New 6mm Advanced Rifle Cartridge

[Gtscotty]

Technically not semi-auto rifle related, but it's good to see that Howa is going to start offering 6mm ARC in most of its Mini line in '22.

New 2022 catalog out:

https://www.legacysports.com/wp-content/uploads/2022/01/2022_LSI_Catalog_LQ.pdf

 

[Shawn1492]

Hmm. I do like Howas.

 

[jLorenzo]

About a year in the making, finally got out to shoot my 6 ARC build this past Monday. Only ran 40 rds of factory Hornady 108 ELDM through it, but it performed flawlessly and looks to be a keeper. Groups are about 25 rds in and after being cleaned.

Upper
Aero Precision M4E1 upper squared by DTech
Shilen Match Grade 20", medium contour, rifle length gas, fluted, threaded. Built and headspaced to my Aero Precision bolt by DTech
SLR Ion Lite 13.7" Handguard
Aero Precision Gas block, low profile, .875", black nitride
BCM Ambi 3x3 Large Charge handle
Aero Precision Bolt Carrier Group
Seekins MXM 34mm scope mount
Burris XTRII 4-20x 50mm, 34mm tube
Lower
Aero Precision M4E1 Lower
Triggertech AR Adjustable
Aero Precision Enhance Carbine Buffer Tube with H2 Buffer and JP Spring
Ergo Tactical Grip
Luth-AR MBA-3 Carbine Stock

First round clean bore flier

That thing is sweet.

 

[yotesniper66]

That thing is sweet.

Thanks

 

[SMTGWKD]

Which of these long bullets can be loaded to magazine length for an AR?

Thinking of seeing what the max BC bullets will do in the ARC:

Nosler 105 or 115 RDF (.571/.634)
Hornady ATip 110 (.604)
Berger 109 Hybrid (.568)
Sierra 110 TMK (.617)
Barnes 112 MB (.624)

Any others?

 

[trdjohn]

barnes 112 match burners

 

[SMTGWKD]

Thanks! Those will fit loaded to mag length?

 

[LongRangeAggie]

Which of these long bullets can be loaded to magazine length for an AR?

Thinking of seeing what the max BC bullets will do in the ARC:

Nosler 105 or 115 RDF (.571/.634)
Hornady ATip 110 (.604)
Berger 109 Hybrid (.568)
Sierra 110 TMK (.617)
Barnes 112 MB (.624)

Any others?

I'm shooting the Berger 108 EH and I can get to approx 0.055" off the lands (SAAMI chamber) at max magazine length.

 

[r.tenorio671]

..finally got out to validate my build and put some handloads down the tube & zero my Arken SH4 Gen2 4-16X50 scope. Tested a ladder of Nosler 70gn VGDN FB's w/8208XBR final load of 30.0gn gave a 3076 FPS average. Wasn't shooting for groups, I use a Chrony Beta Master so I use a constant aiming point to ensure bullets cross the sensors correctly. All the charge weights (28, 28.5, 29, 29.5, 30) were well under a MOA @100yds (lasered). Barrel is a BA 18", RLGS, SLR Sentry 7 AGB, no muzzle device at this time. Starline virgin 6.5G converted (annealed before conversion), CCI 400's, CBOT @1.6415", COAL (avg) @ 2.1215", Duramag & E-Lander mags functioned 100% to include lockback on empty. SLR at 6 clicks out.

...Due the lateness wasn't able to test the other loads, sun angle to low to register properly. More to follow.

 

[LRBuck]

Which of these long bullets can be loaded to magazine length for an AR?

Thinking of seeing what the max BC bullets will do in the ARC:

Nosler 105 or 115 RDF (.571/.634)
Hornady ATip 110 (.604)
Berger 109 Hybrid (.568)
Sierra 110 TMK (.617)
Barnes 112 MB (.624)

Any others?

I have run the Barnes 112s, Berger 108 EHs and 109s at about 2.260. Shoot the Berger 109s primarily with good success out to 1200 over Lever. It about .065” off the lands.

 

[SMTGWKD]

I have run the Barnes 112s, Berger 108 EHs and 109s at about 2.260. Shoot the Berger 109s primarily with good success out to 1200 over Lever. It about .065” off the lands.

Awesome input! Which shot best? Mind sharing your load data via PM? Thanks so much!

Out of curiosity - do you also shoot 6.5 Grendel? I have two rifles in Grendel and am considering selling them since so far my 6mm ARC rifles are more impressive and the two cartridges may be too similar for me to keep and load for both.

 

[LRBuck]

Awesome input! Which shot best? Mind sharing your load data via PM? Thanks so much!

Out of curiosity - do you also shoot 6.5 Grendel? I have two rifles in Grendel and am considering selling them since so far my 6mm ARC rifles are more impressive and the two cartridges may be too similar for me to keep and load for both.

I don’t shoot the Grendel. Went from 224 Valkyrie to the 6mm ARC. I have gotten the 109’s to group as good as .36” on 5 shots and consistently .5 ish if I do my part. Only shot a few groups of the Berger 108 EH and not really dialed in yet but it seems like it will be similar to the 109’s. The Barnes didn’t do so well for me. Couldn’t get them to group consistently under MOA but I also didn’t really invest too much time/components into them either. Tried the Barnes out b/c they were available and I hoped to lower costs a little bit when I was running low on the 109s ... but soon thereafter I found more 109s.

My load under the 109s is 29.5 or 29.6 grains of Lever. I go up to 29.6 when its colder (<50 degrees) Lever is temp sensitive (lots of discussion on Lever early in this thread) and for my set up it seems the 109s are most accurate in the 2690 - 2750 velocity range. Now I use #41 primers.

