Wow!

Had a similar occurrence when I was fireforming 6BR Lapua Brass to 6 Dasher. It was a random receipe …. 30gr of Varget, Hornday something or other projectile, jammed 0.030" into the lands.

That's when I realized the "magic" of the 6mm family and it's performance.

Now with Alpha Brass releasing their 6 Dasher Brass.... fireforming is not required. I have 100 pieces of brass from Alpha waiting to run thru a new Bartlein Barrel that is being turned.

Andrew

quote:

Originally posted by offgrid:
Another 6BRA chambered by jelrod1, Kreiger 4 groove 8 twist 26" Heavy Palma.

That dog will hunt.
Must be some clean burning powder -- no residue on the target, even at 10 yards. Doh!

How's that gee-tar work going? Doing riffs like Joe Bonamassa yet?

Shooting from barricades isn't my strength. I need more practice if I'm going to play the PRS, NRL, and regional steel match game. Now that the majority of the cattle are no longer grazing on our land, I can set up and leave barricades. Cows have this nasty habit of rubbing up against new structures. And pooping both on and around them.

I put together a test of targets against an old erosion dam. Five of the six plates are visible here, with the sixth one being just out of view to the right. The primary target distances are to the face of the dam, which is the circle on the right and the square next to it.


The diamond on the post is the closest target (#1) and is about 50 yards closer than the dam face. The out-of-view plate to the right (#2) is 25-30 yards closer than the dam. The circle and square (#3 and #4) are within 2 yards of each other in distance. The diamond to the left (#5) is 10-15 yards further than the dam face. The square to the far left (#6) is 35-40 yards further than the dam.

My positions started with prone -- two locations 377 and 355 yards from the dam. Next was a post 340 yards from the dam face. The brown cinder-block-like-thingie is a wood sleeve that fits over the 4x4 post. This raises the shooting position by 11". I have the same setup maybe 200 yards away, in a brushy area just over the top of the right t-post. From this location I shot with either the tripod legs and bags for rear support.


Next was a barricade 320 yards from the dam. I used the either tripod or bags for rear support. The tank trap is just over the top of the barricade.


A tank trap at 300 yards. I used a rear bag support, between my thigh and the buttstock.


Finally, a spool at 305 yards. Shot from the top of the spool.


I dialed the distance for the dam face at each position, then held under and over as I progressed from close to far plates. I calculated the holds from the 377 yard prone position, as I didn't want to carry a huge dope card. Hold unders were 1.5 and .7 MOA, hold overs were .2 and 1 MOA. In theory -- I ended up taking a few extra shots, as the dope didn't always work perfectly from all barricades at all distances.

Wind was interesting. Fishtailing from 5-7 o'clock, at 5-10 mph, varying constantly. I loaded 60 rounds of 69 SMK in mags, shot first with a 24" RRA with a 3-15x scope, then switched to a 14" LWRC with a 2-10x optic. Hit to move on, I finished the course of 36 targets in about 55 rounds with both ARs, then burned the remaining rounds at longer plates from the spool.

I think this will be good practice for future matches.

My target tests at 320 and 440 yards has proven valuable in determining the best ammo for each AR15. I had incomplete data on the 24" DSC barrel with a RRA receiver, so later in the day...

Winds changed later in the afternoon -- finishing at 0-7 mph from 8-10 o'clock.

Hornady 73 ELM had promise, but was a bit variable. The first group at 320 showed vertical stringing, as I often see in transitioning to ELD from other ammo. The first group of five was 3.5", the second one settled down to 1.75". At 440 yards the vertical was 3-1/8".

ADI 69 SMK is just pretty consistent, but generally a slight step down from FGMM. 320 yard verticals of 1-7/8" and 2". At 440 yards it was 3-3/8".

FGMM 69 just works. 320 yard verticals of 2-1/2" and 2-1/4". At 440 yards it was 2-3/8", as follows:


With a few minutes of daylight left, time for Hornady 75 Black. I rushed the first group at 320 yards -- ruhroh -- so we won't discuss it. Still in a hurry, I put 4 rounds in 1-3/8" and was all proud of myself, then yanked a high round for 2-5/8" total for five rounds. OK, time to settle down. With the sun about to set, at 440 yards I dialed a bit too much elevation, tried not to be an idiot, and got the following 1-7/8" vertical group.


If this continues, I probably will reduce my ammo inventory to Hornady 75 Black and FGMM 69.

