Can you mic a 5.56 round for me?

[czydj]

I recently acquired some ammo and my AR doesn't like to chamber it w/o some help. FWIW, the reciever is marked 5.56, so I figured I would try some out before I get out of warranty.

Here's the PRVI Partizan 5.56 that I have:

5.67mm at the base of the bullet, just above the case
6.31mm at the top of the case, just below the bullet
8.96 at the top of the case, just before it starts to taper
9.50mm at the bottom of the case, just above the bottom indent/lip

How does your 5.56 ammo mic up? I want to make sure it's the chamber and not the ammo...

[Shihan]

First, what type of AR do you have? The lower markings really have no relationship to what type of barrel and chamber you may really have. It is also possible that if your barrel is marked 5.56 your chamber may be .223

[czydj]

First, what type of AR do you have? The lower markings really have no relationship to what type of barrel and chamber you may really have. It is also possible that if your barrel is marked 5.56 your chamber may be .223

I just pulled the handgaurds off and there are no markings on the barrel. The upper receiver has no markings either. I really didn't want to start any vendor bashing, so I was reluctant to be specific. I guess I can say the first letter of the vendor is an S and the last letter is a W. SN is in the 55000 range...

[Shihan]

I just pulled the handgaurds off and there are no markings on the barrel. The upper receiver has no markings either. I really didn't want to start any vendor bashing, so I was reluctant to be specific. I guess I can say the first letter of the vendor is an S and the last letter is a W. SN is in the 55000 range...

This isnt vendor bashing but some companies are notrious for doing the wrong thing. Your S&W is it is a factory rifle(they are selling components now) will have a factory barrel and chamber. Call them up and they will take care of it for you.

[czydj]

Your S&W is it is a factory rifle(they are selling components now) will have a factory barrel and chamber. Call them up and they will take care of it for you.

I was looking for some ammo measurements for two reasons. One, I wanted to see if my ammo is "in spec" and two, have something to tell S&W on how I've determined the issue is with the rifle. I sure would appreciate some quick measurements....

BTW,

Overall cartridge length is 57.0mm

[czydj]

Still google-fu'ing the 5.56 cartridge, but here's a cool pic of the .223 specs:

[czydj]

AR15barrels.com has some excellent info, for those who are interested. Here's a link to the doc:

http://www.ar15barrels.com/data/223vs556.pdf


A wealth of data:

http://www.ar15barrels.com/tech.shtml



Thanks Randall!

[Shihan]

I was looking for some ammo measurements for two reasons. One, I wanted to see if my ammo is "in spec" and two, have something to tell S&W on how I've determined the issue is with the rifle. I sure would appreciate some quick measurements....

BTW,

Overall cartridge length is 57.0mm

I dont have anyway to do measurements but if you do send it into S&W they will take care of it just tell them what is hapenning and request a call slip.

[czydj]

tell them what is hapenning and request a call slip.

already done and a call tag is on the way...


Thanks anyway for checking... The stuff from AR15barrels.com really helped me understand where those cartridges differ in size...

[gyp_c2]

...what's the date stamp on the ammo?