@2.260 COAL is about .063” off the lands (I was mistaken above). The 109s might be beginning to compress 29.6 grains but I can’t really tell/feel it. Visually, with how deep the bullet sits into the case, it looks to me like it would be beginning to compress.

I am still pretty new to hand loading. No expertise claimed here. So follow the standard warnings of start low work your way up etc. On Hornady’s chart, 29.7 of Lever is max charge in the 108-110 weight bullets for gas guns. But when I used CCI #400s, I did have some cratering and flattened primers. So for my rifle and the 109s, 29.6 might be a bit hot. Hope that helps some. Good luck and let us know how it goes!

 

[SMTGWKD]

I don’t shoot the Grendel. Went from 224 Valkyrie to the 6mm ARC. I have gotten the 109’s to group as good as .36” on 5 shots and consistently .5 ish if I do my part. Only shot a few groups of the Berger 108 EH and not really dialed in yet but it seems like it will be similar to the 109’s. The Barnes didn’t do so well for me. Couldn’t get them to group consistently under MOA but I also didn’t really invest too much time/components into them either. Tried the Barnes out b/c they were available and I hoped to lower costs a little bit when I was running low on the 109s ... but soon thereafter I found more 109s.

My load under the 109s is 29.5 or 29.6 grains of Lever. I go up to 29.6 when its colder (<50 degrees) Lever is temp sensitive (lots of discussion on Lever early in this thread) and for my set up it seems the 109s are most accurate in the 2690 - 2750 velocity range. Now I use #41 primers.

@2.260 COAL is about .063” off the lands (I was mistaken above). The 109s might be beginning to compress 29.6 grains but I can’t really tell/feel it. Visually, with how deep the bullet sits into the case, it looks to me like it would be beginning to compress.

I am still pretty new to hand loading. No expertise claimed here. So follow the standard warnings of start low work your way up etc. On Hornady’s chart, 29.7 of Lever is max charge in the 108-110 weight bullets for gas guns. But when I used CCI #400s, I did have some cratering and flattened primers. So for my rifle and the 109s, 29.6 might be a bit hot. Hope that helps some. Good luck and let us know how it goes!

Thanks again - have you tried Varget or xbr8208 by chance? I've found decent velocity and accuracy out of both running an 18" Proof CF barrel with both 105 bthp, but especially with the 108 ELDm. May try the 109s next...

 

[LRBuck]

Thanks again - have you tried Varget or xbr8208 by chance? I've found decent velocity and accuracy out of both running an 18" Proof CF barrel with both 105 bthp, but especially with the 108 ELDm. May try the 109s next...

I haven’t tried either powder in 6ARC nor have I yet tried loading those bullets. I thought about Varget, but didn’t feel I had enough on hand to experiment with (use it on a 308 load) and or the published velocities. When I started with 6ARC my goal was an AR 15 (weight less than a AR10) with good accuracy out past 1200 yards. I didn’t think that was possible with Varget based on the numbers and also on results posted on this tread.

My gasser carries a 22” Rock Creek barrel spun up by Craddock Precision. Love it. If my goal had been 1000 and not 1200, I might not have ever tried the 109s, but I started out with Lever and the 109s because on the calculations it looked possible to achieve and I could find both (at the time - fall 2020). Being a newbie I didn’t want to push the limits so the 108s and 105s didn’t look as attractive, though both shoot very well as factory loads in my rifle - the 108s to 1000 and 105s out to 8-900. The factory black 105s, in my experience, are light out inside 800 but just don’t perform that well past 900. I understand from reading posts from others the Berger 105s (hybrid target I think) perform excellent and are favored by many on this thread, but I haven’t tried them yet either. Wish I had the time/$ for all the things I want to try out!! But for me, shooting steel is so much more fun than paper groups and so I rarely find time for much more than that.

 

[SMTGWKD]

Completely agree on the shooting steel part. To that end, I used to obsess over every last spec of accuracy/precision when developing loads, but now look for low SD, sub MOA for 3 shots at a relative flat velocity load range in the ladder - pick a load in the middle, confirm with a 10-shot group. then go shoot the crap out of it.

I have an 18" barrel, so range will be limited relative to yours; however, it will be interesting to see how the 108s or Bergers fly out to 1k or 1100 at my elevation of 4200 ft.

For reference, I'm getting 2513 fps with Varget and 108s at 28 degrees temp. Likely 2535 or so in summer months.

 

[newageroman]

... To that end, I used to obsess over every last spec of accuracy/precision when developing loads, but now look for low SD, sub MOA for 3 shots at a relative flat velocity load range in the ladder - pick a load in the middle, confirm with a 10-shot group. then go shoot the crap out of it.

That sounds like a good efficient process. How do you determine your ladder load start and end and interval? I normally start at book low and work up to halfway to book max on the inintial session. Going up by 1 grain or .5 grains and just get used to the rifle while on the low side and look for pressure. Come home, inspect brass, velocities and then determine what the 2nd ladder load will be. I usually overlap the first few charges same as Phase 1 and see if velocities match/close(ish). I usually mix these in with other rifles I'm shooting because its only like 10 or 15 rounds per Phase usually. After that my tuning process is becoming more like yours ^^^. I would tell you that load to mag len for the added challenge, but honestly its one less variable to deal with so I'm good with it(for a gas esp.).

...also I just deleted ALL of my YouTube Content and am moving it all to Rumble. It was only ~30 videos but I already feel less "icky" posting over there.