Given the valuable knowledge gained vertical accuracy testing I did on four of the uppers, I kept it going with my 18" Bartlein -- of course now with the new PRS stock. Winds that day were generally 3-6 mph, with gusts to 8 or 9, switching from 12 to 2 o'clock. A nice day to shoot, but I suspect that morning ranch duties of cutting up downed trees and hauling off the branches didn't help my shooting technique in the afternoon. I also started the practice of jogging out and back to the targets between ammo types -- for measuring results and repainting the steel. As before, measurements are vertical variation only, as wind drift is a whole different matter.

First factory ammo up was ADI (Aussie Outback) in SMK 69. At 320 yards 5-round vertical impact variations were 2-7/8" and 4-1/4". At 440 yards, 3-5/8" and 3-7/8". Decent for this round, but not spectacular. A preview of my day occurred with the first group at 320 yards. Rounds #1 through #4 were 1-3/8" vertical, I got all happy, then yanked #5 low. Cursing, I put round #6 within the area of #1-4. So....unless the winds were funky, round #5 was funky....I yanked the shot. I normally yank high, so low is a new one.

FGMM 69. At 320 yards, 2" and 4-1/4". Dagnabbit, low flyer with round #5 again, putting round #6 with the others. Without the yank the group had 2-7/8" vertical. At 440 yards 2-3/8", 2-3/8", and 3-3/4" verticals.

Hornady 55 Vmax. At 320 yards, 2" and 3". At 440 yards, 3-7/8" and 4-1/4". Not bad. Wind tosses the light bullet however.

Hornady 75 HPBT Match. At 320 yards, 3-3/8" and 5". Crap, low flyer-itis on the fifth rounds. Taking a 6th shot and ignoring sheep-dip shot #5 -- 1-3/8" and 2-1/2". At 440 yards, 5". Taking a 6th shot and ignoring the low flyer on #5 -- 2-1/2" vertical. The ammo works, I didn't that day.

Hornady 75 Black. At 320 yards, 1-1/4" and 3". Another low flyer on the fifth round of the second group, without it vertical of 1-1/4". At 440 yards, 3-3/4" vertical. Again low shot #5, take shot #6, and five rounds in 1-3/4" vertical.

Hornady 73 ELDM. At 320 yards, 2-1/8" and 2-3/4". At 440 yards 4-1/8" and 4-1/4" verticals. No ugly fliers on shot #5 this time. Maybe I'm just tired at sunset, after running a chainsaw and jogging to the targets.

Bottom line -- this is a good barrel. As I saw with 100-yard targets, FGMM 69 is the most accurate round. However as distances increase and winds come into play, Hornady 75 Black is the competition round. Frustrating that I couldn't maintain focus on technique.

quote:

Originally posted by fritz:
As before, measurements are vertical variation only, as wind drift is a whole different matter.

Are you concerned about the effect of “aerodynamic jump” on vertical dispersion in windy conditions?

quote:

Originally posted by sigfreund:

quote:

Originally posted by fritz:
As before, measurements are vertical variation only, as wind drift is a whole different matter.

Are you concerned about the effect of “aerodynamic jump” on vertical dispersion in windy conditions?

Absolutely.
Wind conditions where I shoot can be challenging. I generally shoot downhill, along a couple of shallow drainages. Elevation drop from shooting positions to targets are usually in the 50-70 foot ballpark. When I go beyond 1000 yards, 80-100 foot drops are the norm. Berms are taller to my left (north), with the land flatter to my right (south). Behind me (uphill and to the west) is a substantial forest of tall pine trees. To the east (downrange) is miles of open and rolling prairie. A large wind farm is just a few miles away.

I am beginning to understand the effects of wind when it blows from relatively consistent locations and relatively constant levels. Twitching directions and variable speeds can give me fits. I often see wind directions change 150 to 180 degrees over the course an afternoon's 3-5 hours of shooting.

On some days I'm just clueless why some shots land high or low -- especially when I know I broke those shots correctly. As in when the reticle just doesn't move off the point of aim during the recoil cycle. I have much to learn.

Now on to the 20" Krieger barrel rifle, with SI Defense receivers. This is the AR I've used in Team Safari, with offgrid being the bolt action shooter. I consider this my most consistently accurate rifle, especially at distance.

The day was chilly. Winds cycling 2-10mph, fishtailing between my 4 and 8 o'clock.

First up, ADI 69 SMK ammo. At 320 yards, verticals of 2-1/4" and 2-1/2". At 440 yards, 2-1/2".

FGMM 69. At 320 yards, 1-5/8" and 1-3/4". At 440 yards, 1-3/8" and 2-1/4". Stepping back to 492 yards, vertical of 2-1/2". FGMM 69 never disapoints with this rifle.

