can't decide on 16" or 18" barrel

[GRANTFTW]

Hi all, i checked the search criteria and couldn't find the info i was looking for. If yall could shed some light it would be much appreciated.

I was considering a 18" ss barrel but after looking at some threads most people seem to be going with either a 16" or 20". The velocities seem to be close between the 16" to the 18". I'll primarily be using this for some coyote's out to 300 meters. Possibly for prairie dogs next year too.

My other question is i cant decide between a WOA barrel or BCM (does BCM make the ss barrels in house?). And what FH if any at all?

Just really want to double check before i purchase one. Thanks in advance.

[Ironman8]

I'm guessing you're talking about 5.56/.223, correct?

Did you happen to look at THIS THREAD (https://www.m4carbine.net/showthread.php?t=80882)?

Some of Trident's info in the earlier pages was edited out by himself for some reason, but it's still a good read, lots of info, and there's even ballistic charts comparing the two barrel lengths on page 17.

Short answer is: In the real world, the 16" can do anything the 18" can do.

Being that you're only asking for 300yds for varmints, I think you'll be more than well served with a 16"...especially if there are any plans to add a suppressor. Buy (or load up) some 70gr TSX and you'll be set.

[GRANTFTW]

5.56/.223 is correct sir. And I'm considering a suppressor for possible future but not set in stone.

[Ironman8]

5.56/.223 is correct sir. And I'm considering a suppressor for possible future but not set in stone.

You'll want the shorter barrel for use with a suppressor.

Go with a quality SS barrel (such as the ones you listed) and you'll easily be able to get MOA with quality ammo (factory or if you load yourself).

[Alaskapopo]

Hi all, i checked the search criteria and couldn't find the info i was looking for. If yall could shed some light it would be much appreciated.

I was considering a 18" ss barrel but after looking at some threads most people seem to be going with either a 16" or 20". The velocities seem to be close between the 16" to the 18". I'll primarily be using this for some coyote's out to 300 meters. Possibly for prairie dogs next year too.

My other question is i cant decide between a WOA barrel or BCM (does BCM make the ss barrels in house?). And what FH if any at all?

Just really want to double check before i purchase one. Thanks in advance.

I like the 18 because you can use a rifle length gas system and the recoil impulse is much smoother.
Pat

[kwg020]

My own personal opinion is go with the 18". I like the idea of the rifle length gas system. kwg

[Ironman8]

I like the 18 because you can use a rifle length gas system and the recoil impulse is much smoother.
Pat

I would agree with this, and would say that this as the one real advantage that the 18" has over the 16"...however, this advantage is only really seen if rapid fire and split times while maintaining accuracy is a performance parameter...such as in competition.

Being that this is a 300yd varmint gun, I would go for the slight advantage of manueverability with the 16" (even more so if a suppressor might be attached). Go with a midlength gas system and throw a Vltor A5 on the other end, and you now have closed the "gap" where the recoil impulse is concerned...while maintaining manueverability and lower weight.

[Devildawg2531]

I went with the 18" BCM stainless steel and Geisselle SSA trigger using rifle gas. It will do sub MOA groups with frequency with good ammo. No regrets at all.

[MistWolf]

There is, in general, a greater difference in velocity between the 18" barrel and the 16" than there is between the 18" and the 20". There is even less difference in velocity when barrel lengths get longer than 20". (I am talking about rifles chambered for the 5.56/223. This can change when talking about other calibers.)

What you have to ask yourself is what you want in your rifle. The 18"/20" will give a little flatter trajectory at longer ranges, enough that it is more forgiving of range estimates on targets as small as prairiedogs.

The 16" barrel makes for a handier rifle. But how much handier? Will you constantly climbing in & out of your vehicle while hunting? While I find shorter rifles to be handier getting in & out of vehicles, I usually travel form point to point with the rifle cased to protect it from dust and from being needlessly banged around while driving rough trails. My hunting AR has a 20 inch barrel because it's the most practical length for best velocity. I don't find rifles of that length to be unwieldy even when pushing through heavy brush (my bolt action hunting rifles sport 22" barrels). I must add that when hunting, I carry my rifles muzzle up.

I do find that barrel profile makes a difference. Heavier barrels are more work to hike with.

Best thing to do is decide which you want more- an edge in velocity or the shorter length. Either way, keep the barrel at a reasonable profile or you'll start hating the weight, unless you don't plan to hike with it. If that's the case, there's no sense in worrying about barrel length

[jesuvuah]

There is, in general, a greater difference in velocity between the 18" barrel and the 16" than there is between the 18" and the 20". There is even less difference in velocity when barrel lengths get longer than 20". (I am talking about rifles chambered for the 5.56/223. This can change when talking about other calibers.)

