I chronoed my Marlin 30-30, 20" bbl just this morning, 3 rounds Hornady 160 gr Leverevolution, 2200-2225 f/s, ave 2213 f/s. Hornady advertizes the same cartridge in a 24" bbl at 2400 f/s, so there is approximately a 200 f/s difference between Hornadys numbers and my numbers. I've shot two boxes so far. One just for targets, 5 - 3 shot targets and one 5 shot target, average group was 1 3/4", high of slightly over 2 " and low of just over 1 1/4", the other box went for chronoing and squirrels. Took out over a half dozen real nice. I am also developing a base line for comparison when I convert to 307 or 356.
I think if you chrono the 35 Rem in a 20" barrel you will get similar reduction in muzzle velocity.
NOW FOR THE WORMS...
I installed a Cowboy hammer spring and ground it down to get a trigger just over 3 lbs, that includes polishing the hammer and sear slightly, stoning and polishing the sides of the hammer around the screw hole and generally polishing and stoning the shiny spots after I had worked the lever about 200 or more times. It levers almost with one finger...anyway...
THE HORNADY AMMO WILL NOT FIRE AFTER DOING THIS PROCEEDURE. I had to shim up the spring to a 4 lb trigger to get 2 out of 3 to fire. Any misfire would fire after the second hammer cocking.
THIS IS NOT THE FAULT OF THE HORNADY AMMO, I WANT TO STRESS. The ammo has a hard primer so it is much harder to fire off as a consequence of the gummy tips and safety factors. Modifications and/or replacement of the factory hammer spring is NOT RECOMMENDED if you want to use the Hornady ammo.
I have fired at least 100 rounds of test loads with the trigger set at 3+ lbs without a misfire, using Fed210Match primers and three different powders, three different bullets. The best load was 36 gr RL-15, Speer 150 FNSP, Fed210M, Hornady Leverevolution brass, 2.55" OAL, crimped medium firm with a Lee crimper, 2300-2350 f/s. So far this load is putting 3 shots into 1" or less at 100 meters, 110 yds, depending on how well I hold and the conditions. This load is listed in the Hodgdon #27 manual as the top load for 150 gr bullets and RL-15 powder, 40KPSI. I started at 35 and got a 2" 1/4" vertical group, and 36.5 opened up to 1 3/8"horizontal, went back to 36 gr and fired 3 targets, one classic cloverleaf, one - two in one hole and the third just one caliber out and one - three in one hole a quarter would just cover. I will use this load for most of my shooting.
I won't be using any more Hornady Leverevolution because I reset my hammer spring and trigger back to 3+ lbs and the Speer load is equal to or better in the power department and 100 f/s faster. I find no fault with the Hornady Leverevolution ammo in a stock rifle with stock hammer spring and it shoots groups adequate for hunting.
Enjoy