the whelen being a long action cartridge might look funny to you w/ a short barrel. i conducted a pretty extensive experiment w/ an 8 mauser and took the barrel from 29" down to 17" in 2" increments and chronied each increment. i ended up losing something like 150 f/s over that 12" cut, and when i switched to a slightly faster powder, i got all of it but 50 f/s back.

long story longer, if you don't mind re-visiting your load development, you will find you won't lose enough velocity to get excited about, and if it is a brush gun, why would it matter if you lost any velocity? the range will be short enough the thing will be carrying more than enough steam to be lethal even to a few hudred yards. if you're ok w/ the aesthetics, lop it off! i do have to caution you, though, muzzle blast can be pretty brutal once you drop below 20". since all your range shooting will be w/ hearing protection, that part won't matter - but when you touch it off at game w/o ears, you will certainly know it.

I looked at this when ordering the barrel for my Whelen. I was more interested in velocity gain than barrel length. I don't recall lengths as short as 18.5" but from 20 to 23" it was about 100fps per inch. Longer than 23 the gains were less and not worth the extra weight. Accuracy really doesn't have much to do with barrel length so I wouldn't worry about that. If it were me I'd start at 20" to see if I could live with the length and then go down in 1/2" increments from there.

DD

What they said.

Rule is 50 fps per inch.  But that is a general rule and doesn't hold for either extreme.

I'd also suggest 20 inches for the same reasons of DD and Dak; but in addition the "feel" and balance of the rifle will change drastically from 22 to 18.5

I bought my first new rifle in 1962, M700 with a 20 inch tube.  It was the "rage" then to have a short handling barrel and all the gun writers said it was great for brush hunting and still had enough vel for long range.  I still have that rifle and others with various length barrels.  But in years of hunting the ONLY time I've found a length barrel to be hindrance was in hunting long range bean fields for deer from a box blind.

I just don't think that a 22 inch bolt gun is and worse handling in brush country than a 18.5!  If the barrel sticking up as you walk thru brush, a sling adjustment will let the gun ride lower and not protrude above your head.

Just thoughts...guess I'd keep the 22 incher.

BEAR

 Its hard to say how much velocity you'll loose. Maybe none, maybe 250-300 fps, alot would depend on the powder used.

 Staying with the long action and shortening up 4 inches on the barrel, will for sure give you more muzzle blast, but won't do much for the brush handling characteristics of the bolt gun in the first place.

 Might want to look into a Browning BLR in 358, for 35 bore firepower, and excellent brush handling characteristics.