700 AAC-SD 223 16.5" accuracy questions

[hoguer]

So I picked up a AAC-SD 223 16.5" recently because my big bores are expensive and boring to shoot at 100 yards and now that I live in the city that's all I have within a hour drive. I jazzed her up a bit to keep things interesting but I'm just not getting the accuracy I would expect. I know I may be spoiled by my custom built rifles that shoot sub 0.5" and I may just be jaded but I was looking for input.

Specs
Rifle above
AICS 2.0
Timney 515
Seekins 20moa
ARC M10
Bushnell HDMR with H59
AAC Blackout flash suppressor
PCR Phoenix Bolt Knob

Now I think that's a respectable build for a budget weekend plinker, but she has been a bit of a disappointment. I started off with some bulk 55gr reloads that I burn through my ACR with satisfactory results, and I was getting probably 5"+ groups at 100. It was literally humorous how random my POI were. That was day 1 so I was so blown away I took everything apart and re torqued it to make sure I was GTG. My seekins base actually fit quite well with no need for bedding and the action is way smooth for a factory rifle, I am happy there. I ordered some FGMM 69s and took her out today. I had a few boxes of PMC Bronze 55s that I shot first to try and I was probably 3" then the FGMM was pretty consistent at 1.5" with 3 tight and 2 randomly opening up. While I'm no professional, I can shoot 100 yards comfortably with my 300WM Proof Research unit sub 0.5" 5 shot groups so I don't think it is me, but who knows.
Should I try some 77g FGMM? Is this what I should accept that it is what it is and understand that if I want more I need work done or cook some loads up myself (not a option at the
Moment, everything is in storage)
Straighten me out people!

Quick shot of today

 

[cav1993]

Talk to FCS , he'll roll ya up some sweet ammo!

Ill try to post some pics soon. From my rem factory 223, his loads with berger 70 gn and 65 sgk hammer! He's also got a few other bullets that work well!

 

[ptaylortx]

I've had horrible luck recently with new production Remingtons. My aac-sd would be doing good with reloads ,seated inside mag length, to group 2". Way too much throat and the chamber wasn't concentric. Having it re barreled. I love all my 700s but I'm done with factory barrels and chambers. Custom only.

 

[Ol Rob]

I have the same rifle, but suppressed. It likes 60 gr Noslers and 69SMK's. My first shots were in the 1 inch range. You might have a crown issue. Just a thought.
Rob

 

[58blackflag]

My SPS Tac .223 shot the Hornady 75gr match loads extremely well.

 

[BoilerUP]

While FGMM is the 'standard'...try Hornady 68 and 75gr Match ammo.

 

[Lazer]

Here's a target from Friday. 5x5 at 100yds, only real upgrade was a manners stock w steel bedding. Mine wasn't consistent w heavies these are 52 smk, oh yea mine has a crooked chamber, .476 average!

 

[Deadshot2]

I picked up an SPS-Tactical in .223 last year for the same reasons you mentioned. Wanted something that wasn't as expensive to shoot as the "big bores".

Needless to say the stock rifle was no where near what I wanted for accuracy.

I went to work. First I ordered a Timney 510 trigger assy. I then dug out of storage the stock I'd taken off my 5-R Milspec, the OEM H-S Precision "Varmint" stock. (there are usually a bunch of these for sale as "take-off's" for those interested in doing the same).

I'm becoming less and less impressed with the quality of machine work on the metal "action bedding blocks" so I did a little scraping on mine, added some shims around the action screw holes to make sure the stock would be supported about .020" away from the block metal, and then did a full bedding of he action to about 1-1/2" ahead of the recoil lug.

Using a Cabela's "Tactical" scope mounted on a Blackhawk 20 MOA rail (hey, I had it lying around), a Harris Bipod, and Accushot Monopod for rear support I took it to the range and shot this group during a load development session.

Two things I'd offer. First, bed the action even if it does have an action block installed. Unless the block was made by a custom builder and carefully fitted to YOUR action, they're all a compromise. One shop builds the block and another the action. They may or may not match up well and if they don't there's all kinds of stress built up in the action when the screws are torqued. As much as 1200# of tension on each screw if torqued to the full 65 in/lbs usually spec'd. due to the mechanical advantage afforded by a 1/4-28 thread pitch. Also, the heavy barrels, in my experience, benefit from some support in front of the recoil lug. This keeps the barrel from "flopping" as much with only the action/tenon supporting it. I will usually run the bedding out where the chamber ends as a rule.

Next, don't expect this kind of accuracy from factory ammo. Finding the right bullet, powder, case, primer, and OAL that works well in your rifle is key. Make sure to follow the bullet makers recommendations for weigth/twist rate match. This was done with a 73 gr bullet and a 75 gr bullet in this rifle that has a 1:9 twist doesn't even come close.

You'd be amazed what you can get even a factory rifle to do with just a good trigger, a well bedded stock, and a handload designed strictly for it's 'tastes". Nothing other than stock and trigger have been changed on this rifle, not even the crappy bolt handle.

BTW, I "ate" the Lifesaver while typing this post. Too good to waste.