Ackley Improved Questions

[Scarface26]

Gents,

I'm investigating the Ackley Improved chambering as a means to reduce or eliminate brass trimming. Has anyone any experience in this arena? Looking at .308, 30-06 (lots of info on this one), and 300wm.

Are there any issues with feeding? any issues at all? How do parent rounds usually shoot when fired out of the AI barrel?

My smith, Matt Stewart, is extremely talented and affordable, and re-chambering the three barrels in AI is going to cost me roughly the same as the Giraud - hence my question.

Thanks in advanced God bless America

 

[Sheldon N]

Get the Giraud.

I've had multiple different Ackley or improved cases and like them, but I woulnd't want to AI any of the options you listed.

 

[Hondo1]

I love the idea of the AI cartridges but in practice I’ve learned that all of the fire forming isn’t worth it. I currently shoot the following
.338 Lapua AI
.22-250 AI
.223 AI

Of the three the .338 was the most worth while endeavor.

 

[Scarface26]

Gents, thanks for the replies.

 

[Bradu]

I like my 223 ai and have a 22-250 ai barrel I still haven't shot. I wouldn't go ai just to get out of trimming. I don't mind fire forming, it's good practice so I never understood what the big deal is.

 

[Hondo1]

I like my 223 ai and have a 22-250 ai barrel I still haven't shot. I wouldn't go ai just to get out of trimming. I don't mind fire forming, it's good practice so I never understood what the big deal is.

You’ll understand the big deal when a quarter of the life of your.22-250 AI Barrel is used up just making brass.

 

[Bradu]

Barrels are consumables, if I was worried I wouldn't have bought that caliber in the first place lol

 

[Scarface26]

Gents,

Thanks for your replies and I'm leaning towards the Giraud trimmer head for each of the calibers. At $98 each it's still cheaper than the machine and will save me a ton of time. If I'm smokin crack on this thinking you've got until tomorrow to rescue me from myself, the I order the 3-way trimmers.

Hope you never miss
God bless America

 

[spife7980]

The giraud is a god send for brass prep. Prep went from being the step with the most time spent per piece to the least.

 

[waveslayer]

Buy a Hydro forming die from Whidden to make your AI brass. Then you are not wasting your barrel life. I run a .338 Norma AI. Love it

 

[mdmp5]

Never heard of 308 AI, nor in 300WM.

 

[Scotts556]

I have a 260 AI. I can get the 147 gr ELD-m to 3000fps +. I love mine and will be doing another 260 AI in the next barrel. Brass seems to grow way less.

 

[Forward543]

I found fire forming the hardest part on the .280 ai. I was losing 15-20%. Started running nosler 280 ai brass and have no issue. Get the giraud. And later get an ai chambering on a custom barrel.

 

[DrainTheSwamp]

I have a 260 AI. I can get the 147 gr ELD-m to 3000fps +. I love mine and will be doing another 260 AI in the next barrel. Brass seems to grow way less.

What barrel length?

Anyone have real world data on velocity gain for 223 heavies (69 and heavier) before and after AI?

 

[Hondo1]

What barrel length?

Anyone have real world data on velocity gain for 223 heavies (69 and heavier) before and after AI?

3060 running 75gr Hornady’s. That’s AI I don’t have s baseline on a standard chamber.

 

[Bradu]

I'm getting 2858 fps out of my 223 ai with an 80 grain amax and a 16.5" barrel

 

[DrainTheSwamp]

Those are awesome velocities. Feed out of AICS mags fine? Any one try one in an AR platform?

 

[Bradu]

I'm using mdt mags right at max mag length. Every once in a while it wants to catch but all I do is slightly pull the bolt back and it goes in fine from there. It did it with regular 223 so I would say its more of a mag issue than anything

 

[Scotts556]

What barrel length?

Anyone have real world data on velocity gain for 223 heavies (69 and heavier) before and after AI?

26 inch

 

[spaniel]

If properly headspaced, the parent cartridge will be a slight crush fit in the chamber. This holds it firmly while the shoulder blows out.

I don't get this "using barrel life to fireform" piece. My fireforming loads are high end loads of the parent cartridge and shoot very accurately - I did not load develop them and they were .5 MOA. If you aren't competing where extreme accuracy matters just shoot them as the parent round and be done with it. Once you collect enough formed cases you can load develop. Since the brass last longer without having to trim them, your first barrel may give you plenty of cases to get through a decent part of the second barrel.

My current AI is a 243 and it's totally worth it. I'm always trimming regular 243 for my buddies, but I am on the fourth loading of the 243AI rounds and they have not grown. I bet I have to trash the brass for primer pockets before I have to trim them.

The 308 and 30-06 don't gain a ton from AIing them, but if it's for brass prep why not? The 300WM is already a sharper shoulder, I think I've gotten 8 loadings on WM brass without trimming, I think I'd just shoot that one as it is.

 

[DAVETOOLEY]

There's an easy way to fireform brass that's easy on the barrel. Shotgun powder and instant grits or cream of wheat.
22 cal about 8 grs of unique and fill with instant grits
6MM 10 grs
6.5 12 grs
7MM 14-16 grs
30 cal 16-20 grs.
338 20+ grs.
Adjust powder charge as needed

 

[Scotts556]

Your not wasting barrel life fire forming. if your gonna go AI youll need two loads. One to fire form and your regular AI load.

When I used Lapua brass my load was 40.1 of H4350 under and 140 Nolser custom comp (I'm cheep. you can use you regular bullet if you so choose) for fire forming.

And my AI load was 43.5 under a 140 Berger hybrid target.

I used the fireforming load for local club matches, going out to shoot with buddys and general range practice. Easy on the barrel. Shot like regular 260 REM and the plus side. I could practice, shoot matches, go screw off with my friends and come home with fire formed brass.

I just purchased 200 Pieces of alpha munitions 260 REM small primer pocket brass to try out since getting Lpaua 260 REM is hit or miss. Ill be working up two loads. First one being 140 Nolser Custom Comps and h4350 for fire Forming. The Second is RL26 behind 147 ELD-M's so I can get that wonderful 6.6 Mils at 1 K

I do not agree at all with the cream of wheat method. A your wasting primers and powder that can be used for something else. I'm purposely blowing stuff down my barrel that has no reason to be there. And if done wrong, can and will damage your rifle. I watched one of the guys I shoot with fire forming brass with this method damage his rifle, It cost him his muzzle break. The cream of wheat blew the third baffle almost off the break. Looked like it was pealed back like a banana peal. Having a good accurate fire forming load is not wasting barrel life. It'll still shoot good, and is good ammo for local matches or practice sessions.

Scott