6mm Rem AI acquisition sanity check

[Sgt_Mike]

I've posted in several threads on here about me acquiring a Rem 721 long action chambered in 6mm Remington AI.
The rifle specs: 1-7.5 Twist 24" appears to be a Green Mountain barrel (0.750" at muzzle).
Main usage Varmints.
I know probably quite a few are familiar with this cartridge. that is the reason for seeking input to data sources I've over looked. Although I will admit I haven't dug through all the printed manuals I have on hand.
(I have been abusing Sierra's load data on the cartridge)

I did fire (fireform) a few already loaded up regular 6mm Rem rounds (although I did break the loaded rounds down to anneal the neck shoulder region and re-assembled them, had zero loss). One load kind of stood out, naturally it was the 69grs bullet (with Win 748) that is no longer available as the custom bullet maker has retired.
Now the good on the fireforming, the necks came out exactly the same diameter (0.276") as before firing. Might not have to resize for a firing or two. maybe?? I'm thinking that the chamber neck is tight maybe at 0.277" to 0.278". I can confirm at a later date, when I have the barrel pulled to thread for a suppressor. Which will be the perfect time to have a chamber cast (neck dimension purposes) and the chamber polished bit. It's displaying a bit more roughness than I like. Although not a big deal and the rifle is fine even in it's current state.

All that said above is for background information.

Possible choice for bullets I'm thinking of, and I am open to suggestions.
Nosler 55gr Varmageddon
Nosler 55gr BT ( the 722 in .224 Rem in the 1-12" T really like those)
Nosler 70gr Varmageddon ( partial box on hand)
Sierra 85gr HPBT Game King #1530 ( I do have a partial box of 50 or so before committing)
Hornady 58gr V-max
Sierra 55gr Blitzking
OK gents what am I overlooking in the bullets selection, the lighter weight obviously are for Groundhogs, gopher, and PD's.
The 85gr for up to deer sized, although can be used on the varmints, if using "seconds" to keep the cost down a bit.

Powder
for the 55 to 60 grs I was thinking maybe H335, although IMR 4350 does top out at 100 fps than the H335. My reasoning here was for it to share powder with my .223 Rem.
for the 70 to 85gr class Varget, IMR 4350 are possible suspects. Although I'm selecting those based off sierra's load data for the Ackley version.
Although I do know that the regular 6mm Rem data can be used and worked up from there.
I am looking at the Win 6.5 staball powder as a option, just not sure on it.
So again gents what am I overlooking in the powder selection? That has worked well for yours?

Now to find (source) a seating die and sizer die reasonable. I'm leaning toward the Vickerman 6mm inline seating die, which I think will work. Which as soon as my hunting buddy loans me his I'll know for sure. While I do have brass on hand, in the next two months or so I'll probably wipe out @hm1996 6mm stuff he has listed. Just spent my self imposed allotment of $$ for the upcoming month. But if someone else needs them before me by all means buy it don't hold off on my account.

Now to be brutal in the conversation.
In the light weight varmint bullets really the AI doesn't offer a advantage over the factory Rem according to sierra load data. True IDK ,but will find out, I'm thinking sierra is conservative in the data for a reason.
Supposedly the AI does have a advantage in throat erosion, brass stretching. And over brass life over the factory Rem offering. Again IDK.
As it us a used rifle I'm thinking maybe 2000 rounds left more or less in the barrel life ??

My initial impressions, I do like the looks of the AI over the factory. Well aware I can fireform on the Gophers /PDs . I'm thinking that I will really like it, although not as efficient as some other offerings. But I do have a soft spot for the .244 Rem / 6mm Rem, probably because it's the underdog when it was introduced at the same time as the .243W, another fine cartridge. The increased case capacity is a plus when going heavy vs the .243 which isn't a slouch, by no means. Which I think the AI version will just suit me to a tee.

Yes with me already owning a 722 in .244 Rem / 6mm Rem I already have dies brass etc setup for the factory chambering, so I'm not dead in the water. And that one (722, a short action) with it's 1957 factory barrel is due for a new barrel, just too many rounds down the bore. It would make a excellent choice for the 22 BR Rem that I've always wanted to do. But that is a another story and not pertinent to this thread. My actual hands on knowledge with the AI is very limited, so I do value input from other 6mm Rem AI users past or present.

