I just ordered a new swenson 1911/45acp drop in barrel and a swenson national match barrel bushing with it. I may try this in one of my other 1911's, they say it improved the accuracy. Right now wwwmidwayusa.com has both barrel and nm bushing on sale. The barrel is only $39 and the bushing is $9.99. I figure this would tighten up the standard GI loose fitting standard barrel and barrel bushing for sure. Any thoughts??