 

[SMTGWKD]

I am by no means an expert - much of what I learned was from gents like padom, rob01, yondering, LRRFP(or whatever Mr grendel goes by) on here.

I typically bracket a velocity I'm trying to hit based on Hornady data as it's generally conservative. I also look for data from others with similar setups for hints. Then I load up 3-shoot groups in .3 increments about .9 grains below and .3 grains above the anticipated node. That typically shows both an accuracy and a velocity plateau. I pick a load in the middle of the plateau (or near the top/bottom of it's really hot/cold when testing) and confirm with a 10 round group, then stop wasting components messing around and shoot at distance. If I'm really feeling frisky I'll load up no more than 5 seating depth tests while confirming the load weight - typically works well! Infrequently the load will fall apart at distance - then I swear I'm quitting the support before choosing a different bullet.

I'm sure I'm leaving something on the table, but after achieving true 1-hole groups with my Desert Tech (143 eldx with Reloder 17) I realized ive been wasting too much time and components trying to perfect something I didn't need.

If I can get a solid sub .8 MOA load in an AR and a consistent .5 MOA load in a bolt, I'm good to go. With some luck I've been able to do better than those numbers with decent consistency.

 

[LRBuck]

Completely agree on the shooting steel part. To that end, I used to obsess over every last spec of accuracy/precision when developing loads, but now look for low SD, sub MOA for 3 shots at a relative flat velocity load range in the ladder - pick a load in the middle, confirm with a 10-shot group. then go shoot the crap out of it.

I have an 18" barrel, so range will be limited relative to yours; however, it will be interesting to see how the 108s or Bergers fly out to 1k or 1100 at my elevation of 4200 ft.

For reference, I'm getting 2513 fps with Varget and 108s at 28 degrees temp. Likely 2535 or so in summer months.

I would be surprised if they don’t perform well for you in your Proof at that elevation. Out to 1000 I am under 300 ft. At 1200 about 2600 feet and no problems for the109s with that load (when I am not the problem!).

Just for conversation on load development I will throw this out there as it has been very helpful to me.
Check out Dan Newberry’s OCW method. He knows his stuff. He suggests in other things I read and conversations with him to find the optimal charge weight, then play a little with seating, and reconfirm at distance.

 

[newageroman]

Agree wasting components is much more of an issue nowdays. It is cool to see a group grow and shrink and the velocities stabilize. Another way to look at wasted components is a to know what doesn't work, otherwise you 'd always be guessing if there's a better node.
143ELDx is my 6.5 RAP fav snack. Can't wait until it gets warmer...
I got bored last night and put the big comp on my CZ racegun. gotta make some 9maj rounds to test with. I'm sure it will be cold and rainy this weekend anyway.

Those are great OCW vids, thanks for sharing. I like to run the initial ladder loads before OCW to look for pressure in my setup to help bracket possible nodes. I normally shoot milder nodes, but I like knowing there is or there isn't a hotter node for my rifle with those components.

Also, this may not count, but I add a couple of + marks in general to anyone that hangs review targets from a 3 pedal gear selector with a manual x-fer case in the bg...

 

[SMTGWKD]

Back on the ARC topic, if I'm going to backorder the best bullet for the chambering to maximize accuracy, consistency, ease of jump/loading to magazine length and velocity, which bullet would you choose?

I have about 500 ELDM 108s I can shoot for now (and 267 Hornady 105 BTHP that I'm selling), but want the next lot to be based on the best projectile option.

I'm thinking either Sierra 107s or Berger Hybrid 105s? I picked up 100 of the Berger 105 Hybrids from a buddy to test tomorrow.

Open to ideas from those with far more experience than I!

 

[Lightning8]

I am curious on how the Barnes 105 Match Burners will do in 6mm ARC. Bergers are so hard to get. I am running 105 MBs this year in my 6BR and 112 MBs in my 6XC

 

[newageroman]

I scored some Lapua Grendle brass at the LGS yesterday. It has my name on it I almost forgot, now I have a fun lunch errand. Pics for sure, they will be loaded up with my personal fav 105Berger VLDs and LL..Those are my preferred fav, but I'll try the sierra 107s or Barnes if I see them. (I had surprisingly good/cheap results with Barnes MBs in 6.5).

My local shooting buddy just got a Savage bolt gun in 6ARC so he's on the wagon now to... a year late, I told him waaaaaay back but whatevs...

With regards to bullet efficiency LR, I'm starting to consider the shoulder/neck junction matching the boat tail of the bullet as a higher priority starting point, then ideally the bullet would stretch out to MAX mag len and then have the BC / weight that works with those dimensions. From there, try to match the powder and charge weight that is 90% capacity to as Captain Crunchy as you feel like depending on the color of your shorts that day. Looking at it as the most efficient gas evacuation route point of view per se.

 

[SMTGWKD]

I just watched and re-watched those OCW videos. Inspired me to load up rounds to see what happens tomorrow!

Will be testing Varget with both 108 ELDms and 105 Hybrids

 

[r.tenorio671]

...some chrony results from yesterday testing w/LeverEvolution & miscellaneous bullets. The intent of the tests was to check for pressure signs. Brass is converted virgin Starline 6.5G that was annealed before sizing & trim, CCI 400 small rifle primers. Chrony used is a Chrony Beta Master. Approx 85F/80%H, cloudy w/scattered showers, altitude 600ft. Due this being the 1st firing of virgin brass I expected wildly high SD/ES numbers, which did occur.

