View Full Version : New barrel throat ???
02-21-2012, 03:54 AM
I'm in the process of ordering a new Krieger barrel, for a Savage switch barrel. So far, I've decided on a 375-06 imp with a 15" twist, a .366 bore and .376 grooves, a #4 contour (.670 at the muzzle) 25" long. Is there anything special that I should request about the throating, or can I deal with what they send me. Also, if you can see anything wrong with the direction I'm headed in, I'd appreciate your input. This is my first project so I'm doing the best I can with the info I have. This will be a cast boolit dedicated gun. Thanks in advance for any help you can offer. Ron.D
02-21-2012, 08:48 PM
Cut the throat 1 degree on a side or 2 degrees inclusive. If they can go to half a degree a side or 1 degree inclusive so much the better. The shallower the leade into the throat means you can seat bullets out to touch the lands. I do this with a M27 Finnish moisin nagant and she shoots great. But the bullets won't fit the magazine. They stick out too far. I'm using the Lyman 314299 mold. Frank
02-21-2012, 09:17 PM
first things first, make sure everyone is using the same language.
throats, depending one who you talk to include some freebore, then leade.
02-21-2012, 10:07 PM
I think they're talking about leade. You might like a 1 in 14 twist a little better.
02-22-2012, 05:54 AM
Being new to barrel language, I'm asking for both freebore and leade. I appreciate the input regarding leade, now how much freebore do I want? Thanks for the info on the leade, good to know. Leftiye, I'm interested in speed. The slower twist will keep my RPM's lower. It was a decision between 15" or !6" twist. I won't be shooting anything heavier than 270 grs. Probably a little lighter. Ron.D
02-22-2012, 08:34 AM
How fast do you think you will be pushing a .375cal 270gr boolit? do you think you'll be pushing it so fast as to NEED a 1/15 or 1/16? Will that limit you to lighter boolits?
perhaps a 1/14 would work as well, for the highest speed you expect to attain, AND allow you to shoot heavier boolits?
which boolit? perhaps send the boolit to the reamer maker and they will grind the "Throat" to match, including the freebore and leade.
I'm sure someone with a Calculator can tell you the "Best" twist for a typical boolit in the .375.
maybe PM Larry Gibson with the twist question. He has a great handle on twist/speed ratios, and is very helpful to us with the questions
02-22-2012, 05:53 PM
As for freebore, unless you have long boolits, don't mind exposed lubricant, and want more case capacity, the least you can stand may be best. Some worry about matching the boolit base of a loaded round to the shoulder of the case. So it's pretty much up to you, set up your round as you want it, have a reamer made for that, and use a mild leade angle.
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