Hello all, new here and wanted to share my findings and solutions to getting the AICS mag conversion kit to work on the Ruger American line of rifles. Hopefully this helps some of those who are not getting some AI mags to work, or even those who aren't able to get the conversion to work at all.
First off, I have a Ruger American Predator (RAP) left hand in 308 Win. Ser # 6908xxx. I purchased it recently and I immediately shortened the barrel to 18" since I really just want a maneuverable gun for deer hunting from a box-blind. I am not concerned about shooting past 200 yards with this gun and 18" is what the right handed version of this rifle comes with anyway.
I initially used the rotary magazine that came with the gun at the range, but I got jams when trying to cycle rounds, and virtually every time when chambering the last round from the magazine. As I searched the internet for a solution I learned of the AI mag option from this site. So I wanted to give them a try, especially since I already have a handful of 5 and 10 round metal and Magpul AI mags that go to another rifle in 308. (It rides in a XLR chassis system; not an ideal rifle to be toting up and down ladders to my deer blinds.)
So I called Ruger and got the AI conversion kit coming this way as well as a 3 round polymer Ruger AI style mag. I wanted to get a 3 round mag so I could have a lower profile mag option than just my 5 and 10 round mags. While the 3 round mag is still not flush, it is plenty low profile for my needs.
The kit and the 3 round magazine arrived the same day. I installed the conversion kit immediately. The first AI mag that I attempted to fit was a 5 round polymer Magpul. It fit tight, a little too tight for my liking. Although it did go in, it was about a half millimeter too long for the magazine catch to engage the tab on the back of the magazine. I opened the bolt and smacked the bottom of the mag, and it engaged. But then trying to release the magazine was quite an ordeal. I needed both hands, plus I had to put the gun into a rest and pull down against it to get the mag out. Basically, not going to work with the magpul mags. Another 5 round and a 10 round were all the same way. I stopped those other mag insert attempts as soon as I realized the mag catch would not engage the mag tab with bolt closed.
Luckily, the metal AI mags, both 5 and 10 rounders worked flawlessly. They went in easy, engaged with the bolt closed, cycled dummy rounds with no problem, and they came out easy too.
But the Ruger 3 round AI magazine that I really wanted to work was not even close to being able to work. It was about 1.5 mm from being able to engage the magazine catch. So, I do not recommend what I did next, but I took sand paper to my new Ruger mag and sanded down the top of the mag, without altering the feed lip angles or depth. I sanded little by little until I got the mag to fit. I know I got Lucky, but it works great.
Unable to help myself; I wanted the magpul mags to work as well. So my next idea was to take the conversion kit back out and shim in between the inside of the polymer stock and the top of the AI mag conversion insert. This next idea would not permanently alter anything, so I had nothing to lose with this attempt. But I think it is the answer. I took the conversion kit back out and added thin plastic washers to the top of the conversion kit. They each measured 0.56mm (.0225in) thick. I used a pair stacked on the front and a pair stacked on the back of the insert, so a total of 1.12mm (.045in) of spacing was added.
Also, the torque specs for the action screws is 60 to 80 inch pounds. I stopped at 60 in/lbs because I felt that was more than tight enough, and being the minimum torque it might let the conversion stick just a tiny bit further out than if had I gone to the full 80 in/lbs. All this together now keeps the conversion kit piece sticking just a tiny bit further out of the stock. So it is that much further away inside from the bottom of the action, thus allowing the magazine to be inserted further into the mag-well to make catch engagement. I had to trim the plastic washers on the back side of the shim to have flat spots so that they would not interfere with the mag-well, (not pictured), but you'll get the idea if you attempt this.
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Now the mags can be inserted in far enough to engage the mag latch, making every AI mag that I own able to work in the gun now. Also, dummy rounds feed flawlessly from every mag, from the Magpuls, to the metal AICS mags to the Ruger polymer 3 rounder. Of course I wish I had not sanded on the top of the 3 round mag now, but it was the farthest from fitting correct before any adjustments had been made, and it still works now the way things are. So far so good.
