Im intrigued by 280 AI

Road_Clam

Road_Clam

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*edited* actually after more thought this doesnt make practical sense from having to re-bore as well as rechamber.


So i've pretty much got my 11x29 lathe ready to start tackling some basic barrel threading. If i prove this to be sucessfull i want to have a go at a rechamber. I have some misc Rem 700 parts and specifically i have a 243 Varmint contour barrel thats almost new. Is it possible to rechamber 243 Rem to 280 AI ?
 
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You can do 243 Ackley for a boost. Or any number of 6mm calibers, from 6BR to 243 WSSM. Re-facing a bolt head for a caliber change is easy with older Rem 700s (riveted extractor) or it takes one extra tool for inset extractors.

I'd be content for the Ack chamber, it lets you do a barrel setback and rechamber. Then do the crown. You can fire form plain 243 to AI and make your own sizing die with a barrel stub and your reamer.

If you don't have George L. Hinnant's book, get it. It's pure gold. Buy it direct and send George the check, he's a nice guy.
 
pontiac428 said:
You can do 243 Ackley for a boost. Or any number of 6mm calibers, from 6BR to 243 WSSM. Re-facing a bolt head for a caliber change is easy with older Rem 700s (riveted extractor) or it takes one extra tool for inset extractors.

I'd be content for the Ack chamber, it lets you do a barrel setback and rechamber. Then do the crown. You can fire form plain 243 to AI and make your own sizing die with a barrel stub and your reamer.

If you don't have George L. Hinnant's book, get it. It's pure gold. Buy it direct and send George the check, he's a nice guy.
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Ok, absolutely will do on the reference book, i always prefer reverting to a hard printed reference manuals when trying to work through the processes. On a side note i currently have a varmint contour R700 in 300WM and its not pleasant to shoot long 20+ shot strings (even at 14.5# and muzzle braked). Been looking for a 1400 yd target option. Would i see better gains in ballistics and shooter friendly with 280 AI over my 300 WM ?
 
You would see better gains with a 6mm in my opinion. Right now, all the wanabee snipers shooting in PRS competition are slowly realizing that the 6mm long range performance is superior to the trendy 6.5 Creedmoor, and you are seeing a shift.

I shoot 1000 with 6BR, but 1400 needs more bullet mass and power behind it. Big difference in recoil between a 220 gr magnum and a 115 gr target load. To get to 1400, I think you should be looking at 155 grains and up in 6mm, which is perfect for the 243 AI. The 243 can make 1,000 fps more with the same weight as a BR, and the ackley gets 50-200 fps more than the vanilla 243 depending on all the variables. You will want every bit of 30" for your barrel at 1400 yds, or whatever the longest that the class rules allow. You will also be a lot better off without a muzzle brake.
 
Road_Clam said:
*edited* actually after more thought this doesnt make practical sense from having to re-bore as well as rechamber.


So i've pretty much got my 11x29 lathe ready to start tackling some basic barrel threading. If i prove this to be sucessfull i want to have a go at a rechamber. I have some misc Rem 700 parts and specifically i have a 243 Varmint contour barrel thats almost new. Is it possible to rechamber 243 Rem to 280 AI ?
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Is this a short or long action, Because 280 AI is a great caliber but it's not going to fit in a short action.
 
Road_Clam said:
I currently have a 300 win mag R700 in LA . Looking for something easier to shoot.
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In this case, The bolt face is too large on your magnum bolt and your magazine/feed rails etc are set up for magnum cartridges, Which the magazine issues can be solved with the use of a DBM, And Your bolt could be altered to feed 0.473 family of cartridges too, Or you could buy a standard bolt, But its not worth the expense and trouble involved. Just find a 30-06 length standard action if you want to go the 280 AI route.

But If it was me and I had that magnum action I would probably go with the 7mm PRC if I was contemplating what you are and had what you had to work with.

1678834555144.png
 
If hitting 1400 and reducing recoil is the goal, the 7mm does it well. Good BC, but sending 180 grains at 2800-3000 fps hogs a ton of powder, and the recoil is still pretty stiff compared to target calibers. The 7mm case selection allows anywhere from 55 to 80 grains of powder. Very good at range compared to the 300, it would be a great improvement.

I like to shoot a lot so I like to keep powder capacity down. That comes with lighter projectiles. 105 grains is a little light for 1400 yards, but 130 grains (example 6.5x47) can be sent to that range with just 40 grains of powder. That is the edge of the envelope, though. Now enter the 243 Ack, which pushes a 115 gr with 45 grains to a solid 3300 fps. That's hard to beat, especially with that powder charge. It will cheat the wind and remain hypersonic at 1400. It might not be lethal to game at that range, but it will be accurate.

When you say your game is at 1400 yards, the sevens would be a fine choice. No other way around the powder requirement and the sore shoulder, though.
 
Harry Knutz said:
In this case, The bolt face is too large on your magnum bolt and your magazine/feed rails etc are set up for magnum cartridges, Which the magazine issues can be solved with the use of a DBM, And Your bolt could be altered to feed 0.473 family of cartridges too, Or you could buy a standard bolt, But its not worth the expense and trouble involved. Just find a 30-06 length standard action if you want to go the 280 AI route.

But If it was me and I had that magnum action I would probably go with the 7mm PRC if I was contemplating what you are and had what you had to work with.

View attachment 441178
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Love the pic !

Im actually thinking of just buying a new R700 LA in 30-06 just for the parts. The cheap sps's are $630 at my LGS.
 
I'm older, But I love watching Beavis & Butthead!

I know these rounds burn a lot of powder, But I shoot larger rounds. I have a 30-378 I shoot, It takes on average 110 grains of powder, And it knocks things down on both ends!
 
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