Is a 160 gr bullet too heavy for the 7mm-08 to perform well?
Someone told me that it takes away from the performance of the 7mm-08.

You can get plenty of velocity (2700+ fps) with 160s-168s using RL-17, Ramshot Hunter, and H4350.

Winchester cases have the highest capacity I have measured so velocity will be easier to achieve with those.

What application do you have in mind?

They will do fine, but a good premium 140 gr. will do anything that you should ask of a 7mm-08. As a matter of fact, a 120 gr. TTSX will also. Just my opinion......

Not trying to speak for the OP, but I came into a few hundred 160 grain Sierra Gamekings and a hundred or so 162 grain Hornady BTSP's. The only 7mm I have currently is a 7/08, so I considered working up a load for them. While the 140s work great, if I had 160's I wouldn't be afraid to use them either.

I tried a couple of different 160's in a 7-08 'just to see". Accuracy was great (but then most bullets are in a 7-08) but I didn't Chrony it. If a 7-08 was my only rifle and I was going elk hunting, I'd work up a good load with a 160 and go. Being pretty sure that if I did my part the cartridge would do its.

I shot the 160 sierra gameking BTHP out of my 7-08 with win 760 and it shot 2715 if i remember correctly with wonderful accuracy. I wouldnt be scared to shoot any deer with it

A 7mm-08 160 gr would be like a mini 30-06/180 gr at 2700 fps in performance and trajectory. That certainly isn't a bad place to be especially in animals bigger than deer.

Same as a 7x57, not a bad place to be!

In my experience the "softer" 160's work better in rounds like the 7-08 and 7x57. The 160 Sierra GameKing is just about perfect. This doesn't mean tougher 160's don't kill, but the SGK kills quicker.

I bet the 160 gr Hot Cor and Deep Curl would also be good in cartridges like the 7mm-08.

The bullet second from right was a 160 FailSafe fired in a Model Seven 7mm-08 - 20" - at around 2500 fps. It was one of two (or three?) I put into a moose at well beyond 200 yards, perhaps close top 300. The other(s) showed evidence of expanding well as well as I recall. (It was 15 years ago, or so.) This was the only one which stayed inside the animal, having hit the spine.

I am shooting a Savage 22" heavy bbl in 7mm-08. It really likes the Hornady 162 SST over H4350. I am sacrificing 200 fps for extreme accuracy. It prefers loads under max. The farm offers shots at 300 yards plus. This rifle will group 162SST under a quarter of inch at 100 yds so it goes the the open fields for longer shots.
A light weight Savage groups 120 gr to 162 gr in 1 1/4" to 1 3/4". That rifle goes into woods for closer distances and is loaded with Hornady 139 SPBT over IMR4350. The light weight Savage still gives reasonable accuracy however the gun feels better for off hand shooting. The heavy bbl Savage lends itself to use of bipd rest and slower hunting situations. Confidence is a factor in choices.