5.56 ammo

   / 5.56 ammo #1  

BoFuller

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My son is building me an AR-15 in 5.56
I was going to stock up on some ammo and have a question.
Is 5.56 and 5.56 vs 45mm the same thing?
 
   / 5.56 ammo #5  
My son is building me an AR-15 in 5.56
I was going to stock up on some ammo and have a question.
Is 5.56 and 5.56 vs 45mm the same thing?

The 5.56 X 45 refers to the caliber of the case the 5.56 part and the 45 refers to the length of the cartridge case as in 45 mm.. here is another example. 7.62x39 refers to the common round for an AK47 and all of its semi auto clones, the length of the case is 39mm. 7.62x51 is .308 winchester round the length of the case is 51 mm 7.62x63 is the common 30-06 round .. It is just nomenclature.

James K0UA
 
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   / 5.56 ammo #6  
Is 5.56 and 5.56 vs 45mm the same thing?
In your case, the answer is "yes".
the 5.56 NATO is the 5.56X45 and thats the round your most likely going to be using, how ever there are variations, hence the 45mm designation.
See post 5.
 
   / 5.56 ammo #7  
keep in mind the sammi spec pressure differences and CUP measurements between 7.62x51 nato and .308win same goes for 5.56x45 and .223
if your reciever is marked .223 you should be fine for both.
 
   / 5.56 ammo #8  
Soundguy said:
keep in mind the sammi spec pressure differences and CUP measurements between 7.62x51 nato and .308win same goes for 5.56x45 and .223
if your reciever is marked .223 you should be fine for both.

Sound guy you are backwards on the .223 / 5.56 NATO

5.56 chamber shoots it all, marked .223 you should avoid 5.56 ammo.
 
   / 5.56 ammo #9  
Sound guy you are backwards on the .223 / 5.56 NATO

5.56 chamber shoots it all, marked .223 you should avoid 5.56 ammo.

That is how I have always heard it also..

James K0UA
 
   / 5.56 ammo #10  
Just a thought? Did anyone review my post? It explains the issue in regards to the ammo issue. When the original M-16 was issued to the military, - BTW, Colt got the design from Stoner - , the barrel had a 14 in 1 twist. Now the military M-16's have a 1 in 7 twist. This resulted is longer ranges, and one reason was that the result would be more wounded and reduced kill ratios. This will tie up the enemy's resources to attend the wounded, at least that was the military planner's reasoning. With a 14 in 1 twist, the exit wound would be the size of an orange and more internal injuries were more prevalent due to the slower ballistics - fps and the tumbling effect. Both the VC and NVA used to have a saying: "Beware the soldier with the black gun" - this was with the 14 in 1 twist. One other important piece of info: when the M-16 was first issued to the troops, ball ammo was issued. As a result, there were many jams. Also there was no specific cleaning and maintenance procedures, and many troops were under the impression that you could rely on the weapon without daily cleaning. The truth is the M-16 was unreliable if you dropped it in muck. Unlike the M-16, the enemy could drop his AK in muck, dirt, and leech infested water, and the chances were very good that it would function more reliably. Also in the beginning, there was no 3 round burst. This was implemented at a later date, because the fresh troops would get excited and expend their full magazine. Thanks for listening.
 

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