Absolute MOST horsepower from SA w/ Standard Bolt Face? (Cartridge Options in AI AT)

[LongRangeJunky]

Hello gentlemen,
Say you were limited to AW mags with an internal length of 2.98" and a standard bolt face, however you wanted to achieve the utmost in ballistic performance for some hunting/LR shooting (not PRS type shooting). What cartridge would offer this?

My studies left me with both the straight .284 Winchester or the necked down 6.5x284 Norma. Research shows that the 6.5x284 may not work with modern high BC bullets as the Ogive COULD be beneath the necks. One article showed the .284 Win reaching about 2,950 fps and 160 grain projectiles while staying under 2.98 COAL.

I reload for .223, 6.5CM, 6.5 SAUM and 7 SAUM. I LOVE my SAUMs but in this hypothetical scenario we are limited to SA w/ .473 bolt face.

What cartridge stays at approx. 2.97 COAL and delivers a 6.5mm or 7mm projectile the fastest and hardest?

Thanks for any insight.

 

[Supersubes]

A 284 based case isn’t going to fit in an aw mag because the shoulder will hit the rib inside the magazine. Probably your best bet is a long throated 6.5 SLR. Pretty sure the shoulder is in the same location on those, but larger diameter. A long throated .260 would be right there.


Either of those necked to 25 cal for a 131 blackjack bullet would stomp the parent cartridges pretty good in drop and drift. Should be able to push it to 3050 on the high end with either of those. Put that in your calculator with a .350 G7 and see what it looks like.

 

[LongRangeJunky]

A 284 based case isn’t going to fit in an aw mag because the shoulder will hit the rib inside the magazine. Probably your best bet is a long throated 6.5 SLR. Pretty sure the shoulder is in the same location on those, but larger diameter. A long throated .260 would be right there.


Either of those necked to 25 cal for a 131 blackjack bullet would stomp the parent cartridges pretty good in drop and drift. Should be able to push it to 3050 on the high end with either of those. Put that in your calculator with a .350 G7 and see what it looks like.

Thanks for the reply! The reason I thought it could work is because I called Mile High and discussed it with someone who seemed fairly knowledgeable. He was 100% certain the 284 or even 6.5x284 would fit, function and feed in AW mags, and feed into an AI AT. He said worst case scenario I would maybe need to bend feed lips out just a smidge. I will definitely look into your suggestion.

 

[Supersubes]

The shoulder of the 6.5-284 is at 1.770.

I wonder if he was forgetting about the rib.

 

[Jabot]

Maybe the 260 ai out of a 28" barrel with a 140 Gn Berger or 130 hybrids. Might be pretty cool

 

[natdscott]

.284 Shehane.

If a 284 case won’t fit, then yes, a 6.5 SLR is going to be near the top of the list.

 

[6brshooter]

6.5slr would be solid, but isnt going to be any stouter than 260. It does have a better case shape

 

[Steel head]

Long throated 260 or 6.5 SLR.
147’s at 2800 should be easy with a R16.

7saw is possibly an option as well

 

[BLKWLFK9]

.25CM with the 131s. Done

 

[RyanScott]

7SAW.

 

[Sniperwannabee]

Accuracy International 223 conversion working

I needed a little bit of advice and opinions on this kit. I’ve been getting a few PM’s on the kit since Frank mentioned it. I have a working 223 conversion that we’ve made at the shop. It fed factory ammo really well with a slight stall maybe 4-8% of the time. I can’t get it replicate the issue...

www.snipershide.com

not sure if you be interested but
Gilbert is really close to making a 6.5 prc and 300 wsm conversion for the AI SA platform

 

[natdscott]

.25CM with the 131s. Done

He said 6.5 or 7.

I could have as easily said .338 Federal.

 

[Yote Klr]

The most VELOCITY I've acquired in a SA standard bolt face was a 6mm Rem Ackley Improved. 105 Hybrids at 3350 fps...for 700 rounds.
But to answer the question probably a 6AI.

 

[LongRangeJunky]

Accuracy International 223 conversion working

I needed a little bit of advice and opinions on this kit. I’ve been getting a few PM’s on the kit since Frank mentioned it. I have a working 223 conversion that we’ve made at the shop. It fed factory ammo really well with a slight stall maybe 4-8% of the time. I can’t get it replicate the issue...

www.snipershide.com

not sure if you be interested but
Gilbert is really close to making a 6.5 prc and 300 wsm conversion for the AI SA platform

If that is true then I will most likely go with the AI. I am a SAUM addict and the lack of magnum bolt faces for the SA AI's has given me pause. I am currently debating on going with an Impact build with a few barrels (223, 6Cm and 6.5SAUM) or holding out for the AI and trust that a working 223 and SAUM bolt can happen!

 

[natdscott]

Wonder how fast a .22-243 Middlestead could push an 85 Berger.

 

[Sniperwannabee]

If that is true then I will most likely go with the AI. I am a SAUM addict and the lack of magnum bolt faces for the SA AI's has given me pause. I am currently debating on going with an Impact build with a few barrels (223, 6Cm and 6.5SAUM) or holding out for the AI and trust that a working 223 and SAUM bolt can happen!

its coming

 

[Dolomite_Supafly]

I wonder how a 375 SOCOM would work with pointy bullets loaded to 2.98” instead of short, flat bullets loaded to AR Mag length. It uses standard .473” bolt face.

Feeding might be an issue.

 

[redneckbmxer24]

I’d pick a normal round like 6.5 Creed or 6.5x47 and learn to shoot better.

 

[natdscott]

I’d pick a normal round like 6.5 Creed or 6.5x47 and learn to shoot better.

Oh stfu.

You’ll give away all the secrets.

 

[Simia Dei]

My vote goes to a 7mm SAW with 162 ELDs and RL16. I had no issues getting them safely to 2860fps, I currently run the 160TMK with RL16 at 2840fps. 26" barrel. Pick your flavour of 160gr class projectile and choose between Varget, H4350 or RL16. 2000MR was bloody quick by comparison but no where near as temp stable

 

[BallisticPrimate]

Checkout the 6.5 Addiction (Swedemoor). 147gr ELDM's at near on 3K

 

[LongRangeJunky]

Checkout the 6.5 Addiction (Swedemoor). 147gr ELDM's at near on 3K

Thanks for the recommendation. I'll take a look at it!