mr. beesj, etc.
Welcome to the forum.
You have a very interesting H&R handgun, one that is not often seen.
The "22 EXPERT" (usually marked simply "EXPERT") was derived from the "22 SPECIAL", which, itself, was derived from the "old standard hinged frame" AUTO EJECTING model.
The "EXPERT" is first advertised circa 1927, a couple years after the "SPECIAL" hit the market. It is identical to the "SPECIAL" except for the 10" barrel. During the period 1927 until discontinued in or about 1941, the EXPERT followed all of the variational changes of the parent SPECIAL. The first two years of production will be 7 shot x .22 rim fire (s, l or lr). In 1929 or '30, the SPECIAL and EXPERT were changed to 9 shot .22 rim fire and a variation chambered in the .22 Winchester Rim Fire (the father of the 1950's Winchester Magnum rim fire ctge.) in 7 shot configuration. So yes, the EXPERT was made as a 7 shooter - but the cartridge employed will be marked on the right side of the barrel, just ahead of the cylinder. "Common knowledge" amongst H&R collectors is that only around 200 SPECIALS were chambered in 7 x .22 WRF and it is assumed but not known for sure, that there may have been a couple EXPERTS so chambered after 1929. I've never seen one of those, and in fact, over 15+ years of collecting, I've seen darn few EXPERTS. So few are sold, publicly, each year that I've gone by the little bit of info with which I have personal experience, and as I've posted in the 32nd Ed. of "THE BLUE BOOK...." by Fjestad, an EXPERT in V. Good to EXCELLENT condition will RETAIL in the$300 to $350 range. In reality, I believe that is pretty low for a rare variation.
I've not seen an EXPERT in 7 shot, personally, nor pictured anywhere. PLEASE post what is the cartridge stamping on the right side of the barrel. If the stamping is .22 W.R.F., the cylinder breech face should also be stamped with W.R.F.. If it is stamped in both places as such, you have an extremely rare item - value would be what-ever you could get, if presented on a national venue, such as an on-line gun auction site.
Will you also provide the serial number?