Aviphot 200 (expired 2014) and infrared - very thin negatives

Hi, I got some 4x5 sheets of Aviphoto 200 (expired 2014, sliced by @MCB18 from giant perforated rolls). I went and exposed 6 sheets with Hoya R72 filter and rated at ISO 6. It was very sunny and hot in California, so f/22 and 1/4s. I developed in fresh one-shot F76+ 1+9, 6.5 min at 73F. The negatives are all very thin, like barely see much kind of thin.

I'm a bit surprised, since last time I used same combination with fresh Rollei IR400 and the results were perfect. I thought Rollei IR400 was also based on Aviphot 200, albeit fresh.

So my question is: what do you guys recommend to expose this film for infrared? Which filter will you recommend, just Red 25A or continue with Hoya R72? Any change in development needed?

P.S. I'm not complaining about MCB's sliced film, I just want to find a good working solution for my remaining sheets.

I have the same stuff in 8x10 from MCB18. At EI 6 with a 720 filter, the negatives are thin, compared to Rollei IR. I have better luck at EI 1.5. I've been using PC-512 1+100, and Pyrocat-HDC 1+1+50. Expired film is bound to lose speed over time.

I’ll be completely honest, I am not 100% sure what speed I shot this film at with an IR filter. I ran out of NOS Aviphot 200 in 70mm long ago and I’ve switched to Foto-100 and FN-64, which are fresh Aviphot 80 and 200, respectively.

I do know that the 120 worked best at EI 80-100 in visible light, and I want to say I got good results at EI 3-6 with a 720nm IR filter, same as @Andrew O'Neill uses. I would need to find my notes from then to confirm though.

I also used D-76 1+1 and HC-110 as developers, with Rollei superpan 200 times.

I do hope that helps a little, sorry I can’t be of more assistance at the moment.

Thank you both. I will try ISO 1.5 next time.