M14 vs AIA magazines - what's that little hole for?

[Martin248]

The AIA mags work in an M305/M1A rifle in that they feed, no problem. I have three, and have puts lots of round through. The rifle goes bang, no problem.

M14 mags have a little hole in the front that the AIA's lock, and looking in the magwell, it looks like the M14 spring guide pokes into the magwell and the end of it pokes into that hole.

First question, why? What's the point of having the spring guide poke into a hole in the magazine? What is that accomplishing in the design?

Second question, what's the consequence of not having that hole? Presumably the AIA magazine is putting pressure on the spring guide. Does that have an impact on accuracy? Remember this is a part everyone swaps out with a thicker one claiming that it improves accuracy. So?

Third question, would it be better to file off that end of the spring guide, if the plan was to run AIA magazines? Thoughts on that?

 

[Gobc]

Having the spring guide poke into the hole locks the magazine into place. With an AIA, the magazine is held into place by friction. Technically, it can slip out. But an M14 magazine can't, since it's locked into place, thus more reliable.

If you file off the spring guide, your AIA magazine won't fit into your rifle.

 

[nowarningshot]

AIA mags are held by friction in that they are slightly wider, and the guide is holding the mag where there is no hole in the front of the magazine.

My M1A mags will not stay in my AIA, they are narrower and there is no spring guide to click into on the front. While its up to you, for me since its not broke i will not fix it. If you try it the worst scenario is you buy another spring guide or reinstall the OEM.

The upgraded spring guide is reported to aid accuracy. My M1A/M305 has a purpose, extreme accuracy is the job of another rifle in my battery.

 

[Grizzly Adams]

The M14 mags are made to hook on the operating guide by the hole and then swing into position, much like FAL mags.

Grizz