I shoot a 'straight' long-freebore 7-08 in short to mid-range F-Class successfully, although even at 600 yards I'll take my 284 or 300 SAUM on 'rougher' days. My original intention had been 7-08 AI and I still believe this is a wise move. (The rifle was rebarrelled to 7mm during the great tools and components shortage period and it was near impossible to get hold of an AI reamer and/or dies at the time.)
I shoot the 160gn Sierra TMK at around 2,850 fps in necked-down Lapua 308 Win 'Palma' small-primer brass with a compressed load of Viht N160. With annealing every three to four firings, I'm pretty sure the cases will outlive the barrel. Barrel life should be good if the well known 'barrel-burning' powders are avoided. I'm at nearly 1,900 rounds and the barrel still performs very well. When Covid restrictions are lifted and I can get back onto a range, I'll try the higher-BC but much more VLD-formish 162gn Hornady ELD-M. It'll do well though to group tighter than the TMK which is also a very jump tolerant design in this weight/calibre combination. (Not all TMKs are!) I've shot the TMK out to 1.000 yards and it'll still group at half-MOA there subject to wind changes, but the 284 is a far more effective model at this distance.
I did try 175 and 180gn bullets in larger capacity Winchester cases and although acceptable MVs were just about achieved I simply didn't see any benefits, especially with a 284 available to make better use of these bullets. I'm a fan of the old superseded 175gn Sierra MK which like the 160gn TMK is a very jump tolerant, flexible design that shoots better than its paper ballistics might suggest in a very wide range of air temperature and wind conditions out to 1,000 yards. If I were relying on one rifle for all distances / conditions, either the AI version or 284 would be my first choices with this bullet.
Before I went down the 7-08 road I did a great deal of modeling (quickLOAD for internal ballistics and Bryan Litz's tested G7 BCs for the external side). Whichever way you play it, 7-08 gives little or no benefit - or even a disbenefit - over an optimised 6.5mm of around the same case size. 6.5mm bullets in the 130-147gn weight range have seen so much development in recent years, they take a lot of beating in straightforward external ballistics performance and a long freebore 260 or 6.5 Creedmoor, even the 6.5X47mm Lapua all match 'straight' 7-08 MVs. Recently introduced powder grades such as Re16 and Re23 have enhanced performance in this size of 6.5s and sevens too, although I wouldn't speculate right now as to which cartridge gains most, or even if 7-08 gains or loses against say 260 right now. The plus from the 7-08 is that barrel life will be better than in equivalent 6.5s.
I also have a short-distance / sheltered range load - 150gn Lapua Scenar-L in prepped Winchester brass over a modest charge of Czech Lovex SO-65 (Shooters World 'Long Rifle' in the US), an excellent plain-Jane extruded single-base propellant that fills the VarGet/ 4064 to 4350/Re16 burn speed gap, probably closer to the slower end. The 150 Scenar-L is an easily tuned tangent ogive model and is really well made / consistent out of the box albeit with relatively high drag by 7mm match bullet standards. I've obtained near BR quality groups from from this load at 200/300 yards and it is up to good 6mmBR standards and competitiveness in quiet days in 200-500 yards F-Class matches. (The 7-08 is a much more versatile cartridge though for F-Class than the 6mm BR these days over a wider range of distances.) MV is 2,830 fps and barrel wear is probably very light with this load.
In summary, look hard at 7-08 AI. The 'straight' 7-08 can be made into an excellent little performer, but the AI gives that extra bit of vital capacity and speed with the case-filling slow burning powders, also allowing sensible use of 175/180gn bullets where desired. The other bit of advice I'd add is to see what competition you face if you intend to shoot in local matches. At my (English) club, F-Open has changed dramatically in recent years. Smallish sixes and 6.5s were the norm in short-mid range matches, but no more nowadays. 284 Win is in danger of being pushed aside by SAUMs and WSMs and some very hot-loaded / heavy bullet 6.5 Creedmoors running very high pressures in small-primer brass are becoming popular too for 300-800 yard F fixtures. As this is on a notoriously 'difficult' range for temperature and wind conditions, sheer horsepower and ballistics often give a difficult to beat 'edge' and the 7-08 is definitely on the 'light side'.
