Service Rifle Barrel Length

I got my 10.5" for CQB just because it looks cool cou:





If you were building one from scratch for regular service rifle out to 600M (or DM please run these again next year :D) and money or availability was no object, then a medium weight 18" match barrel would probably be the best tradeoff in terms of accuracy and usable length. My opinion only for what little it is worth.:nest:
 
This person's posting mirrors my thoughts exactly...

I don't have as many ARs as Zak, and I sure as heck ain't no "Sully"... but ARs are my hobby, and I have owned owned 11.5", 14.5", 16", and 20" ARs with carbine, mid, and rifle length gas systems. I can say whole-heartedly and without reservation that the mid-length 16" is BY FAR my all-time favorite.

From my FIRST HAND experience on a 500 yard range, even a 14.5" barrel can consistently hit the target. The biggest factors there were the optic (ACOG) and the ammo (77gr black hills). So anybody that tells you you need a 20" to go past 200 yards is exaggerating. You do get the benefit of flatter trajectory and less wind drift with a 20", but have to learn both with any length barrel. The 16" will give you more ammo choices for longer range shots than the 14.5" (not that you were asking about that).

I bought an Armalite 20" rifle for those "long shots", but after only ONE trip to the range I discovered that it couldn't do ANYTHING my RRA 16" couldn't do just as well, so I traded it off. I now only have 14.5" carbines and a 16" middie. Well, I do have a rifle on layaway, but that's a bit different... :cool:

The mid-length gives you a lower gas impulse than a carbine (reportedly the SAME as the rifle length) and 2" additional sight radius over the carbine without the extra weight of the dissipator.

I'd go "off the beaten path" a bit and check out the "RECCE" uppers from Global Tactical (http://www.globaltactical.com). They're SUPER-accurate 16" mid-length ARs that would have NO trouble shooting out to 500 or 600 yards with a good scope and a good shooter.

I've updated my motto since that layaway purchase I mentioned...

If it's a carbine, I prefer 14.5". If it's a mid-length, I prefer 16". If it's a rifle, I prefer .308 :D
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All of my uppers 14.5", 16.75", & 20" are H-BAR although it is only stamped on the 20"... and people are saying that the 20" H-BAR version is an addition 1 pound front end heavy over the standard Gov't issue 20" :(

My favourite is the 16.75" :D It got me the hightest scores in Service Rifle this year, but I was also more rested and the weather much cooler during that match too ;)
 
I don't think you will find a mil-spec 18" barrelled upper.

M4 is 14.5" and M16 is 20"

Recently there have been 16" -ish mid-length configurations.

My 16.75" mil-spec upper was made by Sabre Defence, prior to their board of executives being incarcerated (actually, all of my uppers are from Sabre Defence).


Canadian eh! said:
I got my 10.5" for CQB just because it looks cool cou:

If you were building one from scratch for regular service rifle out to 600M (or DM please run these again next year :D) and money or availability was no object, then a medium weight 18" match barrel would probably be the best tradeoff in terms of accuracy and usable length. My opinion only for what little it is worth.:nest:
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The grouping capabilities of a rifle are not dependent on barrel length, so much as on barrel quality. Optimum barrel length can be governed by factors other than grouping ability. Handling and balance are certainly factors in effective performance for a rifle not being shot from a rest.

For known distance target shooting, flatness of trajectory is not really an issue, as long as precise elevation settings are known. If distances are not known, and are being estimated, a flatter trajectory is an advantage, and will help compensate for errors in range estimation, particuarly as ranges stretch out.

Reduced wind drift is a definite advantage at longer range. Correctly compensating for wind is a real skill, and a rifle/ammunition combination producing less drift is a real advantage. Correctly compensating for wind changes during delinerate shooting can be challenging. Compensating during rapid fire, snapshooting or moving target stages is an advanced skill. Reduced wind drift really helps.

You report that you observed no differences in elevation settings with a 16.75" barrel vs a 20" one, even though velocity was reduced, back to 500y. This I find hard to believe. It is certainly an observation that could be easily tested.
 
Transitional ballistics is from the point the bullet ogive is exiting the barrel until it is no longer affected by propellant gases.

