Fireformed another 100rds on my tired barrel. Another random load. This time 28.5/4895/115Dtacs. Once again no brass prep, load and shoot. Shot 5 through the Magneto, didn't check zero, figure it's close enough for what I'm doing. Magneto recorded a SD 4.3 for those five shots. Shot 5 at 540yds through my buddies Shotmarker, did not watch these as I shot. Not bad for a tired barrel, random load! The Shotmarker has all kinds of targets in its library. Lets try a scaled FClass target. By this time the wind picked up a little and the mirage was getting a little tough. My attempt at FClass, blew the 2nd shot, high at 12:00! Different deal for me watching shots on a screen as I shoot opposed to whacking steel watching the impact through the scope. The DTACS just like the 107SMK's come factory pointed. Interesting the Dtacs have a better SD at the target. Shows us the Dtacs have a more consistent BC. Another interesting point, velocity shown at 540yds is within a couple FPS of what my Kestrel predicts. Soon we'll shoot some Hornady A-Tips and Berger 109 Hybrids, see what we see.

The Shotmarker is a ton of fun. Next time out we'll start with a cold shooter shot, closest to the bull for bragging and heckling rights!

.28 MOA for a "bad" group with a flyer. Using an old barrel, while fire forming new brass, with a random load.

Wow. Seriously wow.

Hello offgrid, that is some mighty fine shooting you showed there. Excellent results.

Those DTACs are excellent bullets and the 6mm is just a great caliber.

I have quite a bit of experience with the Shotmarker, so if you have questions, I can try to answer them. We have a 36 of those at the club and I spent wayyyy too much time dealing with them than I care to remember. Spent lots of time on the phone with Adam, and countless emails. When they work, they are great.

Please do not take the MV at the target to be precise and accurate. It's more of a trend, a by-product of the algorithm, so to speak and it can be influenced by the wind, from any direction. That said, I like having the "MV" at the target as it let's be verify the JBM stuff and my load. My A-tips at 1000 yards show a single digit SD and that makes me happy. Then the wind starts up from everywhere and the SD goes up. Weird.

So, let us know how the A-tips work for you, I am interested.

Seeing how close the MV numbers at the target were to our Kestrels, pleasantly surprised. Nice to see that as you say. Thanks for the heads about getting weird numbers when the wind picks up. We were shooting in 0-7mph L-R winds. Fun shooting the FClass target, 20 shots is long string! Thought I did a respectable job seeing the slight wind/mirage shifts

How did the A-Tips SD's compare to the pointed JLK's at the target?

Ya, the 6BRA is a hummer. Blows me away how well it shoots fire-forming.

Haven't shot a match since 1st week of February, stupid virus! If the first match available is a 600YD any/any FClass, I'm in. The FClass match directors allow suppressors. Score won't count for record, more then OK with that.

I've done enough chrono testing to be certain my 6.5CM Bartlein barrel sped up between 400 and 500 rounds. MV is now stable, and the barrel has 640 rounds. Most of the ammo lots I tested in July 2019 are 70-80 fps faster now. The lots I first tested in April 2020 are 30-40 fps faster now, which implies they were first tested in the middle of the MV speedup.

I now essentially have three groups of ammo, based on MV. One is 2790-2800 fps, which is pretty close to the MV of 2810 that I've used for the prior two barrels. The next is 2850-2860 fps, which might work for matches with longer distances. Then there's the problem lot I used at the Q-Creek match, which started this whole anal-retentive MV analysis -- it's at 2765 fps. Handloading is looking more appealing.

I found it interesting that a clean bore tends to have a slightly slower MV than a fouled bore. Not by much when I just use my normal cleaning, but enough to notice on the chrono.

The following picture is a Hornady 140ELD lot from 2018. MV of 2775 in July 2019, now right at 2850. The left side impacts occurred at a thunderstorm was rapidly approaching. I rushed the shots to get 5 shots on the chrono. The final round was shot just as flash-to-boom was only 2 seconds. Yeah, those are close strikes. I threw everything into the vehicle and waited out a few ugly black, flat-bottomed clouds. Winds were 5-10 from 10-11 o'clock. And yes, like a sheep-dip, I started to spray paint over the group before pulling out my cell phone for a picture. 630 yards -- 5" vertical and 2.5" horizontal.

