Jump to content
308AR.com Community
  • Visit Aero Precision
  • Visit Brownells
  • Visit EuroOptic
  • Visit Site
  • Visit Beachin Tactical
  • Visit Rainier Arms
  • Visit Ballistic Advantage
  • Visit Palmetto State Armory
  • Visit Cabelas
  • Visit Sportsmans Guide

98's 6mm ARC


98Z5V

Recommended Posts

On 8/3/2020 at 3:24 PM, DNP said:

I’ve been looking at cameras again. I think you’re gonna seen 400 minimum for a setup that works. Prices are down from what they were last year....I bet @Lane could whip something up....just sayin. 

I looked at the options briefly; for assembling something from off the shelf parts. Unfortunately I don't have a good way to test something like this here. I have at best 200-300 yards of semi-line-of-sight available. I might be able to test something at a park though; there are places I can get a better line of sight distance. The biggest issue I see is that there are some high angle shooting setups; that might require an antenna adjustment. Usually; to get that kind of distance you're talking about a directional antenna, which would need to be angled up towards the shooting/viewing station. 

Anyway; I've seen some WiFi units that advertise a 7 mile range line of sight (12,320 yards). I can't guarantee a cell phone would be enough on the receiving end; one might need two long range units to work reliably at extreme distance. That said; I'm guessing 800 yards wouldn't be a big deal at all. I've seen those long range units for about $20. That would still need a small computer, power source, and camera. I'd guess about $100 would make a pretty functional build.

On the other hand; it might be a LOT easier to just put a cell phone in a plastic ammo can. Most of them have reasonably high resolution rear facing cameras. One simply needs to serve that video up somewhere; and probably add an external battery. Beyond that; just don't shoot the target camera.

Link to comment
Share on other sites

  • Replies 581
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

5 hours ago, Lane said:

Beyond that; just don't shoot the target camera.

That right there may be the biggest issue with this group. We all have heard the t-post story so a camera should be an even easier target. :thefinger: It would suck to spend 500 bucks on a target camera to have it blown to hell first time out.

Edited by Radioactive
Auto correct again
Link to comment
Share on other sites

13 hours ago, Swiftab said:

Gun is ready to fire

 

6.5 Grendel to 6mm ARC. Cases form very easily. Bumping the shoulder back adds a small dimple. I am sure this will fire-form right out. On to load some up. 

 

 

Watch your OD at the neck, as well.  I ran into this necking down Hornady .308 Win Match brass for .260 Rem.  The ID of the neck is always right - because of the die.  That brass has to go somewhere, and it's left in the OD of the neck.  I have to trim the necks on my .260 makings, or they won't chamber.  If I'd force them to chamber- they'd be stuck cases.

Check the drawings on 6 ARC, at the neck OD - and compare it to your formed case neck OD - 0.002" can screw you, royally. 

Just what I've seen, necking down cartridges. 

Link to comment
Share on other sites

20 hours ago, Swiftab said:

Gun is ready to fire

 

6.5 Grendel to 6mm ARC. Cases form very easily. Bumping the shoulder back adds a small dimple. I am sure this will fire-form right out. On to load some up. 

 

EDA8FF5A-C6B4-42A2-A68B-1FE869070A03.jpeg

2C1B8FEC-3523-4F63-9797-415ED3CD43D3.jpeg

I think if you try the imperial sizing die wax you will not get those dimples. Lanolin from the drug store will work nearly as good if not as good.

Link to comment
Share on other sites

15 hours ago, Swiftab said:

Thank you!  I checked the necks. Th drawing shows .274  I finished up some dummy rounds to check over and chamber. My necks are at .270.  The rounds chamber without any assistance and are not scratched up.

ps, I like how you warn of potential issues and not say after “oh yeah, that happened to me too”  I really do enjoy this forum 

Hey, I learned it the hard way, and screwed up some of my initial pieces of Hornady .308 Win Match brass-to- .260 Rem Match brass - before I discovered what was up.  That's a pretty big neck-down size jump, from .308 to .264 - it mattered, big time, in my case.  Reloading Lesson Learned, for me. The jump from .264 down to .243 isn't as severe - but it's something I didn't want to happen to you when you try to fire this beast.  It's a let-down, when it happens, and you start questioning everything you did, until you FIND it. 

It was just a heads-up.  Didn't want you to hate the caliber, or torture yourself on "what did I fuk up here?!"...  Always check that when necking down a caliber.  It sucked for me to learn, man...   I was MAD!...   As Fuk!...

