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I have not so far,, But it could be an option.

6.5 CM - 143gr ELDX
270 AR - 120gr MKZ
30 Herrett / TAC 30 - 125gr MKZ
6.8 - 105gr MKZ
257 Bobcat - 100gr NBT
5.56x42 - 70gr MKZ....

oops - forgot my TAC 6. Thanks Chris.

5 tags to fill... decisions, decisions.
 
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Discussion Starter · #4 ·
I have not so far,, But it could be an option.

6.5 CM - 143gr ELDX
270 AR - 120gr MKZ
30 Herrett / TAC 30 - 125gr MKZ
6.8 - 105gr MKZ
257 Bobcat - 100gr NBT
5.56x42 - 70gr MKZ....

5 tags to fill... decisions, decisions.
I've used Tac6, Tac30, 6.5CM and 6.8. All ARP builds. Thinking seriously about trying the X42. I'd be very interested in seeing a gel test with the 70 MKZ.
 

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I have not shot deer but .... when I was fixing up a second 6.8mm for son to hunt hogs with me, he asked why can't I use my 5.56. I stepped back and decided the 70 MKZ was the best option. He shot two hogs that night upwards of 200 pounds, one behind the shoulder and one thru the shoulder. It was a 16" 1:7 twist barrel and I was impressed with out quickly they went down. I don't think you will have any problem with deer with good shot placement.

Note, I've done a lot of testing with about all the .224 copper bullets, e.g., TSX, TTSX, GMX, MKZ, E-tips. Not including the MKZ, a 1:9 twist 16" barrel doesn't get much expansion beyond 100 yards. A 24" will add 100 yards of effective range. Even a 1:8 doesn't improve the situation much. A 1:7 or 1:6.5 twist really wakes up copper bullet expansion with impressive expansion out to 200+ yards.

The MKZs have not shown to be twist rate sensitive, out expands them all, and I believe will stabilize in most 1:9 barrels.
 

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Xman / Chris -
I tested Roberts V2 prototype 70grn MKZ in my 5.56x42 with 20" Kreiger 7.7 twist from Harrison.
Tested:
AR Comp 25.5gr - 3051fps - 0.943" at 100yds.
AR Comp 25.7gr - 3071fps - 0.967" at 100yds.
OAL 2.215" Temp 50 degrees.

Also ran CFE223 at 29.5 and 29.7gr - at a little more than 3160fps.
Did not show pressure on cases but no accuracy 2.67 to 3.070" at 100yds. Do not recommend CFE at this level.
Did not retest either ARC or CFE at length other than 2.215" OAL.

Dennis
 

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Discussion Starter · #8 · (Edited)
Xman / Chris -
I tested Roberts V2 prototype 70grn MKZ in my 5.56x42 with 20" Kreiger 7.7 twist from Harrison.
Tested:
AR Comp 25.5gr - 3051fps - 0.943" at 100yds.
AR Comp 25.7gr - 3071fps - 0.967" at 100yds.
OAL 2.215" Temp 50 degrees.

Also ran CFE223 at 29.5 and 29.7gr - at a little more than 3160fps.
Did not show pressure on cases but no accuracy 2.67 to 3.070" at 100yds. Do not recommend CFE at this level.
Did not retest either ARC or CFE at length other than 2.215" OAL.

Dennis
Found a load using CFE 28.6 2.200 /1.847 with a comparator in a Hornady case manufactured by S&B. Three shot group into a cloverleaf hole. 20" barrel 1:7.7 temp was 73 3066 fps. No pressure signs. Going to go up a little higher in charge weight.
 

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Good to hear CFE at 28.0gr and 2.220" OAL was accurate for you. Will dial my load down and try again.
29.5gr was no bueno.
Thanks for the heads up!

Found a load using CFE 28.0 2.220 in a Hornady case manufactured by S&B. Three shot group into a cloverleaf hole. 20" barrel 1:7.7 temp was 64° and 3136fps. No pressure signs. Going to go up a little higher in charge weight.
 
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