Brakes, crowns, suppressors, and bullet bases.
 
I am now considering getting my 24 inch bull barrel turned down to 0.75 contour to reduce weight before I start into service rifle.

I was thinking that I should leaving it 24 inch to start with cause I can always reduce down to 20 inches later (but I can't add on). Some have advised to go right to 18-20 inches.

Is there a significant draw back to having a 24 inch rather than 20 inch barrel? I don't think I can cut it less than 18.5 according to the CFP rules so the 16 inch barreled option at the start of this tread is not on the table for this particular barrel.

Anyway, I am open to opinions for consideration. Thanks.
 
As long as the 24" barrel doesn't adversely affect balance, handling and position shooting, it could be left at that length. A 24" barrel with a brake is going to run at least 25", perhaps 26" or more.
I'm assuming that you find the rifle a bit awkward at present which is why you are wondering about turning it down.
I have seen some excellent shots who used longer barrels.
If the barrel is .750 from the gas block out, how much would weight be reduced by shortening to 20"?
 
Does anyone have a link that shows actual dimensions for different barrel profles? I keep reading about Hbar, A1, pencil but I can't find actual numbers on diameters.

I am assuming that I will still find a 24inch 0.75" diameter heavy but it is probably livable? I am not married to the 24 inch length but I have it now so why loose it.
 
Reading with interest. Nice to see you service rifle guys getting along and not jumping down each others throat because of differences of opinion....

I've recently sold my Colt AR with 24" heavy bbl. It shot amazingly well out to 600m...in practice. I have little experience with the service rifle game so I cannot comment on how well it handled. Nothing to compare it to. The next opportunity I have to compete in a service match I'm going to use my M1A Nat'l match with 22" bbl. Not sure how gangly it will be and have been wondering about replacing the 22" with an 18". Thoughts?
 
Bolivar said:
Shoot it as is for now. Then decide. Hmmmm, maybe I should just be taking my own advise.:)

Other than that, 308 is expensive to feed and has more recoil. But if that is what you have, that is what you have. Shoot it and have fun.

Just my less than expert opinion.
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Ya good advice. Trying to convince myself to put a nice Krieger or something on my rifle.

I'm not too concerned about cost of shooting the 308. If I stressed about spending money I wouldn't be a shooter.

I was concerned about the recoil. I was wondering if I would be able to get back on target quick enough at the closer ranges using optics. I have a fixed 10x I'd put on the rifle but was thinking about a 3.5x15 to give me more flexibility depending on the distance and type of match.
 
hend238 said:
Ya good advice. Trying to convince myself to put a nice Krieger or something on my rifle.

I'm not too concerned about cost of shooting the 308. If I stressed about spending money I wouldn't be a shooter.

I was concerned about the recoil. I was wondering if I would be able to get back on target quick enough at the closer ranges using optics. I have a fixed 10x I'd put on the rifle but was thinking about a 3.5x15 to give me more flexibility depending on the distance and type of match.
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The High Power matches down south have seen the M1A/M14 losing to (and largely displaced) by the AR-15/M-16 platform. They shoot out to 600 yards too.

Nothing wrong with the 223/5.56 out to 600 yards.

Something to think about.
 
hend238 said:
The next opportunity I have to compete in a service match I'm going to use my M1A Nat'l match with 22" bbl. Not sure how gangly it will be and have been wondering about replacing the 22" with an 18". Thoughts?
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Bring it out already!

I have used m14-type rifles, and 20inch 308 bolt guns on the course of fire. I don't think that the shorter barrel will help much. As Bolivar mentions 308 more recoil. That is a big issue to overcome. It also kicks up more dust, which comes into play at homestead. In using both an m14, or my 20inch bolt gun, I have had occasions on the rapids where I had to wait on dust for a shot. Could shoot through it in hindsight, but it isn't like I get 10 aimed off with my boltgun anyway.

hend238 said:
I have a fixed 10x I'd put on the rifle but was thinking about a 3.5x15 to give me more flexibility depending on the distance and type of match.
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I would go with a lower power. I have trouble using a 10x in comp. Time is wasted ensuring I have the right target lined up, and there is a bunch of wobble in a 10x picture.

