Co-Witness: Absolute or Lower 1/3

 

 

The internet is full of speculation as to what the “best” co-witness is for your red dot and iron sights.  Frankly there is no right answer, you have to decide what works best for what you are trying to do with your rifle.

First of all what is co-witness? Sights should always be co-witnessed, which means that the iron sights and the dot are zeroed at the same distance. Zero the irons, zero the dot  and they should both point at the same place. The decision point is in determining if you prefer Absolute Co-witness or Lower 1/3. The choice really comes down to what optic mount height you chose,  the irons will stay the same height.

Lower 1/3 Co-witness is just like it sounds, the iron sights (specifically the front sight) will be in the lower 1/3 of the optic. The idea behind this is the shooter can look over or flip down the rear sight and have a “less cluttered view” but, more on that later.

 

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Absolute Co-Witness means the front sight is in the middle of the optic. The idea here is cheek weld is the same for both sighting methods. This is the method I prefer. As you can see below it is not as cluttered as some suggest.

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I’ve gone a step further than most with absolute co-witness.  As I am a believer in marksmanship with iron sights, I use a fixed rear sight in conjunction with an Aimpoint T1. I’m not a tactical trainer, but I like being able to keep my head in the same place to use both.

The LMT rear sight allows me to use the irons to shoot known distances using the elevation knob and the red dot allows me to acquire targets faster and shoot from weird positions. Best of both worlds in my humble opinion.

There are some things the shooter will need to “be smart” about with this set up.

1. For taking quick shot, use the dot. Don’t try and line up the irons.

2. Focus on the target if using the dot, focus on the front sight if using the irons.

3. Use the 0-2 aperture once the zero has been established, the smaller aperture is too slow for quick target acquisition. If there is time to dial in a known distance, there is time to flip the aperture to the small side.

 

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Larue Tactical offers two very nice Aimpoint Micro mounts: the LT751 (absolute) and LT660 (lower 1/3). Both are solid mounts and they have a nice quick detach leaver and repeatable zero. See the mounts here.

They have an interesting picture that they use to try to make the case that with an absolute co-witness, part of the target will be blocked.  Compared to the pictures above I’m not sure that is an honest description. The eye should be close enough to the rear sight that it is almost entirely blurred out especially with the 0-2 aperture. Even with the shooters’ head all the way at the rear of the stock, the sight will not block the target as pictured below.

In my opinion, it all boils down to the user knowing when to line up the irons and when to rely on the red dot.

 

 

Picture linked from this thread http://beta.ar15.com/archive/topic.html?b=3&f=18&t=542595

CMP International Harvester Service Grade Range Report

I was lucky enough to get a IHC from CMP back in June. Here is a quick range report, it shoots pretty dispite its Muzzle and Throat erosion numbers, how loose the gas tube is, and the jerk behind the trigger. I’m very happy with it. Plus now I can take this picture of all 4 manufactures of the M1 Garand 10431530_734765289906669_8652228661072381725_n[1]

Small Arms Firing School at Camp Perry 2014

This year at Camp Perry, I attended Small Arms Firing School (SAFS). I’ve been working on off hand but I have been in desperate need of some more coaching so this was a perfect opportunity for me.

It’s a three day event. Well, sort of, the first day is just registration. There is only one registration day for SAFS and there are no same day registrations. Since there were almost 500 folks in SAFS the welcome center was busy when I rolled in around 10, after a leisurely breakfast, so get there early.

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It took me around 2 hours to get all the way processed and buy some t-shirts at the CMP store.

Day two starts at the theater at 7. It was an unusually crisp morning for High Power week at Camp Perry.

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After some  review of the features of the M16, line and pit commands the USAMU went over some basics of marksmanship. I took several pages of notes it was good stuff.

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At this point the class broke into 2 groups “beginner” and “advanced” the advanced group stayed in the theater for more classroom instruction i left with the beginner class. We gathered our stuff and took the long walk down Viale to the 200 yard assembly line. There was time to gather my gear from my truck which I had parked near Rodriguez, however there were some folks that had trouble getting to the line in time after retrieving their gear from the barracks. I would recommend either covering and parking your stuff outside the theater or, keeping it in your vehicle between the theater and Viale.

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Once on the line, we were broken up into firing points and every 2 firing points had a coach. We then spent a couple hours dry firing, working on our positions and generally getting advice from our coach. I got a lot of value out of this, and I made some changes to my off hand position so I feel a bit more stable.

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Some time around noon the rest of the group joined us and we went into live fire practice. Just like a “regular” match we broke up into 4 relays two of us went to the pits 2 stayed to shoot and score. I went to the pits first.

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We each shot 10 rounds slow prone, 10 rapid sitting, 10 off hand. No sighters but no scores were recorded. I took this chance to try “center mass” hold which USAMU seemed to be pushing hard. My coach however preferred 6:00 hold. I decided to stick with 6:00 at least for the rest of the season.

We wrapped up around 4:30 which gave me time to spend some money on the row, again.

Day three is the “M16 EIC” match which is a proper CMP EIC match with a slightly different course of fire, 5 sighters  and 10 shots slow prone, 10 rapid prone, 10 rapid sitting, 10 off hand. all fired at 200 yards. Everyone must use the issued CMP Rock River match rifle and the issued web sling, Shooters can use their other shooting gear, coats, gloves, mags, and lucky shooting hats.

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I must have learned something, as I beat my best pretty significantly. While I didn’t make points, a couple of guys from my club did on their first trip to Perry, which was very cool.

It was a great experience, and I learned a lot. I have been trying to remind myself to “focus on the front sight control the trigger and breath” with every shot. While pretty basic it helps. Anyone looking to improve their marksmanship regardless of skill or experience level would benefit from SAFS, I highly recommend it, I intend to keep coming back until I can make points.

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New CBI Barrels at Camp Perry

Somewhere on the internet I read that if you buy a new Criterion Barrel at the north store during the National Matches the CMP armorers van will install it for free. So, I hauled my rack grade Winchester with me to the Matches.

I rolled in to Camp Perry late in the afternoon on the Sunday before SAFS. There was not a lot going on in Camp at that time, it was nice to have the place more or less to myself. I stopped by the CMP van and confirmed that the internet was right, then headed over to the CMP store and picked up a barrel.

CMP went above and beyond again. Not only did they install the new barrel for free they tuned the op rod, replaced some small parts and gave me some advice on other parts to replace. All in about a half hour, which was enough time for me to spend too much money on commercial row.

There are some conditions on this. You will need to be a registered participant in the national matches and turn around and ability is based on how busy they are.

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Now that this rifle has a nice new barrel I plan to replace the stock and perhaps the gas tube which should give me another nice rifle to use for JCG matches.

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While I didn’t think to bring the receiver with me, I also picked up a CBI barrel for my 03A3 which brings me close to completing my 03A3 build.

I met up with Josh from CBI during the Vintage Sniper Match. He was working on a story about some shooters on the line using CBI barrels. We talked a little bit about the matches, CBI’s background, their future plans and firearms in general. I was impressed with their focus on quality and how they have strived to maintain quality during the “panic.” They have some exciting things in the pipeline. I won’t give any spoilers but it’s probably going to end with me spending more money!

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03A3 Update

Just a quick update on my 03A3. I’ve picked up a few more small parts. I have a couple more on the way and I plan to pick up a Criterion Barrel at Perry.

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Once I have the rest of the parts I intent to send it to CMPs custom shop to finish.

See the the progress of my 03A3 build here 03A3 Build