I bought a used Schulz Trophy Hunter, it had a twist in the lower limb, that could not be corrected. Probably the result of the original owner using the the step thru method over many years. In the early years it was common to find recurve bows with a twist. If corrected after stringing, it was easy to correct; later with the use of stringers, it became less of a problem. The best policy is to check every time it is strung and correct it then. I had three longbows from one company that developed twist about an hour after stringing, it was a combination of factors, limbs were off center, poor alignment.