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Posted: Thu Nov 12, 2009 3:09 pm
by Kurt
Orville.
I thought you had a 15° did you change it?
Yes the lead and paper rings are part of the past but I can see I have to get some new PP moulds for the .44 and .45 for a better fit in the throat.
Kurt
Posted: Fri Nov 13, 2009 8:30 am
by Orville
Kurt
The two 45 caliber reamers I have, 45 2 7/8 and 45 2.4 have the 15 degree lead. I had a seperate cutter made to go into standard chambers and cut a new lead, this is 7 degrees. The new 44-77 reamer has the 7 degree lead.
With tight chamber which keeps the bullet under groove size until it is in the barrel, the 15 degree works great, but as the chamber gets bigger I believe a shallower lead works better, makes it easier for the over groove size bullet to slip into the barrel without tearing a patch or shaving lead off the bullet.
Posted: Fri Nov 13, 2009 11:19 am
by mdeland
You guys are talking included angles of leade, no?
A 15 degree would be 7.5 per side and a 7 degree would be 3.5 per side, yes? MD
Posted: Sat Nov 14, 2009 7:54 am
by Orville
MD
your trying to make thing way more complicated then the need to be.
The angle is measured from the end of the chamber to the top of the rifling. When you look at a reamer drawing, where it shows the standard 45 degree at the end of the chamber just change it to 15, 7, or what ever you want.
Posted: Sat Nov 14, 2009 3:01 pm
by mdeland
Thanks for the explanation Orville.
This sounds quite similar to the 11 or 18 degree forcing cones cut in revolver barrels to better accommodate lead bullets. There is no parallel section.
How deep in relation to the case mouth width and thickness do you make this angle cut? Another way to ask the same question. Where does the angle of the cut terminate in relation to the case? MD
Posted: Sat Nov 14, 2009 5:46 pm
by Orville
Without drawing you a picture, if the case is long it can be right where the angle starts or if the case is shorter you will have some chamber wall exposed for the bullet to upset into. With the 7 degree angle cut at the end of a larger chamber I have shot pure lead with no paper rings or lead in the bore and still shot very good.
It will shoot even better if the chamber is tight or use thick walled brass.
Posted: Mon Nov 16, 2009 8:08 am
by w44wcf
Kurt,
I just checked the throat on my .22 rifle and there is a rapid transition from the groove to the bore diameter....looks to be at least a 30 degree angle. My Marlin is 1948 vintage and has a "sporting chamber".
I do know the .22 L.R. "match chamber" has a much more tapered throat and it engraves the bullet when the cartridge is close to being completely chambered.
John Boy,
Thank you for the neat catalog info.
I have dissected some semi-smokeless .22 L.R. and they were in the 2.7-3.0 gr. range.
w30wcf