The ability to travel to other states without playing "Mother May I?"

This is the easy and simple all that's needed fix.

Though I would disagree with your assessment from there. The 10.3" DD barrel with an H3 will already have its cyclic rate tuned down to say a 10.3" Colt barrel or a 10.5" LMT barrel - so I'd wager that parts wear would be on par from there. Though I'd also wager that the DD barrel is more accurate than the Colt or LMT barrels (DD's are notoriously known tack drivers), and also CHF (which the Colt and LMT are not), yielding a likely longer barrel life out of the DD as well.

This is why the 10.3" DD gas port talk always is laughable to me. Just an H3 buffer yields it no different than the other two most popular options out there , Colt and LMT, but the DD is very arguably more accurate and more durable than the competition. Just seems stupid to go a different route unless cloneness is the utmost important thing to you.

I'll admit that the Noveske barrel is also CHF and likely around as accurate as the DD, but it's rarely ever one mentioned in this comparison. It's also kind of irrelevant as a 10.5" barrel as well (yes, I realize it's just a .2" difference). The only reason why the 10.5" LMT barrel is relevant is because some were at least known to be fielded, and therefore have been deemed "clone appropriate," and are regularly part of the barrel discussions.

The true comparison should be between the two 10.3" barrels - Colt and DD. And frankly, as said, with an H3 buffer, you'll never notice a difference between the two. The DD however is known to be more accurate and more durable. The DD barrel is less expensive as well. I find it to be a no brainer, and will reiterate that the gas port size discussion is a joke.

Pistol advantages over SBR:
In Oregon and probably other states you can hunt with it with no magazine restrictions.  Semi auto rifles are limited to 5.
I think in some states you cannot hunt with rifles, but you can with pistols.
Lots of states have rules about loaded rifles in vehicles, which do not apply to pistols.
Lots of states have concealed handgun licenses which are good for pistols but not rifles.
Do not need the Sheriff's permission to make or buy one.
200 extra dollars in your pocket.
Can travel to other states without ATF permission.

SBR advantages over pistol:
Greater variety of stocks available than braces or tubes, including adjustable ones
Some of those stocks are lighter than braces
If you run into a range officer or cop who knows some of the laws but not all of them, you have a stamp that says "This is legal" rather than trying to explain that through the loopiest of loopholes your 3 foot long M4 is a pistol and that you don't need a stamp (which you wouldn't have for a pistol)
Points in the clone threads

It's overgassed, its a fact. You may find it trivial but it is still a fact. Using an H3 buffer and a heavier spring will work but you still have the gas volume to contend with. I like to fix the cause not just a few symptoms. I would use a Govnah on a DD M18 if I was inclined to have one as it would be a much more comprehensive solution than just adding weight and spring resistance.

I would just take a 14.5 rifle if I did not feel like filling out the forms.  The forms are not that big of a deal, however.

As said, I own a 10.3" DD with a Govnah, and two 10.3" DDs with the factory gas blocks. I'd think it's safe to say that I can speak more personally on this topic than just about anyone else.

Frankly, if I have my Govnah equipped DD dialed to .070 with an H2 (as recommended by the manufacturer), the difference between it and either of my .082 DDs with H3s is essentially nothing. You'd be hard pressed to say there was any difference at all if you thought they were all equally equipped.

Another reason why this conversation is a joke to me is because a lot of the people who hate on the .082 DD barrels are the same people who hate on 14.5" mids. They are walking contradictions. They act like 14.5" carbines are the way to go because they will reliably cycle pretty much any ammo in any environment/scenario. Well, that's what the .082 DD barrel is supposed to do as well. Though, for some reason, when it comes to 10.3" barrels, those for 14.5" carbines and against 14.5" mids opt to prefer the configuration that's more finicky with ammo and extreme conditions. Very interesting...

Regardless, as said, DD puts out a better barrel than the competition it's most often compared to in this category, and with an H3 buffer, you'd never notice a difference in recoil impulse, etc.

Since when is a 10.3" Mk18 a bench gun tho?  Also, you would be surprised at how accurate Colt barrels can be.  I opt for CHF barrels as well but you are not really going to put the type of stress on your barrel that makes CHF so appealing.  The fact is that there is no real world difference in a 1moa Mk18 and a 1.5moa Mk18.  DD barrel quality is definitely awesome but that gas port just represents a sad sell out on the part of DD... its a real issue although there some easy "fixes".  Spending a shit ton on a DD upper doesn't get easier knowing that you probably need to order a $160 gas block to correct an issue that shouldn't have happened in the first place.  Is there any reason you would choose a DD Mk18 over a BFH 11.5 BCM?

