I created this account just to reply to this specific thread and apologies if someone already posted this information:
I have three of the Pro Mag 10 round magazines (RUG17 - purchased 07-06 this year) and a Ruger factory magazine (Italian).
No range time with the Pro Mags as of yet, so no real experience of full function of the magazines (I.e cycling/feeding while shoot, not just hand-cycles).
I only do have the RUG17, but it is safe to assume that ProMag uses the same or similar tool/dies/presses to make the RUG16 (7 round). I do not have a US made Ruger factory magazine, so I unfortunately cannot compare the RUG17 or the Italian magazine to that.
What I can tell you so far is that, although they look alike by a quick glance (the RUG17 is a lot longer for obvious reasons), but there are some subtle differences between the two. The most obvious one I have noted are the feed lips
PM- Pro Mag RUG17, RFI - Ruger factory, Italian
Measurement error +/- 0.02mm
- Feed Lip opening: PM 8.8mm, RFI 8.6mm)
- Top of Feed Lip: PM 16mm, RFI 14mm
- Bottom of Feed Lip: PM 18, RFI 16mm
- Magazine Length and Width: both are 32mm x 12mm, with the RUG17 obviously taller due to its 10 round capacity.
- Extended Floor Plate shape: PM rectangular, RFI dovetail (tapers in front)
- Follower:
PM open U-shaped with 15.6mm rear, 16.5mm front
RFI U-shaped with left side enclosed by supporting brace, rear 15.6 rear, 17.8mm front
Note: extended floor plate (ProMag only comes with an extended one) are interchangeable, as well as the followers.
What does this all actually mean, though?
There are videos of people having follower tilt issues with a fully-loaded RUG17, although no one seems to actually state it is a follower tilt issue, with the top round "nose-diving" (reference Pro Mag 10 round magazine issue on YouTube).
This might be caused with the ProMag follower being shaped like it is; I have been able to squeeze the ProMag follower almost in half (front to back), while this is almost impossible with the factory follower due to the left side supporting brace. Within theory, the ProMag follower might compress (front to rear) under tension causing it to tilt and "nose-dive" the top round.
There are also videos showing a possible feeding issue in the RUG17 where there is gap between the top and proceeding round (the rears of the rounds touch, but the fronts are gapped about 2-3mm). I was able to reproduce this by loading both the RUG17 and factory magazine with 7 rounds (capacity for the factory magazine); "round gapping" in the RUG17 starts around the fifth round and really widens (2-3mm) on the seventh, while the factory magazine does not do this at all.
Again within theory, this may be caused by the follower but also the wider feed lip opening of the RUG17. Even though 0.2mm might not seem that much, it might be enough to allow the top round to tilt up and create a front gap with the next round. I unfortunately have not measured the angle of the feed lip, but that might be an issue as well.
The ProMag feed lip design also might cause a feeding issue. The top of the RUG17 feed lips are 2mm longer than the factory magazine, which causes the round to be released from the magazine later, which leaves more of the round in the magazine when it comes in contact with the LC9's feed ramp. While this may not be an issue with FMJ or round-nosed bullets that can use its shape to slide up the ramp, it can jam a HP bullet into the feed ramp, which is what most people are having issues with.
I did contact ProMag about the RUG17 and its issues, and this is their reply:
Yes the mag is in the process of a redesign for a variety of issues. The are design elements that are there because we can not "copy" any factory magazine directly as they are copyright protected. The factory lc9 and lc9s magazines are interchangeable, ours are not because the design issues we are working on. If you purchased these direct from us we can offer a refund, however if they were purchased from a vendor I can offer a replacements when available, or a in house credit to use for any product we make. The lc9 has been changed as well by ruger several times since it was introduced and we are playing catch up to meet their design changes as well.
Thank You.
Tech Support
So, to buy or not to buy ProMag?
There are a lot of reviews out there, with a lot being negative. Ruger factory Italian magazine (some people are having issues with the US ones) can run anywhere between $35 to $45 US, and are limited to 7 rounds. Yes, Ruger does make a 9 round extension, but there are complaints about cosmetics (there can be a gap between the extension and the grip) and they can run around the same price as the 7 round magazines or more.
If you have the budget to get Ruger factory magazines, go for it, although some people are having issues with the US made magazines. A lot of people do have the ProMag magazines, but they are often reserved only for range use. In the end, it is your money.
I am on pretty tight firearms/accessories budget and I have already spent money on the ProMags, so I am kind of stuck on the issue.
What I am planning to do is:
- Modify one of the ProMags by filing and shaping the feed lips to as close as to the Ruger factory magazine measurements as possible. This would mean shortening the length and closing the opening.
- Run one magazine as is.
- One stays in NIB.
I will run the same ammunition on both, run 7 rounds (5 loads) at first to see how the ProMags stack up to the factory magazine (no issues with the factory magazine), then 10 rounds as they were intended to a 100 round total. Yes, 5 loads of 7 rounds would equal 35 and leave 6.5 load of ten rounds, but I want to see how the magazines are after a 100. I will post the results after range time.