Barrel: 18" Ballisitic Advantage, RLGS w/SLR AGB, std carbine buffer system, VG6 6.5 GAMMA Brake. New barrel, less than 40 rds down the tube of 70gn Varmageddon's w/8208 and 105 RDF's w/748 previously.

Berger 95 Classic Hunter, CBTO 1.686", COAL 2.174"
28.4 = 2595 fps avg
28.7 = 2623 fps avg
29.1 = ERR

Berger 95 VLD, CBTO 1.660", COAL 2.257"
28.4 = 2600 fps avg
28.7 = 2632 fps avg
29.1 = 2669F fps avg

Berger 105 VLD, CBTO 1.659", COAL 2.255"
28.4 = 2603 fps avg
28.7 = 2594 fps avg (had 1 round 50fps slower than rest, possible chrony issue)
29.1 = 2677 fps avg

Hornady 87 VMAX, CBTO 1.661", COAL 2.130"
30.0 = 2817 fps avg
30.4 = 2881 fps avg
30.9 2965 fps avg

Hornady 90 ELDX, CBTO 1.655", COAL 2.167"
29.8 = 2790 fps avg
30.1 = 2789 fps avg
30.4 = 2867 fps avg

Hornady 108 ELDM, CBTO 1.684", COAL 2.250"
28.5 = 2594 fps avg
28.8 = 2583 fps avg
29.1 = 2611 fps avg

Nosler 105 RDF, CBTO 1.679", COAL 2.245"
28.4 = 2596 fps avg
28.7 = 2614 fps avg
29.1 = 2672 fps avg

The biggest take-away for me was that I more than likely can go up in charges for more speed as none of the brasss had any visible or obvious pressure signs, no ejector marks, shines or digs, brass was ejecting on a 3:30-4:00 pattern approx 2 steps away in a nice little pile. I started my loads in the approximate "middle" charge of data available between Hornady & Hodgdon. The recommendations I received from Berger for their bullets was VERY conservative, I exceed them. Next round will be the highest charge weights from this test in this now 1x fired brass. My goal is for all bullets to have a fps that stays supersonic to 1100-1200. Based on the numbers from yesterday, the Nosler RDF (per JBM) remains supersonic to 1300.

YMMV, work your way up safely!

 

[Chasingpro]

Ready for more manufacturers to start producing them. They aren’t cheap rounds if you’re a factory load guy.

 

[SBRSarge]

Ready for more manufacturers to start producing them. They aren’t cheap rounds if you’re a factory load guy.

Amen to that. I was buying the TAP loads at 23/box for cheaper shooting, but now they’re over 30/box.

 

[Dino11]

My take on the 6 ARC is that this is a reloaders round. Availability is a big contributor to this, then you factor in price. When it first came out it wasn't to bad, but the current ammo factors across the board in all calibers has driven the price and availability out of reasonable realm. Then you have to look at the accuracy of the round and the gains you achive by load developing and loading your own. Manufactures need to produce and make brass more available, I have not seen any brass available since it came out. And I had my first rifle in hand two weeks after release. You had to buy factory loaded stuff just to get the brass or convert Grendel which is a lot of work above the price you have to pay for it, might as well buy factory stuff and shoot it for the brass.

 

[newageroman]

...some chrony results from yesterday testing w/LeverEvolution & miscellaneous bullets. The intent of the tests was to check for pressure signs. Brass is converted virgin Starline 6.5G that was annealed before sizing & trim, CCI 400 small rifle primers. Chrony used is a Chrony Beta Master. Approx 85F/80%H, cloudy w/scattered showers, altitude 600ft. Due this being the 1st firing of virgin brass I expected wildly high SD/ES numbers, which did occur.

Barrel: 18" Ballisitic Advantage, RLGS w/SLR AGB, std carbine buffer system, VG6 6.5 GAMMA Brake. New barrel, less than 40 rds down the tube of 70gn Varmageddon's w/8208 and 105 RDF's w/748 previously.

Berger 95 Classic Hunter, CBTO 1.686", COAL 2.174"
28.4 = 2595 fps avg
28.7 = 2623 fps avg
29.1 = ERR

Berger 95 VLD, CBTO 1.660", COAL 2.257"
28.4 = 2600 fps avg
28.7 = 2632 fps avg
29.1 = 2669F fps avg

Berger 105 VLD, CBTO 1.659", COAL 2.255"
28.4 = 2603 fps avg
28.7 = 2594 fps avg (had 1 round 50fps slower than rest, possible chrony issue)
29.1 = 2677 fps avg

Hornady 87 VMAX, CBTO 1.661", COAL 2.130"
30.0 = 2817 fps avg
30.4 = 2881 fps avg
30.9 2965 fps avg

Hornady 90 ELDX, CBTO 1.655", COAL 2.167"
29.8 = 2790 fps avg
30.1 = 2789 fps avg
30.4 = 2867 fps avg

Hornady 108 ELDM, CBTO 1.684", COAL 2.250"
28.5 = 2594 fps avg
28.8 = 2583 fps avg
29.1 = 2611 fps avg

Nosler 105 RDF, CBTO 1.679", COAL 2.245"
28.4 = 2596 fps avg
28.7 = 2614 fps avg
29.1 = 2672 fps avg

The biggest take-away for me was that I more than likely can go up in charges for more speed as none of the brasss had any visible or obvious pressure signs, no ejector marks, shines or digs, brass was ejecting on a 3:30-4:00 pattern approx 2 steps away in a nice little pile. I started my loads in the approximate "middle" charge of data available between Hornady & Hodgdon. The recommendations I received from Berger for their bullets was VERY conservative, I exceed them. Next round will be the highest charge weights from this test in this now 1x fired brass. My goal is for all bullets to have a fps that stays supersonic to 1100-1200. Based on the numbers from yesterday, the Nosler RDF (per JBM) remains supersonic to 1300.

