Groove dia- older 22 Hornet

[Dean of Id]

Hello all;

I have a 158 Topper model in 22 Hornet.  The serial number starts with AU, so it should be from 1980.
Can anyone tell me if the groove dia is .223, or is it the standard .224?  

Thanks for any answers.

[quickdtoo]

Just slug the bore to see what it measures, see BORE SLUGGING & CHAMBER CASTING in the FAQs and Help sticky.

Tim

[Dean of Id]

Thanks for replying, Tim.  I know how to slug the barrel, but thought someone here might already know the answer.

Regards,

[quickdtoo]

Modern barrels are .224",1:12"(1:9"now) twist, but it's hard telling what it was then, slugging it will leave no doubt. 

Tim

[Dean of Id]

Yer right, Tim. 

I ran a 22LR lead head through it.
Just in case anyone else wants to know, Mr. Starret's and Mitutoyo's dial calipers say it's .224".  A micrometer I have that is made in China says it's less, but I'll trust Starret.  (It is the "Last Word", after all.)

The twist on this barrel is 1:16", so probably no 52 grainers for me.
It shoots Sierra 45 gr Varminters and Speer 40 gr soft points very well, though.