Fritz, get your Brother-in-law to shoot the Team Assault Challenge with you in May. Most of the targets are going to be big and easy.

Going Long!

Just received a 30" 7saum barrel from jelrod1. Reamer used is designed for the 180 Hybrids in a short action using Accurate 300WSM mags. Took off one of my Dasher barrels for now. Swapped out the 308 bolt head for a magnum bolt head, easy peasy with the Bighorn actions. Plan is to shoot a couple Magnum matches in Raton (2100yds max distance) and a ELR PRS match, all prone. After those put the Dasher barrel back on, 7saum barrel back on next season... Traded a non folder AICS for a folder, makes lugging it around easier and adds a little weight.


Shot 30rds through it today, so far H4831/180 Hybrids shooting very well. Guessing should be up against 3000fps. Haven't shot a large caliber in quite awhile, recoil pulse not bad with a long barrel, rifle tipping the scale at 18.5lbs and a APA Fast Bastard brake. First few shots muzzle was going a tad left after recoil, swing my hips a tad right, recoil straight back.... I will definitely be leaning into/loading the bipod a bit more then the Dashers! Fun Stuff!



https://s31.postimg.org/m7vec0i0b/7saum.jpg

I'm getting tired of trying to shoot in this spring's high-winds-from-hell. Spent a few hours at my somewhat "sheltered" 100 yard berm on Saturday, with winds of only 7 to 15 mph. Most of the long-range shooting positions in our pasture were seeing 15-20 mph winds, with higher gusts.

As I suspected from a couple prior sessions, the 2-10X scope I purchased in December for my 16" barrel AR-15 won't hold zero and has tracking issues. Crap. Back to the factory it goes, and I will accept only a new scope -- not this one's being repaired. From one session to another, zero can change 3-4 MOA. Between tall targets, dialing elevation & windage to max and back again, I experienced a 5 MOA downward shift after roughly 100 rounds in 3-round groups.

Shooting good ammo, I saw groups range from .25" to 1.5", all while my technique was rock solid. Rarely did my reticle move off the aiming dots during the recoil cycle. One group might have 1/8" vertical, then after dialing the next one might show over an inch in vertical.

I won't say the brand at this time -- the manufacturer first gets the opportunity to respond to my extensive target documentation.

Frustrating, really. I've never experienced tracking issues with any of my other scopes -- makes me think I shouldn't have strayed from the NF brand.

BR stuff is not my bag. Fun to look at the calibers setting records. Certainly an impressive group.

Three fellow shooters around me had jelrod1 chambered them 6BRA's. Two of them have loads worked up, shooting amazingly well. All on repeaters. Just when I think the Dasher can't be topped! Even more efficient, easy load and shoot fire-form with the Ackley shoulder.......

http://bulletin.accurateshoote...-group-at-600-yards/

quote:

Originally posted by offgrid:
Certainly an impressive group.

Whoa There Francis....

A .28" group at 100 yards is beyond the abilities of the vast majority of shooters. A .28" group at 600 yards is mind boggling.

I'm tired of shooting in the wind.

Next week I shoot the Battle of Breakneck precision rifle match in Nebraska. It was time I made certain I could still shoot my 6.5 bolt action, and to make confirm the scope's zero. By mid afternoon I had finished ranch chores; I was warmed up from shooting ARs. Winds had steadily increased during the day, and were now 16-22 from my 3 o'clock.

I was shooting from a blunt ridge on the prairie, slightly down hill into a shallow depression. A blunt ridge was to the left of the target array, rolling plains to their right. Targets were 2 to 2.5 MOA steel from 479 to 906 yards. From the get go I was shooting high -- as in 1 MOA or more high. WTF. Now when I yank a shot from prone with a rear bag for support, it's usually high. With right-twist barrel and the wind from my right, longer shots tend to go higher than normal -- but only a click or two high. I'm 4-6 clicks high. Crap.

So I put up a target backer at 100 yards with three 2" Shoot & See pasters on it. First 5-round group had all bullet holes touching, just to the side of the aim point. Ditto with the second 5-round group. Measured the groups edge-to-edge with a tape measure, both were right at 1/2". OK, I just shot two separate 1/4" groups at 100 yards. Technique is OK, zero is OK. I know this NF ATACR 5-25x scope tracks well.

It turns out there was a huge vertical effect on bullet flight yesterday that I hadn't seen before at our ranch. Or other places I've shot.
The 479 yard target required only 7.25 MOA elevation, but dope was 8.25. So I needed 1 MOA less than predicted.

The 550 and 609 yard targets required 1.75 MOA less than predicted.
For 632 and 792 yards I needed 1.50 MOA less.

At 906 yards the actual elevation was 2.25 MOA less than expected -- 19.75 instead of 22. This target is a 20" round, so that's the height of the target. With a 22 mph cross wind I had to hold 9 MOA of wind, and aim dead center of plate. A 16 mph wind required a 6.5 MOA wind hold, and aiming at the top of the plate.

I spent quite a few rounds on the 792 and 906 yard targets, trying to wrap my noggin around changing both wind and elevation holds, depending on the wind speed. I must to remember this experience for the next time the wind really messes with my POI.

Frickin' wind.

I’m curious: Does your calculated dope include the correction for “aero jump” caused by the strong 3:00 o’clock wind? I obviously don’t have all your data, but using some possible inputs based on my data, a 19 mph wind would lower the elevation required by about 0.7 MOA at 632 yards with a 170 yard zero as compared with no wind according to the Applied Ballistics solver.

That’s something that puzzled me greatly when I first encountered it using the AB software, but I’ve never had any real chance to investigate it for myself because most of my shooting is limited to ~200 yards and in much more variable winds.

quote:

Originally posted by offgrid:
BR stuff is not my bag. Fun to look at the calibers setting records. Certainly an impressive group.