What you have to ask yourself is what you want in your rifle. The 18"/20" will give a little flatter trajectory at longer ranges, enough that it is more forgiving of range estimates on targets as small as prairiedogs.

The 16" barrel makes for a handier rifle. But how much handier? Will you constantly climbing in & out of your vehicle while hunting? While I find shorter rifles to be handier getting in & out of vehicles, I usually travel form point to point with the rifle cased to protect it from dust and from being needlessly banged around while driving rough trails. My hunting AR has a 20 inch barrel because it's the most practical length for best velocity. I don't find rifles of that length to be unwieldy even when pushing through heavy brush (my bolt action hunting rifles sport 22" barrels). I must add that when hunting, I carry my rifles muzzle up.

I do find that barrel profile makes a difference. Heavier barrels are more work to hike with.

Best thing to do is decide which you want more- an edge in velocity or the shorter length. Either way, keep the barrel at a reasonable profile or you'll start hating the weight, unless you don't plan to hike with it. If that's the case, there's no sense in worrying about barrel length

That is a good point on barrel profile. I have hunted with a few rifles with heavy barrel profiles and after a few hours the get heavy

[Ironman8]

RE: Velocity Difference

If you throw a suppressor on the end of the 16" bbl, you'll get a velocity boost (somewhere around 15-25 fps depending on suppressor) that will close that gap as well...which was negligible to begin with.

See the chart that Trident posted on Pg. 17 in the thread I linked above. Since the OP mentioned 300yds, the difference in drop at that range between a 16" & 18" bbl. is 1.3". Since that is well within the realm of what the gun/shooter combo is typically capable of at that range, I'd say that you'll never even see that difference manifested on paper or especially live targets.

[usmc1371]

I built an ar for pretty much the same purpose you are looking for last year. 16" bcm ss on an LMT lower. It has been an outstanding coyote gun and has made mist out of more that a few sage rats in the last ye
I shoot mostly crap ammo and its impressive, 10 shot groups right around moa and some better. Under MOA with black hills stuff. I couldn't justify an exra 2" of length for what I use it for and I don't miss it at all.
<a href="http://s1090.beta.photobucket.com/user/usmc_1371/library/" target="_blank"><img src="http://i1090.photobucket.com/albums/i365/usmc_1371/arscoped.jpg" border="0" alt="Photobucket"/></a>

[GRANTFTW]

Thanks everyone for all the pointers. Im definitely gonna go ahead with a 16" barrel.

[usmc1371]

Check out this post. https://www.m4carbine.net/showthread.php?t=101372

This is the AR I built with coyote hunting in mind first and 3 gun matches as a second. It started out with a Leupold VX3 4.5x14 LR but now wears a Leupold VXR 1.25X4. I have been nothing but impressed with this rifle. The trigger is the only thing I am going to change, the LMT 2 stage is ok for coyotes but I don't like it for matches so I am waiting for an S3G for it. You won't be sorry you went with the 16".

[2nd.amendment]

My other question is i cant decide between a WOA barrel or BCM (does BCM make the ss barrels in house?). And what FH if any at all?


To address the other part of your question, either should be plenty accurate for what you're talking about.

BCM does not make them in house.

A couple other similar options to consider
-Rainier Match 16" (should be very similar to the White Oak)
-Rainier UltraMatch
-Noveske 16" SS

A2 flash hider is probably fine, unless you're looking to use a brake/comp (which will then mean you have to decide if you want it to be more/less flash hiding, more/less loud, more/less compensating).

[taliv]

there are three primary differences, some of which have been mentioned above

1. effect of weight and length on maneuverability favors the shorter bbl

2. use of rifle length gas favors the longer barrel for smooth, rapid follow up shots

3. when using FMJ ammo (e.g. m193 / m885) projos "reliably fragment" at 2700+ fps (according to Fackler) so the longer barrel --> more velocity --> longer effective range

from ammo oracle:
distance to 2700 fps for m193
20" bbl - 190-200m
16" bbl - 140-150m
11" bbl - 40-45m

[SteveS]

Since I am all for you getting those Coyotes and prairie dogs I would get a 24 inch match type barrel with a match type trigger group ,have no mercy on them coyotes .Once you see the way they kill pets and rip the after birth from a cow and kill the calf !!!!!!

[Evergreen]

I've been contemplating this same question myself. However, I would like to modify the question with a 16" or 20" barrel? I am planning on bench/prone target plinking from 300-600 yards and looking to improve my accuracy. In the 5.56, what advantages would there be for shooting at these distances when you use a barrel 20" and beyond?