Once the two thunderheads passed, I shot the right group. Downdrafts we "fun" -- 10-15 mph from 11-1 o'clock, varying constantly. I didn't even try to guess wind holds -- I just held the orange spray dot. Again at 630 yards -- 1.75" vertical and 6.5" horizontal.



I know understand why I sometimes had elevation dope issues in prior matches. I just assumed lot-to-lot MV variation was insignificant. Live and learn.

quote:

Originally posted by offgrid:
Seeing how close the MV numbers at the target were to our Kestrels, pleasantly surprised. Nice to see that as you say. Thanks for the heads about getting weird numbers when the wind picks up. We were shooting in 0-7mph L-R winds. Fun shooting the FClass target, 20 shots is long string! Thought I did a respectable job seeing the slight wind/mirage shifts

How did the A-Tips SD's compare to the pointed JLK's at the target?

Ya, the 6BRA is a hummer. Blows me away how well it shoots fire-forming.

Haven't shot a match since 1st week of February, stupid virus! If the first match available is a 600YD any/any FClass, I'm in. The FClass match directors allow suppressors. Score won't count for record, more then OK with that.

Yes, 20 rounds is a long string, especially in switching winds. I've been known to finish the string in 10 minutes and other tines, I'll take the whole 22min or 30 mins at LR. You did great.

You did pause 10 seconds between shots, right? Not just machinegun the rounds downrange.

The Atips do really well at the target if you mean velocity SD. The 210 JLK pointed bullets were also really good at the target, but the terminal velocity was substantially lower.

Many MDs will allow supressors, but scores won't count. We do that.

Oh, and the 6mms are the darlings of the F-open crowd at 600yards. You can see why.

quote:

Originally posted by NikonUser:

You did pause 10 seconds between shots, right? Not just machinegun the rounds downrange.

No machine gunning. Let the mirage dictate how fast I shot. A few times the mirage almost stopped, boil up. I waited til what I thought was the same as previous mirage. If mirage didn't change or only change slightly, held a little more/less, shot quicker.

Worked up a load for the Kelbly/6BRA in cold weather, 20-30 degrees. Now that it's warmer, ammo baking in the sun... a few slight stiff bolt lifts. That'll give me problems when even hotter, shooting elsewhere. Need to lower the charge, find the next lower node. When testing loads I don't pay attention too much to the wind, chase it a little to make sure I hit the target. Only looking at vertical. Very gusty day shooting in the mountains, measured 8-24mph. Good thing this range has a pile of lead shot bags, come in handy to hold down my mat!

4 shots at 500yds. Not bad vertical Crazy accurate cartridge!

Lapua 6BR brass fireformed, FL sized, stainless media tumbled, dried, load and shoot. That's it! In general I don't like reloading. Like the fact these 6BR based calibers shoot so well w/o all the prep fuss. In the process of setting up my Dillon 650 to FL size. A few friends have figured out how to set up the tool head to get consistent shoulder bump. Dump a bunch of lubed cases in the feeder.... gonna like that!

Nice!
Good shooting, bruh...brah...bra

Looks like your BRA fits you.

You appear to have a good cold weather BRA. Now you need one for summer.

Is this BRA too revealing when I bend over for a barricade stage?

I'm here all week. Tip your waitress. Try the veal.

quote:

Originally posted by fritz:
Nice!
Good shooting, bruh...brah...bra

Looks like your BRA fits you.

You appear to have a good cold weather BRA. Now you need one for summer.

Is this BRA too revealing when I bend over for a barricade stage?

I'm here all week. Tip your waitress. Try the veal.

Not too big, not too small, just right

I've tried a few different grips on this XLR chassis. Two different Ergos and Magpul K2+. Those didn't quite get my trigger finger at the perfect "bend" or 90 degrees of the fixed trigger shoe w/o squirming around. It's important to get that right to shoot consistently. A friend let me try his MDT adjustable grip. Works great, able to get my finger in the perfect spot. Smart product!

https://mdttac.com/us_en/mdt-vertical-grip.html

quote:

Originally posted by offgrid:
A friend let me try his MDT adjustable grip.

Thanks for mentioning that, but I’m curious about these two statements:
“MDT’s vertical grip is compatible with standard AR pistol grip boss. … Please note, it was not designed to work on Ar-15 type rifles.”

