I load 3006 and 270 reduced loads running imr 4895 for the 3006 with 150s and H4895 in 270 with 120s and 130s. With the 3006 I dropped back 5 grains from the starting load in my manual. Starting load was 47 so I started around 42 grains. I ended up using 44 grains as it was extremely accurate and consistent with a 150 sst at about 2650. 22” barrel. Actually one of the more accurate loads I have ever used. It’s a very comfortable load to shoot.
For 270, I ended up around 38 - 40 grains of H4895 with a 120 or 130 grain bullet. If I remember correctly those loads ran 2550-2600 from a 22” barrel and did fine on deer and hogs. Hornady 120 and 130 sst. Those loads were for my son and nephew when they were 7-8 years old. They handled it no problem. The 120 has the cannelure that’s suited to the 6.8 so when i loaded it I did not seat all the way to the cannelure. For 130s I did seat to cannelure.
Another solution for one of my 270s which was a vicious kicker was to drop down to the starting load of Imr 4350 with a 130 nosler ballistic tip. 52 grains was the load and ran right around 2800fps. For some reason with imr 4350, 55 grains and 52 grains or thereabouts always seem to shoot well With 130s. 52 was accurate, comfortable, and I killed deer out to 400 yards with it,
I’m not sure exactly how much reduction you are looking for but with 308 it should be very easy. 41.5 of H or imr 4895 under a 168 grain Amax is pretty much an accuracy load for 308 and runs about 2600fps in my AR10 with 20” barrel and 2750 in my 26” bolt gun. If that load has a bit too much recoil for you just use the h4895 and back down until it is comfortable. 39 grains should put you at 2400 from a 22” barrel. I use the 168 Amax for deer depredation out of an AR 10. It starts out at 2650fps and is tailor made to the lower velocity impact and expansion. From 50 to 500+ yards it just flat out works
If you prefer a 150 just start out at 42 grains of H or IMR 4895 and work down until you find an accurate, comfortable load. 42 grains will put you close to 2600 with the 150s in a 22” barrel. The 150sst is good here but there are certainly a lot of good 150s to choose from. I prefer the Amax, Ballistic Tip, SST, or Gamekings because they will perform well at the lower speeds you will be working with. The 168 Amax is my personal favorite in the 308. Check out Hodgdon and Hornady’s Service rifle data for the 308. There are quite a few loads there that will be very comfortable.
I should mention that with 270 and 30-06 case fill can be a concern with lighter loads. i like to use a Winchester large rifle primer or a magnum rifle primer with those loads. Especially if I am dropping way down the scale just to help make sure I get proper ignition. For really light loads I would recommend something like Trailboss for better case fill.
Standard large rifle primers will work fine for you with the 308.