SS's New Build

[survivalshop]

LR PMag measurements.

 

 

  20 rd. first gen.

  

 

   25 rd. Gen 3

   

 

   20 rd. Gen 3

  

 

 

  These represent the smallest reading I could get from the individual mags . , so the Gen 3 20 rd. mags I have , there is a small but big difference in the width/thickness of the mag .

Edited August 3, 2015 by survivalshop

[survivalshop]

The CMMG Lower with the Lancer & the 25rd. PMags feed with out a hitch , but I did have some failure to Eject , all with the 155 gr. Nosler Match loads & they are not light loads , maybe on the high side because there was slight cratering of the primer , not too flat but it was spread out a little .

 I had five total with the 155's , but none with the 168's , though to be fair ,I shot about 75 155's & about 20 168's , but I'm thinking this Bolt is still tight in the Carrier & may be some of it . I may use my other Bolt to see if that makes a difference , next time out .

  I am going to do a complete cleaning & inspection . I have built a lot of AR's & never had a problem with Ejection , that I can recall , but will see how the Ejector looks like , when Bolt is apart . every thing works the way it should .

 

  Had a 30-40 mph gusting wind & it shows on the grouping , one was a good group the rest , not so , but the rifle has potential , the Criterion Barrel seems to do its part , its me that is the problem . <dontknow>

  First group in the center I had no data , # 1 group is top left , # 2 is top right , # 3 is bottom left , # 4 is bottom right & # 5 is center bottom , with the aiming point at the bottom of the center line .

 

  Some Chronograph results with the 18"  Criterion Barrel , just some data for my records , I was shooting the rifle to break it in , since I'm having problems with it at this time .

 

Three strings of the same load , first one was still trying to get the new Magnetic chromo to read & finally found its position on the Barrel for it to read , with out errors messages .

 

  Case     Bullet              Powder chg.wt.        Powder          Avg. Vel.        ES             SD          Primer make

 

# 1 LC         155Match            43.2                          Tac            2678 fps         20fps         14 fps         CCI  ( five shot )

 

# 2 LC          155 Match           43.2                         Tac             2683 fps         34 fps        11 fps         CCI ( five shot )

 

# 3 LC          155  Match           43.2                        Tac             2664 fps          61 fps        23 fps         CCI  ( five shot )

 

# 4 LC           149 M80              42.8                          ?               2773 fps          18 fps         9 fps           ?   ( only three shots )

 

# 5 FC           168 SMK             42.5                      4064             2628 fps           15 fps         5 fps          Fed. ( five shot  )

 

Note , the Powder charges with the Tac were charged with my Redding micrometer Powder measure & I checked a lot & all were exactly 43.2 gr. .This barrel is also new so they may get better after a higher round count .

Edited August 6, 2015 by survivalshop

[survivalshop]

     Looks like every thing on the Bolt is OK ,might be the Extractor is holding the spent case too long , not sure at this time .I disassembled the Bolt & found nothing out of the ordinary , but did find some carbon on the inside of the Bolt Carrier where the gas rings seat . Since this is a used BC , I thought it was just discoloration inside from heat ( Chrome DPMS BC ) , but it was a build up of carbon , had to be scraped off & now the Bolt's gas rings feel & work better , which may have been the problem with Ejection . 

    Barrel had some green come out of it in the first several patches with cleaner( not copper solvent ) on them , but cleaned up pretty easy . Nice & shinny in there after cleaning . Will test next week , with more test loads , may put them in the Reloading section & compare the three Barrels with the same loads .

[survivalshop]

 Range trip today with 155gr. Amax with 43 gr. of Tac , , Avg. was 2681 fps , ES -24 fps , SD -10 fps . , had some slightly cratered primers , so the loads are not on the light side . I had what seemed a failure to Eject every other round . I posted on the DWilson Bolt thread in 'Parts " section .

 I replaced the Extractor with a new DPMS one & it didn't make a difference , I didn't have my tool for Ejector removal , so I couldn't replace it , I did have a new Ejector & Spring with me .

 I did bring my spare Test Bolt , a complete DPMS Bolt , well used , I changed it out & the rifle functioned flawlessly , even with 20 rd. mag dumps . 

 I replaced the DWilson Bolts , Ejector & Spring when I got back & took some measurements of the new , old & DWilson components & read the thread in " Parts " section of DWilson Bolts , to get the info .

  Its got to be an issue with the Ejector Spring , iMO .

[survivalshop]

  I can say , I 'm digging the Lancer Mags , they work like a charm , also the Magpul 25 rd. Gen.3 mags work also , this is a first with this CMMG Lower , it always liked & worked with Metal Mags , just didn't like the Plastic ones .