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18" vs 20"


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#1 Blazer11

 
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Posted 12 February 2012 - 03:22 AM

Im new to this site and starting my first build. I'm building this gun for deer hunting mainly maybe some elk. I'm stuck on what size barrel to get. Is the extra 2 inches worth the weight? Just looking for some help.

#2 imschur

 
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Posted 12 February 2012 - 03:23 AM

I'll vote no unless you are shooting extreme distances

#3 Jgun

 
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Posted 12 February 2012 - 03:45 AM

At what range do you intend your longest shots to be?

#4 unforgiven

 
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Posted 12 February 2012 - 03:49 AM

Welcome from Indiana brother Blazer.More is good IMO. <dontknow>
If you fail to plan ~ You plan to fail---Don't complicate poop ~ With complicated poop--- I will die on my feet ~ than live on my knees

#5 Blazer11

 
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Posted 12 February 2012 - 04:04 AM

Hopefully no more then 450 yards but who knows when you have one in your sights.

#6 98Z5V

 
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Posted 12 February 2012 - 04:44 AM

You could rock a 16" barrel to 500 with ease.  <thumbsup>

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#7 mantawolf

 
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Posted 12 February 2012 - 05:05 AM

Only makes about 90fps difference. I went with a 16"

#8 Slash

 
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Posted 13 February 2012 - 06:12 AM

This is always a controversial topic, but here is my opinion:
16" - 400 yards
18" - 600 yards
For longer ranges I would want a 21-22" barrel.

I firmly believe that 18" is nearly ideal for most .308 applications.  VERY, VERY few guys ever shoot past 300 yards, and even fewer go past 500 yards.  18" is the perfect compromise of weight, muzzle velocity and ergonomics (have you ever tried toting an AR with a 24" barrel through the woods?).





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#9 Robocop1051

 
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Posted 13 February 2012 - 06:23 AM

The US military is confirming kills out to 1200 yards with a 20" barrel... 16"-18" is plenty for anything I ever plan on doing.

Having Tom and I post on the same thread is like having two fat chics at a night club. It doesn't matter what song is playing, we are going to take over the dance floor.


#10 planeflyer21

 
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Posted 13 February 2012 - 02:51 PM

There is a guy on another forum, who goes to the local "high power" matches at his club and uses his Marlin 1894C in .357 Magnum.  He consistently does well against the .223 crowd.

For those tuning the load to their barrel length with handloading, you should be able to find a more suitable powder for more suitable power out of 16" and still retain more than acceptable performance for long-er distances.

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#11 survivalshop

 
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Posted 16 February 2012 - 05:16 PM

16 " HB , short stiff barrel for best accuracy out to mid ranges .

For hunting the short bbl. rules & the 16" HB I have is only about 2 oz. heaver than an 18" light weight .

#12 cz777

 
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Posted 24 April 2012 - 01:06 AM

This is always a controversial topic, but here is my opinion:
16" - 400 yards
18" - 600 yards
For longer ranges I would want a 21-22" barrel.

I firmly believe that 18" is nearly ideal for most .308 applications.  VERY, VERY few guys ever shoot past 300 yards, and even fewer go past 500 yards.  18" is the perfect compromise of weight, muzzle velocity and ergonomics (have you ever tried toting an AR with a 24" barrel through the woods?).

hate to say this but bump the yardage to 200 yards to each given range so 18'' is the over-all sweet spot ....you can do all of 800 yards easy and push to 1000 with 175 VLD ...of course the scope too 

#13 ThBrtmn

 
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Posted 07 September 2012 - 06:14 PM

The US military is confirming kills out to 1200 yards with a 20" barrel... 16"-18" is plenty for anything I ever plan on doing.


Just to clarify is that with the semi auto AR platform or Bolt?

#14 tolbndfishin

 
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Posted 07 September 2012 - 07:10 PM

M110.  KAC-produced 308 with a 20"  semi-heavy barrel.  The profile is .875" at the gas block, not .936" as with true heavy barrels.