I also have an 11.5" BCM BFH and an 11.5" KAC CQB - so I have those bases covered as well.

I really like 10.3s for what they are though. They're 200 yard capable rifles that can punch paper well beyond that.

There's no scenario I can dream of where I need to engage a threat beyond 200 yards, and a 10.3" is practical for any threat I'd ever have within that range.

I am still confused....  If DD is such a highly regarded company then why the gas issue and why do they use an H buffer?  It wouldn't cost them anything to swap for an H2/3 at the factory and I am sure they did tests and settled on the H.  



As for the range of a 10.3", as the poster a few above said...  These are good up to 200 yards.  I got the piston for HD and SD so I cant ever imagine shooting more than 50-75 yards with it so the range isn't an issue.  It is WAY easier to maneuver around the house than a standard 16".  I also looked at the 14.5 pinned and buying a new rifle to save that small amount of length didn't seem worth it.  Side by side they were so close.

The reason that they do it is because they are for civilian sales and a lot of civilians run cheap ammo like Tula, Wolf Mil Classic, PMC Bronze ect.  With a smaller gas port, these underpowered rounds won't cycle the rifle reliably.  Therefore, they drilled an oversized gas port to avoid getting phone calls from Bubba 5 times a week saying that his rifle is broken and won't shoot his Tula for shit.  DD has made 10.3" barrels for the .mil but these have gas ports that have a .070 diameter instead of the .083 of the civ productions.  You will need to add your own H3.

There isn't a gas issue. While I didn't previously clarify, there was a reason why I mentioned 14.5" mids and 14.5" carbines in this thread earlier.

Essentially, DD set out to make their 10.3s reliable with any ammo in any scenario. Similar to how a lot of 14.5" carbines are tuned.

No one ever acts like 14.5" carbines are overgassed or a "problem." Sure, several may prefer 14.5" mids over 14.5" carbines, but no one argues the reliability and function of a 14.5" carbine.

This is why I find the 10.3" DD gas port talks so ridiculous. It's overall pretty much like the 14.5" carbine compared to 14.5" mid scenario. One is more geared for milspec pressured ammo, and the other is geared to run anything when even dirty or in harsh environments.

No one refers to 14.5" carbine gas ports as a "problem" though. It's just some strange double standard that is easily "fixed" if you do want to tune down the gas/cycling.

Don't let it bother you.

Is the gas port on the DD barrel a bit fat?  Yes.  I am one of those whiners Ryan mentioned, but I want to put in perspective.  I have a lot of ARs.  I tinker with them to get them to cycle as smooth as possible, and the 10.3 was noticeably snappier, that's all.  When I put my supressor on, the bolt speed was so hot that it outran mag spring, and the bolt cut a gouge in a couple of casings.

Now, let's be fair, we all know what the supressor does for back pressure, and after I added a Sprinco Red, and the ADM Reliability buffer (got the same results with an H3) life was perfect again, and she was chuckin' shells happily at 3:00

The perspective I was speaking of was that none of the 4 other SBRs I have had that issue after adding the can.  They are ALL still overgassed now, with the can, and will require something to mitigate the affect.  

My plan is to add adjustable gas blocks that I already own, and a couple of Govnahs.  At least if the rifle gets muey fouled, I can switch it to the unsupressed position and keep it reliable.

I love Daniel Defense products.  My other 2 barrels do not have a fat port.  In fact, I would put my carbine 14.5 against a 14.5 midlength to see if a guy could tell the difference.  It is that smooth.

I understand why they went with the .080 or .082 port.  They made it idiot proof for dudes with Tula in their ammo fort.  If they would let me order one, I would opt for a smaller port.

It ain't the end of the world.  I have probably 3K through it now, and the bolt has not exploded, and no evidence any of the other accelerated wear issues that the haters preach about, has shown up.

Don't sweat it.  Worry about that Form 1, and get it in the pipeline

How about gas issues running it suppressed? I know it will run fine with a heavier buffer / spring combos but I figure that a gas port that is very large is going to exacerbate gas face. What has been your experience?

