I have had my 22 ARC up and running for close to a month now. It is what I would consider to be a pretty average example of a 22 ARC. The Barrel is a 20 Inch Saturn/Liberty.
I have managed to come up with Three Box's of Hornady 75 ELD-Match Ammunition, as well as Two Box's of 88 ELD-Match Ammunition.
I also have rounded up Hornady Loading Dies, as well as a Hornady Case Gauge.
I have done lots of research on Load Data on the 22 ARC as well as the Original Version, the 22 Grendel. Note: Most 22 Grendel Data that I located is HOTTER than the 22 ARC Load Data from Hodgdon.

This past Tuesday I did some additional Chronograph testing using a new Garman Xero C1 Chronograph. I test fired three different lots of ammunition.
Hornady Factory 75 ELD-Match, Hornady Factory 88 ELD-Match, as well as my Handloads using Hornady 75 ELD-Match Bullets.

Hornady Factory 75 ELD-Match
I fired a three shot velocity test a couple weeks ago with outdoor conditions Blue Cold, and Heavy Fog. Firing was done from a heated Building with an internal temperature of approximately 65 Degrees. The ammunition was at the shop temperature also.
The Results were an average Velocity of 2949 FPS, with an SD of 4.8.
The Velocity listed on the Hornady Ammunition Box is 3075 FPS. This is reportedly from a 24" Test Barrel.

Round two was done Tuesday with much warmer outdoor temperatures. Pretty much a beautiful day for February in Southern Missouri.
We fired a Five shot Test this time, again from inside a 65 degree shop.
The Results were an average velocity of 2964 FPS SD 5.2.

We are getting Velocity Loss numbers 25-30 FPS per Inch of Barrel. What I would consider to be fairly normal velocity loss for a 20 Inch Barrel, and 24" barrel numbers.

Next up will be my Reloaded Ammunition. My loads came from the Hodgdon Web site. The fastest loads are:
CFE 223 Max Load of 30.2 Grains for 3074 FPS from a 24" Test Barrel.
AA2520  Max Load of 29.3 Grains for 3061 FPS from a 24" Test Barrel.
Lever     Max Load of 29.4 Grains for 3047 FPS from a 24" Test Barrel.
WW748  Max Load of 29.0 Grains for 3030 FPS from a 24" Test Barrel.

Hornady lists a 24" Barrel Velocity for the 75 ELD-Match of 3075 FPS, Hodgdon's Fastest Load is 30.2 Grains of CFE 223 for a 24" Velocity of 3074 FPS. Pretty Close to the same velocity.

My Five Shot Velocity Numbers for 30.2 Grains of CFE 223 were not even close to Hodgdon's reported Velocity Numbers.
Hornady 22 ARC Once Fired Case
Hornady 75 ELD-M Bullet
Powder 30.2 Grains of CFE 223
Primers Remington 7.5 BR

Average Velocity was 2887 FPS with an SD of 7.6

The Factory loads Chronographed 2964 FPS from my 20 Inch Barrel, while the Reloads only came in at 2887 FPS, for a loss of 77 FPS. I am not sure what Hodgdon did differently to get the reported velocity numbers. The use of CCI 450 Primers might up the velocity numbers a little. Possibly a Heavy Crimp. I am pretty sure that Hornady Factory 22 ARC Ammunition is loaded on the HOT side. This determination came from seating new primers using an RCBS Bench Mounted Priming Tool.
I had room for more CFE 223 in the case. I am sure that I could add more powder and get the velocity numbers higher. Getting up to Factory Ammunition Velocity Numbers while probably doable will no doubt be very hard on the Case's.
While a little disappointed in the Velocity Numbers, this should translate into less Pressure, and longer Case Life.

I about forgot the Hornady 22 ARC 88 ELD-Match Velocity Numbers.
Five Shot Test, all conditions as above.
2700 FPS with an SD of 14.9

My 22 ARC is a Re-Barrel of an older Accuracy Build 204 Ruger. The Scope is a SWFA 20X Super Sniper, and it has an older Jewel Trigger. I have a Harris Bench Rest, Swivel, Notch Leg Bipod with the Badger LPHM Picatinny Rail Conversion attached to the Geissele Automatics MK IV x 13.5 Handguard's forward 3" 1913 Rail section.

