[azguy]

If the .223 is almost 5.56 NATO
and the .308 is the same as the 7.62x51 then
is the .270 the same as 6.8?
Just thought I would ask?

[lefty o]

if your asking about bullet diameter, yes. if you are asking about the complete cartridge, NO.

[samuel]

The .270win. is a necked down .30-06 from .308" to .277".The 6.8mm came from the .30Rem.casing which was .308" necked down to .277".The .270win. with a 110gr bullet developes about 3200fps with about 2500lbs energy.The 6.8mm with a 110gr bullet developes 2550fps with about 1588ft lbs.The .270win is much longer and has a much greater powder capacity.To me the 6.8 might be okay for deer size game but not a good choice for varmints because of its drop table and the fact that it doesnt develope enough energy to fragmentise bullets and so leaving the chance of riccochettes.The old .30rem was comparable to the .30-30,but was rimless. samuel.

[azguy]

Good to know. I thought I was on to something there. Thanks.

[riverider]

Make sure the bbl is marked 5.56 not just .223

[lefty o]

a .223 chambered gun is just fine if you dont intend to use 5.56 ammunition.