YMMV, work your way up safely!

Dang, quite a variety there, thanks for tuning us in! This is my first 6mm.
I'm most interested in the Berger 105s looks pretty similar to my fav load. I'm hoping to have a decent shooting day and try the 1250 plate with it sometime this spring. It really depends on how windy it is at the time for me.

Have you considered trying copper solids? I'm wondering if the PVAs or Flatlines would stretch to 1250 better. Save the "plinkers" for 750 and in.. I'm not sure about the twist rate though.

As far as brass goes you just have to actually look for it, then convert it. Converting it is really pretty easy IMO. I had a friend way back a couple years ago tell me "just buy factory and shoot that brass" I LOLed out of my chair.

I found over a hundred pieces of 1x Hornady on Mewe last week for cheap. I just went yesterday and picked up a box of Lapua Grendle cases at the LGS. I saw where a guy stated Starline recently opened up backorders and he got some, I called them yesterday and they said "Don't know when keep checking the site, no we don't have an email list". I let them know they could have had my money but I'm buying Lapua now.

Hope all have a great shooting weekend!

 

[SMTGWKD]

This is what I did/am doing. I've found both 105 bthp and 108 ELDm pretty easily and consistently available for reasonable prices online to shoot them for testing and brass. I consider reasonable prices to be $1.00-$1.30 per round these days. I have enough brass to reload for many thousands of rounds if primer pockets hold up.

Would be really nice to see supply chains catch up and prices wane - my LGS has a stack of CCI 450s for $90 a brick. It dwindles periodically, but folks are still buying at those prices.

 

[SMTGWKD]

Alright - the videos above motivated me to test some Berger 105 Hybrids over Varget. Guessing many don't have access to these components right now, but may be interested.

Let me know your thoughts on the attached OCW - hand fed and shot one round at each load (first time doing that and really, really liked it vs shooting all the same load so no favoritism or barrel soak). Funny that this almost identically follows the pattern he talks about in the video. If the scatter +/- 1.5% is true on this string it would seem that 26.2 and 27.0 would fit his definition of scatter and 26.6 shows the curve he mentions getting "red hot" to the node. 26.8 turns in a nice, neat group - maybe 26.7 is the money maker?

Regardless of whether Dan Newberry is a genius or high, this was a fun experiment with surprisingly similar results!

 

[SMTGWKD]

Also - to foul the barrel after cleaning, I shot 1 factory round and loaded 3 at .1 grains above/below my current load of 26.7 gr Varget under 108 ELDs and shot the attached group.

Shot 1 - factory 108 clean bore fouler
Shot 2 - first shot 26.6
Shot 3 - first shot 26.8
Shot 4 - second shot 26.6
Etc

I shot a few other groups that landed same poi as shots 3-7 so I do think shots 1 and 2 were off due to refouling after thorough bore cleaning.

In short - seems to validate the 26.7 of Varget under 108s.

For some reason I get really low SDs (for a gas gun) with this range of load with the 108s:

26.6 - 2520 fps 4.0 SD
26.7 - 2529 fps 9.1 SD (10 shots)
26.8 - 2535 fps 6.4 SD

Feel free to share insights - fun game we play here.

 

[r.tenorio671]

I scored some Lapua Grendle brass at the LGS yesterday. It has my name on it I almost forgot, now I have a fun lunch errand. Pics for sure, they will be loaded up with my personal fav 105Berger VLDs and LL..Those are my preferred fav, but I'll try the sierra 107s or Barnes if I see them. (I had surprisingly good/cheap results with Barnes MBs in 6.5).

My local shooting buddy just got a Savage bolt gun in 6ARC so he's on the wagon now to... a year late, I told him waaaaaay back but whatevs...

With regards to bullet efficiency LR, I'm starting to consider the shoulder/neck junction matching the boat tail of the bullet as a higher priority starting point, then ideally the bullet would stretch out to MAX mag len and then have the BC / weight that works with those dimensions. From there, try to match the powder and charge weight that is 90% capacity to as Captain Crunchy as you feel like depending on the color of your shorts that day. Looking at it as the most efficient gas evacuation route point of view per se.

....I went the reverse, loaded to max mag length for the charge weight determination. The +90-100 grain secant bullets typically exceeded mag length when measuring where they touched the lands, leading to some various (some might say 'large') jumps when loaded to mag length. Some of the heavy "hybrid" ogives would as well. Haven't been able to get my hands on any heavy tangent's yet, but want to try the Sierra offerings, not only for their performance reputation but pricing as well.

...For the lighter bullets, regardless if tangent, secant or hybrid, the amount of bullet retained in the case neck was the more critical concern for me, I want the base of the bullet to at least be equal to the junction of case neck & shoulder. The majority of them would invariably be within mag length.

In my mind, being able to work backwards to adjust jump to find a more accurate round with a larger safety margin re: pressure spikes. The amount of deeper seating depth would be so small I doubt it would increase pressure significantly and cause undue pressure spiking, but the charge weight can always be adjusted if required to attain the same fps if fps is an objective. I'm not a proponent of "chasing the lands", I haven't observed a change in any of my builds to convince me to adopt that approach. If I have a barrel suddenly become a scattergun, I just change the barrel and move on, I don't desire going into perpetual analysis, testing and component consumption. Its a disguised "money pit" IMHO.