I went out to the Range in the afternoon. Between Robert, the Club Secretary and I, we fired up the remaining 15 rounds of the 88 ELD-Match Ammunition. We were pretty impressed with the Group we got on the Steel at 200 yards on the Upper Range. A Golf Ball would not have been safe at 200 Yards.

I still plan to chronograph Factory 62 ELD-VT Ammunition when I get a chance to pick up a box. I have a box of the 62 ELD-VT Bullets on the shelf for testing.

More to come as components become available.

Bob R.

Thanks!
Yours is the first real world report I've seen on the 22 ARC.  I'm intrigued by it but hesitate to be an early adopter until I see more.  Especially after the .224V fiasco.

How does the brass look after firing?

The Factory Brass all has Swipe Marks. It is loaded hot.
It would be nice to have some "new" cases to load. Not holding my breath, unless I form it.
It might be tempting to pull the bullets on a few Factory 88's, then reload that brass, with no swipe marks to begin with. I bought the 88's for the brass anyway. This would also let me feel the Primers Seat in Brass not fired with hot loads in the first place.
I am pretty sure that the factory loads are hot enough that they are loosening up the primer pockets a little. Not bad enough to trash, but not as tight a fit as I would like.

I may need to mix my powder (One Pound Cans) so they are all the same exact burn rate. Then start adding a little powder at a time keeping track of the velocity on each batch fired. I probably will want to stay below factory velocity to get some life out of the cases.

Bob R

Appreciate the detailed "real world" numbers!
I was on the fence with the 22 ARC since I already have a 224 Valkyrie that's working.  I'm slinging 65 grain Sierra Gamekings at around 3050 fps from an 18" barrel.  
I can't wait till you test the 62 grain ammo.

Are you seeing any belting issues in your brass?

I have some 62 grain ELD-VT factory ammo showing up on Saturday (listed at 3300fps with a 24" barrel). Someone I know with an 18" - 1:7" twist 22 ARC barrel is getting 3052fps with the same factory load.

I've been shooting the 62 grain ELD-VTs in my 22 Grendel. I'm shooting a medium charge of CFE223 out of my 21" - 1:8" twist barrel and settled on an accurate winter load that is 3339fps.

As a 6.5 Grendel guy here, I definitely advise caution there on running this hot.  maybe you're already well aware of this and at the risk of being insufferable - the bolt head for the 7.62x39 size case-head just doesn't have the strength like a .223 bolt, or even a .244V (6.8SPC) bolt.  It's somewhat OK because the larger case-volume allows for a larger volume of pressurized gas, so running at the lower 52000 PSI Grendel spec doesn't hurt as much as you might fear - for the most part (or in Grendel at least).  But if you can see pressure sign on your case head in a Grendel/7.62x39 parent round - broken bolt-lugs are in your near future.  

TBH, I'm not sure I see the point of .22 Grendel over .224 Valk; and appreciate your posting your findings - which perhaps will show me!   And hey, as a Grendel shooter - I hope this round takes the world on fire.  Because just like 6mm ARC, that brass is just one quick mandrel die away from feeding my 6.5Grendel again!

While I own neither a 224V nor a 22ARC, the Hornady guys did a podcast on 22ARC and said it was remarkably easier to develop loads for the 22ARC compared to the 224V. I've read here and on other forums of folks having issues with getting the 224V to shoot. Some of this was from bad chambers getting cut early on, but it seems 224V has just been more difficult for folks to develop consistent loads compared to the Grendel-based cartridges.

I, too, have a 6.5G upper, and probably won't be getting a 6ARC anytime soon. But I could see a 22ARC upper making its way home someday...

This is good info, I have both the 6.5g and a 6 arc.
I may rebarrel the Grendel at some point.

Hornady puts a lot of emphasis on chambers and ammunition that all use the same leade. If you’re another company and you’re trying to use existing stubby 60gr bullets and various pointy bullets that are seated too far into the case you’ll probably have more trouble.

Are you using an adj gas block?

I have done AR wildcats for 15 years or so and swipes can be from improper timing; ie the bolt unlocking too soon from being overgassed.

When you say swipes, are you talking about scarring on the back of the case where the headstamp is? All of my Starline brass has this and I'm wondering if I need to get an adjustable gas block. I'll try to post a picture of what mine looks like.

Yes. Typically a smear looking mark. Or even the rim gets jacked up where the extractor grabs the case.

