I have a rifle with a 22 inch Lilja barrel and chambered for the 7x57. A gunsmith chronographed the Federal Premium 140 grain nosler-partition in this gun at 2652 ft/sec., just 8 ft/sec. less than the 2660 ft/sec. factory rating using a 24 inch barrel.
Would this barrel be a bit faster than one would expect?

Nope..........

Leo,
As the previous writer said, "NOPE". The velocity that you are reporting is just what one would expect.
There is a thing called expansion ratio. This is the internal volume of the rifled tube, plus the internal volume of the 7x57 case divided by the internal volume of the 7x57 case. This is a measurement of how long that the powder gases have to work on the bullet in pushing it out of the barrel.
The 7x57 doesn't need a real long barrel to get decent velocities. The 22" barrel will produce velocities very near those produced by a 24" or even a 26" barrel.
By the way, I have owned and hunted with a number of 7x57s over the years here in Montana. In situations out to 250 yards one doesn't take a back seat to even the 7mm Rem Mag. The 7x57 loaded with 150gr Nos Partitions to about 2750fps will take down anything here in MT with one well placed shot. Incidentally, this velocity can be reached using H4350 without resorting to a high pressure load.
Hope this helps.
Great Shooting
The Bearman

My 22" Model 70 in 7x57 get's 2600fps from Lapua 170gr factory ammo.

Thanks guys. It's just an efficient cartridge I guess.