pls help id this cartrige

[Hawken50]

recently my dad and i were looking for something in his basement and i came across an old, 20mm cartrige (rendered inert, more on that later). i asked him where it came from and he muttered something about when he was in the service. couldn't tell me any thing more about it so please help me out.

it's a 20mm, obvious because of the markings, i'm wondering what type.

7 1/8" over all
case is 4 1/2" long and 1 18" wide at the base and appears to be steel
bottom of the case is marked with "20MM - MK5 MOD. 0 RNO 10 65"
there is a brass (or something brass colored) ring where the bullet meets the case with the markings "*20-MM MK.11-0 A LOT (unreadable) 1-5*"
the case has no primer and has several holes drilled in it (i'm assuming to empty the powder.
also on the case are marks from what i'm assuming is the round being in a belt

the bullet itself is what confuses me

it's 2 3/4" long from case to tip
from the tip to 1" down seems to be a seperate piece as there is a seam and it wiggles slightly from the rest of the bullet.
the tip part is marked 3/4" down with "1211649-1"
the main body of the bullet has 2 holes in it. (to remove something????)

is this an AP or HE round? just a plain old 20mm shell? my dad did say they were used in F-4 phantoms.
sorry for the long description, if i can i'll post pictures.

thanks!

 

[HI express]

hawken50

Here's my nephew's response to your query. He is going on his 2nd tour back to Iraq and he didn't have time to respond to you.

So here goes...if I can paste it to you;

Tell him what he has in his hands is a United States Navy MK 11 20x110
Dummy
Round ... the MK13 is the Armor-Piercing Incendiary version of it.

The "brass-colored thing" that says "MK 11-0 A LOT etc etc" is the
driving
band. The unreadable part should read "HMC".

The round should be steel-tipped, and the casing should have no primer
and
should have exactly SIX holes drilled into it. The steel casings all
are
stamped MK 5 ... the last sets of numbers "2-68" means they were made
in
February 1968.

These things are worth maybe $6-10 bucks to a serious collector if
they're
in good condition. Nice souvenir.

He said he got the information because your dad is a vet.

Good luck.

 

[Hawken50]

thank you

thanks for your help and please thank your nephew for me.

He said he got the information because your dad is a vet.

if it matters any - you two helped out 2 generations of veterans, myself and my father.