I have a 1975 production Citori, 20 gauge. I would like to know if TSS shotshells could damage the barrels. The fixed chokes are F and M. Thanks for any advice.

Yes, they could. TSS and steel are the same as far as most manufacturers are concerned for choke recommendations. According to Browning, steel and tungsten are no-gos in fixed full choke barrels.

So, you're on your own-- no one is going to replace your barrels if damaged by the use of no-recomended ammo. You might want to look into having screw-chokes installed.

Thanks for the info. I knew steel was a no-no, but wasn't sure about TSS. Thanks again.

The TSS loads that I’ve seen tested are very small shot size
(size 9)
So could the small shot size help make them less damaging to a full choke barrel?

Tungsten is used to cut steel, tungsten is about 5 times harder than tool steel, about four times harder than titanium. That's not a good choice for a 46 year old lead-only Citori barrel.

Thanks Randy

It’ll be lead and bismuth for my stuff.