Overgassing can cause these signs because the rifle is extracting the case while the case is obturating causing excess drag during the extraction/ejection stroke.

Will an adjustable gas block correct this?

It usually means excessive gas pressure at the port causing over vigorous and early bolt rotation.  So yes, throttling back on an adjustable port could temper that.

Super heavy buffers are a good trick to eliminate false pressure signs too.

Slash’s buffers are always a top choice and he’s industry here. I like to pair them with a slightly higher power spring so return isn’t sluggish.

I had much better luck with a cheap adjustable gas block. I tried 3 different buffer springs, a standard, red and blue Sprinco. These were combined with 3 different buffer combinations.

In my experience with a very over gassed grendel, a adjustable gas block is the way to go.

My only follow-up to that good advise, is beware of carbon-locking.  In my experience, adjustable AR15 gas blocks become non-adjustable after a few months.

I have tried a lot of different styles over the years and this is definitely true, SLR is the worst in this regards in my experience, but only cause my personal sample size of SLR’s is high.

The Odin Works block uses a much larger adjustment bolt compared the SLR and I haven’t had any issues with those yet, nor the Aero blocks either… so far.

However, I have learned the hard way a little preventative maintenance goes a long way, which for me a simple squirt of CLP down the block around the adjustment bolt and sometimes moving the adj bolt out a couple clicks and back before putting the rifle back in the safe, stock down.

The whole heavier buffer thing can work too, but controlling gas is a better solution.

I have not tried a BRT gas tube yet, but lots of people are going that route since it’s cheap and easy to do. For the OP Black River Tactical (I think that’s the name) make gas tubes with smaller ports, so you reduce gas that way.

Lastly, I have moved to using low mass carriers exclusively on my wildcat/hunting AR’s. I only shoot suppressed, and using an adj block with a low mass carrier allows me to turn the gas way down. Which not only reduces swipes, but a host of other advantages too.

Would that be an ideal “SHTF” set up? Maybe not… maybe… I haven’t had issues; once I set my gas it prettt much stays there.

The Rifle Speed gas system looks superior to all legacy adj blocks, but I haven’t bought one yet to replace anything since my systems work, but will likely use one in my next build.

Calibers where I have employed my low mass carrier with adj block combos are 556 (x a ton), 300 blk (x2), 6mm Mongoose (x1), 6.5 G (x1), 6.8 (x4), 25-223 (x1), 6mmx68 (x1), 25x68 (x1), 358 Yeti (x1) and probably another wildcat I’m forgetting. All suppressed, I don’t shoot any AR’s without a can.

Springs don’t do a whole lot to retard bolt unlocking. Weight and gas are the keys.

lazyengineer is correct.

I will take the locking setscrew out and drop some CLP in there and tighten back down. All without moving the setscrew that adjusts the gas. Then stick it back in the safe.

Again these are the cheap adjustable gas blocks. I think the last one I bought was an Ergo.

I have a Seekins Adjustable Low Profile Gas Block. I set it using my First Reloads that were almost 80 fps under the factory ammunition velocity. I may need to readjust the gas fixture for the hotter ammunition, and make sure the gas fixture setting is not causing the swipe marks.

My last range session I set up the Garmin while shooting groups. This Chronograph is handy as pockets on a shirt.

Brass: Hornady
Bullets: Hornady 75 ELD-M
Powder: CFE223
Powder Charge: 30.2 grains (Hodgdon Max Load)
Primers: Winchester SR
NOTE: The Hodgdon 24" Barrel Velocity with this load is almost identical to Hornady 24" Barrels listed Velocity.

Average Velocity for Eight Rounds was: 2966 fps.

My gas was set using the Remington 7.5 BR Primers with a velocity of 2887 fps.

Looking like the Hodgdon Velocity numbers were closer than I originally thought to factory Hornady velocity numbers. Using the Winchester primers my average velocity was 2966 fps. The velocity numbers for the factory 75 ELD-M loads were 2949 fps and 2964 fps.

Bob R

FYI: Hornady has published their load data for the 22 ARC for both gas and bolt-action rifles on their app.

Hornady 88gr, 22” Rainier barrel is at ~2965, std. dev of 11fps.

Barrel is fresh, so it may speed up slightly. Ready to load up some 80 eld’s and Berger 85.5’s