I remember seeing a guy on Youtube who had a DD MK18 run into issues with a suppressor, something about the bolt moving too fast and not giving the mag spring enough time to feed the rounds, thus causing some stoppages. He said he was running an H3 in it.

ETA: found it. he talks about it around 7:30. check it out and take it for what its worth. I thought it was an interesting vid. He may or not have already had an H3 in that vid but I remember him mentioning either in another vid or on a forum post that he has an H3 in it
https://www.youtube.com/watch?v=aUs1Gbo647U

I have run two of my three 10.3" DD rigs 100 suppressed since day one.

Is there gas in the face? Sure. Is it much more noticeable with the .082 port compared to the .070 port? Nope.

I think what people have to realize is that 10.3" 5.56 carbines are gassy and snappy compared to other longer SBRs regardless. The .070 to .082 difference really is negligible across the board. I've done a ton of side by side comparisons with the two. And not just with my own rigs - I've shot a few .070 10.3" Colt barreled rigs next to mine, other 10.3" DD barreled uppers with factory GBs or Govnahs, etc. I've shot a ton of 10.3" uppers in general. The differences are negligible until you step up to a Govnah, and tune that gas down to .052 or .049.

I've experienced one 10.3" DD upper a buddy has that cycled a bit too fast for the mag spring with a can on and an H2 buffer. He simply dropped in an H3, and it's run like a raped ape ever since.

But back to the gas in the face, as said, it happens with all my suppressed SBRs - 10.3s and 11.5s. I don't find it any more noticeably obnoxious when comparing a .070 to .082 ported 10.3" though.

I'll also add that I recently switched to PRI Gasbuster charging handles, and the gas in face is not even a thought anymore.

My two 100 suppressed 10.3" DDs for reference:

Thanks. I was under the impression that it would a lot more pronounced. IME with 12" PSA CHF barrels,  they are ported to .072 IIRC and the difference between running it suppressed with the stock gas block and tuning it with an SLR adjustable was obvious in recoil and gasface. I guess the difference in dwell time makes a difference here.

I said from my first post that you aren't really going to notice the difference shooting a .082 and a .070 side by side.  Regardless, you don't really want that extra gas... its about the longevity of your parts.  If it didn't matter everyone would drill giant f'n gas ports.  If it were just fine, why would they drill different sized ports in their commercial barrels and contract barrels.  They didn't do it to make it better, they did it so they wouldn't have to deal with complaints if someone's rifle wasn't 100% with Tula.  This is the first I've heard of anyone actually trying to argue that the .082 gas port makes the rifle better.  No chance.  Also, love the paint on that rifle on the left... good stuff.

Makes sense about cheap ammo and cycling. I didn't realize this is why they do that. I only run good, factory ammo so I guess I should consider an h3. This barrel is more snappy but I expected that when I got it. If an h3 will make it smoother and still cycle fine and give the chance of having parts last longer I might switch.

But why jump from the h to an h3?  Won't a 1 or 2 be a good trade off?

And what about running American eagle 50g jhp 223?  I have to use that at my indoor range. Will it have issues w an h3?

I wouldn't think so.

You made a good choice by the way... with companies like DD you can kinda start getting into things that aren't necessarily major issue and it isn't to detract from the overall quality of their products.

Your best bet would be to get a good adjustable gas block.

Don't know who you are replying to, but the H3 a couple of us mentioned was with supressor use.  H is an H1 BTW.

I know nothing of 50 grain JHP.  Sucks you have to use that.  I cannot even imagine the flash and bang of a 10.3 in an indoor range

They always put me against the wall with a rifle too!!!!  Its super loud with this barrel.

I ask if H3 will work with .223 50g because I would think that underpowered 5.56 is = to a .223 and I have to shoot that at times.

I get why you are asking.  Again, I use the H3 with a can, you can get by with an H or H2 unsupressed.  It should be fine with anything but Tula.

I use an H3 suppressed and unsuppressed.  I keep my H and H2 buffer in my pack unless something comes up where it isn't working but its worked with all the ammo I have used (mil surplus, wolf gold, hornady, CBC).

I think you're missing what I'm trying to point out here. The .082 port will run any ammo in any environment. Period. Shitty ammo, incredibly dirty rifle/parts, extreme cold, etc, etc. The .082 port will keep it going and going. Is that something everyone needs? No. Of course not. Is it an advantage? I'd certainly say that you could argue yes.

