Hey, Piper
If your bows are coming in under intended weight, you're maybe being a bit too impatient, and rushing it. It's a common beginners mistake. Remember: wood which is twice as wide is twice as strong, but, wood which is twice as thick is eight times as strong! In other words, it doesn't take much wood removal to decrease the poundage. All else being equal, a 50# and a 30# bow are not far off in thickness. You've got some good advice here... the best for me has been "stalking tiller" from Dean Torges. You have to sneak up on your final destination... in other words, slow down to a crawl near the end. A couple of scrapes is sometimes enough!! If you haven't read his book, you should, it's very good. Some of it took me a couple of reads, but once you get your head around it, his advice is awesome. Keep going. If you want a 50# bow, start off with that as your goal. I agree with Gordon, it's harder to make a well tillered 25# bow, cuz you have to remove more wood!