5 round magpul mag
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3 round Ruger AI mag
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First off, I have a Ruger American Predator (RAP) left hand in 308 Win. Ser # 6908xxx. I purchased it recently and I immediately shortened the barrel to 18" since I really just want a maneuverable gun for deer hunting from a box-blind. I am not concerned about shooting past 200 yards with this gun and 18" is what the right handed version of this rifle comes with anyway.
I initially used the rotary magazine that came with the gun at the range, but I got jams when trying to cycle rounds, and virtually every time when chambering the last round from the magazine. As I searched the internet for a solution I learned of the AI mag option from this site. So I wanted to give them a try, especially since I already have a handful of 5 and 10 round metal and Magpul AI mags that go to another rifle in 308. (It rides in a XLR chassis system; not an ideal rifle to be toting up and down ladders to my deer blinds.)
So I called Ruger and got the AI conversion kit coming this way as well as a 3 round polymer Ruger AI style mag. I wanted to get a 3 round mag so I could have a lower profile mag option than just my 5 and 10 round mags. While the 3 round mag is still not flush, it is plenty low profile for my needs.
The kit and the 3 round magazine arrived the same day. I installed the conversion kit immediately. The first AI mag that I attempted to fit was a 5 round polymer Magpul. It fit tight, a little too tight for my liking. Although it did go in, it was about a half millimeter too long for the magazine catch to engage the tab on the back of the magazine. I opened the bolt and smacked the bottom of the mag, and it engaged. But then trying to release the magazine was quite an ordeal. I needed both hands, plus I had to put the gun into a rest and pull down against it to get the mag out. Basically, not going to work with the magpul mags. Another 5 round and a 10 round were all the same way. I stopped those other mag insert attempts as soon as I realized the mag catch would not engage the mag tab with bolt closed.
Luckily, the metal AI mags, both 5 and 10 rounders worked flawlessly. They went in easy, engaged with the bolt closed, cycled dummy rounds with no problem, and they came out easy too.
But the Ruger 3 round AI magazine that I really wanted to work was not even close to being able to work. It was about 1.5 mm from being able to engage the magazine catch. So, I do not recommend what I did next, but I took sand paper to my new Ruger mag and sanded down the top of the mag, without altering the feed lip angles or depth. I sanded little by little until I got the mag to fit. I know I got Lucky, but it works great.
Unable to help myself; I wanted the magpul mags to work as well. So my next idea was to take the conversion kit back out and shim in between the inside of the polymer stock and the top of the AI mag conversion insert. This next idea would not permanently alter anything, so I had nothing to lose with this attempt. But I think it is the answer. I took the conversion kit back out and added thin plastic washers to the top of the conversion kit. They each measured 0.56mm (.0225in) thick. I used a pair stacked on the front and a pair stacked on the back of the insert, so a total of 1.12mm (.045in) of spacing was added.
Also, the torque specs for the action screws is 60 to 80 inch pounds. I stopped at 60 in/lbs because I felt that was more than tight enough, and being the minimum torque it might let the conversion stick just a tiny bit further out than if had I gone to the full 80 in/lbs. All this together now keeps the conversion kit piece sticking just a tiny bit further out of the stock. So it is that much further away inside from the bottom of the action, thus allowing the magazine to be inserted further into the mag-well to make catch engagement. I had to trim the plastic washers on the back side of the shim to have flat spots so that they would not interfere with the mag-well, (not pictured), but you'll get the idea if you attempt this.
Now the mags can be inserted in far enough to engage the mag latch, making every AI mag that I own able to work in the gun now. Also, dummy rounds feed flawlessly from every mag, from the Magpuls, to the metal AICS mags to the Ruger polymer 3 rounder. Of course I wish I had not sanded on the top of the 3 round mag now, but it was the farthest from fitting correct before any adjustments had been made, and it still works now the way things are. So far so good.
5 round magpul mag
3 round Ruger AI mag
