I got out last week to test out my 6,5 Grendel in concert with the new Starline brass they sent me to evaluate. I also shot my 6.8 with some new components but most of all it was to test the new Young Manufacturing 6.8 bolt. Of course small groups was my goal no matter what the reason or if not very small at least usable. I was a bit concerned as the temperature was predicted as being 110 or so. I forgot my Kestrel so I didn't have my onsite temps as usual so I had to go by the PHX airport temps. I was really relieved that it only hit 108 thee but I suspect,LOL, it did hit the full 110 where I was out. I guss I'll take it as a win even though it probably has an asterisk attached.
I started out with the Grendel. This is a 20" tube done with my regular round NM hand guard. Lower for the day was my F-class set up with the Geissele High Speed Match trigger. I went with an old 6.5X20 Simmons scope for this test period. I shot 85's and 123's in teh Grendel. Both ends of the usable spectrum for most guys. I didn't select any load levels that were flat out barn burners as I wanted itto be a fair test on the brass.
85 grain Sierras were shot first with three powders at three charge weights. Velocities at max weights for the day ran CFE at 2888, AA 25520 at 3070 and the speedster was TAC hitting it's stride at 3217. The A 2520 was the most consistent for me and I was pleased with it's results. All three had at least two out of three under a minute with the AA offerinbg being a solid three for three. The harder I pushed it the better it did. Here's an example of why I like this powder in many chamberings.
No grass growing there and a PD would have issues with it.
I switched to the 123's for my next go around. Temps started at 95 with the 85's and I finished up the 123's at 99. Not terribly bad thanks to the shade. For simplicity's sake at the bench two weeks ago when I loaded these. I used the same three powders as above backed down slightly as an admission that more mass does mean more pressure. Max loads showed me a bit narrower band with TAC running 2519, 2520 at 2614 and CFE 223 hitting 2691. All decent Grendel speeds but nothing to crow about. Five of nine groups shot were under a minute. In this case TAC was the hands down winner with all three under a minute. Just a hair over 0.7 average so that was not bad.CFE did show some promise at the top end and I may well revisit it.
This is pretty representative of the 123's that day with TAC. For some reason though the 2520 keeps making me come back to look at the targets. The groups were decent there but I was pounding one out of the mix on each try. Maybe next time!!
I'll be looking at the 123's again for sure.
The brass behaved nicely. I put 101 rounds down the tube so that gives me 104 ion it. I'm sure it was getting a tad dirty at the end . Across the board primers were nice and round and I had no case damage from the load levels. I'm very pleased and will see how it does on next test. I do need to calculate the fired capacity on this one. I had five marked so maybe I'll get the harpoon out later and see what I can shoot them up with. Mirage was a factory in the last shots as it started kicking in right at the end of the 85 test. None of the
I swapped out the Grendel upper for my 17 1/2" 6.8 for my next foray. I sat down and had a nice cold slug or two of ZH2) and a glazed honey bun. Have to keep the sugars pumped up a bit.powders acted squirrel y in the heat so that was also a plus for a data point. Had a chat with a fellow F-class competitor about his new stick.
Getting to the bench the temp had finally hit 100 and I was feeling more natural in that AO of heat. Us old guys need that heat to get the circulation going. All 50 shots on the first try were done using Benchmark powder in Starline 1X brass and 450 primers. I wanted to see how it did with various weights and it performed about like I expected with speeds being a bit down. On the 6.8 I shot three bullets for both teats batches. The Sierra 90, the Speer 100 and the Sierra 115 SMK were put to the test.. Once again nothing that caused one to cringe at tipping the powder can. I had not shot any of these three bullets so it would be new territory. This test was for groups but with the new Young bolt in my BCG I wanted to see how it would do.
The 90's gave me decent speed at 2722 with and I was rewarded with three sub-MOA groups. The last one blew up vertical so I want to reshoot it plus maybe 0.3 and 0.4 looking for some magic at higher speeds. The cases looked pristine so why not. I really believe this one can do a lot of these groups given decent conditions and someone that can shoot better than I can. Mirage was stepping up so I was happy.
I moved up to the 100 Speers and the speed dropped as expected. All groups were round but only one of the three would get a blink with most of you guys on here. The first group on a bullet jacket change really shouldn't count and that was the worst one here. Mediocre group. Usable for most any game animal but it would need more verification. This would make one heck of a coyote killer. I really like this bullet and will be doing more with it down the road.
