Hodgon CFE 223 & 6MMAR Turbo Imp. loads

[Bigame1]

Hey fellows just wondering who out there has had some experience loading this powder for the 6mmAR Turbo Imp.? I'll be using either the 107 Sierra or the Berger 108 pills. Lapua brass of course & CCI br4 primers.
Thank you for this info.

 

[rcw3]

It's on our list to chrono and post results this spring (now that the snow melted and winter moved on).
www.6mmAR.com

 

[rcw3]

Got to the range today (60 degrees f) and here are the results with a 24" barreled AR-15 upper, 1:8" twist, with naked Berger 108's loaded magazine length (i.e. 2.260" OAL), using fire formed and re-sized AA Arms (Lapua) brass, BR-4 primers and CFE 223 Hodgdon powder (with all thrown charges, not individually weighed) all magazine fed:

30 gr. CFE223 - 2621 MV, ES 31, SD 12
31 gr. CFE223 - 2715 MV, ES 27, SD 10
32 gr. CFE223 - 2801 MV, ES 25, SD 10

There were no pressure signs with the above loads and it seems like another .5 to 1 grain of powder is workable at that temperature.

Great powder for that cartridge!

 

[dbduff]

How did they print?
D

 

[rcw3]

I don't shoot groups when I chrono test loads - - not good to try to do two things like that at once - - either you focus on putting the rounds straight down the middle of the chrono screens or you focus on a target 100 yards down the line - - over the years I shot two chronographs trying to do both at once - - way too expensive!

 

[tonysnoo]

Very interesting Robert. I have been shooting that powder since last year. I found a sweet spot at 31.4-5 with my Rat and 31.3-4 with my AR turbo 40, with coated 105s and 108s. My buddy's turbo like 31.3 with bare 105s. My magnetospeed says that I was making 2880 with the 28" rat and 2830 with the 24" Turbo. I can't imagine that our elevation would make any difference but? We are at 4000 to 5000 ft. Cooler (40ish) weather I seem to stay closer to 2870+ when it warms up (80ish) I have seen the low 2900s. Even then, with the old powder the there were no pressure signs and the pockets stayed snug well into 7-8+ reloadings.

This year's new batch of CFE powder is showing a little more ejector shine at these loads, but the primers are great. I did use a reduced load of CFE for fire forming, but I don't think I reduced it enough and I feel I hurt that brass cause it's primer pockets just don't feel as tight as some of my much older brass. Maybe fire forming needs a little faster powder?

Its really dirty black, but I never see copper, so I don't know if its the coating or the CFE or a combo.

I'm anxious to see if you like the accuracy as much as we do.

Good luck!

 

[rcw3]

FWIW - The 24" barrel I chronoed is a little slower than others and it's made from a lower end button rifled barrel blank (i.e. it gets expensive to just burn up premium barrels doing testing). I didn't measure the bore dimensions but it's likely a little oversized, the lower end button rifled barrels tend to be that way sometimes, and they typically run slower as a result (need more powder to get same result but usually the barrel can handle it too). Most of the premium barrels I have had and chronoed in the past are faster barrels (and their bore dimensions are true too), but that's the only 24" barrel I have set up for testing right now.

FWIW - - On the side - - take a look a place like Green Mountain barrels - - they are straight out that their 6mm bore dimensions are .238" x .244", and most of the Bartlein, Brux or Krieger barrels we get are .236" x 243", it makes a difference.

 

[tonysnoo]

Very cool data. Thanks Robert.

That could very well explain why one of my buddies has a barrel that just won't run as fast as mine..same length,.same day, same loads. It's about 70-90 fps slower. It sure is accurate, however.

 

[rcw3]

2nd Round Update (supplement to earlier post - my first post on 4/11 above) - - - Got to the range again today (65 degrees f) and here are the results with a 26" Krieger barreled AR-15 upper, 1:8" twist, .236" x .243" , with naked Berger 108's loaded magazine length (i.e. 2.260" OAL), using fire formed and re-sized AA Arms (Lapua) brass, BR-4 primers and CFE 223 Hodgdon powder (with all thrown charges, not individually weighed) all magazine fed:

31 gr. CFE223 - 2792 MV, ES 19, SD 7
32 gr. CFE223 - 2867 MV, ES 14, SD 6
There were no pressure issues and another .5 to 1.0 gr of powder is likely workable pressure wise up to 2900 fps.

FYI - - Here are some other loads chronoed at the same session today with the Berger 108's magazine length and mag fed with everything else as noted above:

29 gr. H335 - 2756 MV, ES 24, SD 9
30 gr. H335 - 2836 MV, ES 14, SD 5

32 gr. 2000-MR - 2811 MV, ES 17, SD 6
32.5 gr. 2000-MR - 2869 MV, ES 29, SD 10
No noticeable pressure signs, may go another .5 to 1.0 gr higher pressure wise probably in the 2900 fps range

28 gr. 8208XBR - 2711 MV, ES 13, SD 5
29 gr. 8208XBR - 2793 MV, ES 33, SD 12

28 gr. H4895 - 2708 MV, ES 27, SD 9
29 gr. H4895 - 2806 MV, ES 9, SD 3

Robert
AR-X Enterprises, LLC
www.6mmAR.com

 

[SG4247]

Good info!

How many shots fired in each chrony session?

 

[rcw3]

Chrono results represent 5 shots for each particular loading (e.g. 5 shots for 31 gr. CFE 223, 5 shots for 32 gr., etc.). All charges were thrown (i.e. not individually weighed)