Best AI magazine (long action)?

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I’ve got a standard metal AI long action magazine and one of these https://riflemags.co.uk/magpul-pmag-5-ac-l-magnum-aics-long-action-magazine/ for my bighorn custom stalking rifle and to be honest, neither are a patch on my factory Sako magazine. The standard AI metal one isn’t the slickest feeder and is a rattley big lump. The plastic one is ok but has a horrible, loud springy twangy when loading. Are there any better options out there?

i spoke with Paddy Dane a while ago about Curtis mags and he really didn’t rate them. 

[Catch-22]

What stock/chassis do you have?

If you’ve a stock, what bottom metal are you using? Is it designed for normal AICS long action (.300wm) or CIP length?

And when you say “...the AI mag isn’t the slickest feeder and is rattley” what do you mean exactly? The round is hard to strip from the mag? And the mag to bottom metal is rattley, or that when stripping a round, the spring is rattley?

I would say if the mag is rattling in the bottom metal itself, then there’s a poor fit somewhere. Sure Mags will move a bit, they’re never going to be completely stiff, but it shouldn’t be flopping about (that’s what she said!).
 

If your stock/chassis is AICS, do you have the correct model/length of AICS magazine? The long action come in several sizes, including standard and  CIP length. There’s even a wider AX type cut, which is a wider mag well opening for double stack, double feed.Could you by chance be using a shorter standard length mag in a stock/chassis/bottom metal that’s designed for CIP length or even AX mags?

If the round is hard to strip from the mag, you can always carefully adjust the feed lips just a bit, opening them outward to let the round sit a little higher in the mag and with less tension, this permitting a smooth bolt cycle. Go gentle here if you do open the feed lips a bit, a little goes a long way and you need to keep the lips straight.

Otherwise, I think I’d be speaking to the person who built you the rifle for clarity on what’s going on.

And in terms of alternate mags, you can look at Accurate Mags or American Rifle Company (ARC) but tbh, you’ll be hard pressed to beat a genuine AI mag!

[baldie]

You won't have the wrong mag length, there is 1/8" difference, and a short one wouldn't latch in a CIP length stock.

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So to expand... The mag rattles when inserted into the action - it's fully retained and won't fall out, but rattles side to side - so yes, mag to bottom metal is loose fit. I wouldn't say floppy, and a couple of bits of insulation tape on the sides of the mag have taken up some slack to stop it rattling in the field (but a fairly agricultural approach on a nice custom rifle!). I was led to believe AI mags are designed for squaddies to bang around and are robust rather than precise.

The feed issue is as you describe - shoulders of the case run into the feed lips at the front of the magazine and it sort of jams the case rather than lifting and feeding it upwards into the chamber. I've never been unable to chamber a round, but it's definitely not slick. Bolt travels forwards smoothly until the shoulders run into the feed lips and then in needs a bit of a clunk to push the round forwards so it pops up and into the chamber.  Pics below - second one you can see how the round feeds forwards rather than being lifted at the tip. It's a 6.5x284 if it makes any odds.

And yep, spoke with the builder at the time and he wasn't aware of any other mag alternatives, but I thought it was worth a check on here just in case anyone knew of anything else around.

[Ronin]

If the feed lips (the rear longer ones ) were adjusted properly the loaded cartridge would be presented at a slight upwards angle negating the “grab” as the case shoulders touch the forward lip which is there to “push up” the case into the chamber mouth

 

simple fix with proper wide mouth panel beating tonges 

Second - bottom metal - not sure what type you have not some are “better quality” than others 

Badger bottom metal and Tier One are a decent slip fit without much wobble 

Tape is a good idea to prevent the rattle and as Dave says you have the correct length mag as it would be retained by the catch of it wasn’t (it would t fit ) if too long for B/M

 

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Thanks Ronin - that makes sense - round is currently pushed down into the forward lugs rather than at a slight upwards angle. I've dropped you a PM.

Not sure on bottom metal tbh - I think it might be badger as I'm not sure Tier One did LA when I had it built. I can live with the tape if it was a smoother feed though! 🙂

[baldie]

Those feed lips are too tight at the front, and possibly too tight at the back. The round could possible sit higher in the mag by lip manipulation.

AI didn't make any mag to work in a detachable bottom metal, they were designed purely for their own stocks, and the fault lies with the DBM manufacturers if the mags are loose.

It won't be a Tier one DBM....they dont make one.

Tape works, stick on furry velcro works better.

The mag would also sit tighter and rattle less, if the locking catch is altered to make it fit further up in the action.

If you have more than 1-1.5 mm of vertical play in the fitted mag....its too loose.

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Cheers baldie - sounds like a bit of fettling could have it feeding a lot smoother... 🙂

[1in9]

In mag terms the go to choice of many manufacturers is Accurate Mag's dedicated AICS mag, newcomers MDT are very similar.

https://riflemags.co.uk/aics-magazines/

As the other posters have mentioned adjusting the lips of a .300WM magazine to better match your case and preferred feed angle is the first port of call. Obviously that may preclude using polymer mags if you have a case size falling outside the standard cases and feed angle it was designed for.

I like to polish up the inner gripping edge of the magazine at the same time for a smoother feed and less case scratching.

As mentioned by Baldie consider adjustments to the catch lockup point if there is vertical play.