Estimated speeds of 22" .280 sherman?

I'm curious if anyone has ever just rechambered a 22" .280 or 7x57 to the Sherman? Back in the 90s I tried doing that from a 22" Mod700 .280 to Ackley Improved and only gained about 50fps. I was using R22/150 NBT ( 2950) and 7828/160HC (2800). Thinking the Sherman should go faster...Reason I ask is rechambering is fairly easy/inexpensive compared to rebarreling and some folks may just be interested in just getting more speed from a Mountain rifle? Anyone care to take a S.W.A.G.?

Other than being stuck with factory twist rate, it could work out well.
A Smith in my area wants $125-175.00 for a rechamber and suggests a re-crown, almost demands it.
The Sherman will be hotter than the a.i.
How much wear is already on the barrel in ?, will the bullets wanting to be ran in the factory twist perform?,
I am putting together components for a .280 Sherman right now, mine is a semi custom, starting from scratch. Here are two other things that cost.
Cost of dies
Cost of premium brass(Norma or RWS is recommended), most other brands have low life expectancy
There are a few more costs but these are the main ones I see.

Dies and brass (RWS .270) plus a hydro die case former and add the rechamber job, it doesn't make $ sense. However, just for the grins of thinking about it, I wondered how much speed will be lost from 26" barrel.

Ask Rich I think his handle is Elkaholic here at LRH

My WAG would be 3075-3120, depending on how far you want to push it. I'm getting 3175 with Retumbo and 3215 with N-570 and 140s, that's my accuracy nodes, no pressure.

How long is your barrel Dok?

Sorry, 26"

Rich got back with me via email. He said a lot depended upon the magazine length of the rifle. At 3.450" or so with the 180 berger, he still thinks it would be over 3100fps. Wow. I'm thinking ( away from the safe, can't check) this Mod 70 FWT (80's model) is a lot shorter than optimum. It still seems to be all the speed one can get from a standard case in a 22" barrel. I don't "need" that kinda speed, but IF I got antsy to try it, I'd still do it, just for the experiment, ha. I'd just stick with the shorter Premium heavies for the extra "thump" on game, rather than the extra yardage. I currently have this rifle in 7x57 and loaded to 60K, hey, that's a lot of thump with a 160-175. But you never know.....

At equal pressure you will get equal performance out of either the Ackley version or the Sherman version.

"...when both are loaded to, say, 60K, the Sherman is still going to be a bit faster."

I tend to think the extra bit of powder in the Sherman would add more speed? I can see why LR hunters would want the really long bullets(B.C.) and the long COAL ( more powder room) as opposed to the 7x57/7mm08 ( though the .280 makes a good run at it) Still, the way I hunt, with the newer powders/bullets, I have all I can use in my 7x57 ( I also used a little Kimber 84M/7mm08 for years) The old Hornady LM 139SST load got 3100fps in that M84, so its all I used. A "tad" more powder space, the modern brass/rifle and nostalgia are working their mojo for me in the 7x57. BUT...if this rifle is as finicky as the one I tried back in early '90s...well, hey, I'm dreaming! ha Thanks guys for all the replies. Merry Christmas to ya!