Respectfully
Mike

added,,
just went and picked up locally some more of the sierra 85 BTHP SGK. The box I had was a older as in marked sierra Santa Fe Springs California price on the box $9.39 vs the $35.00 I just picked up... Man it's amazing how the dollar has devalued....

 

[DAA]

I've only had one 6AI and it was a long time ago. I'd have to dig up some old data to remember what powders worked well for me. Mine was very different though, as a 12 twist, with short freebore. It was on a L579. Yours being a 7.5 twist, was no doubt chambered for long, heavy for caliber bullets and likely has a country mile of freebore. Don't remember the powder off hand, but mine had a 28" Krieger and it was running 75 Vmax at 3800 fps and it was about the most filthy thing I have ever seen on chucks. Broke them into a thousand pieces all approaching escape velocity. Just filthy. The long ago, infamous "Taliban chucks" video clips that were stolen from me and posted across the internet were with that rifle and load.

The rifle was not accurate enough to satisfy me though, averaging 5/8" groups with the best load I could come up with. So down the road it went. Available brass quality at that time was, well, it was crap. No idea what is available now, but the crap brass was another sore spot and another reason to send the rifle on.

But with your twist, I think 2,000 rounds to go is very optimistic. I'd put it at less than 1,500 starting brand new. But also with your twist, and likely long throat, heavier bullets may well do better for you. Of the lightweights you've listed, I've had good results from both the Nosler and Sierra 55's on 'chucks (and coyote too, for that matter). But whatever shoots best, is what it is.

Old pic of mine on a p-dog shoot.

I'll look to see what powder(s) worked best for me with the lightweights.

- DAA

 

[Sgt_Mike]

@DAA
I did before posting the thread shoot some 68grs loaded with Win 748 @ 43grs, to fireform some cases. I averaged /held at most 1/2" MOA in the factory case configuration load, no load development, just what I had left over from the 722. As in total of 10 rounds, 1 to check if the brass filled out correctly the other 9 in three shot groups for a rough idea.
I do know that the win 748 is a bit fast for the AI, but toned down enough should work to fireform my existing brass (some). Just loaded some more for fireforming again Win 748. Old powder that I don't load for anything else, so rather than sit on the shelf and go bad... This time with some of the 85 gr SGK's varied the weight on the charge (0.3grs) to see if there is a sweet spot or not stopped at the recommend 42.2gr top load per Hodgdon.

But with your twist, I think 2,000 rounds to go is very optimistic. I'd put it at less than 1,500 starting brand new.

You are probably right, but a guy can wish lol... besides my intent (dangerous word there) is to kind of hold in reserve, for when out of the AR's range or when the AR's are heated up.

On the freebore / throat I haven't checked it yet. So yeah you are most likely spot on, but I have seen long throats do well with shorter. But I do know that the odds are stacked against me on that. Hard I might add.
I normally would have preferred the 1-12" to 1-10" twist rate with the original .244 reamer (short throated / freebore). However I do know that a quick call to Dave Kiff could net me a reamer for the AI with the short throat.
But I picked this one up in a pawn shop, and the guy had no clue the twist. I did look down it and looked at my buddy and said it's faster than a 12 twist how much I don't know. It's a gamble at this rate.
Like you said I might have to shift it's purpose to the heavies in order to shoot acceptable groups. Or be stuck with the 70gr offering if they will hold a decent group at range. Everything you mentioned is in the back of my head when I made the purchase, so yeah might be spinning my wheels here.
BTW beautiful rifle Sir. And thank you for your response

 

[DAA]

I just dug up old notes. Looks like I tried quite a few but N-550 and Big Game were the powders that worked best for mine with the 75's. And it shot them notably better than lighter bullets, for whatever reason.

