Small parts came from small manufacturers all over Japan and other countries. I have seen/owned at least 3 different styles of safeties for the 6.5. Some do not interchange too well without a little fitting. This may have more to do with the machining on the back of the bolt than the safety knob. There are at least two different style F/pins too. The F/pin and safety knobs will interchange between the 6.5 and the 7.7, but * NOT * the bolts, if that helps you find the stuff easier. Might be a good idea for you to make sure you have the correct bolt in it. I bought more than one at a flea market with the wrong bolt in it. The location of the locking lugs and blow hole are different between the two. There. Documented. Not rumor, I owned them. I also made quite a few in my day ( F/pins, safeties, and bolts) * The post about loose tolerance 6.5's : I worked on/owned quite a few Type "I" 6.5's (Made during the war). The chamber tolerance on some of these guns was so tight that I had to force the bolt on some of the original Japanese ammo. Tolerance on military weapons varied from every country. That is why you will see a "First quality" stamp on some 6.5's and not others. Overall, the Arisaka was a well made and designed rifle. If you have trouble with bullets keyholing, try a 160 grain bullet. I still hunt with one I cut to 6.5x55. It keyholed at 50 yards until I figured out that the real early 6.5's had a different twist rate. Yes, at times the Japanese used mismatched numbers. Sometimes the guns were restamped sometimes not. Look under the bolt handle where it drops down on the receiver and there should be a partial serial number. The F/pins and safeties were usually marked too, but not always.