Quote History some chf i believe had an oval stamp with fn inside the oval. i remember the threads "i bought chf but it doesn't say chf". i am 8% sure of it.
eta - it appears i was wrong.
"Thank you all for your comments.
OP - It appears you may have received the incorrect barrel, as it should have been marked CHF. If you would please IM or email us with your order number, we will get you taken care of.
A note of clarification: Our Palmetto marked hammer-forged barrels have always had CHF in the roll mark, however, from time to time we get the rare opportunity to purchase FN CHF barrels with a generic FN rollmark. FN does not specify barrel type or testing process in their standard rollmark, just the logo, the caliber and the twist. So if you have the FN oval on the barrel, it will not have any other markings other than caliber and twist. We apologize for any confusion this might cause."
https://www.ar15.com/forums/ar-15/_ARCHIVED_THREAD_____PSA_CHF_16___5_56mm_1_7_M4A1__Was_told_barrel_is_CHF_but_no_CHF_stamped_on_barrel_Can_this_be_true_/118-633637/?page=1
eta #2 - i do believe that all 20" chrome lined barrels from psa in the past were fn manufactured but not all were chf. back in the day when i was buying the non chf 16" fn barreled uppers from psa these 20" were about $120 more (about $400 without bolt carrier group). i always wanted one but wouldn't pay the extra (half the price of another m4ish upper).