I just bought a krieger in this contour, but havent assembled yet to shoot, only to check fitting of everything.  I consider it a bit heavy for a hunting rifle barrel, but isn't unbearable.  Lugging it through rough terrain i might think different, although that isnt the primary purpose for this rifle, so no worries.

Russ

#15 jeffreyC

 
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Posted 07 September 2012 - 08:15 PM

Watching Magpul's Art of the Precision Rifle, Todd Hodnett is saying that 16", or 18" or 20" makes no real difference, all will work to 1,000 yards.

Makes me reconsider a longer barrel, maybe I will just get a lighter one instead.
"Every good and wise man should be wary lest he be deceived by sham internet quotes. " – Thomas Jefferson

#16 washguy

 
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Posted 19 November 2012 - 10:09 PM

Watching Magpul's Art of the Precision Rifle, Todd Hodnett is saying that 16", or 18" or 20" makes no real difference, all will work to 1,000 yards.

Makes me reconsider a longer barrel, maybe I will just get a lighter one instead.

Jeffrey  now your on the right track  my 16inch will smack moa steel at 500  and its easy to carry  wash

#17 unforgiven

 
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Posted 19 November 2012 - 10:55 PM

Watching the Military channel,Marine sniper one of the instructors I think mentioned they would wind up going to 20" barrel w/1-10 twist.
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#18 MaDuce

 
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Posted 19 November 2012 - 11:34 PM

I'm no expert but based on what I have read from people who've extensively tested these barrels, the real difference between the two lengths is not what distance you're shooting at but what kind of ammo you're putting through it. Standard and light loads from what I've read peak at 20 inch barrel, but an 18 inch barrel launches them at typically 20 to 70fps slower. In other words, you can probably throw the bullet at the speeds that make up the difference. Not worth the extra size and weight, hence why 18 inch barrels are so popular.

However, heavier loads require longer barrels for maximum performance, peaking at 24 or 26 inch (I can't remember which. However, most of the heavier loads peak in a 20 to 22 inch barrel and most of the ones that peak in longer barrels; like the 18 and 20 incher relationship, get very little boost.

However, loads that peak in an 18 or 20 inch barrel start to slow down in a 24 or 26, while 20 inch barrels don't impair them at all.

In short, 18 inch is the ideal barrel length for light and standard loads. But for the absolute maximum in load versatility across the board, go with 20.

I myself went with 20, but an 18 incher wouldn't have bothered me.

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#19 pridekills

 
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Posted 03 March 2013 - 09:37 PM

http://www.tacticalo...com/SWATbarrel/

The above link has provided me with the best experiment I have found on barrel length for a 168gr .308.  Hopefully it proves useful to all of you also.

"During the development of the Tango 51, Tac Ops took a standard 26-inch barrel and cut it down to 18 inches in one-inch increments.  Between 10 to 20 rounds were fired at each invrement.  They found that a 20-inch barrel provides for a complete propellant burn and no velocity loss when using Federal Match 168-grain BTHP, a cartridge that has become something of a law enforcement standard.  Going to an 18-inch barrel only resulted in a loss of 32 feet per second (fps). "

Per Federal's data, the muzzle velocity in 2650fps, this would mean 2618fps out of an 18" bolt gun.  If someone could verify the speed out of an 18" or a 20" AR, I would be appreciate it.  With current powders, you could reload a 168gr SMK with CFE223 up to 2828fps.  Rather that load is accurate in your rifle is another story though...

I'm building my first rifle, and with the research, I'm sticking with an 18" barrel for a 600yd hunting and high power rifle.

#20 Robocop1051

 
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Posted 03 March 2013 - 09:51 PM

That's a great link <thumbsup>

It has been posted several times over the years, but its always a good read.

My .308 is a 17" heavy barrel (.875@GB). I'll bet I'm still at 2600fps with factory 168gr.

Having Tom and I post on the same thread is like having two fat chics at a night club. It doesn't matter what song is playing, we are going to take over the dance floor.





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