As far as parts longevity, adding heavier buffers and stiffer springs slows down the cyclic rate. That's part of the point. My buddy has a 10.3" .070 Colt barreled rig with a Colt BCG. He runs it with an H2 buffer and 100 percent suppressed with a SOCOM RC. At just under 6k rounds, his bolt bit the dust - which isn't too out of the ordinary with a suppressed 10.3. Well, one of my 10.3" DDs with DD BCG recently surpassed 6k rounds. Has been run with an H3 buffer and 100 percent suppressed with an AAC Mini 4 since day one. It's still going strong. Yeah, I get that I just have a few more rounds down the pipe than when my buddy needed to swap out his bolt, but the point still remains...if you tune it right, the premature parts wear will be a non issue as well.

And mind you, I get where you're coming from. Problem is, not many higher-end barrel manufacturers offer 10.3/10.5" barrels. If say BCM offered a 10.3" BFH barrel with a .070 port that was around the same price as the DD, I'd say that would be a great option, and for some, likely a better route to go than the DD. However, they do not, and DD's primary competition in this barrel length is Colt and LMT. Well, the DD is CHF, and more accurate than that primary competition. I find it hard to argue going with the non CHF and less accurate alternatives (especially considering they also actually cost more than the DD barrel in most cases). I strongly believe that DD churns out the highest quality barrel in this length, and with how easy it is to "fix" the larger gas port, I just don't see any argument for the alternatives outside of wanting to go Colt due to being as clone correct as possible for a MK18/CQBR.

That's all I've been trying to point out. And thanks for the compliments on my rattle canned rig. That was actually my very first (and still only) attempt at rattle canning anything.

And OP, I'd still run an H3 buffer even if you won't be running your DD with a suppressor. One of my 10.3" DDs has been run 100 percent without a can, and 100 percent with weaker 55 grain PMC Bronze 223 since day one - H3 buffer since day one as well. It has run smooth and flawless with perfect 3:30/4:00 o'clock ejection every time.

Here's a pic of that setup before I tossed a T1 on top:

Ok...  

What buffer do I get and do I need a new spring?  I may as well buy one, they aren't that much.

I'd just get an H3 buffer and keep your standard spring. You won't need a stiffer spring without a can. I don't even run a stiffer spring with my can.

I run Sprinco White springs in mine. They are standard power springs, but have a nearly infinite cycle life. I only run Sprinco springs these days...regardless of configuration.

I run the VLTOR A5 system on mine and its a nice shooter. I'm using their "standard" H2 buffer for now but will likely get something heavier when my can gets out of jail.

I've got the M4A1 build using a Colt LE6920 M4A1 Carbine complete factory lower and a complete factory M4A1 RIS II upper. This is one of the older M4A1 upper, back before they started selling them with a 14.5 pinned and welded flash hider.



That said, it is one of the heaviest AR's I've ever owned but I feel as though that's due to all the crap attached to it.



I don't see where a MK18 10.3 inch build would be so much noticeably lighter than the M4A1 RIS II. Almost feel like if you want a light weight rifle, you should build a light weight rifle.

I feel like that want to be a MK18 but it just can't do it! It really wants you to buy an MK18 RIS II rail for it on Christmas.





 

Lol, it originally was going to be. However, the MK18 rail is not worth the extra money to me. I'm not a cloner so I'm good with "-ish" varients!

I don't know if  LMT and Colt are the only viable options if you you want a good durable barrel. I am fully aware that certain rebranders are not accepted as top tier but there is at least one more seller of 10.5 CHF made by FN. You who I am talking about. Throw an LMT E BCG in there and you are as bomb proof as your going to get with good accuracy. The only thing missing from a MK 18 mod0  build would be some etching and a mil-spec bcg.

Thing is, I don't care for 10.5" barrels. The LMT is solely being mentioned because it is often part of this discussion for whatever reason.

10.5s look wrong to me on the 9.55" RIS II and 9.5" Geissele handguards. The 10.3s look just right. Just enough room for a can to clear by a few hairs.

If this topic was about 10.5" barrels, then DD would be irrelevant, and there would surely be a handful of solid options.

I'm with you there. Just doesnt look right to me either. That's why I mentioned the mod0 navy version.


