Hi there,
I have a Remington 7615, can 5.56mm ammunition also be fired in this rifle as well as .223. I’ve heard so many differing opinions saying you can and you can’t. They say 5.56mm ammunition is loaded to a significantly higher pressure than .223 Remington ammunition Correspondingly, 5.56mm chambers are designed and built to withstand the increased pressure, while .223 Remington chambers generally are not. Additionally, .223 Remington chambers have a shorter leade (the distance between the mouth of the cartridge and the point where the rifling engages the bullet) with a steeper angle than 5.56mm chambers. But Is this the case with the 7615 or can this firearm shoot both? I’d be really keen to hear someone who owns one as well.
I hope you can give me a solid YES or NO and an explanation please..... that would be awesome.
Thank you for taking the time to read my post.
Cheers - Stu ??

I would go with what the barrel has stamped.

Hi NotIssued thank you for your reply. So are you suggesting what is on the barrel is what can be used. Cheers - Stu

Correct.

That's assuming of course that the barrel is stamped.

If it's stamped 5.56, then you can use .233, but not vice versa.

I believe the early Colt M16 and the Ruger ranch rifles were stamped "223"so don't believe everything you read

Chamber dimensions between 223 and 5.56 are the same or very close until you get to the throat length .

Some load books (Sierra comes to mind) list different loads for 223 and 5.56.

Then there are some differences between commercial brass and military brass with regards to internal volume.

I am cautious but some claim they run any ammo in the bolt guns.


Has anyone directly contacted the mfg of any bolt rifles to ask if their chamber was ok for 5.56?

Thanks NotIssued, yes the barrel is stamped .223/5.56mm
Cheers mate - Stu 😊

Anyone own a 7615 that can give some input on this subject please?

Cheers - Stu

If it's stamped 223/556, you can use both.  Earlier models were listed as 223 only

Give us a range report.  I always thought the 7615 was an interesting idea, especially for ban states.

Ruger specifies in the owners manual it can safely shoot 5.56

you will be fine, theres no actual proof that using 223 in a 556 gun or vice versa is dangerous.

The barrel being stamped .223/5.56 is the best indicator that you are GTG.
It should be no surprise that Remington made it so since the rifle was a hopeful contender for the law enforcement market.
YMMV
TheMULE

I used to shoot lots of M193 in a savage 340 back in the day, never had any issues. This was before I knew you weren’t supposed to according to SAAMI.