YMMV

 

[r.tenorio671]

...some chrony results from yesterday testing w/LeverEvolution & miscellaneous bullets. The intent of the tests was to check for pressure signs. Brass is converted virgin Starline 6.5G that was annealed before sizing & trim, CCI 400 small rifle primers. Chrony used is a Chrony Beta Master. Approx 85F/80%H, cloudy w/scattered showers, altitude 600ft. Due this being the 1st firing of virgin brass I expected wildly high SD/ES numbers, which did occur.

Barrel: 18" Ballisitic Advantage, RLGS w/SLR AGB, std carbine buffer system, VG6 6.5 GAMMA Brake. New barrel, less than 40 rds down the tube of 70gn Varmageddon's w/8208 and 105 RDF's w/748 previously.

Berger 95 Classic Hunter, CBTO 1.686", COAL 2.174"
28.4 = 2595 fps avg
28.7 = 2623 fps avg
29.1 = ERR

Berger 95 VLD, CBTO 1.660", COAL 2.257"
28.4 = 2600 fps avg
28.7 = 2632 fps avg
29.1 = 2669F fps avg

Berger 105 VLD, CBTO 1.659", COAL 2.255"
28.4 = 2603 fps avg
28.7 = 2594 fps avg (had 1 round 50fps slower than rest, possible chrony issue)
29.1 = 2677 fps avg

Hornady 87 VMAX, CBTO 1.661", COAL 2.130"
30.0 = 2817 fps avg
30.4 = 2881 fps avg
30.9 2965 fps avg

Hornady 90 ELDX, CBTO 1.655", COAL 2.167"
29.8 = 2790 fps avg
30.1 = 2789 fps avg
30.4 = 2867 fps avg

Hornady 108 ELDM, CBTO 1.684", COAL 2.250"
28.5 = 2594 fps avg
28.8 = 2583 fps avg
29.1 = 2611 fps avg

Nosler 105 RDF, CBTO 1.679", COAL 2.245"
28.4 = 2596 fps avg
28.7 = 2614 fps avg
29.1 = 2672 fps avg

The biggest take-away for me was that I more than likely can go up in charges for more speed as none of the brasss had any visible or obvious pressure signs, no ejector marks, shines or digs, brass was ejecting on a 3:30-4:00 pattern approx 2 steps away in a nice little pile. I started my loads in the approximate "middle" charge of data available between Hornady & Hodgdon. The recommendations I received from Berger for their bullets was VERY conservative, I exceed them. Next round will be the highest charge weights from this test in this now 1x fired brass. My goal is for all bullets to have a fps that stays supersonic to 1100-1200. Based on the numbers from yesterday, the Nosler RDF (per JBM) remains supersonic to 1300.

YMMV, work your way up safely!

...because I use a Chrony Beta Master that relies on optical sensors I have to use a consistent aiming point downrange to ensure the bullet crossed the sensors properly. It's not shooting for groups, but occasionally the accuracy potential of a load makes itself known. Here's the group from the referenced powder test of the Berger 95 VLD Hunting @100YDS (lasered).

 

[r.tenorio671]

...has anyone tried the Barnes 105 Match Burners yet? The pricing on them (when available) is really attractive.

 

[MSTN]

Ten rounds of Hornady 108 ELD out of a Proof 18" CFW barrel:

 

[357Max]

Ten rounds of Hornady 108 ELD out of a Proof 18" CFW barrel:

Great speed for a 18"! How many rounds on barrel before this?

 

[SMTGWKD]

This is about the same I see on average from my 18" proof CF after about 60 rounds down the pipe. It started a bit slower and sped up nicely.

 

[newageroman]

....I went the reverse, loaded to max mag length for the charge weight determination. The +90-100 grain secant bullets typically exceeded mag length when measuring where they touched the lands, leading to some various (some might say 'large') jumps when loaded to mag length. Some of the heavy "hybrid" ogives would as well. Haven't been able to get my hands on any heavy tangent's yet, but want to try the Sierra offerings, not only for their performance reputation but pricing as well.

...For the lighter bullets, regardless if tangent, secant or hybrid, the amount of bullet retained in the case neck was the more critical concern for me, I want the base of the bullet to at least be equal to the junction of case neck & shoulder. The majority of them would invariably be within mag length.

In my mind, being able to work backwards to adjust jump to find a more accurate round with a larger safety margin re: pressure spikes. The amount of deeper seating depth would be so small I doubt it would increase pressure significantly and cause undue pressure spiking, but the charge weight can always be adjusted if required to attain the same fps if fps is an objective. I'm not a proponent of "chasing the lands", I haven't observed a change in any of my builds to convince me to adopt that approach. If I have a barrel suddenly become a scattergun, I just change the barrel and move on, I don't desire going into perpetual analysis, testing and component consumption. Its a disguised "money pit" IMHO.

YMMV

when you mention the bullet base matching the shoulder/neck junction: do you mean the absolute base of the bullet or the boat tail bearing junction. I have been trying to basically match both junctions together, but maybe I'm doing it wrong, (again??). When I seat 100 gn Hornady SPs to work junction to junction, they are well below mag len (but they are also not the pointiest bullet).

I did get some more good results today. Both sets of my Starline Straightwall Grendel Basic Brass (some with 100gn BTSP and some with 105 VLDs) fire formed great, no issues. This brass is available now, but its more of a pain in the but to convert. I'll be loading up another 200 cases with cheap hornady 100s to continue fire forming.

