

16" barrel with carbine gas system:

16" barrel with midlength gas system:
 

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barrel length is the same, but on the midlength the gas system, front sight post are moved up a couple inches. Midlength has lower pressures due to some extra volume of the tube. Due to lower pressures its easier on the BCG and supposedly less recoil. Recoilwise I didnt notice a difference b/t my midlength and carbine. I prefer teh midlength due to its more proportioned looks and everyone had a carbine so I felt like a non conformist.

16" barrel with carbine gas system:

16" barrel with midlength gas system:
Ignore the barrel profile and just measure the gas tube! ;) Just thought I'd state that, b/c to some people the way the barrels look could be taken as "oh so the top one is carbine b/c it's got a notch on there!" :)
 
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