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Normal Topic Does my firearm fit correctly - Part two (Read 647 times)
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Does my firearm fit correctly - Part two
Aug 26th, 2018 at 10:45pm
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First and foremost, the firearm must fit the firer, not the other way around.

The absolute golden rule of shooting is “The firer must be able to maintain the correct sight picture without conscious or subconscious effort in total comfort as long as necessary, while maintaining the correct points of contact/control at all times” meaning that once the correct sight picture is obtained the firer should be completely relaxed requiring NO PHYSCAL EFFORT of any degree to keep the correct sight picture while holding the firearm correctly.  This is often referred to as maintaining Natural Point of Aim (NPOA).

For clarity, the correct sight picture is achieved when the sights are aligned precisely on the desired point of impact.

In order to achieve the NPOA fit is vital.

A Couple of quick tests

1.      Snap alignment test:
Look at your target (desired point of impact with both eyes open, keeping both eyes on the POA, mount your rifle (bring your rifle into the firing positon). You should be able to clearly see the POA almost perfectly aligned in your sights. If your rifle fits, you will have a good clear sight picture on or almost on the desired POA.

2.      Relaxation test:
Get into you preferred firing position, ensure you are comfortable and obtain NPOA on your chosen target. Having ensured you have a correct sight picture, close your eyes and count slowly to 30. Open your eyes. If you still have correct sight picture (or very close to it) your rifle fits. With a correctly fitted rifle, the sight should be moving rhythmically across the target due to respiration and heartbeat, the desired point of aim should be more or less in the middle of the visible movement. 

3.           Sight alignment test (Optical sights):
Get into your preferred firing position.  Maintain your position and then close your eyes and lift your head until your cheek lifts clear. Ensure you keep your head and neck as naturally aligned and comfortable as possible, lower your cheek bone down onto the comb. Keeping perfectly still as soon as a solid, stable weld between cheek and comb is felt. Open your master eye while keeping perfectly still. If you need to move around to get the correct view thought the sight take note of how far and in which direction you need to move. Move your sight the same amounts in the opposite direction to get it aligned or pack your comb to move your weld point to align your eye.

4.      Cant test:
Using a cant level (verify it is indicating correctly before use) obtain and maintain the correct sight picture. Have an observer check the cant level (photograph if desired). If the rifle is canted one or more of butt, length of pull, sight position or comb (cheekweld) require adjustment.

5.      Laser test:
Using a boresight laser (cartridge case “snap cap” type) obtain the correct point of aim and sight picture. While videoing the target, fire a group. Use the video to plot hits on the target and then preform a target group analysis. While not as precise as actually firing this will allow you to identify the various faults without burning up barrel life. You can also use the visible movement pattern on the target to diagnose trigger operation and breathing cycle issues. If you can stretch finances to a quality laser sight and mount that on top of the scope at the same time so there are two lasers running even more can be gleaned and the firer can also see exactly what is happening throughout the shot cycle.

6.      Blind group test:
Have an observer with you to ensure safety. Have second firing observer for the test. Fire a couple of baseline 4 or 6 round groups to “get into mode” and confirm you are ready to proceed. Obtain correct sight picture and fire the first round. As you are doing so you must pay attention to breath control, trigger control and follow through, particularly how everything feels as you release the shot. For the second shot proceed as normal but instead of breaking the shot, close your eyes and go thought one more breath cycle with your eyes closed then break the shot at the same point in the next breath cycle, as you normally would. Keep your eye closed until you have rest the trigger using correct follow though. Upon opening you should find you are still correctly aligned on the target with the correct sight picture. Your observer should record each fall of shot on the target. Repeat this to provide a group of either four or six. The finished group should not be significantly larger than your baseline groups. There may be a slight split in the group. The two blind shots should represent the two sighted shots in appearance and size. The “split” will reduce as you get used to this test.  This takes a bit of time to get used to before it will work for you. If your group is markedly split or larger than baseline, further fitting is required.

(Note: content added and reorganised at 1950hrs 28/08/18)
« Last Edit: Aug 29th, 2018 at 7:47am by 50BMG »  

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