If you want a reamer that actually matches the print you send in, especially the throating, you might want to look elsewhere than Kiff. I've had terrible luck with him, like a print with zero freebore and a reamer with .050 freebore. JGS seems to be the go to these days. Got a .22 Dasher barrel back a couple weeks ago that used a JGS and it actually has zero freebore and a tight neck as specified.

- DAA

 

[Sgt_Mike]

elsewhere than Kiff. I've had terrible luck with him, like a print with zero freebore and a reamer with .050 freebore. JGS seems to be the go to these days. Got a .22 Dasher barrel back a couple weeks ago that used a JGS and it actually has zero freebore and a tight neck as specified.

Now that you mention it, I do recall reading your troubles with the Dasher and PTG. Thanks for the reminder, JGS yes familiar with them too as well as Manson
N-550 / Big Game ... Thank you I'll keep that in mind I did see some data for Big Game (Sierra). I'll scrounge around for the upper and lower side of Vit N-550. If nothing else a call or e-mail to the US office might yield a range on that powder for the case.
Again Thank you.

 

[steve garrett]

I've only had one 6AI and it was a long time ago. I'd have to dig up some old data to remember what powders worked well for me. Mine was very different though, as a 12 twist, with short freebore. It was on a L579. Yours being a 7.5 twist, was no doubt chambered for long, heavy for caliber bullets and likely has a country mile of freebore. Don't remember the powder off hand, but mine had a 28" Krieger and it was running 75 Vmax at 3800 fps and it was about the most filthy thing I have ever seen on chucks. Broke them into a thousand pieces all approaching escape velocity. Just filthy. The long ago, infamous "Taliban chucks" video clips that were stolen from me and posted across the internet were with that rifle and load.

The rifle was not accurate enough to satisfy me though, averaging 5/8" groups with the best load I could come up with. So down the road it went. Available brass quality at that time was, well, it was crap. No idea what is available now, but the crap brass was another sore spot and another reason to send the rifle on.

But with your twist, I think 2,000 rounds to go is very optimistic. I'd put it at less than 1,500 starting brand new. But also with your twist, and likely long throat, heavier bullets may well do better for you. Of the lightweights you've listed, I've had good results from both the Nosler and Sierra 55's on 'chucks (and coyote too, for that matter). But whatever shoots best, is what it is.

Old pic of mine on a p-dog shoot.

I'll look to see what powder(s) worked best for me with the lightweights.

- DAA

thats a pretty spiffy looking shootin iron there dave. must have been in a mood for the "high power" option that day on the prairie dogs.

 

[DAA]

thats a pretty spiffy looking shootin iron there dave. must have been in a mood for the "high power" option that day on the prairie dogs.

It was a looker for sure.

- DAA

 

[Sgt_Mike]

But also with your twist, and likely long throat,

I actually did find contact with the land and grooves (70gr Nosler FB Varmageddon, and a 69gr FB, luckily both have same profile) @ 2.950" COAL ( the Hornady comparator measures that at 2.4715"). Backed off 0.020" from there to start the seating depth base line. Which honestly I did not expect to be able to make contact with those two.
The 85gr Sierra SGK I figured I would, but not the FB ones. Hopefully things will settle down a bit around the house so I can do some range / trigger time.

 

[Badbrass]

Nosler 55gr Varmageddon
Nosler 55gr BT ( the 722 in .224 Rem in the 1-12" T really like those)

I use them interchangeably. Both print one hole results in my "junk yard" 6mm rem not AI, 26" barrel. It's a 1x12 twist, so the biggest I shoot is 85 gr. They are ramped up to 4200 fps. For deer, big deer 400 yards + the 85s slap them like the hand of god.

 

[Badbrass]

The 85s are ttsx 3600 fps

 

[Sgt_Mike]

Both print one hole results in my "junk yard" 6mm rem not AI, 26" barrel. It's a 1x12 twist, so the biggest I shoot is 85 gr.

Yes, I have the regular 6mm Rem and the AI in the 6mm Rem / .244 Rem .
The AI is a fast twist the Regular a slow, but like I said the 722 just has too many rounds down the barrel. But will shoot the 55gr noslers still, any thing else not so much.
That is the problem that prevents a new barrel, as well as just prefer it to keep it's barrel. Although I know it would be better to rebarrel, /or rechamber. That family the .243 /6mm Rem like Dave eluded to is not really known for a long throat life.