Last time I performed this process, I bumped the shoulder back a bit too much and it would not set off the primer. I had to load the bullets long, and jam them into the lands for the primer to go off. This time all 20 went off no prob, so learning process = success.
Might be a while before the next update, yall carry on and good luck on finding primers!

 

[r.tenorio671]

when you mention the bullet base matching the shoulder/neck junction: do you mean the absolute base of the bullet or the boat tail bearing junction. I have been trying to basically match both junctions together, but maybe I'm doing it wrong, (again??). When I seat 100 gn Hornady SPs to work junction to junction, they are well below mag len (but they are also not the pointiest bullet).

I did get some more good results today. Both sets of my Starline Straightwall Grendel Basic Brass (some with 100gn BTSP and some with 105 VLDs) fire formed great, no issues. This brass is available now, but its more of a pain in the but to convert. I'll be loading up another 200 cases with cheap hornady 100s to continue fire forming.

Last time I performed this process, I bumped the shoulder back a bit too much and it would not set off the primer. I had to load the bullets long, and jam them into the lands for the primer to go off. This time all 20 went off no prob, so learning process = success.
Might be a while before the next update, yall carry on and good luck on finding primers!

...it would depend on the bullet. Some boat-tailed bullets have really long boat-tails, others relatively short, almost truncated boat-tails. Flat-based bullets I will typically load so the base aligns with the junction. If it's a really short bullet, I would seat so that at least the caliber equivalent of the bullet is contained in the neck, i.e., 0.24" seating depth for a .243/6MM bullet (which is a really old concept from back in the stone ages that has stuck with me, LOL). If I want to use the heavy long & sleek bullets in my 6ARC gasser, I already know I'm going to encounter large jumps by limiting to mag length restrictions. In my mind, starting at the max length gives me the most flexibility for adjusting CBTO/seating depth for accuracy and without having to make much, if any charge weight changes once the charge weight determination has been made.

My methodology for bullets that will exceed mag length is load at max mag length length, test for powder charge weight, adjust seating depth for accuracy as required. For these bullets I record the CBTO measurement once the bullet is seated to the max mag length allowable.

For bullets that won't exceed max mag length, determine ogive touch point COAL, record CBTO, load starting at 0.05-0.10 off lands seating, test for powder charge weight, adjust seating depth for accuracy as required.

 

[MSTN]

Approximately 300 rounds. It is only about 15 fps faster than when new.

 

[newageroman]

Created a new Channel on Rumble - Ricky Ace Range Review...
Added a quick video on 6ARC case conversion from Startline Grendel Straightwall cases (w/ annealer)

Ricky Ace Range Review

Browse the most recent videos from channel "Ricky Ace Range Review" uploaded to Rumble.com

rumble.com

 

[r.tenorio671]

...some chrony results from yesterday testing w/LeverEvolution & miscellaneous bullets. The intent of the tests was to check for pressure signs. Brass is converted virgin Starline 6.5G that was annealed before sizing & trim, CCI 400 small rifle primers. Chrony used is a Chrony Beta Master. Approx 85F/80%H, cloudy w/scattered showers, altitude 600ft. Due this being the 1st firing of virgin brass I expected wildly high SD/ES numbers, which did occur.

Barrel: 18" Ballisitic Advantage, RLGS w/SLR AGB, std carbine buffer system, VG6 6.5 GAMMA Brake. New barrel, less than 40 rds down the tube of 70gn Varmageddon's w/8208 and 105 RDF's w/748 previously.

Berger 95 Classic Hunter, CBTO 1.686", COAL 2.174"
28.4 = 2595 fps avg
28.7 = 2623 fps avg
29.1 = ERR

Berger 95 VLD, CBTO 1.660", COAL 2.257"
28.4 = 2600 fps avg
28.7 = 2632 fps avg
29.1 = 2669F fps avg

Berger 105 VLD, CBTO 1.659", COAL 2.255"
28.4 = 2603 fps avg
28.7 = 2594 fps avg (had 1 round 50fps slower than rest, possible chrony issue)
29.1 = 2677 fps avg

Hornady 87 VMAX, CBTO 1.661", COAL 2.130"
30.0 = 2817 fps avg
30.4 = 2881 fps avg
30.9 2965 fps avg

Hornady 90 ELDX, CBTO 1.655", COAL 2.167"
29.8 = 2790 fps avg
30.1 = 2789 fps avg
30.4 = 2867 fps avg

Hornady 108 ELDM, CBTO 1.684", COAL 2.250"
28.5 = 2594 fps avg
28.8 = 2583 fps avg
29.1 = 2611 fps avg

Nosler 105 RDF, CBTO 1.679", COAL 2.245"
28.4 = 2596 fps avg
28.7 = 2614 fps avg
29.1 = 2672 fps avg

The biggest take-away for me was that I more than likely can go up in charges for more speed as none of the brasss had any visible or obvious pressure signs, no ejector marks, shines or digs, brass was ejecting on a 3:30-4:00 pattern approx 2 steps away in a nice little pile. I started my loads in the approximate "middle" charge of data available between Hornady & Hodgdon. The recommendations I received from Berger for their bullets was VERY conservative, I exceed them. Next round will be the highest charge weights from this test in this now 1x fired brass. My goal is for all bullets to have a fps that stays supersonic to 1100-1200. Based on the numbers from yesterday, the Nosler RDF (per JBM) remains supersonic to 1300.

YMMV, work your way up safely!

