My BL22 (purchased Oct. 2012, New, from Cabelas) 5 lbs 10oz, measured with Wheelers Trigger pull gauge
My Winchester 94/22, Legacy, grade "E" not shot much, only taken apart and put moloy on trigger. Measures 5 lbs
My Ruger 10-22, 1993 and only has Power hammer no other mods. Measures 3lbs 8oz.
Here are my current BL-22's All of these rifles are first year production.
Here are mine in descending order by pull weight:
Browning BL-22 Grade I SN: 8B04216..........4.91 lbs Made in 1968
Browning BL-22 Grade I SN: 70B29053.........4.42 lbs Made in 1970
Browning BL-22 Grade II SN: 69B17826 4.11 lbs. Made in 1969
Browning BL-22 Grade II SN: 69B18880 4.06 lbs Made in 1969
Browning BL-22 Grade II SN: 70B29726 4.01 lbs Made in 1970
I included the pictures to address the wood quality question. Bear in mind that the finish on first year BL-22's was a hand applied shellac finish, very different from the urethane finish used after about 1972. Also many of the first year production rifles were made with beautiful reddish French Walnut, especially the Grade II rifles. This was also discontinued after about the end of 1970 to the beginning of 1971. All of the rifles pictured say "Patent Pending" on the barrel near the rear sight. Obviously most of the Grade I rifles will typically have fairly plain wood. The Grade II rifles vary widely in wood quality...most are very good, a few are rather plain, and some are truly exceptional. I hope this helps!
There is no doubt that use over time combined with a good lubricant like lithium grease will improve the trigger on BL-22 rifles. The bearing surfaces begin to get smoother with use and certainly there will be less "gritty" feel and eventually a lighter trigger pull. This will vary much between individual rifles, but the pull will get better with use. I don't know about the newer models from 1998 and after, but this is true of older rifles.