Three fellow shooters around me had jelrod1 chambered them 6BRA's. Two of them have loads worked up, shooting amazingly well. All on repeaters. Just when I think the Dasher can't be topped! Even more efficient, easy load and shoot fire-form with the Ackley shoulder.......

http://bulletin.accurateshoote...-group-at-600-yards/

I know it's totally irrelevant to the discussion at hand, but that's also a really beautiful stock.

quote:

Originally posted by sigfreund:
Does your calculated dope include the correction for “aero jump” caused by the strong 3:00 o’clock wind? I obviously don’t have all your data, but using some possible inputs based on my data, a 19 mph wind would lower the elevation required by about 0.7 MOA at 632 yards with a 170 yard zero as compared with no wind according to the Applied Ballistics solver.

I use JBM data, without the effect of wind on elevation requirements. Based on last year's Albuquerque match, I have a rough idea how much my bullet climbs with wind from 3 o'clock and falls with wind from 9 o'clock. Saturday's deviation from normally good data was noticeably greater than the wind effects I have previously experienced. I'm confident I was shooting well, that target distances are accurate, and that my MV didn't magically speed up a whole bunch. Hopefully it wasn't a scope tracking issue, which I could have confirmed easily enough with the recticle -- but I didn't.

I chalk it up to vertical wind effect of the terrain. Haven't really seen this while shooting 6.5 or 308 at our property. To a lesser extent I've seen it with 223. But I have seen wonky elevation requirements in this same drainage with my 22lr. Of course, at shorter distances with 22lr. But sometimes an unexpected rise or fall of POI by a couple of feet with a change in wind -- a variation greater than what should be expected with match-grade ammo.

Our property's terrain isn't as complex as other places I've shot -- say, the Battle of Breakneck, Blue Steel Ranch, and T3. Wind at those locations can fool the bejeezus out of you. Wind currents that are up, down, & backwards of the expected flow.

Thanks. I always appreciate wind discussions.

quote:

Originally posted by fritz:
As I suspected from a couple prior sessions, the 2-10X scope I purchased in December for my 16" barrel AR-15 won't hold zero and has tracking issues. Crap.

Update -- I wasn't ready to send the scope back to the factory. So I put my NF 2.5-10x on the upper. Initially this combo shot a little better. Then I started dialing elevation a lot, in combination of getting the barrel pretty warm. Dagnabbit, the wandering zero resurfaced. I noticed that the gas block seems to be moving (rotating) in relation to the opening in the 12 o'clock portion of the rail that allows clearance for the gas block. When the barrel was pretty warm, the gas block touched the rail. With the barrel totally cold after being the safe a couple days, the gas block no longer touches the rail.

I saw this gas block position issue during my prior session, so prior to this shooting session, I centered the gas block relative to the rail and really tightened the rail's screws. As in really tight. I can't imaging the the rail is rotating relative to the receiver.

I will next test both the 2-10x and 2.5-10x scopes on a 14.5" LWRC upper that I know shoots very accurately. But for now I suspect both 10x scopes are good to go, but there's something wonky with the 16" upper. Maybe the castle nut is a little loose. Anyway, I plan to take it back to the 'smith for review as my schedule permits.

That’s not something I would have anticipated, so it’s good information as well. Please keep us posted.

I'm finally going to find out what the fuss is all about. I'm having a Lapua 6 Dasher built on an Impact Precision action. I have 500 Lapua 6BR cases in bound. What's a good fire forming load?

quote:

Originally posted by swage:
I'm finally going to find out what the fuss is all about. I'm having a Lapua 6 Dasher built on an Impact Precision action. I have 500 Lapua 6BR cases in bound. What's a good fire forming load?

Cool!

29 Varget, 28.5 H4895, 31.5 H4350 with any 105 class bullet. Softer primer to FF. Winchester, Federal.

What bullet you plan on shooting?

quote:

Originally posted by offgrid:

quote:

Originally posted by swage:
I'm finally going to find out what the fuss is all about. I'm having a Lapua 6 Dasher built on an Impact Precision action. I have 500 Lapua 6BR cases in bound. What's a good fire forming load?

Cool!

29 Varget, 28.5 H4895, 31.5 H4350 with any 105 class bullet. Softer primer to FF. Winchester, Federal.

What bullet you plan on shooting?

Offgrid...I have 500 Berger 105 Hybrids inbound that I plan on using for matches. I was thinking about using a flat based bullet of the same weight to fire form. I have the mandrel and die to use the false shoulder method. Others have stated it's not necessary. I want to keep brass loss to a minimum. Thoughts?

FF'd both ways. I prefer the false shoulder method. Consistent OAL, all go bang. Still will split case necks. Last batch of 300 false shoulder, split 2.

32-33 Varget, 31.4-32 H4895, CCI450, Hybrids jumped .015.

With my actions stock 10rd AICS mags with the feed lips flared out toward the muzzle are 100% Dasher rounds. FF'ing not 100%. 6BR's around me have good luck with the Primal Rights kits, still need to bend the feed lips.

So use the mandrel to expand the neck (I have a .264 on hand). Then full length resize with the expander ball removed just enough to have resistance the last 30% of bolt close?

Yes, that will work great. I use a .264 mandrel.

Look forward to your report. Believe you'll be surprised how well the FF loads shoot!

Thanks Offgrid. I appreciate the help and guidance.
The rifle should be done shortly. I'm looking forward to shooting it.

The first day of the Battle of Breakneck match was cancelled due to heavy rain and wind. Dirt roads are almost impassable. Lots of standing water in ag fields. The new nickname for the match is Battle of Wetneck. Tomorrow we get to meet at 5am and shoot in the mud. Yes frickin' haw.