...some follow-up data of post-firing measurements taken of the brass. Measurements were taken of the loads listed above, but I'm only posting those from the max loads as the differences between the min & max loads were negligible (4th & 5th place decimal).

...Original Hornady die setting gave measurement's of Shoulder= 1.188 ; Base= 0.438 and cases trimmed to 1.480 ( the middle of the SAAMI max of 1.490, min of 1.470).

Bullet / Shoulder / Base / Powder
Nosler 70gn VG : 1.1932 , 0.441, 8208XBR
Nosler 105 RDF : 1.1938 , 0.441, W748
Berger 95 Classic Hunter : 1.194166667 , 0.4407 , LVR
Berger 95 VLD Hunting : 1.1940 , 0.441, LVR
Berger 105 VLD Target : 1.195166667, 0.441, LVR
HDY 108 ELDM : 1.195, 0.441, LVR
HDY 90 ELDX : 1.1935, 0.4415, LVR
HDY 87 VMAX : 1.194166667, 0.4415, LVR
Nosler 105 RDF : 1.194, 0.4415, LVR

My takeaway's are: I can now fine-tune my sizing die for more efficient shoulder bump. Negligible to zero brass flow affecting trim length. No measurable differences between the pre-annealed and non-annealed virgin brass I converted for their 1st firing. No differences in the cases that were fired with adjustable gas block closed completely to those when adjustable gas block opened for full functionality.

YMMV

 

[newageroman]

That's a great test. I have been leaving my brass long around the max and had no issues and minimal/no trimming after initial (annealing every time). I like that you added testing the gas block wide open and closed. One other thing I did a while back was disassemble the bolt and check max trim length without any extractor/extractor present. it was waay longer than 1.490" but that's what I trim to.

 

[tjh011]

Is anyone using a Rainier Arms Ultramatch Mod2 barrel in 6mm Arc? Im looking at the 18". I know generally speaking they are good barrels, but I cant find many reviews in the 6mm Arc. Wondering if anyone has any first hand experience they would share?

 

[Gtscotty]

Is anyone using a Rainier Arms Ultramatch Mod2 barrel in 6mm Arc? Im looking at the 18". I know generally speaking they are good barrels, but I cant find many reviews in the 6mm Arc. Wondering if anyone has any first hand experience they would share?

I'm curious as well, I'd like a lightweight more general purpose 18", and the fluted Ranier seems like the only game in town under CF Proof pricing.

 

[SMTGWKD]

Looking to possibly load for varmints with a 58, 65, or 75 grain ELD M. Which would you choose given my barrel and current powder stash:

18" CF Proof 1:7.5 twist

58 ELD M - I have no powders referenced in the Hornady load data
65 ELD M - I have one powder in the Hornady load data (xbr 8208)
75 ELD M - I have 3 powders in the Hornady load data (xbr 8208, CFE223, Leverevolution)

 

[357Max]

Is anyone using a Rainier Arms Ultramatch Mod2 barrel in 6mm Arc? Im looking at the 18". I know generally speaking they are good barrels, but I cant find many reviews in the 6mm Arc. Wondering if anyone has any first hand experience they would share?

I couldn't find any reviews on them either.

Went with a 22" Ultramatch Mod 2 with + 2" gas. Not enough rounds to give good review yet. Just scope zero, & magneto data while breaking in the barrel.
Head spaced perfect on a Maxim bolt.
Gas port was a little on small side for + 2" gas .086 I drilled it to .092 before installing. Gas half open ejects @ 3:30 RCA low mass BC with JP Std wt silent capture & Black spring. For reference the Odin 21" + 2" gas had a .101 port & ejected the same 3:30 with 1 more click open on same gas block.

The 22" Rainier was 2635 avg with factory Hornady 108 = 70fps faster then the 21" Odin @ same exact round count.

It did manage just under moa for 2 x 5 rd groups. A little disappointing, but hoping it's capable of better with hand loads.

The lot of Hornady 108 ammo I have has the dam shoulders .012 short of a fired case. Not ideal for accuracy, but I'm also a little rusty with the AR.

Trying to get some Berger 105 & PVA 100 solids loaded up with Lever for Saturday. The 100 PVA's are loong! 95's would be better whenever they are back in stock.

 

[rpoL98]

FWIW, PTG finally shipped my set of headspace gauges (Go, No-Go, Field).

 

[JKGTR]

Seems like this cartridge doesn’t like to group. I just put together a build with a 20” BA premium barrel, JP BCG, odinworks billet receiver set.

Went to do a hasty zero at 50m. Took two shots to get the scope dialed. 3-shot group, just under 2”.... at 50 meters.

Took it home and did a hasty clean. Went back out a few days later to do some groupings and find sweet spot for barrel torque etc... Had one 5-shot group that was just over 1 MOA with barrel nut torqued to 40 ft lbs. All the other groups were way worse.

Sending the barrel back and looking for a new one.

 

[r.tenorio671]

Seems like this cartridge doesn’t like to group. I just put together a build with a 20” BA premium barrel, JP BCG, odinworks billet receiver set.

Went to do a hasty zero at 50m. Took two shots to get the scope dialed. 3-shot group, just under 2”.... at 50 meters.

Took it home and did a hasty clean. Went back out a few days later to do some groupings and find sweet spot for barrel torque etc... Had one 5-shot group that was just over 1 MOA with barrel nut torqued to 40 ft lbs. All the other groups were way worse.

Sending the barrel back and looking for a new one.

....what you experienced is unfortunate.

....my experience with handloads @100 yds (lasered) to determine pressure was the opposite, I'm not sending my barrel back