:laffs:

Fire-forming these case will be mandatory.  Don't use the initial cases to work up a badass handload - they'll be a little different once they're fire-formed, and shot through your own chamber.  Learned that on the .260 Rem, too.  And .300BLK brass that I made from 5.56 brass.  For those brand new cases, just load up something that will go BANG!, and make real brass.  After they've been fire-formed, it's time to use them for the real load-up.  :thumbup:

Edited by 98Z5V
Link to comment
Share on other sites

1 minute ago, 98Z5V said:

.224 Valk gutted, rebarreled as a 6 ARC gun.  This is tomorrow morning's shooting platform:

P1080824.thumb.JPG.b43b7290802d4c435b4fac3a72a5025d.JPG

Click it- it gets bigger...   :thumbup:

Setting up the MagnetoSpeed now... 

I know that’s not the LaRue you want it to be, but still a damn fine looking rifle sir. If it wasn’t a 12 hour ride, I’d be there in a heartbeat to help break the fuker in.

I think Monday I’m gonna have to start shaking the tree over at LaRue and Brownells. I ordered that rail well over a month ago, still haven’t heard shitt out of them. Barrel is not too far behind that, probably 3 weeks or more now. Everything else is here, I’m ready to build a god damn rifle!

Link to comment
Share on other sites

3 minutes ago, DayWalker said:

I know that’s not the LaRue you want it to be, but still a damn fine looking rifle sir. If it wasn’t a 12 hour ride, I’d be there in a heartbeat to help break the fuker in.

 

I'd hand you the loaded mag, and let you rip the first rounds, brother.  Seriously.  :thumbup:

Link to comment
Share on other sites

12 minutes ago, 98Z5V said:

I'd hand you the loaded mag, and let you rip the first rounds, brother.  Seriously.  :thumbup:

I appreciate that brother, but I couldn’t take that honor away from you. Rip that fuker up in the AM for me. Can’t wait to pit the 6s against each other this fall, should be a great time. 

Link to comment
Share on other sites

In the interest of Full Disclosure, I fucked my own .224 Valk up, and pretty bad, too.

I never noticed this when I built it.  I DAMN SURE noticed it when I swapped the 6 ARC barrel tonight, though.  What i found probably trashed all my .224 Valk data- I'm positive it did, it was that bad...

I built the .224 Valk and put a MagPul M-Lok rail section on the bottom of the handguard, so I could run a KAC vertical foregrip.  My military love for those will never end.  They'll live on every combat-type rifle I ever build.

This piece right here, in red, the rail section:

889646101_Valkmistake.thumb.jpg.54bfda1b1df5b69ea5e1c06232068c19.jpg

So, I ripped the Valk apart to get this gun going, and when I'm putting it back together with the 6 ARC barrel - I noticed that the screws for that MagPul M-Lok rail section contacted the barrel on the new 6 ARC barrel... Hmmm. THAT needs to change!  I dremeled those bastards down short, so they would NOT contact the barrel, and I was successful. No contact and plenty of gap, so they'll NEVER touch the barrel.

So, I dug out the .224 Valk barrel - now, bot these barrels are the Ballistic Advantage 18" SPR profile barrels - apples and apples, for @sketch.  I grabbed up that .224 Valk barrel to look at it - sure enough - two screw marks on the bottom of the barrel, RIGHT where that pic rail was attached.  I fucked my OWN self, not catching that before.  :bitchslap:

ALL of my Valk accuracy data that I previously did is compromised.  It's bullshiit. I'm lucky I even hit a target with that bastard in the first place, with those screws hitting the bottom of that swet-ass BA Mk12 barrel.  ALL of my Valk data is shiit now. 

Guess it's time to start over with the Valk, eh?...  :popcorn:  Maybe it'll perform this time?  I definitely think it'll do better now, knowing what I found, and figuring out a MAJOR building mistake...  :thumbup:

Eff that Valk though, that thing is on the backburner. :thefinger:

Edited by 98Z5V
Link to comment
Share on other sites

I too love the look of the KAC grips. Eventually I want to track down a KAC rail and grip for my m16A4 clone I’ve been slowly working on.
 

I can’t believe the screws were long enough on that Mlok rail section to actually contact the barrel. You’d think the rail would have had enough depth they couldn’t reach the barrel, but obviously not. Definitely defeats the purpose of a free float barrel either way. 
 

On a different note for tomorrow morning, assuming you see this before then. Try out a standard Pmag with the 6mm, I’ve heard rumors they will feed fine. I’d love to not have to buy Grendel mags for mine. 

Link to comment
Share on other sites

49 minutes ago, DayWalker said:

I too love the look of the KAC grips. Eventually I want to track down a KAC rail and grip for my m16A4 clone I’ve been slowly working on.
 

