When did Mini-14's become 5.56x45 instead of .223?

What testing and/or manufacturing method was changed to allow the Mini14 to safely shoot the 5.56x45 in the carbine? A true rechambering? A .223 caliber stamping sure seems to limit the versatility of a Mini14 so stamped.
I suppose that a .223 Mini14 should be clearly marked with the difference, much as a person with .300 Blackout AND 5.56 uppers for an AR pattern rifle should also do to avoid tragedy(?)
Thanks. Don

The 5.56 vs .223 issue only came up about, what, 15 years ago? Up until then, many hundreds of thousands or millions of rounds of USGI M193 ammo had been fired through Mini-14s and we never heard a word about any problem. It's very likely that the Mini was built with 5.56 chambers all along.

I was told by Ruger back in 1984 when I bought mine that it would shoot either one safely.

This does not apply to the target mini 14. 223 only in those .

Ruger changed the rollmark to 5.56 NATO only a few years ago.
Chet15

chet15 said:

Ruger changed the rollmark to 5.56 NATO only a few years ago.
Chet15

Click to expand...

:wink:

Say. Thank you friends. Now having access to an OLD Mini-14 , from about the first year stainless was an option (1980?), I wondered if there were truly differences. A very handy carbine for smaller folks here. Don

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Thank you so very much. I have learned so very much here in 11 years. And continue to learn.
Don

Thank you so very much as well. Great info COSteve.

Rich

I'd like to ask advice & opinion on my Mini-14 and it's OK-ness for 5.56.

At the very back end of the receiver it is stamped:
Ruger
Ranch Rifle
CAL .223

I bought it new in OCT 2002.
The serial number is 197-1164x ..... I checked a couple of websites and they indicate of date of manufacture of 2003, so that's a little confusion factor.

SO, based on what I've read in the above posts, it is OK for 5.56 ..... but I'd sure be happy to know for sure.

Thanks Much for the help.

45 you are good to go on 5.56.

Thank You, I appreciate the help.

Tallbald said:

Say. Thank you friends. Now having access to an OLD Mini-14 , from about the first year stainless was an option (1980?), I wondered if there were truly differences. A very handy carbine for smaller folks here. Don

Click to expand...

Besides some rollmark changes and changes in rifling (3 different) I really couldn't tell you what internal external changes have been made through the years.
I guess, the early guns also had a wood handguard.
Then the 180- prefix guns have an external mechanism on the left side of the receiver.
The very earliest 180- guns (around the first 1400 or so) had a gold bead front sight.
Be aware also that there was a recall on the earliest stainless Mini-14's. Guns up to 182-51928 should have a double proofmark on the receiver indicating the receiver was double checked for proper hardness.
Chet15

Memory is somewhat unreliable but I think the box on my 180- series was marked .223 / 5.56
on the end label

My 2011 model is marked 223cal.
My 2018 model is marked 5.56NATO
Have shot lots of 5.56 in both.
Zero issues