PRW I know but not LR anything. The abbreviations QRW and PRW mean; Quick Release Weaver and Permanent Release Weaver. The QRW rings can be installed or removed without tools while the Permanent rings require tools to install or remove.
Regardless, I don't like the Burris rings specifically because they mask any problems with the rings. Using a rubber bushing to help compensate for ring alignment or shape errors isn't a solution, it's simply a way to cover up the problem so that the shooter THINKS that there isn't anything wrong. But in reality the scope and rifle will still shoot less accurately than if you had lapped the rings properly. Most people don't see a problem because they don't engage in any shooting discipline that requires absolutely consistent accuracy and precision. If you buy the Burris rings you'll know if you've made a bad choice if from time to time the scope rings loosen, or the scope suddenly looses it's ability to track well, or your zero moves from time to time; then you'll know that you should have lapped the rings rather than buying a band aid fix.
You really have no clue what you are talking about! Have you ever used them? The Burris with inserts are my go to rings and have been for many years. Kevlar vest on! Lmao.



Paul