Which Kentucky Challenge Load? Aug 5, 2015 8:12:50 GMT -5
Post by Richard on Aug 5, 2015 8:12:50 GMT -5
Weather yesterday morning at 6:30 a.m. was 70* with little to no wind; humidity was somewhat less than the past few weeks but the mirage picked up considerably by mid morning. Again, Clays and H-4198 powders used on all loads including singles; .060” veggie wads used on all bullets; full Formed bullets were all of the .451” variety and knurled up in and around .454” before being run thru Airborneike’s FF die. The cool rod used on and off after about every 3 shots to keep the barrel from getting hot vs. warm!
To foul the barrel is used the 225 FTX FF with a 5/65 duplex. The first shot printed out of the five shot group although velocity wise it was right with shots 2 & 3? In any event it left the last four shots in a .867” 100 yard group.
At this point I was attempting to showcase three progressive duplex loads and try to come up with which might be better suited to the Kentucky Challenge? They would be 8/60, 9/60 and 10/60 along with the 290 gr. Barnes TEZ FF.
Starting with the 8/65 I got an average of 2688 fps (10’ from muzzle-Pact chronograph) with a 19 fps ES and a 3 shot .867 cloverleaf.
9/60 yielded 2707 av. With 17 fps ES and a somewhat vertical 1.1” three shot group.
10/60 gave 2719 fps with 32 fps ES but a Five shot .711” group slightly horizontal. Edge had noted in some of my past groups with 10/60 that they had very little vertical although some horizontal………..which is evident here.
Moving on to a 250 gr. TEZ FF with the same 10/60 duplex I got an average velocity of 2779 with a whopping 70 fps ES? But a nice little .499” three shot group? A contention of mine has been that you can still get small groups with large ES’s at close range.
Don’t feel that because I put some of my opinions on paper that they are carved in stone because many times they come back an bite me! I just look at “stuff” over a long period of firing many shots, some “trends!”
For the benefit of Riverrat who questioned why I don’t test single powders? I loaded up Five vials of 72 gr. H-4198.
The first group ( or start of a group?) was with this 290 TEZ. Velocities wee 62 fps apart and the two bullets printed 2.1” apart and I scrapped the remainder of the group.
With only three vial left I went to the 300 gr. BE FF and here go much better results posting .742” group at 2767 fps with 17 fps ES (chorono only captured two shots- sun getting into photo cells likely). Noticeable with both groups was a more distinct/heavy recoil than occurs with the duplex loads.
So much for 100 yard testing. The next two are shot at 300 yards!
290 TEZ FF with the 10/60 duplex. Started out hitting the steel target to check on POI; then five shots at the target. Vel. for all six shots was 2729 with a 51 fps ES (the first shot at the steel was the slowest and opened the ES from 40 to 51? The first three shot did well at 1.822” with shots 4 & 5 opening the group to 3.1”
The final group with the 250 TEZ (chrono only captured the first shop) and 10/60 duplex gave a nice three shot .719” group! I was tempted to shoot five but was instructed NOT to!
So, a little more testing/tweaking next week before the Challenge; with the likes of quite a few good trigger pullers being in attendance, it will be interesting to see how things shake out.
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