I can’t believe the screws were long enough on that Mlok rail section to actually contact the barrel. You’d think the rail would have had enough depth they couldn’t reach the barrel, but obviously not. Definitely defeats the purpose of a free float barrel either way. 
 

On a different note for tomorrow morning, assuming you see this before then. Try out a standard Pmag with the 6mm, I’ve heard rumors they will feed fine. I’d love to not have to buy Grendel mags for mine. 

MagPul screw-wise - they might not have known that is was going on a BA SPR barrel, with a slim-ass Aero handguard - no way they're gonna know that.  I don't blame MagPul - I blame my dumbass self for not seeing that one when it originally happened...  :bitchslap:  Didn't even catch it. 

Caught it the second time, though...  Fuckin' Dummy... 

I'll risk a standard P-Mag, try it out.  They don't do well for Grendels, so I don't think they'll do well on the 6 ARC. I'll give it a shot, though.  I'll try a 20 and a 30 and see what happens.  I have 200 round of factory match ammo to burn down, so I can have 200 pieces of Hornady Match brass to reload...   :thumbup:

Link to comment
Share on other sites

57 minutes ago, DayWalker said:

Eventually I want to track down a KAC rail and grip for my m16A4 clone I’ve been slowly working on.
 

I really hate to bring this up...  but are you talking about THIS KAC rail for the M16A4?...   :popcorn:

https://forum.308ar.com/uploads/monthly_2020_01/P1080457.JPG.cb4f5d1537fabc7a03103c999e6d4775.JPG

 

 

Link to comment
Share on other sites

32 minutes ago, 98Z5V said:

I really hate to bring this up...  but are you talking about THIS KAC rail for the M16A4?...   :popcorn:

https://forum.308ar.com/uploads/monthly_2020_01/P1080457.JPG.cb4f5d1537fabc7a03103c999e6d4775.JPG

 

 

Why yes, that would be the KAC rail in question :drool: I don’t know what it is about those KAC rails I like so much, but damn it I want one. They’re expensive, and not free floated, and I don’t care, just love the look. Probably the fact they’ve been the go to for the military for so long. 
 

20 inch ARs are just fun to play with, in my opinion. That a4ish beater I built for the desert last year ended up being the one I put the most rounds thru. They’re just easy to shoot and super smooth. With the PA 2.5x scope I put on it, it was effortless to just sit and tag targets all day in camp. It’s also nice to have the extra velocity from the 20 in wide open areas.
 

I’m seriously debating building an M16A1 clone after I finish the MK12. They’re lightweight and just fun to play with. Also I’d like to do it properly, 1-12 twist like the originals. Most of what I run is M193 anyway, might as well have the proper twist for that bullet and maximize its power. 

Link to comment
Share on other sites

Alright, I'm impressed.  VERY impressed!!!   DAMN, THIS THING SHOOTS!!! 

Put out paper at 100 and steel at 100 and 500.  The 500 today turned out to be 482 yards, based on where we set the canopies up when we got there.  Didn't concern me too much, though.

Weather data:   Got up this morning and packed the truck at 0630 - it was a pleasant 80*, which was surprising.  Got out there about 0715 and started setup.  It was about 0800 once we were ready to shoot.  Installed the MagnetoSpeed on the barrel, and then gathered my weather data from the Kestrel.  95*, 44% humidity, dew point 66*,29.68 in/hg pressure, 1405 feet of elevation, density altitude 4360 feet.  Dirt Bike Tommy was already out there when I got there...  

Didn't take long to get a new zero on the scope, on paper,  and I went through the mag, gathering the speeds.  16 rounds.   At 0925 it was 101*, first three shots out of the gun were 2660, 2666, 2664 fps.  SD was 3.4.   4 more rounds were 2678, 2665, 2657, and 2676 fps.  Across all 7 shots, SD was 7.7...

!!!   WOW!!! 

I pulled the MagnetoSpeed off, made sure the zero was good with it off, and moved over to the steel at 100. 

First shot, dead-ass center of the plate.   I just laughed...   :laffs: So, I put 7 in the head, and gave him a smily face...   :lmao:

P1080825.thumb.JPG.076fd231c80013e3ee52e6c5d3d52bfc.JPG

P1080826-1.jpg.b0603b4e4f7aa821c6cef101204f4137.jpg

Okay, I'm happy.  Time to move it over to the 500 yard target - the 482...  I consulted my 18" Grendel chart, and 500 is 3.4 mils of drop. 

