barrel Bore quality

[chiefs50]

Several have mentioned a barrel's "hardness".  If Green Mountain and Rayl are on the hard end, where would you say Colerain ranks?

Mike

[Rootsy]

With hardness being spoken of... What HRc are we discussing?  Most of these barrels I've played with cut like butter...

[Daryl]

In comparrison to a GM barrel, some do indeed, cut like butter. I have no experience with Ed's barrels, but think Taylor is about to work on one very soon.  I don't know the actualnumbers but in comparrison, is's like maching 4140 comparred to 416 stainless.

[Rootsy]

The reason I asked is because the GM I am working on right now isn't very "hard".  Relatively speaking.  4140 Pre-Hard runs 28 - 30 HRc.  Machines considerably more difficult when compared to A36 or 1018.   4140 Natural state runs about 10 pts less in the 18 - 20 HRc area.  You don't get into the file test until you are above 50 HRc... I have no idea what the actual materials of manufacture are amongst the various mfg's but I would tend to think they are using a 10XX grade of material... something in the 1030ish ish ish range or there abouts... But as I suggested, that is but a guess on my part...

[Dphariss]

1137 is harder to drill, ream etc than leaded screw stock.
4140/4150 is harder to machine than 1137. Though it can be made somewhat easier to machine by cryogenic treatment.
Draw filing 4150 is not a lot of fun, I used to do it all the time.
But I don't think you can get insurance coverage for any steel other than gun barrel quality or better 4140/4150.  Or so I was recently told.
There are valid reasons why 4140/4150 is the common carbon steel for BL barrels, GM uses 4140 for their cartridge barrels when it would be easier to use 1137. But 1137 is not really suitable for cartridge gun use.

I would also point out that some of the barrels of the interior finish everyone seems to like as ML barrels would be relegated to tent pegs or barn door stops by cartridge gun shooters.

Dan