This is also legit mil-spec MK18 despite the 10.5" barrel

Edit PIC... There we go (KNS pins...oh well)....

obsess over aesthetics much?  10.5" barrels and 10.3" barrels are basically the same thing and that is why it was brought up, and as ridiculous as it sounds, not everyone bases the parts they buy on clone correctness.  I agree with the majority of what you are saying but I'm not on board with the .082 gas port being some all conditions, all ammo panacea.  If this were the case, an H3 buffer would be counter productive, demising the "gains" you get from the oversized port.  I'm also not really seeing any difference between a 10.3 or a 10.5.

Weird, not only is that LMT sight installed backwards, the sight parts are installed backwards in the backwards mounted LMT housing. That is confusing as shit.

I still don't quite think you are fully getting what I have been pointing out.

First of all, I firmly believe that DD produces the overall best quality CHF barrels made. They are all tack drivers, reasonably priced, and come from arguably the most stand-up company in the entire industry. 10.3 or 10.5, me personally, I want a DD barrel regardless. Well, DD happens to churn out a 10.3, and not a 10.5, so it's a win win there - as I also happen to highly prefer the look of the 10.3. But as said, looks aside, I still want a DD barrel.

You continue to harp on the .082 gas port, and I continue to explain how this is identical to the whole 14.5" carbine vs 14.5" mid debate, but with a huge double standard. You know how many people run H3s in 14.5" carbines as well? A ton. This whole 10.3" with a .082 gas port vs 10.3" with a .070 gas port is truly no different than the 14.5" carbine vs 14.5" mid debate. 14.5" carbines are known to be gassier and more reliable with a wider range of ammo, and in extreme/dirty conditions. 14.5" mids are at times known to be a bit more finicky with ammo and certain environments/conditions.

While we are comparing identical gas port lengths here with the 10.3s, the comparison still is identical. The .070 ported 10.3s are designed to be run with milspec pressure ammo. Period. That is a fact. Just like many 14.5" mids, they won't always be finicky with weaker ammo, but they can be finicky with weaker ammo. The .082 ported 10.3s are designed to run any and everything without a hiccup.

As I continue to say, it's an identical comparison to 14.5" mids vs 14.5" carbines. Problem is, when the 14.5" mid vs carbine debate comes up, while there are surely supporters on both sides, no one ever flat out chastises 14.5" carbines for being gassy messes, etc. But for some reason, and as you continue to prove here as well, when it comes to .082 10.3s, some people just can't stop harping about the gas and port size. It's a double standard, and a lot of the clone guys are very guilty of it. A lot of the guys who would argue against 14.5" mids in favor of 14.5" carbines for reliability and function in the M4A1 Block II thread are the exact same guys who sit in the MK18/CQBR thread talking shit about .082 port 10.3" DD barrels in comparison to .070 port 10.3" Colt barrels. Frankly, it's a joke. It's a massive contradiction.

You continue to go on and on about the large port size as well. I've explained this plenty of times already, it's designed to just flat out run with or without a can with any type of ammo in any environment/scenario. The .070 ported 10.3s can be finicky with weaker ammo, when dirty, in extreme cold, etc - especially if they don't have a can on for the added back pressure it provides.

haha... I didnt even notice.. i just pasted up  the first one i saw

Its been shown by many that they have problems running suppressed from the factory. I realize running is usually just a $40 dollar buffer change away....but it still has to be altered.

Well, most factory ARs need to be altered in some way to be tuned for use with a can.

I can tell you that a 10.3" .082 DD is far from the only configuration that's gonna be too much with just an H buffer when used with a can and milspec pressured ammo.

A swap to an H2 buffer instantly fixes that. An H3 even moreso.

I understand what you are saying... its just an issue we don't see eye to eye on it happens haha.  

So do you bash 14.5" carbines as well? If so, I find your stance on this subject appropriate then.