I moved up to the Sierra 115 SMK as my last test in the Benchmark series. Speeds were a bit less than the 100's on the top end. Interestingly the speeds with 30 and a 115 gave me 2950 but the same charge under a 100 was 26 FPS faster. Right on what one would expect but there are limits to that little comparison on the teeter totter of speed vs. pressure. Two of three were sub-MOA so I guess I can't complain about it much. Nothing fancy but adequate for deer if one had the urge to use a target bullet. I don't but some do.
Across the board the brass held up nicely and came out unscathed. No bent rims or bad markings. I was happy for the Starline .
I moved on to OLD Silver State 2X brass for my final shots. I was now in my AZ shooting zone of 106-108. Very cool. I must admit though the one group was STELLAR until I had one of those tear jerking movements. You know, sweat tear running in the eye just as you pull the trigger only it was painful jerk!! went from a nice 1" or so to 2.269 at 2900 FPS!! Oh well.
I shot three bullet weights this time as noted but each weight got another powder. Once again gathering data points for my needs down the road. I pushed the 90's using LT 30 that is very similar to H322 in how it behaves. Not overly impressive but the speeds wee there. Two of three were sub-MOA but nothing screaming to shoot me again. I'll have to look over the LT 30 again.
Next up was the 100 Speer setting on top of AA 2230. I want to try some 2520 on this one.. Everything looked good on the brass but it only eked out one sub groups. Lots of vertical in all three loading levels.l. Was it the load or the boiling mirage? I don't know but I'll give it another shot with a cleaner guns next time.
After about six hours in the six and a half hours in the heat I was ready to call calf rope but I had thirty more to go through.The 115 SMK's were setting on the 2230 and they seemed to like it. Speeds were about average. Not too fast but not slow. The first charge weights shot well enough to make me not hang my head in defeat on this pill. Definitely keepers for the little guy. I was pretty happy across the board on this one. It's a decent target bullet that is a viable alternative to the 123 SST that so many guys shoot. If one doesn't work the other usually will.
Here are the keepers.
As I mentioned this was not only for accuracy but as test on the new Young bolt. I can say it was money well spent for me. It is beefier than a stand bolt and as far as I can tell more so than anything else out there that I have held in my hands. Maybe a bit of overkill as 6.8 bolts rarely let go given SANE loading levels. I've seen a couple broke but they were getting run in the red line area on some wildcats. There loads and their bolts. Not me. A bit of extra insurance is always nice and I have that with this one. I'll be adding more to the shooting gear as money allows. 95 rounds down range on this bolt with zero issues. Extraction and feeding from the magazine were 100% as I would expect and with the plating they sure clean up easy. I stopped by YM on the way home and billed him for a gallon of cold water. He was quite pleased to get the report so they will be going great guns selling them. I personally saw over 100 that were ready to go setting in the ubiquitous egg crate holders that everyone uses in the industry. I even picked one up and mailed it off to Ritch for his endeavors. We have some plans for these strong boys!! (Piggy bank time boys!!)
The range day was nice. I had three other shooters show up through the day. They only stayed about thirty to forty minutes so that is verifiable proof there are some sane individuals left in Phoenix. The range manager came buy to say Hi and check on me a couple times. Always nice to have someone concerned about your welfare. He always has a cooler of water just in case a guy runs out. I had my usual gallon jug with me so I was fine.
I sent the last two days crunching numbers and data entry on the targets. I used a LabRadar and recorded 195 shots. I had two readings that were hokey. One was a 6,000 FPS'er and one showed an increase in velocity between the muzzle and ten yards. The numbers just didn't look right on that so I delved into its innards of data points and fixed that one. The unit is rated for, IIRC, 105 and I did have it shut down once for the heat. Using the rechargeable battery packs lets me run all day with one battery without any issue. The 4X scope on top for target /beam line up woks like a charm. I haven't missed a shot in well over 500 now.
I will be going through the brass and getting it ready for a polish. I've got my G-son tomorrow so maybe he can run the Frankford deprimer as he thinks it's cool. I'll put some more fodder together and hit the range week after next if all works out. I think there's a 500 yard F-class to do late in the months. Time for some belly time for sure. I might even stick that 32 X Mueller on the Savage and see if it helps. I know that if 1000 yards jump up it will be moved quickly.