Hornady 73 ELD, what I've used in prior matches. ELD often takes a few rounds down the pipe to shoot consistent groups. This day was no different. At 320 yards, 4-1/2" pattern for the first group on the right circle, 1-5/8" group for the diamond on the left.


At 440 yards. First group in the center target at 3-1/2" vertical, when winds were bouncing around. Second group on the right was 3", with the wind more consistent. Third group on the left, 2" vertical, with total group size of 2-3/8". Realizing that the wind laid down a bit more, this group was shot in no more than 15 seconds.

At 492 yards the vertical was 3-3/4".

Hornady 75 Black, evaluating for future matches. Switching away from 73 ELD often causes a few rounds of accuracy issues, and it occurred here. At 320 yards, first group of 4-5/8" on the left. Second group of 1-1/2" vertical on the right.


At 440 yards, 3-3/4" for the center plate. The wind died for the plate on the right -- I held center of target, fired off 5 rounds in no more than 10 seconds for a 2-3/8" vertical group.

One group at 492 yards was 5-1/4", with winds bouncing all around.

I also shot Hornady 55 Vmax at all distances. Generally a little over 1 MOA of vertical, with a boat load of horizontal from faster and more variable winds.

Bottom line -- FGMM 69 probably has the best accuracy. Hornady 73 will continue as my match round, as it bucks the wind pretty well at distance. Hornady 75 Black offers a good option, in case I want to reduce the types of ammo I inventory -- by eliminating Hornady 73ELD

Nice shooting. Tnx.

Based on another local competitor's success with using an SBR in a regional 2-rifle match, offgrid and I went down the path of 223 SBR uppers. Wilson Combat had holiday sales on barrels. I bought a few -- the new SBR, plus down-the-road replacements for my carbines. Offgrid also bought an SBR barrel, likely based on my success with Wilson products.

Offgrid wasn't pleased when his Wilson barrel arrived. The barrel extension measured .996" O.D. IIRC, which would produce a lot a slop with a 1.000" I.D. upper receiver. He sent the barrel back to Wilson for a refund. Offgrid went down a different path, using a custom barrel shop, which produces barrel extensions measuring .999" IIRC. Definitely a tighter fit.

My Wilson 14.5" barrel measured .998" O.D. and thus there was a fair amount of slop in my 1.000" I.D. upper. But I found this is within spec. Hmmmm, not so happy. My gunsmith wasn't overly thrilled about the slop, either. But we decided to move forward with the build. My 'smith considered using some .0005" shims to tighten the fit, but went with his tried-n-true use of red locktite. On to accuracy testing to see if this works...

Initial break-in and zeroing with American Eagle 55 FMJ was promising, especially considering how FMJ generally shoots like crap. But my accuracy with factory varmint and match ammo was just OK -- 5-round groups of .8" to 1.2" at 100 yards. Although I was fighting winds from my left, most of the group-size variation was vertical stringing. Which generally points to crappy technique on my part. Maybe it wasn't such a good idea to run a chainsaw all morning, then shoot in the afternoon.

But then I started hitting my stride with Hornady 75 Black ammo, producing a group of .66". Game on, going to longer distances on steel. Winds now 8-12mph, fishtailing from my 5-7 o'clock, on 12" plates.

320 yards. 1st group on the right -- 3" vertical, 3.5" horizontal. 2nd group on the left -- 2" vertical, 1.5" horizontal.


340 yards -- 1.75" vertical and 2.5" horizontal.


300 yards -- 1.75" vertical and 3.5" horizontal.


Time will tell, but so far with about 100 rounds through the tube, the less-than-ideal barrel to receiver doesn't seem to be too much of an issue.

During the holiday sales I bought another Nightforce 7-35x ATACR. This one goes on my 308, which ripples into scope changes on 3 other rifles. Office work load kept me from installing the 7-35x until a couple of days ago. Ongoing snowfall at our family ranch is making for less than ideal shooting conditions, but I needed some trigger time.

My basement bore sighting wasn't perfect, but I was on paper at 100 yards in 2 rounds, and zeroed in 3 rounds. It took a couple more 3-round groups to confirm the zero stop was set where I wanted.

This rifle's barrel has a little over 5k rounds, and is getting a little long in the tooth. Still shoots fine, however. The first 3-round group at 100 yards measured .54" and the second one .37". OK, on to a longer target. Unfortunately the snow, mud, and limited terrain resulted in only one sort-of long-range opportunity -- a paper target at 537 yards.

