Can't decide... 18" or 20" bbl

[AdamO]

I used the AP receiver set with a plain ole no frills DPMS branded .308 buffer tube and buffer assy that I picked up from Brownells.  No heavy buffer, no special springs, etc.etc.etc...  Guess what, it does the job it's intended to do and the gun runs beautifully w/ mid length gas.   I did use a syrac adj. gas block with it and dialed in the recoil is very livable with zero cycling issues in either 7.62 NATO or .308.  Brass spits out right at 3 o'clock.

Edited November 25, 2014 by AdamO

[Christopher67]

I used the AP receiver set with a plain ole no frills DPMS branded .308 buffer tube and buffer assy that I picked up from Brownells.  No heavy buffer, no special springs, etc.etc.etc...  Guess what, it does the job it's intended to do and the gun runs beautifully w/ mid length gas.   I did use a syrac adj. gas block with it and dialed in the recoil is very livable with zero cycling issues in either 7.62 NATO or .308.  Brass spits out right at 3 o'clock.

 

 

Very nice thanks Adam, something for me to ponder to.  <thumbsup>

Edited November 26, 2014 by Christopher67

[StainTrain]

Even with this buffer/tube/spring i have listed here? 

It should.  If not, sell it to one of us and get the lighter one.  

[StainTrain]

Even with this buffer/tube/spring i have listed here? 

It should.  If not, just sell the buffer to one of us and buy the other one.  

[Christopher67]

It should.  If not, just sell the buffer to one of us and buy the other one.  

 

 

<thumbsup>

[Croaker]

8)

Edited December 17, 2014 by Croaker

[BLKSHEEP]

If this is strictly a bench gun weight is a good thing so why not go with a 20-22" barrel if you're concerned with milking every fps that you can get out of it? Although with length you get more barrel whip so a heaver contour would be better. <dontknow>

[survivalshop]

The

39.0 IMR-4064 loads (#11 & #16) show the same stats for bot 16" & 20" so I figured there was a typo in that set.

 

   You caught me again , another Doooooo! , but they're data are next to each other , so it was an easy typo . I will edit & change them .

 

16" bbl.-   39 gr. 4064 , 175 gr. Nosler match , avg. vel.-2234 fps    ES - 91 fps    SD - 32 fps.

 20" bbl. - 39 gr. 4064 ,  175 gr. Nosler match , avg. vel. 2370 fps.   ES  - 82 fps.  SD - 27 fps.

 

  Just so you know , both rifles were shooting 1/2" groups @ 100 yards off sand bag rests. To me the barrel length thing means nothing , unless you are going for the top limits in range for this cartridge .

Edited November 27, 2014 by survivalshop

[Croaker]

8)

Edited December 17, 2014 by Croaker

[survivalshop]

  Nice spread sheet .

     As long as we know , its not about just Velocity , its about how well the loading shoots consistently . I'm sure you know that having a consistent grouping load /rifle is far more important than how fast its goes.

  Running out of steam, in what sense ?

[Croaker]

8)

Edited December 17, 2014 by Croaker

[survivalshop]

  WC846 Ball powder ( aporx. burn rate of BLC2 ) a slower burning powder than the extruded IMR 4064 , not sure about that one . First off , all loads were hand weighed to precisely the weights shown with a Pact Digital scale . There was a lot going on then just the components used , some fresh annealed brass was used & I think I specified that . All were trimmed to the exact trim to length of 2.005" . There were some Full length sized & Small Based sized , so it could have slight differences in the outcome , but these loads were for testing & working up a loading for BOTH rifles . I too don't want to have a different load for both rifles , but if you want to get the most out of any barrel/chamber/length , you will have to make different set ups for them .

   I really don't care what one load does to another as long as the end results are a consistent groups at all ranges .The reloads were posted just to show the comparisons between the two bbl. lengths & may or may not show the same results with another barrel/brand . Powder burn rates & a different primer can make much different pressures , thats why there are different sweet spots ( groups ) in any velocity/bullet powder combo.

 

  I'm not sure what your getting at , because I think you are over thinking this whole thing , my loadings were just for reference for my two different length barrels made by the same manufacturer. 

 

  Also , we are talking about 308AR's , not Bolt action rifles .

 

 As far as losing steam , I don't want to be the one standing in front of any 30 cal. bullet @ 1000 yards , be it a supposedly tumbling 168 SMK or what ever. <thumbsup>

Edited November 28, 2014 by survivalshop

[Croaker]

8)

Edited December 17, 2014 by Croaker

[survivalshop]

     WC 846 is a batch to batch load , your right my WC846 is close to BLC 2 , but I can't load 308's using WC 846 to the load data of BLC 2 . Its close & if you use the rule to start any powder 10-15 % above the lower load data  , you can be safe enough using it . 

    I have looked at least three burn charts & all there read the IMR 4064 as slower , but in my experience the Ball powders are all faster than Extruded . There are so many factors involved with changes in powder charges , that unless you have some very expensive monitoring equipment , you would not know the effects of charge weight changes & there effects on Velocity , Could also be changes in Bullet composition or variances  in that batch of bullets . Even though I weigh my brass , it could have a factor in it also .

  Trying to find that needle in a haystack would be full time job .

 

    You whole question is about barrel length & which is best & that boils down to what you want to use it for . Bench rifle , go long , Hunting or Combat rifle , go short . The 308 is a very powerful cartridge & if keeping with normal ( rifle type , not pistol  ) lengths , they will all reach out there. Of course I'm talking about well made barrels , not bargain basement barrels .

 

    Yes , I already miss not finding any WC 846 , its my go to powder & the 40 gr. charge ( with this batch of WC 846 ) its the best shooting in both , 16 & 20 " barrels , but a lot of others are close . The IMR 4895 with the Nosler 175 Match , was real respectable .

[Croaker]

8)

Edited December 17, 2014 by Croaker

[survivalshop]

 We require photo's of all builds & parts . <thumbsup>

[AngelDeVille]

New to the 308 ar, and I decided on an 18" mid length. I shoot out to 500 regularly and 1000 when I have the opportunity. If I was limited to 500 I'd go with the 16" barrel.