I thought I'd start a new thread involving the 6X6.8 wildcat that was developed by Ritch Johnson. Pretty straight forward it is a 6.8 SPC case necked to 6 MM with no change in shoulder placement or angle. This will let the average guy load it with a set of standard bushing dies that don't cost an arm and a leg. The goal was to have a good varmint round and with proper bullets a decent medium game load could be worked up. Black Hole did the barrel and will be supplying them in July.
I got a notice from the USPS and wandered on down after a match on Monday and this is what I got.
Inside I received a new 24" 6X68 upper from Ritch/RPG along with another little item I will write about in another thread. This was my second 6X68 as the first one was a 20” and was threaded and was a 1:10 twist.
I really like the big bullets so felt a 1:9 would serve me better as would a bit more burning tube. The reamer had been revamped on the shoulder angle and placement from my initial build so I was very interested in seeing how my preference in twist and length would compare with barrel #1. Accuracy in the first barrel was decent but I felt there was some left on the table and that following the parent case a bit closer would pay off in this version. Ritch did a great job assembling the upper and I was very impressed with the engraving done by Kiz from Black Hole.
There are some parallel shakedown testings being done across the country with the new reamer and Ritch asked me to shoot the "heavies' as the light varmint weight bullets are being covered by the other guys. Since I am shooting the F-Class stuff I wanted to try a long range bullet anyway so this dovetailed right into my predilection for the 6 MM family. I selected my regular Hornady 87 grain HPBT as I have shot them going on three decades and know how well it can shoot...I thought!!
I had a supply of previously shot brass from the first barrel so decided that I would move things along as I was anxious to get some numbers on this new stick. Of course on Monday afternoon the weather was, shall we say, not conducive time to shooting. It was 113 and 30 MPH winds on Monday PM so I deferred the trip to the desert. I used a Hornady tool to check the lands measurement to see where I stood and found plenty of room if I seated to max magazine length. I looked over my notes and I picked IMR 8208 XBR, TAC and RL15 for my propellants. The 8208 is doing VERY well across the board in most of the calibers I shoot so I had it on hand. The TAC was some I had used in my 20 Tactical and had just a small amount on the shelf so figured the numbers looked good in the DTI and Grendel and thought this one might be a good one too. I am using a ton of the RL15 as is my current powder of choice with this bullet in 6X45 at 500 yards.
Like any well planned endeavor I hit a snag called FAMILY on Monday and I didn't get everything loaded I wanted. I shut the reloading room down at 2200 about 1/3 of the way done. I was up at 0415 on Tuesday and finished the loading. I mounted up a Leupold 24X scope on the upper and dropped it on my match ready lower.
I was on the road and in the desert at 730. I had it made as it was only 85 degrees when I got out in the no mans land although it was 90 by the time I had everything set for the chronograph and the other needs. I cleaned the bore with a couple patches of Hoppes and started getting on paper. I started at 25 like usual and after making some adjustments was ready to rock at 100.
First three shots for record using 8208 in the new 1:9 barrel:
Velocity was good at 2932 and a 0.354 had my attention PDQ. I patched out with some more Hoppes as I had shot quite few rounds getting ready for this first proof of performance and let it cool a few. I didn't do my regular break in today and I was shooting this gun HARD. It was hot to the touch just from the sun and I would normally spend a long time doing the process but even I get impatient.!!.
I waited about ten minutes and settled in again with a charge that was bumped a tad. The speed came up just about the degree that I expected up to 2992 and showed me a very nice group of 0.658 for my first test of this load level.
I had another set of cartridges with another bump and went for a big eight shot try. I was not disappointed with a 1.038 at 3041. Overall I was pleased with the results with the 8208 and after examination of the cases figure I can go up a bit more. I think it is capable of a bit more sped and still hang on to the accuracy.
I had now fired twenty seven rounds so it was Hoppes time again. I have found that after cleaning and if I am going for serious results as in a match or at the bench a pair of foulers is in order. Some may disagree but I’ll stick with my acquired traditions.. Just my experience over the years. YMMV
I decided to go with the TAC for my next set down. It has done well in light varmint bullets in my 20 Tactical for me so I was interested to see how it would do on a game weight bullet. My brass supply was limited so I made a decision to shoot one five shot and one three shot group but I only had eight of each of the light charge weights so I was relegated to two three shot groups after the two cleaning foulers.
The TAC indicated it wanted to work right from the get go. Velocity was at 3000 right off the bat and I liked that. The first three shot group were not shabby and I considered it a keeper. I worked hard on the first pass and this is what I came up with. There is a saying that says three shots test the load and five test the shooter. You decide.
Thinks were heating up and it was now 95 degrees so I let the barrel cool a tad and went back to my quest I knew the first ones were good by looking through my spotting scope but I was not sure how good. The next eight shots were "interesting" for me and I I think show what the Black Hole barrels can do. Velocity was coming up nicely to 3047 heading for that magic 3100. Of course so was the mirage but I didn't have time for that!!
The biggest TAC load showed a VERTICAL trait displacement at 3086 with a spread of 2.095 vertical and about 0.3 horizontal. The three shot group right after that printed at 0.760 with two in one hole. Overlaid with the previous five it dropped right in the vertical pattern. When you see a straight vertical dispersion invariably the rifle is letting you know to pour on the coal and I’ll do that in the near future.
Twenty-something more rounds down the barrel meant it was time to do a Hopes cleanse and let the barrel try to cool down. At this point it is hitting 100 and I could fry bacon on it. There is no cool down at that air temperature under a cloudless desert sky Ten minutes later and the barrel still sizzling I loaded my RL 15 loads for the final tests of the day. I only brought a gallon of water with me and it is sloshing low at this point.
RL 15 is doing well for me in the 6X45 and I had feeling it would do very well in this slightly just seem to get good consistent results with it. Below are all the record shots for the RL15. Velocity started at 2969 and stopped at 3066. Lowest charge was a pair of three shooters followed by three and five round groups for the other two loads. Not the smallest groups but a very consistent shooting powder that can still be cranked. I do believe the RL15 is a viable powder and the primers looked like they were just struck with the firing pin. Rounded edges and more case available. I'll be pushing the envelope on this one.
So, what did I learn?
The new reamer is producing great results. It specs out right where it was supposed to. Pressures are lower across the board and I am not pushing primers like I was on the first tube. The barrel will shoot 'HOT" and I value that. This will be a viable mid-range F-Class round and may, with a Berger VLD, be a 1000 yard candidate. That intrigues me as the 243 LBC was going to be a candidate for that. I am now in the dilemma stage of Ennie, Meenie, Minnie Mo !!
The Silver State brass is holding up and the primer pockets are tight. I have 400 more cases to process and will start on that soon. I am waiting for some of the Tactical Ammunition factory stuff to test and look forward to trying it out.
After hearing how the other guys are doing with groups and stupendous velocities I am starting to think I only need one AR and this may well be the multi-purpose round.
I'll leave you with it and will post more. Next week.
Greg
PS: One last little thing. I hate to leave the range with only an odd round or two so I will use those as my “reward” for a day at the range and do some blasting. I had taken the chrono down and figured I’d shoot the last three I had. One was one charge and two were another. Both TAC loads. I used a staple as my aiming point so maybe aim small, shoot small holds true? What do you think of this one?