I seen one gentleman I know decide to actually push his .243 AI (fast twist, brand new Krieger barrel) hard with every bit of Retumblo he could get in the case .. Throat was toast in 500 rounds. Now that was to his match standards, not minute of deer or game which honestly moves that point to a higher rounds count. As the standards are a bit more forgiving.

The AI is scratching that itch, so to speak. I've always like the Ackley's. Just really like that 40 degree shoulder angle.
Just looking at the load data from Sierra, in the 55grs I'm not seeing a great improvement with the AI, but moving up in bullet length and weight yes there is a slight advantage to the AI.

For deer, big deer 400 yards + the 85s slap them like the hand of god.

I figured the 85gr weight class would be good for this application. Although I'm using the Sierra vs the Barnes (only because I have the Sierra's on hand and can get then locally.
Hopefully they work.

 

[Sgt_Mike]

Honestly just a update as I just feel the need to post boredom maybe???? Or just excitement with a new caliber? one or the other I'm sure.

Yesterday finally got to the range, mostly had fireforming loads. Which most did well in the groups as well as the fireforming, save two pieces which came out the chamber looking like a Weatherby round. Not sure if it was neck tension or even got skipped in annealing the neck and shoulder area?? But the other 18 formed perfect everything was the in the load was the same. Didn't see any leakage around the primer. Next outing will finish those two off properly. So non issue.

Left is the 6.5 CM for comparison, then the 6mm Rem / .224 Rem Factory, next a fully formed 6mm AI, the far right is one of the two rounded shoulder like a Weatherby case

I did have enough fireformed to try a idea with a faster powder than conventional wisdom. Using 68gr moly coated FB bullet ( not sure but I think is the discontinued Berger lineup). There was two loads of H335 36.8gr netted a 0.790 CTC 5 shot group. 37.1grs netted a 0.695 CTC both 5 shot group. According to Sierra's data Velocity (for the 6mm AI) should be 3300 to 3400 (36.5-38.8grs). Not actually worried about velocity until the load is established. Keep in mind that those groups was After 60 rounds of fireforming from a clean bore may have been better who knows.

Once I get caught up some, I'll head my tail to LR to procure some more "appropriate" powder selection. Big Game, IMR 4350 (getting low on the shelf), maybe some StaBall 6.5 just not sure but should work.

Now to increase the above loads by 0.3grs and see how it will perform if it falls apart or tightens up. Once I get in the middle of a node I'll mess with the seating depth. My idea for this powder was being faster in the burn charts, should be "cooler" than a slower quicker powder in the throat. My observations was the barrel stayed at a fairly decent temp (I could hold it comfortably) until the 6th shot, at which point it warmed up to the well I need to let it cool down a bit mode. Which worked great shoot five cool shoot five more cadence. "IF" the barrel profile was another 0.100" bigger at the muzzle, it should have helped with this, as well as slightly stiffened the barrel. But it is what it is so to say.

This morning resulted in a care package from @hm1996, Thank you Clarence the brass, & bullets will come in handy. Once looking at the Hornady 87gr BTHP I was surprised to see how much the older Hornady product matched the Sierria 85 gr SGK in profile of the ogive etc. I know the newer offering of that bullet has a quite different ogive.
I then set in and annealed the once fired (55) to put in the rotation for forming to accompany the 71 already fire formed.
The remaining brass that he sent is held in reserve.
I had mentioned to Clarence that the stock for what ever reason still retained the pressure point at the end of the stock. Even though the previous owner went through the trouble to bed the action. I debated removing it, finally today in between writing this and doing other things, I floated the barrel via opening the barrel channel ever so slightly. I may have messed up doing that but I'm sure one can fix it.
Only things left to do today clean the rifle bore, grease the bolt lugs after cleaning. Inspect the fireformed brass again after the final tumble in the vibratory tumbler for flaws (I use the walnut Vibratory tumble to make sure all the pins are removed after the SS pin cleaning. over kill? yeah it probably is.) . And load some more for when the range opens on Wednesday. Which I'll know for sure then if I made a bad choice with the stock.

