Extended length 223 in Remington 700???

[ImBIllT]

I see that Wyatt’s offers a 2.450” 223 magazine, but measuring my loaded ammo, I’m getting longer than that, and was considering a longer bullet as well as a potential rechamber to 222mag AI or 22-204Ruger AI. Is there any info out there for getting longer in a Remington 700 magazine? I read somewhere that pulling the block and putting any s/a follower in would work, so I tried pulling the block at the rear and putting a 308 follower in the 223 box, but it wouldn’t hold rounds in the mag and would spit them all out into the action. It’s an ancient 222 Rem box that had a longer block and shorter follower than today’s 223 box. Maybe the box is the issue? Any info from someone who has done it would be great.

 

[Rob01]

I use MDT AICS mags with my .223 and it can be loaded out to 2.550".

 

[ImBIllT]

I use MDT AICS mags with my .223 and it can be loaded out to 2.550".

That’s definitely good for future builds. This particular one is an old ADL that will remain an ADL.

 

[Eagle1899]

You can pull the block out of the Remington box and install a thinner spacer. I made one from delrin. Then you can still use the factory 223 follower. The cast/milled aluminum followers work better than the stamped steel ones.

 

[Eagle1899]

If you're going with a detachable AICS style magazine. I really like Accurate mags. They can be notched in the front for longer loading.

 

[Eagle Six]

MDT AICS magazines have a longer COAL than Accurate magazines without modification, 2.50". Either work well.

 

[ImBIllT]

You can pull the block out of the Remington box and install a thinner spacer. I made one from delrin. Then you can still use the factory 223 follower. The cast/milled aluminum followers work better than the stamped steel ones.

That’s what I did initially and the follower started jamming in the box because it would can’t excessively. Then I welded an extension onto the back of the follower and it stopped jamming and works fine, but I decided that I want to go longer, and thought I would see what others have done before I waste time learning something the hard way that someone else has already figured out.

Being an old 222 that had a longer box at the rear than newer 223’s come with, and since the spring presses up on the rear of the follower much more than the front, and differently than any of my 308 magazine springs, I wonder if I’m having problems that people with newer 223 mag boxes do not have.

 

[ImBIllT]

MDT AICS magazines have a longer COAL than Accurate magazines without modification, 2.50". Either work well.

Which I may try on a different build, but I plan to keep this one an ADL.

 

[Eagle1899]

You can bend the follower spring to an extent to change the pressure from rear to front. They can and do break. Don't get too crazy without a spare on hand. I can dig out my set up and take pics this coming weekend. I switched over to AICS style mags and haven't looked back.

 

[BK7saum]

A little late to this party, but my solution for running 223 based cartridges (long 223 and 7 TCU) in a short action rem 700 is to remove the block/spacer and use a standard short action magazine spring (308) with the 223 follower. The magazine spring takes up the extra space at the rear (vehind the followerr) and in both of my rifles, the magazines work as expected and feed correctly.