I have an early 80’s near new condition HK91 (IB date code) that I have owned since new. Along the way I ended up with a complete spare bolt carrier w/ bolt-head.
Today I was reading about how important it is to check bolt-gap and that it should be between .012 and .020. So I checked it for both bolt carrier assemblies. One complete assembly has a .011 bolt-gap and the other complete assembly has a .009 gap. If I swap locking pieces the gap measurement swaps between assemblies (gap follows locking piece). I find this strange because this gun only has fired about 2000 rounds since new. Oh well. The measurements don’t lie.
So I need to order new rollers for both bolt-heads. Given these bolt-gap measurements (.009 and .011), which number rollers should I order for each bolt-head? I assume I want to get as close to being slightly under .020 as possible, correct? Do I need any other replacement parts to do the roller job other than the 2 rollers?
Today I was reading about how important it is to check bolt-gap and that it should be between .012 and .020. So I checked it for both bolt carrier assemblies. One complete assembly has a .011 bolt-gap and the other complete assembly has a .009 gap. If I swap locking pieces the gap measurement swaps between assemblies (gap follows locking piece). I find this strange because this gun only has fired about 2000 rounds since new. Oh well. The measurements don’t lie.
So I need to order new rollers for both bolt-heads. Given these bolt-gap measurements (.009 and .011), which number rollers should I order for each bolt-head? I assume I want to get as close to being slightly under .020 as possible, correct? Do I need any other replacement parts to do the roller job other than the 2 rollers?