I put an 8" shoot-n-see paster on a re-purposed coroplast political ad sign. I forgot to bring elevation dope info for FGMM 168, so I guessed from dope for my 24" barrel AR15 with 75-grain ammo.

Pretty cool -- I guessed only 1/4 MOA low. Winds were 5-10 mph from 11 o'clock. My first 3 rounds were pretty much right on top of each other, with only 1.2" of vertical dispersion. Woo-hoo, and the ATACR scope made seeing the impacts easy.

Then things went south. Shot #4 hit just below the 16" square coroplast backer. WTF. Shot #5 hit the base of the coroplast, severely bending the sign's support wire. Crap -- time to slog out to the target, with pliers to repair the wire and another paster.

I hit the new paster only twice with five rounds, with shots going way high and low. Crap. Five more rounds of FGMM 175, with the same results. I checked the rings to see if they were loose. The rings were nice and tight, but the 20 MOA base was really loose to the receiver. I could move the base a good 1/8" in all directions. The screws holding the base to the receiver were obviously loose.

Craptastic. I should have checked the base's screws when I mounted the new scope.

The scope ripple continues. My Wilson Combat 16" AR15 received a older Nightforce F1 3.5-15x NSX, replacing a NF 2.5-10x. Zeroing at 100 yards was quick, IIRC 7 or 8 rounds. Winds were interesting that day -- 5-15 mph from my 3 o'clock, varying constantly, but generally staying within a 5 mph range for a few minutes at a time.

This barrel does well with factory Hornady 75 grain HPBT Black. The first 5-round group at 100 yards measured 1.0" and the second one measured .78". OK, time to confirm at distance.

The following plate shows 5 rounds at 410 yards. Point of impact is a little low, so I'm guessing I got in a rush and dialed for only 400 yards. But the results were good -- 1-1/4" vertical and 4-3/8" horizontal variation. Wind drift per JBM was 1.4" per MPH of wind.



I'll take .3 MOA vertical, especially in crosswinds.
More in later posts, for the AR10s that received better glass.

Here's a Black Rain Ordnance AR10, chambered in 6.5 Creedmoor. During the ongoing panics of the Obummer years, it took some two years to acquire all the components at reasonable prices. Black Rain for receiver set, BCG, handguard. Wilson Combat trigger, Krieger barrel. Once assembled, it sat idle for most of another couple years due to lack of a proper scope. It now sports a NF ATACR 5-25x.


Sighting was quick and easy, as the scope from the factory was close to being bore sighted in. My time constraints were a bit tight. I shot only one group of five at 100 yards, after confirming the scope was zeroed and the zero stop was set as I prefer. With Hornady 140 ELD the group was just barely over 1", mainly due vertical stringing. AKA, due to me. OK, so I wasn't warmed up yet, and I wasn't accustomed to the recoil of an AR10. Compared to an AR15, an AR10's recoil is noticeably heavier and lasts longer -- there's a whole lot more steel and gas moving around in the rifle.

On to steel at 412 yards, hopefully with better shooting fundamentals. I shot one group of five, with vertical of 1-3/4" and horizontal variation of 4-1/2". Winds were cycling 10-15mph from my right. I'll take vertical of just over .4 MOA, and I packed up the 6.5CM upper.

Here's the new 6 Creedmoor upper on the existing Black Rain lower. Black Rain upper, BCG, and rail. Bartlein/Craddock Precision barrel and ATACR 5-25.


I broke in the barrel by cleaning every third round, until it had 15 rounds. No copper fouling, and carbon fouling dropped off noticeably after the 6th round. I shot a mix of factory Hornady 105 HPBT Black and 108 ELD, initially at 100 yards to sight in and set the zero stop.
- 105 Black showed slightly better vertical accuracy from the start, although 108 ELD was no slouch

- The barrel has no problem switching from 108 ELD to 105 Black, but it doesn't care much for switching from 105 Black to 108 ELD. I've seen this before in other calibers. The ELD bullets can be picky about fouling. It took 4-5 shots with the ELDs before they settled down. Which means I must pick one round and stay with it.

On to longer distances, which was 340 yards for the first day. Winds were constantly varying 5-15mph, from my 4-7 o'clock. Even at such a short distance of 340 yards, the wind was enough to mess with consistency.

I started with the 105 Black ammo. 5-round groups with verticals of 2" and 2-1/8"; horizontals of 4-3/4" and 3-3/4" respectively. POI was a little lower than I expected.