 

[Sgt_Mike]

pulled out some fireformed cases then set up the loads fired them today. The Berger 68gr FB Target moly with H335 seems the most promising. Why H335? I have several pounds on hand. Yeah it's a bit fast for this case.
Ran from 36.8grs to 38.6grs (0.3 grs increments) no adverse signs of pressure
Test 4 (37.7gr set CBTO @ 2.451" 0.010" from jam) 5 shot group 0.537 CTC, 0.537 MOA, this seems to be the sweet spot to settle in
Ran Test 2 load twice ( 37.1grs with same seating depth as above) shot a 0.828 and a 0.695 CTC, shot on different days.
That bullet and powder combo netted me sub MOA from 36.8 to 38.6grs. Worst 5 shot group was 0.954 CTC.
According to Sierra load data that range should be 3300 to 3400 fps.

I thought great the rifle like a bullet that is discontinued, to my glee I found out they had only dropped the moly option. I've fired both moly & non moly no difference the rifle does have a weakness for this bullet.
Not that velocity is more important than accuracy, Candidates for more velocity on that weight class look like Varget, IMR4895, IMR 4350 , and Big Game, but has to hold the accuracy.


Then played with the Sierra 85gr and Varget... only had 1 node at 40.0grs that produced under a inch, then went up 0.3gr and the load blew out 1.116" CTC. Down 0.3grs same effect.
Not sure if it's bullet or powder. I'm thinking that DAA was on it with big Game Powder, and I'm thinking it's powder. Just have to head to Little Rock to get a pound and try with this weight class. (but for deer /hogs under 1.5 MOA 5 shot group would work to harvest game)
According to the Sierra manual I have there is no listing for Big game data with that bullet combo.
I did find it (Big Game) listed with Hodgdon's with the Regular 6mm Rem, Topping out at 43.5gr with a 87gr Hornady BTHP. Thoughts are drop about a grain and work up as the increased case volume will net less pressure. Just have to work up slowly.

Now to throttle the LGS into ordering some Noslers in 55gr and 70grs ....
Thank you for reading
Respectfully
Mike

 

[Sgt_Mike]

Now to throttle the LGS into ordering some Noslers in 55gr and 70grs

I do have a bit (20 -30) of the 70grs Varmageddon FB on hand and refraining from actually playing with them until I can get another box on hand. Past experience is that with them and the NBT usually shoot well across the bore sizes.
I'd hate to find "the load" and not be able to have at least a box of the bullets on hand. Thus the comment I made above, I need to add a box or two of the Bergers as well.

H335 so far has produced under 1 MOA with the 68grs 37.7grs +/- 0.1gr has my interest as a go to load. For anything heavier than a 70gr bullet, well H335 is simply to fast a burn . Meaning the conversation with Sierra's ballistician I had comes into play, at greater than that weight (70grs) the powder has a tendency to spike quickly. So not a good choice for the 85gr SGK's.

I have been using W748 to fireform with, and noticed that they seem to do pretty well with the factory Remington chamber sized brass fired in the Ackley chamber. Thinking I maybe overlooking a powder, I'm going to try that powder in the Ackley fireformed. So I also threw together two test groups with the 68gr Bergers, and three test groups with the 85gr Sierra Game Kings with W748. (the other thought is it is closer to Big Game's burn rate. Although faster, and not by much, W760 is a bit slower than Big Game, StaBall 6.65 is a bit slower than W760). The ONLY hold off on trying Big Game has been the drive to Little Rock, I just hate driving in that town. Which is the only place I know of close that has that powder.

Also, the 722 (.244 Remington) when I first got it, gave me fits in the accuracy department. Until I put some 55gr NBT and IMR 8208XBR together shot like a house on fire.
Figured I would couple that powder and the 68gr Bergers for two test groups. As the 721 Ackley seems to like the 68gr Bergers every time I've assembled a powder bullet combination.