Not that I would want to use it on an AR, but if it fits on AR-type rifles, why doesn’t it work on them? Do you know?
Also, if I understand it correctly, its only adjustment is forward and back; no angle adjust—correct?

quote:

Originally posted by sigfreund:

quote:

Originally posted by offgrid:
A friend let me try his MDT adjustable grip.

Thanks for mentioning that, but I’m curious about these two statements:
“MDT’s vertical grip is compatible with standard AR pistol grip boss. … Please note, it was not designed to work on Ar-15 type rifles.”

Not that I would want to use it on an AR, but if it fits on AR-type rifles, why doesn’t it work on them? Do you know?
Also, if I understand it correctly, its only adjustment is forward and back; no angle adjust—correct?

Won't work on a AR because of the safety plunger spring hole that's needed in the grip, fixed location in the grip. Adjustment is only forward and back.

quote:

Originally posted by offgrid:
Won't work on a AR because of the safety plunger spring hole that's needed in the grip, fixed location in the grip.

Ah, ha. Thanks.

Back in early March, my 308 bolt action crapped out. The rail that's mounted on the action suddenly became loose -- loose enough that I could wiggle the rail by hand. Of course, accuracy went south. I finally got the rifle to my 'smith yesterday.

The rifle has a Defiance action, with a scope rail attached via four #8 screws. The two rear screws sheared off at the top of the Defiance receiver. The lower halves of these screws are still in the receiver. The two forward screws still appear to be fine, although they were noticeably loose when I discovered the problem. The two forward screws are able to tighten fully, with the rail being (pretty much) solid on the top of the action.

My 'smith is a bit perplexed on how this occurred. If all four rail screws loosened at the same time, then maybe the recoil forces imparted on the NF 7-35x scope & mount was enough to break the two rear screws. But unlikely, as the rail movement with loose screws is really only left/right and up/down. Furthermore, the forward screws still seem OK.

Assuming my 'smith has no issues with extracting the two sheared-off screws from the receiver, he will just install 4 new #8 rail screws. I suspect he will use some Locktite, too.

Maybe chalk this one up to a set of defective rail screws. Maybe it's a message that I should ixnay the 308 and join folks shooting 6BR-based chamberings....

My guess fritz, the screws were over tightened, fatigued?

Yeah, over tightening could easily have been the issue. The rail wasn't loose to the touch when I took off the old scope and installed the new one in March. I didn't check the mounting screws for torque. I experienced a 3-ish MOA vertical shift in POI at 500-something yards from one shot to the next, not a progressive change in POI as I might expect with screws slowly loosening.

Fatigued...it's the fatiguing recoil of the 3-oh-hate (as you are so fond of stating)

A friend who shoots a 6BR knows I shoot Berger 105 HVLD's jammed in my 6BRA. He asked if I have tried the Berger VLD jump test. Not in the 6BRA, but have in other calibers. OK I'll try it, just 12rds. Loaded three different charges 30/30.5/31 H4895. Shot those three charges as a group at four different seating depths, .010 jam, .050/.090/.130 jump. Clearly this barrel prefers the VLD's jammed.




Top target is me shooting my buddies 6BR. No doubt his gun shoots. Expect nothing less from a 6BR! I got up and down between groups. The cheek height didn't quite fit me, suspended above the cheek rest a little to get a sight picture. See the affect of that as well as a strange to me rifle in the point of impact between groups.

At my local range I commonly run into a Benchrest competitor and his son. They shoot 6PPC rail guns. All about itty bitty groups and load tuning. Even though he's shooting a completely different discipline, I enjoy talking to him. Learning things that transfer over, load tuning is the big one. One time he was was at the range with 3 freshly chambered barrels, he's a gunsmith too. What are doing? I'm looking for a "Hummer" barrel that will shoot "Screamers", one holer. He explained to me 1 out of 4-5 barrels are competitive in his game. I've seen his crazy tiny group targets with his Hummer barrels. The barrels that are not Hummers are perfectly acceptable for my game. Over the last few years I've had one Hummer barrel. It shot incredibly well. HawkHill barrel chambered in Dasher. Got me another Hummer barrel This one is a Bartlien 4 groove chambered in 6BRA. Will be a sad day when this barrel dies!

Shot this a couple days ago at 500yds. Fun stuff!