Anniston walk-through, rebuilding M4's and M2's

[markm]

Isn't the military accuracy requirement something like 30 inches at 300 yards?

There's some mean radius calculation to make a simple idea complex. I forget what it worked out to in simple MOA.

[lysander]

There's some mean radius calculation to make a simple idea complex. I forget what it worked out to in simple MOA.

New M4A1, 5.6 MOA:

3.6.6 Targeting and accuracy. Ten (10) rounds shall be fired from each weapon at a target, the heavy outline specified in Figure 1, located at 100 yards. The extreme spread shall be in accordance with Figure 1. The M855, 5.56mm ball cartridges shall be in accordance with drawing 9342868 and shall have an average vertical and horizontal standard deviation between 3.4 inches and 4.0 inches at 600 yards. For each weapon, the target and accuracy measurement shall be taken using rounds number 5 thru 15 of the function firing semi-automatic (see 3.6.4.1) verification.

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You can still qualify Expert with one on the USMC Qualification Course.

I envy the digital work package, beat the hell out of paper manuals.

[HKGuns]

That's FAXON levels of suckness.

Are Faxon barrels bad? No experience with them but always wondered.

[AndyLate]

Are Faxon barrels bad? No experience with them but always wondered.

More like inconsistent. I had a 20" 5.56 Gunner that was very good but other members had very poor barrels from them.

Andy

[lysander]

Interesting. Couldn't imagine being a good shooter and drawing that one 5moa gun, think that thing would meet a tracked vehicle pretty quick.

That would be awful.

That was indeed a cool video. And very upsetting about the 5 moa being ok.

I guess the looser the spec, the fewer rejects.

Actually, 5.6 MOA (the guy in the video misspoke, the limit is 5.6 MOA), is perfectly adequate, even for really, really good shooters.

The specification accuracy for an M4A1 Carbine is that ten shots will be fired and the extreme spread of those ten shots will be less than 5.6 inches at 100 yards. Or, more simply: 5.6 MOA. With the M14 was an extreme spread of 6.1 inches, but later tightened up for a figure of merit (FM) that would be 3.2 inches. The FM is just the average of the extreme vertical and the extreme horizontal spreads.

My god! How can we issues such an inaccurate things? 6 MOA? 5.6 MOA? The horror, the horror . . .

Well, let’s say we have one of those super talented shooters that can actually shoot a 500-24X on an NRA National Match Couse, and he was issued one of those horrible 5.6 MOA carbines, how bad would he do?

Assumptions: The shooter never makes an aiming error at the ten ring, and the distribution across the maximum dispersion (5.6 MOA) is normal and that 2 standard deviations falls inside out 5.6 moa limit.

Based on the size of the 10 ring (in MOA), how it compares to the 5.6 MOA, and the percentage of bullet fall in each standard deviation, you get:

For a National Match Course of fire with 50 rounds and maximum of 500 points, our expert shooting with a 5.6 MOA Carbine would probably* shoot a 470 plus or minus ten points, That’s not bad.

If we go back to the early 1960s and give another expert marksman one of those 6.0 MOA M14s and let’s see (statistically) how he should do on the old “A”-course.

The “A” Target has a black filled 5 ring (highest score) 12 inches in diameter and is used on the 200 and 300 yard line.

The “D” Target is a human outline filled with black 19” at the shoulder and 26” tall, this is also valued at 5. This target is used for the 300 yard prone rapid string.

The “B” Target has a black filled 5-ring 20 inches in diameter.

Stage 1 - 10 rounds, standing, Off-hand, slow fire, at 200 yard at an A-Target, 12 inches is 6 MOA so 50 points is possible.

Stage 2 - 5 rounds, sitting, slow fire at 300 yards at an A-Target. 12 inches is only 4 MOA, so statistically you will average 24 points.

Stage 3 - 5 rounds, kneeling, slow fire at 300 yards at an A-Target. Again, 24 points.

Stage 4 - 10 rounds, prone slow fire at 500 yards at a B-Target. The 20 inch 5-ring is again only 4 MOA, so statistically 48 points.

Stage 5 - two magazines of 5 rounds, standing to sitting, rapid fire at 200 yards at a D-Target, (see below).

Stage 6 - two magazines of 5 rounds, standing to prone, rapid fire at 300 yards at a D-Target. The black silhouette of the D-Target is 19 inches wide, the height is 26 inches, with the ‘head’ being about 7 inches, so the body rectangle is 19” by 19”, the 6 MOA dispersion is within the black. If you do your parts, you get all 50 points for these two stages.

Probable score if the shooter make no errors – 246 out of a possible 250.

That will get you that Expert badge.

So, the Indian can have a pretty bad bow and still kill many deer, if he’s a good Indian.

How good are you?

_ _ _ _ _ _ _ _ _ _
* If he shot an infinite number of matches, his average score would be somewhere in that range.

[ST911]

New M4A1, 5.6 MOA:

My god! How can we issues such an inaccurate things? 6 MOA? 5.6 MOA? The horror, the horror . . .

He speaks true.

For a bit of perspective, the black of a B8 bull (9 ring) is ~5.5" in diameter. Take a sample of shooters and see how many will put 10 rounds in the black. Or even score 90+ if you gave them the 7 or 8 ring.

[markm]

Are Faxon barrels bad? No experience with them but always wondered.

We had one that was complete shit. The booger eater told PB it looked like 10k rounds were through it and didn't do shit for him. Bad QPQ job most likely. I will NEVER buy a melonite/QPQ barrel again, and will never buy any faxon product.

For a National Match Course of fire with 50 rounds and maximum of 500 points, our expert shooting with a 5.6 MOA Carbine would probably* shoot a 470 plus or minus ten points, That’s not bad.

That course is wildly doable. I had a vision of these impossible strings of fire where only the most patient and disciplined shooter stood a chance. Still anything over 2.5 moa is bounced for us. Too much time making ammo for that crap.

[lysander]

That course is wildly doable. I had a vision of these impossible strings of fire where only the most patient and disciplined shooter stood a chance. Still anything over 2.5 moa is bounced for us. Too much time making ammo for that crap.

You must also remember that 5.6 inches at 100 yards includes standard M885 ball, not match ammo.