Ammo is loaded, gun has been cleaned from the last outing, Just dried the bore from the Kroil / Hoppes #9 cleaning after firing. Once everyone gets up and settled I'm in hopes to head to the range in a bit.
(fingers crossed, no drama once they get up, otherwise I'd already be at the gate waiting for them to unlock it.. hahaha)

edited and added later:
shift to IMR 8208XBR and W748 results, with the 68gr Berger.
45.3grs W748 had a 0.851" group (5-shots).
43.3gr IMR 8208XBR had a group of 0.834" (5-shots).
I did attempt to try loads with the 85gr SGK, sadly lost the results so back to square one, on that combo.
None of the combos presented pressure. The statement of DAA about brass quality lingered, so I checked the necks on 15 pieces of brass, many which after fired wouldn't allow the bullet to seat by finger pressure in the neck. And could actually be loaded without sizing. So I sat in and turned the necks to make them a little more uniform (50 pcs). The thought of shifting to using either 7x57 or 6.5x57 brass came to mind. But I thought the neck turning of the 6mm Rem brass would assist to getting to a charge quicker many. At minimum reduce one variable. Not expect it to really cure anything much.
The supply of Berger is getting low, so until more can be ordered in I guess I need to shift projectiles, to the Sierra's for a bit. Going to use the Sierra #1530 85gr Game Kings and Hornady #2442 87gr BTHP for a bit.

Added 16 Nov 2025:
Decide to attempt to see if Winchester 6.5 StaBall with it's slow burn rate (than H4350) would produce positive results with the 80gr to heavier. Picked up a Lb to try.
No true Ackey data exists although I did request form Hodgdon.
My start point was from 6mm Rem load data from online Hodgdon website with a 87gr bullet @ max charge (47.5grs) +0.3grs, then incrementally up by 0.3grs to 49.0 grs.

Using math and it has a great fault to it, the Ackley case is 9% greater capacity. I calculated the max charge of that powder (Remington 6mm load data for a 87grs bullet) added 9% the result was 49.875grs. I know that this is NOT accurate or even safe calculation. Merely a rough idea, I guess to see where the pressure might be, and to see if there is a correlation in reality of where the upper pressure actually is by sneaking up on it at 0.3grs at a time. I'm expecting to hit that mark before the 49.0grs that I have loaded and stopped at. Would be interesting if they did correlate together. But I doubt it and consider it a unsafe practice. Just sharing a thought which I think is flawed.

Added on 17 Nov 2025:
Doing this method of just updating a existing post to keep the clutter down, and honestly a sounding board / notes vs bothering everyone with thoughts.

Going over the cartridge, it's limits, capabilities, and pitfalls. It is one sexy looking round, then again so is the 243 Ackley. The 6mm AI has definite advantages, although it honestly is a bit beyond diminishing returns, I'm getting to a opinion that the regular 6mm Rem case is the actual point of diminishing returns. There are more efficient cartridges. The 243 AI, 6x47L, 6mm CM, and the 6mm Dasher are just a few that come to mind.

Although the 6mm AI is a true hotrod among them. I'm not condemning the 6mm AI just out loud debating IF I would go down the route with a new barrel when the time comes, or simply rechamber to more efficient caliber. The parent case is pretty close to the Ackley so far, but I've not fully explored where the upper limit actually is with the Improved case. I'm glad that the rifle was chambered in the cartridge as it allowed me to explore the Ackleys a bit. I've been turning necks on some of the fireformed brass to see if a difference shows up. I have been debating attempting some X57 cases (7x57, 6.5x57) to see if the uniformity is improved vs the .244 Rem /6mm Rem cases offering.

I've not shot the rifle since picking up the 6.5 StaBall powder, Although yesterday I did pick up some 108g ELD-M bullets to try, which should be a hoot. Right now the action is out of the stock scope and bases removed ready to have the barrel pulled and threaded for a suppressor. Hopefully today, which would put me back on track for shooting this Wednesday / Thursday time frame to test the powder / bullet combos. Rounds are loaded . It has been a fun cartridge so far, no bad manners in the quirks department thus far.

