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A tool for bulk collection of location data, including MGRS coordinates, to be used by intelligence analysts. Finally, MGRS search for Google Maps!

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GridScout™ Blog

This blog is dedicated to the proficient defensive use of MGRS maps, the GridScout™ Google-Maps client, and other tools well suited to the goals of GridScout™.

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Google put the kibosh on Gmap4! :O

Google recently changed its API usage policy, effectively putting the non-profit Gmap4 out of business. That’s unfortunate, as Gmap4 was designed to benefit disaster-management organizations and was doing a great deal of good in that realm. Since GridScout™ used Gmap4 for its aerial views, that feature currently won’t work. While this does not affect GridScout’s primary goal of searching Google Maps and performing bulk collection of MGRS location data, it does make it harder to verify the relevance of unfamiliar search results. The maker of Gmap4 has made appeals to Google in hopes of coming to an agreement, but Google refused. In order to continue using the Google Maps API in his volunteer efforts, he’d have to shell out $46,000 per year. So Gmap4 is now gone. Bummer.

I am now considering alternatives to Gmap4, so that I can restore GridScout’s aerial-view feature.

RC1 — a lightweight defensive carbine

The ultimate purpose of the GridScout™ map-search tool is to provide for a better community defense. For that same purpose, I’m building a new firearm. I call it the RC1. Why RC1? Because it’s easier to explain that RC1 stands for Reeder Carbine #1 than to explain that PK6 (my original name for the RC1 concept) stands for Piŝta Karabeno je 6,5 Grendel.

Weapon design

My intent is to create a weapon that is easy to operate in close quarters, very well suited for up to 300 yards, and still practical up to 500 yards. While many PDWs are especially good at close quarters and a typical modern carbine is pretty good up to 300 yards, it seems to me that both are severely handicapped beyond that range by their low bullet energy and high aerodynamic drag.

I think I can more fully achieve my chosen goals by creating a custom carbine than by selecting any of the off-the-shelf offerings that I’ve already considered. So I’m going for it, and upon completion we’ll see how it does.


The RC1 will be based largely on the Alexander 6.5 Grendel Incursion, which is relatively light and fires the most effective general-purpose cartridge yet devised for AR15-format firearms. Thanks to the versatility and popularity of Eugene Stoner’s modular design —the Armalite AR-15 upon which the Grendel Incursion and many other modern weapons are based—, we now have a standardized means of interchanging parts to fit the needs of the shooter. The RC1 will take advantage of this in two important ways.

  • The bolt will be cycled by a gas piston, based on the Armalite AR-180 design, which has proven substantially more reliable than direct gas impingement.

  • Other part selections, inspired by PDWs and by ultralight carbines derived from the Colt AR15A3, will serve to make the RC1 lighter, more comfortable, and more maneuverable.


The barrel of the RC1 will be just long enough to avoid the red tape associated with a short-barreled rifle. This length also serves to keep the muzzle velocity and bullet energy high enough for practical medium-range use. If I put a muzzle brake on the barrel, it’ll be a short, single-chamber model to minimize the added weight and length.


The RC1 will have a very short, fixed-length buttstock. This would make it uncomfortable with the standard 33° grip angle, so its pistol grip will instead be nearly vertical, as is common in a PDW. This will place the wrist of the shooter’s dominant hand in a neutral position, while the short length of pull will put the entire mass of the RC1 closer to the shooter’s body where it is more easily supported. This gun will be as lightweight as practical, in order to further limit muscle fatigue, as even minor fatigue can affect the steadiness with which the shooter holds his sights on target.


The RC1 will be equipped with two sighting systems:

  • A lightweight fixed-power riflescope, sufficient for 500-yard engagements
  • Offset iron sights, optimized for quick target acquisition within 50 yards


Progress on this project is as follows. Initially, a few paper parts stand in for some of the actual parts that I have not yet acquired. With a scope and a full magazine, I anticipate a total weight of about 6.8 pounds, and a total length of about 32 inches.

This Anderson receiver set (8.7-oz lower, 6.7-oz upper) from Wisconsin has no ejection-port cover and no forward assist, frills which frankly aren't worth their weight. The receivers are held together by 2A Armament titanium takedown pins made in southeast Boise, adding 0.1 oz. The TacStar 10" carbon-fiber handguard weighs in at 7.3 oz, mounting hardware included. I envision a short skeleton stock and a grip angle of about 14°. 2018-07-05 — Initial concept

This Japanese fixed-power 6X scope, without mounting rings, weighs 9.8 oz. 2018-07-27 — Weaver K6 scope (paper model)

This carbon-fiber buttstock, produced within spitting distance of my daily commute through Boise, weighs just 2.33 oz. 2018-07-31 — Incognito Arms buttstock

At just 13°, this is slightly more vertical than other PDW grips (14-17°) and far more so than the standard 33° grip angle. It gives the most comfortable wrist position that I've found thus far for a gun with such a short length of pull.  It's also shorter front to back than the Tactical Link PDW grip previously pictured, giving my index finger and thumb more reach for operating the controls. And it lacks a backstrap, allowing me to place my hand higher for better recoil control. 2018-08-02 — Ergo Swift Grip (paper model)


When the RC1 is complete, I will assess the performance of this weapon in a future post. I’ll provide a link here to make it easy on you.

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