Haywire Haywood
12-04-2005, 04:26 PM
http://i11.photobucket.com/albums/a193/imh_98/375win.jpg
I cropped this 375 Win chamber drawing from what Leverguns had and I'm hoping to get some education on what the different areas are called and how they relate to fitting a cast boolit to a gun. I added the red letters.
I was under the impression that the leade was the area between 'A' and 'B'. The freebore was the area between 'B' and 'D' and the second angle before the rifling starts simply didn't exist. As you can see, my impressions were way off kilter. From looking at this, I deduct that the 2 deg angle is in fact the leade. What is the other angle called? What area would be call the 'throat'.
Fitting a boolit to this chamber: As I understand it, ideally I would nudge the ogive past all the angles and into the rifling, and if that isn't possible a bore riding nose would need to be as close to the diameter of the area between 'B' and 'C' as possible to get the boolit started as close to center of the leade as possible.
How would I measure a chamber impression to deturmine the proper nose length? As you increase nose length given a set boolit weight, either the bearing length would need to shorten or the nose would get skinnier. I'm not sure what to do there.
Maybe there is a good, easy to read explaination on the net somewhere that someone would link to. I realize I've asked an indepth question.
thanks,
Ian
I cropped this 375 Win chamber drawing from what Leverguns had and I'm hoping to get some education on what the different areas are called and how they relate to fitting a cast boolit to a gun. I added the red letters.
I was under the impression that the leade was the area between 'A' and 'B'. The freebore was the area between 'B' and 'D' and the second angle before the rifling starts simply didn't exist. As you can see, my impressions were way off kilter. From looking at this, I deduct that the 2 deg angle is in fact the leade. What is the other angle called? What area would be call the 'throat'.
Fitting a boolit to this chamber: As I understand it, ideally I would nudge the ogive past all the angles and into the rifling, and if that isn't possible a bore riding nose would need to be as close to the diameter of the area between 'B' and 'C' as possible to get the boolit started as close to center of the leade as possible.
How would I measure a chamber impression to deturmine the proper nose length? As you increase nose length given a set boolit weight, either the bearing length would need to shorten or the nose would get skinnier. I'm not sure what to do there.
Maybe there is a good, easy to read explaination on the net somewhere that someone would link to. I realize I've asked an indepth question.
thanks,
Ian