 

[Sgt_Mike]

The Win 6.5 Staball didn't pan out in the 6mm. Did work well in the CM though.
Winchester StaBALL Match powder and the 85gr SGK results.
I did turn the necks in this batch of brass to even out the 0.003" variance a bit.
At 43.1 gr no pressure signs in the Ackley case.
Load data for the 6mm Remington case, with the 85gr SGK with the Winchester StaBALL Match powder is supposed to redline at 40.7grs per Hodgdon.
So I'm not surprised that the Ackley case can handle the almost extra three grains versus the parent case, debating on trying 43.4gr +.
Results for today:
41.0gr - 1.500" CTC
41.3gr - 1.492" CTC
41.6gr - 0.696" CTC
41.9gr - 1.193" CTC
42.2gr - 0.874" CTC
42.5gr - 0.874" CTC
42.8gr - 0.680" CTC
43.1gr - 0.760" CTC

The node at 41.6gr looks too narrow for my taste. However the other node of 42.2gr to 43.1gr is pretty wide and looks to be the most promising for seating depth adjustments. 42.7grs looks to be center of the node, for seating depth adjustments.
Yeah the throat /"freebore" is a bit longer than I would have set for my purpose.
COAL is sitting at 2.864" or CBTO 2.493" with the Hornady comparator tool. I had originally thought I was away from contact with the lands, only to find out that I was in fact touching with above load. My thoughts are to start with seating a little deeper to see where the "sweet" spot on seating depth is. Below is where I will attempt to see on the seating depths for this bullet.

C.B.T.O	C.O.A.L	Bullet	Powder	Charge Weight
2.490​	2.865​	85gr Sierra #1530 HPBT SGK​	StaBall Match​	42.7 gr​
2.487​	2.862​	85gr Sierra #1530 HPBT SGK​	StaBall Match​	42.7 gr​
2.484​	2.859​	85gr Sierra #1530 HPBT SGK​	StaBall Match​	42.7 gr​
2.481​	2.856​	85gr Sierra #1530 HPBT SGK​	StaBall Match​	42.7 gr​
2.478​	2.853​	85gr Sierra #1530 HPBT SGK​	StaBall Match​	42.7 gr​
2.475​	2.850​	85gr Sierra #1530 HPBT SGK​	StaBall Match​	42.7 gr​

While I have to yet pick up a pound of a suggested powder Big Game. Only because of the drive to where I know does stock it. It's not the distance it's the traffic with folks I lovingly call idiots when I'm driving there. I've tried to get as close to that burn rate as I can find locally. And yes it does help that there is a pretty decent cost saving per pound to try the StaBALL line.
(below copied from Hodgdon's burn rate chart)

114 Win 748
115 Win StaBALL Match
123 Big Game
130 IMR 4350
133 H4350
138 Win StaBALL 6.5

 

[Sgt_Mike]

Have not taken the loads above to the range to see on the bullet seating yet.
Once I get those ironed out they will be the Hog / Deer loads, for the future.

But thinking I would see where the upper side in pressure for the Ackley is with some 108gr Hornady ELD-M's and the StaBALL Match powder. These I really do not see a useful purpose for this exercise other than just to know, and settle curiosity. For varmints, I'm inclined to the 55 to 70gr, which one? Well accuracy and cost will dictate that. As the main purpose for me to buy this rifle was exactly that varmints, not hogs deer or long range shooting. But nothing wrong with simply knowing what the ole girl is capable of in each of those roles.

C.B.T.O	C.O.A.L	Bullet	Powder	Charge
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	38.7gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	39.0gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	39.3gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	39.6gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	39.9gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	40.2gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	40.5gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	40.7gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	41.0gr​
2.528​	3.077​	108gr Hornady ELD-M​	StaBall Match​	41.3gr​

These should be about 0.010" off contact with the ogive and the throat so pressures should not act erratic. As I mentioned before the StaBALL Match powder is listed under the regular 6mm Rem data section. Although Sierra does have data for the AI, they don't have data for that powder.
Once the Barnes 68 gr Match Burners get here, I'll turn my attention towards them.

 

[Rockchucker ll]

Why not buy the 722 and go from there? The 244 and 6mm were short action.