I looked at Tommy, and said, "We're gonna try 2.5 mils, just to see what happens..." He laughed, and spotted for me through binos.  Slight left-fo-right wind, maybe 4 or 5 mph.  I held left edge, and HIT THAT BASTARD.  First impact was inside the white square, lower left corner.  I gave it one more click, to 2.6 mils, and sent two more.  All are on the left edge of the white square, below:

P1080828.thumb.JPG.5e37443baeba7f8a748676bf38628295.JPG

Shocking, to say the least.  Didn't even have 40 rounds through it yet!  I turned the rest of the mag over to Tommy, and let him play with it.

This is a pretty unreal little cartridge, men.  I'm not joking.  I suspected it was gonna be good, but I didn't think it was gonna turn out THIS good!

Hot DAMN!!!   :banana:

Edited by 98Z5V
Link to comment
Share on other sites

1 hour ago, 98Z5V said:

Hot DAMN!!!   :banana:

Fantastic. Fuking Fantastic! This is everything I wanted to hear on this. Also, love the smiley face on the steel, that’s a nice touch. You’re welcome by the way, for all but forcing you to build one :thefinger: :lmao:

Did you try feeding it with a regular 5.56 mag? Or just the Grendels?

Link to comment
Share on other sites

14 minutes ago, DayWalker said:

Fantastic. Fuking Fantastic! This is everything I wanted to hear on this. Also, love the smiley face on the steel, that’s a nice touch. You’re welcome by the way, for all but forcing you to build one :thefinger: :lmao:

Did you try feeding it with a regular 5.56 mag? Or just the Grendels?

Only thing I had with me was the Grendel mags - I completely forgot to take a PMag with me.  I'll hit it again next weekend, because this thing is going over to the 850.  With the data I got today, I'll make up a chart tonight for it.  I gotta hit that thing at 850 and confirm the chart.   Only shot 50 rounds today - enough to load up some ladders and get busy. 

2.6 mils at 482 yards - just blew me away, brother.  That was nuts...  

Edited by 98Z5V
Link to comment
Share on other sites

6 hours ago, Radioactive said:

 44% humidity surprised me.

Supposed to be heading into monsoon season - even though it has barely rained here, like zilch.  It's a little humid in the mornings, but as soon as the heat comes out, it's gone.  By 0925 it was already 101* and 22% humidity. 

Link to comment
Share on other sites

This will work right now for a Drop Chart.  I'll verify the 850 next Sunday.  This is pretty damn close.  My input data is correct, but it was a little hotter out once I went after that 500/482.

Keep clicking it -it gets bigger.  I think it's 3 clicks, total, and you get the large, readable version.

Pretty damned impressive for an 18" gun.  

119617168_6ARCHornadyMatch108ELD-M2666fpsHEATData.thumb.png.3337a1b13bde61b66e5e655cc9378609.png

Edited by 98Z5V
Link to comment
Share on other sites

This is all good news - this is gonna be a great cartridge.   I'll consider making a 12.5" pistol out of one - but there are no barrels like that out there right now.

8 hours ago, Swiftab said:

Reloads were 108 Hornady ELD, 28.5g of LEVERevolution powder, CCI #41 primers, Brass - Reformed 6.5 Grendel

Any idea on the speeds of those ones?

Hornady is listing 28.1 grains of Accurate 2520 as their max load for that powder, giving that one 2500fps from an 18" barrel.  I'll be taking that one north of their max, I can see that now.  Testing, testing, testing. They don't even list a powder that will give me the 2666fps that I got yesterday, and all their load data is 18" load data.  I'm thinking I'll rip one of these Match rounds apart and see what's going on inside...   :popcorn:

Edited by 98Z5V
Link to comment
Share on other sites

Lee shipped my Factory Crimp Die for this beast today, even though the website says it's still "out of stock, backorder yours today."  Don't be afraid to order one, reloaders.  :thumbup:

Wasn't supposed to available for a few more days, website says the 14th.  

https://leeprecision.com/factory-crimp-die-6mm-arc.html

Edited by 98Z5V
Link to comment
Share on other sites

Plan right now stays the same, shoot 850 and determine drop at that distance, this coming Sunday, 16 Aug.   My Lee crimp die shows up Monday, 17 Aug, so I'll get 50 test loads made up, and shoot those the following Sunday, 23 Aug.  Hopefully, by the time I shoot those first handloads, I'll have some fancy LaRue parts on the way, and I can paint a bitch the following weekend after that...   :thumbup:

Bottom line is:  this thing MUST be done, in final form, scope zero'd, handload developed, tested and locked in...   prior to 5 Nov.  That's a must.

We'll see.  This Sunday's plan is locked in, though - it's going on the 850, and I'll have the dope for that up here that afternoon. 

Edited by 98Z5V
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...