[Alaskapopo]

I would go longer vs shorter. More velocity and softer recoil. The only advantage to shorter guns is getting in and out of vehicles or moving in confined spaces. Thats not an issue for most folks.
Pat

[polymorpheous]

BCM in a heartbeat.
If you knew who makes them...

[MIDGAPATRIOT]

I went with the 18" BCM stainless steel and Geisselle SSA trigger using rifle gas. It will do sub MOA groups with frequency with good ammo. No regrets at all.

Same here. That barrel is more accurate than I will ever be.

[Noodles]

I would go longer vs shorter. More velocity and softer recoil. The only advantage to shorter guns is getting in and out of vehicles or moving in confined spaces. Thats not an issue for most folks.
Pat

Not really. For the 50-70fps difference the 16" has lost to the 18", I'd rather have the 16. The recoil "feel" is going to be completely subjective because you can easy have an 18" rifle that isn't as smooth as a 16" middy, too many variables so discount that.

There are advantages to shorter guns. When assuming you have long rails on both, you have the barrel weight difference, rail weight difference, and then felt difference when you add a suppressor. Lever arms make that 18-20oz suppressor seem like more and more the longer it gets out there.

I have zero interest in a low range gun that isn't suppressed so these are considerations to me even though getting in an out of vehicles is the last thing on my mind. There has been noticeable differences in swinging suppressed 16" and 18" guns around that I've been playing with, I'd go with 16" or full 20".

[Alaskapopo]

Not really. For the 50-70fps difference the 16" has lost to the 18", I'd rather have the 16. The recoil "feel" is going to be completely subjective because you can easy have an 18" rifle that isn't as smooth as a 16" middy, too many variables so discount that.

There are advantages to shorter guns. When assuming you have long rails on both, you have the barrel weight difference, rail weight difference, and then felt difference when you add a suppressor. Lever arms make that 18-20oz suppressor seem like more and more the longer it gets out there.

I have zero interest in a low range gun that isn't suppressed so these are considerations to me even though getting in an out of vehicles is the last thing on my mind. There has been noticeable differences in swinging suppressed 16" and 18" guns around that I've been playing with, I'd go with 16" or full 20".

As for recoil feel I disagree a longer gas system is always smoother. The same way a 16 inch midlegth is smoother than a 16 inch carbine gas system. But if you prefer a shorter barrel and it works for you then go with it. But everything has trade offs.
Pat

[Noodles]

a longer gas system is always smoother

:rolleyes: Absolutes huh?

I see our conversation has reach an impasse.

[Alaskapopo]

:rolleyes: Absolutes huh?

I see our conversation has reach an impasse.

Its physics. When you have a longer gas system you have more dwell time which smooths out the recoil impulse. It is an absolute. Perhaps you need to do some research on how these rifles work.
Pat

[Ironman8]

Its physics. When you have a longer gas system you have more dwell time which smooths out the recoil impulse. It is an absolute. Perhaps you need to do some research on how these rifles work.
Pat

I think what he was trying to get at is that the length of the gas system isn't the ONLY thing that comes into play. The flow of the gas itself via the size of the gas port and, to a lesser extent, the buffer system and maybe even something like a LMT Enhanced bolt carrier will also play a role.

An example would be if I were to tune the gas system with an adjustable gas block on a carbine length system. I am positive that I can make the felt recoil of a tuned carbine system less than a mid and possibly the same or less than rifle.

Like he said, too many variables to speak in absolutes.

[a0cake]

The point is that the longer gas systems are inherently "smoother" as a matter of fundamental construction, not that individual carbine setups cannot be made to feel as good as or even better than certain rifle-gas guns.

You have to compare "like with like," i.e., an optimally tuned rifle-gas system vs an optimally tuned carbine-gas system. Who would doubt that a sub-optimal rifle-gas gun wouldn't feel as good as the best possible carbine-gas gun? That's obvious, and not the point.

[Alaskapopo]

I think what he was trying to get at is that the length of the gas system isn't the ONLY thing that comes into play. The flow of the gas itself via the size of the gas port and, to a lesser extent, the buffer system and maybe even something like a LMT Enhanced bolt carrier will also play a role.

An example would be if I were to tune the gas system with an adjustable gas block on a carbine length system. I am positive that I can make the felt recoil of a tuned carbine system less than a mid and possibly the same or less than rifle.

Like he said, too many variables to speak in absolutes.

True and I am not bagging on his choice just saying that a longer gas system will have a smoother recoil impulse and that is one of the advantages of that choice. The shorter barrel has other advantages. Pick what suits you the best.
Pat