Thanks a lot for the excellent review. I'm a southpaw, and have been thinking about trying an ambi mag release.
I've been looking at the HVA as well as the others that are mentioned in the OP. I'm surprised more aren't running the HVA. I've been waiting for the Forward Controls Design EMR-A to release before I buy one though.
This on looks to be new as well, but I don't know anything about it.
Master of Arms Volkscatch
http://www.tacticallink.com/Master-O...le-Rifles.html
Great write up, it touches on many of the issues, and solutions that we bake into ours (EMR-A). It's quite astonishing to me that users think of things that designers/manufacturers don't.
Yes the ABC/R was from the ground up designed to deal with a particular problem introduced by the Norgon's presence on a receiver, that of interference with the bolt catch's lower paddle. The angled paddle protrudes further from the receiver, and provides a unique surface / sensory feedback that differs from anything a finger will encounter on the receiver, (specifically, the Norgon Ambi-Catch's lever), a good thing to have for fast recognition and in low light / no light environments.
Shown is the original ABC/R. ABC/R v2 due out this month will not have lightening cuts, but will have a thinner and tapered upper paddle to clear wide billet receivers.
When our (Forward Controls Design) EMR-A (Enhanced Magazine Release, Ambidextrous) gets closer to release in a month or so, we'll talk about its features and how it mitigates some of the concerns.
Couple of things I can share:
EMR-A pivots on the receiver (sorry it wasn't designed to go on safe queens)
Custom made spring included (but not required)
Low profile levers
Will not be compatible with battery assist device levers (was not a consideration)
Optional bundling with EMR (through hole) and EMR-C (blind hole) mag release buttons.
We took into account of force amplification afforded by the lever, and this alone explains the lever choices and inclusion of custom made spring.
More on all this, and more specifically, the aspect of accidental/unintended mag drops, later
Roger Wang
Forward Controls Design
Simplicity is the sign of truth
For a retrofit ambi mag release, Norgon has done a very good job. It has but two minor shortcomings: interference with the bolt catch's lower paddle, and the extra force required to press the lever.
I suspect that Norgon also took into consideration of mechanical advantage from the lever, it has a built-in spring, like the KAC.
So there's the give and take. To address these issues, the lever needs to be further away from the bolt catch paddle, which means a longer lever, and force amplification (makes the lever easier to press). KAC addressed this by putting a small spring underneath its long longer.
That it's easier to press is the fix for folks that think (and are correct) the Norgon's lever is harder to press, our instrument confirms it, but not by as much as one might imagine. If you're a right hand shooter, your left hand isn't as strong. So a weaker hand pressing a harder to push lever can and does easily result in the perceived difficulty in using it.
But we can't make it too easy to press, because now we'll have more likelihood of accidental/unintended mag drop risk.
A receiver with built-in ambi mag catch can have fences that mitigate this, but for retrofit parts like EMR-A, Troy's and KAC's, we have to deal with it in other ways.
No free lunch, unintended consequences and all that.
Roger Wang
Forward Controls Design
Simplicity is the sign of truth
Good write up.
Have you noticed any problems with the Troy?
The problem I have with the Troy (sample of one) is the pin that holds the wedge in place is always backing out. I have to use a punch and push it back in. This happens with 100 rounds or less with 223 and as few as 20 rounds with 300 BLK.
Here's a Norgon clone for $25.
https://www.armsunlimited.com/Ambide...e-p/au-amr.htm
Bookmarks