U mention durability of parts but ur point is invalid. By you adding an H3 buffer youre not doing anything but slowing the carrier down to keep up with the mag, the bolt is still absorbing the same amount of pressure pre buffer change. So the parts durability is the wrong argument

It's not exactly the same thing.  The 10.3 has to take in a lot of gas in a very short period of time (the 10.3" has less than half the dwell time of a 14.5" carbine) which makes it a lot harsher than the 14.5" so I am much more willing to take the extra pressure in the longer barrel.  That being said, I would prefer a mid 14.5".  Everyone knows short barrels are harsh so you have to choose if you want to POSSIBLY not be able to shoot Tula (both LMT 10.5s I have owned shoot Tula and PMC bronze fine.. I've never owned a Colt 10.3 so IDK) or if you want to really stress the moving parts in your rifle.  But yea, the consequences of the higher pressure in the 10.3 are a lot more severe than the consequences of the higher pressure in the 14.5 (in regards to the described circumstances).  Not to mention, the gas port diameter is changed so there is a larger gas port but less dwell time in the 14.5 mid vs 14.5 carbine... in the case of the 10.3s there is a difference in the gas ports but there is no change in dwell time... its not a valid comparison.

This is true, but slowing the cyclic rate still reduces the stress on the bolt and chamber. And as I said, suppressed 10.3s have short life expectancies to begin with. As I've already personally witnessed with a buddy's 10.3" .070 Colt, you aren't really going to get extra parts longevity with a .070 port compared to a .082 port. The bolts in most 10.3s will be counting the days after 5k rounds regardless, and the bolt is the primary concern.

I disagree in regards to not having a valid comparison aside from dwell time - hence why I already acknowledged that there was no difference in gas port location with my comparison in contrast to the 14.5" carbine vs mid comparison. I understand dwell time and its effects well. I will definitely acknowledge that as a fair point, but it far from yields this 10.3" comparison not relevant.

The .070 port 10.3s are in fact designed for milspec ammo. They can be finicky in several scenarios that the .082 port 10.3s will not be. I have already explained this in detail. No need to do it again.

I agree that the stress put on the internal parts of a 10.3 is far more severe than that of a 14.5, but that can also be said about your 11.5. The point continues to be that the 10.3s are gonna have a short internal parts life regardless. The .082 10.3 will be more reliable than the .070 10.3 in a few different scenarios though.

Correct, it is invalid because of the dwell time difference.

 

Also, if someone prefers the 14.5 mid, it's totally inconsistent to prefer the larger gas port in a 10.3. You can't have it both ways. You either sacrifice some recoil reduction for a larger operating window, or sacrifice operating window for a softer recoil.


It's incongruent doctrine to argue for a softer shooting 14.5 mid that won't run Tula, and then argue AGAINST the smaller mil spec .070 ported 10.3, ESPECIALLY when used with a silencer.


In other words, that's real retarded, sir.

I feel if a .070 has issues cycling with weaker ammo i'd just throw a standard carbine buffer in. In which case it should be able to cycle all sorts of ammo, and will have less added moving mass compared to a rifle with an H3. What think?

Shocked you waited this long to jump in on stirring the pot with me. As many know, it's long been one of your favorite pastimes around here.

If you've read all of my comments here, you'd understand why I prefer 14.5" mids over 14.5" carbines, but prefer 10.3" DD barrels to the Colt and LMT barrels I'm comparing them to. DD makes a higher quality barrel. I'll deal with having to run a heavier buffer for the better barrel.

As I've already pointed out, there are essentially no producers of 10.3" barrels aside from DD. DD also happens to make the highest quality and most accurate CHF barrels IMO. Once again, "taming" these DD barrels is an easy task. I ultimately want the better barrel. Period.

I already mentioned that if BCM offered a10.3" BFH CHF barrel with a .070 port, I'd likely go that route instead. But they don't, and no other factory CHF 10.3" barrels from big name producers are available. It clearly vastly limits the options.

Me pointing out the epic contradiction of the crap several give the larger gas port DD barrels is just that...me pointing out the irony. When you have people notoriously known to praise gassier configurations because they will always cycle any ammo in any environment that turn around and have exact opposite opinions with 10.3" barrels...it's very ironic to say the least.

Is this turning into some AZ pissing match?

FWIW, I've never understood setting the rifle up from the factory to run cheap ammo. First, because the cheapest I buy is PMC or AE .223, and second because every rifle I've bought (I only buy factory whole setups) has fed everything without a complaint. So I was surprised at all the gas in the face from my Mk18. After some research here and the understanding of the port size, I concluded a Govnah gas block was the right answer over a buffer change. I run suppressed all the time, but should the need arise (some emergency) to run complete shit ammo without the can, I like the ability to adjust the rifle to feed whatever without accepting I have to live with gas face or a busted bcg.