The 2 biggest downsides I encounter with an m14 is that you can't shoot off a mag(at homestead anyway. I do see others in Ont/BC doing it on their golf course berms), and it is not free floating -- how's your sling/foregrip use.

I am far from an expert though, and I have the scores to prove it.

smak_daddy said:
Nothing wrong with the 223/5.56 out to 600 yards.
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Not in paper, but 308 can be hunted.


carbonrod said:
Bring it out already!
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smak_daddy said:
The High Power matches down south have seen the M1A/M14 losing to (and largely displaced) by the AR-15/M-16 platform. They shoot out to 600 yards too.

Nothing wrong with the 223/5.56 out to 600 yards.

Something to think about.
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Oh yes absolutely. As I originally posted I don't have my AR anymore but I did use it in service rifle matches. I sure would like to get another one though at some point. I just can't justify the cost right now. I'd like to get a Swiss Arms. I have it in my head lately I don't want a restricted rifle anymore. My $1800 Colt AR sitting in my safe most of the time was a waste. I'd rather have something I can shoot service rifle matches with and go coyote calling if I felt like it.
 
carbonrod said:
Bring it out already!

I have used m14-type rifles, and 20inch 308 bolt guns on the course of fire. I don't think that the shorter barrel will help much. As Bolivar mentions 308 more recoil. That is a big issue to overcome. It also kicks up more dust, which comes into play at homestead. In using both an m14, or my 20inch bolt gun, I have had occasions on the rapids where I had to wait on dust for a shot. Could shoot through it in hindsight, but it isn't like I get 10 aimed off with my boltgun anyway.



I would go with a lower power. I have trouble using a 10x in comp. Time is wasted ensuring I have the right target lined up, and there is a bunch of wobble in a 10x picture.

The 2 biggest downsides I encounter with an m14 is that you can't shoot off a mag(at homestead anyway. I do see others in Ont/BC doing it on their golf course berms), and it is not free floating -- how's your sling/foregrip use.

I am far from an expert though, and I have the scores to prove it.



Not in paper, but 308 can be hunted.
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Ya ya. Sean I would love to come out and shoot with you guys more often. Just need to be home when there is a match on.
I had the same problem with the 10x on my AR. Too much time wasted ensuring I was on the correct target. For now that's the only scope I have that I'm willing to put on my M1A.
Could one shoot off a 30 rd mag at Homestead?
Yes the 308 can be hunted AND I can use my M1A in the precision rifle matches. Well sort of. Can't hit s**t with it beyond 800.

Perhaps I'll see you on the 25th.
 
.308 for the legacy 12 type matches has drawbacks(although small depending on who you are) that can cause you grief.
#1. Recoil. There are some rapid fire matches that require you to place 5 aimed shots on one target change a mag and then fire 5 more on another target in 30 seconds. You must also start standing which, depending on the position you are trying to get into, can eat up valuable time.
And that brings me to ...
#2. Positional shooting. 308 platforms are generally heavier. Trying to hold an M14 or whatever steady while standing and aiming at a moving target 100m away that is only up for 6 seconds AND after running 100m , can have its drawbacks.


In my opinion the .223/5.56 type rifles are better suited to this game.
 
Longshot said:
.308 for the legacy 12 type matches has drawbacks(although small depending on who you are) that can cause you grief.
#1. Recoil. There are some rapid fire matches that require you to place 5 aimed shots on one target change a mag and then fire 5 more on another target in 30 seconds. You must also start standing which, depending on the position you are trying to get into, can eat up valuable time.
And that brings me to ...
#2. Positional shooting. 308 platforms are generally heavier. Trying to hold an M14 or whatever steady while standing and aiming at a moving target 100m away that is only up for 6 seconds AND after running 100m , can have its drawbacks.


In my opinion the .223/5.56 type rifles are better suited to this game.
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I shot 2x SR matches this year with an M14 and can attest to both points #1 and #2, but they are managable. Once you realize you are primarily/realistically only competing against yourself, it's great.

Now, if there was a 2nd M14 shooter there next year, it would be game on! :D
 
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