On to 108 ELD. The first group was 3-1/4" vertical and 5-1/4" horizontal -- square plate. Ugh. Second group was 1-5/8" vertical and 2-1/4" horizontal -- diamond plate. Yep, here's the fouling issue.


Time to pack up, go home, and give the barrel a good cleaning. Which resulted in no evidence of copper, and pretty quick removal of carbon.

Day 2 with the 6CM upper, trying to get a feel for the 105 Black vs. 108 ELD ammo. At this time I didn't have enough rounds down the barrel to obtain stable muzzle velocities. But I noticed that the 105s aren't flying as fast as the 108s, and that the 108 ELDs buck winds better.

I started with a 5-round group of 108 ELD at 100 yards to confirm zero was still good. Yeehaw, .73" total size, with vertical of just .52". This barrel shoots. At 412 yards the group was 2-3/4" vertical and 3-1/8" horizontal. On to 525 yards, with vertical of 2-3/8" and horizontal of 4". Woohoo, I'll take that in 6-16mph winds from my 3 o'clock.


Back to 412 yards with the 105 Black ammo. Vertical variation of 2-1/4" and horizontal of 2-3/4" Nice, but the POI was 3/4 MOA lower than the 108 ELD. On to 525 yards, but with only 6 rounds left of 105 Black ammo. I dialed up 1.5 MOA more than the 108 ELD, but it still wasn't quite enough. Winds were brutal, too. I landed only 3 of the 6 rounds on the plate, with the misses seemingly on the exact same elevation of the impacts. The three hits had only 1-1/2" of vertical variation, but a whopping 8" of horizontal.

I definitely will be using 108 ELD ammo in this upper.

There was noticeably less recoil from the 6CM ammo than the 6.5CM ammo. It was easier to keep the rifle on target during the recoil cycle. It sure seemed that the 6CM loads impacted the target sooner than the 6.5CM ammo. I suspect the 6CM ELD ammo is about 300 fps faster. There is noticeably less movement of the steel targets with the 6CM loads. An edge hit with 6.5CM spins the plates hard -- not so much with 6CM.

My 6CM upper will experience low round counts per match -- likely only in team events where the carbine shooter isn't limited to 223 Remy. I like this Black Rain AR10 pair.

Consider shooting the 6CM at the Steel Safari?

quote:

Originally posted by offgrid:
Consider shooting the 6CM at the Steel Safari?

I think that it could be good for both Steel Safari and Team Safari. Maybe better for Team Safari.

I need more time with the 6CM first. I must obtain good MV and be comfy with the elevation and windage of the 108 ELD. I also need to be certain I can control the additional recoil of the 6CM from a tripod -- as compared to that of the 73 ELD 223 Remy that I've used in prior Team Safaris.

I shot the 14.5" Wilson Combat upper recently -- the upper with the originally sloppy barrel-to-receiver fit. My 'smith liberally used loctite to fill the .002" gap. This upper will forever be known as the "loctite upper". This time I measured MV of a few loads, while shooting at steel at 450 yards. ARs just look a little goofy with a Magnetspeed clamped to a suppressor.

In variable crosswinds of 3-12 mph from 2-3 o'clock, most of my factory ammo held .8 to .9 MOA vertical. That works for this upper's purpose.

The star performer was Hornady 75 Black, which makes sense given its earlier performance at 300-ish yards. The first 5 rounds were the upper group, which occurred after shooting 2 groups with FGMM 69. IIRC, I held 2 MOA off the right edge of the plate, 1 MOA below shoulder line. Rounds 1&2 were low, as often happens after an ammo switch. Rounds 3-5 were stacked on top of each other.

For the lower group, I held 1 off the right edge and 2 MOA above the plate's bottom. 1.5" vertical and 2.25" horizontal. Woohoo, 1/3 MOA.


I have a couple of boxes left of Federal 53 Vmax. I had never tested MV, and I under estimated how well the rounds fly. For the first group I held 2 MOA right of the shoulder line and 1 MOA below. Oops, POA is higher -- 5 hits in the head area, with 2.25" vertical.

For the second group I held the same, but dialed elevation down 2-ish MOA. The 5 rounds near the middle, with 2" vertical variation.

The third group was held 3 MOA right of the edge, and 2 MOA up from the bottom. Totally jazzed with how the groups were going, I got slap happy and yanked shot #5 low. Doh! Which took a group with 2" vertical to one with 5" vertical.


I doubt that I will buy anymore Fed 53 Vmax, but it's interesting to know that it flies well.
Mongo like loctite.

Thanks for the update. Good to read something here that's related to guns and shooting.