.125" -.130" cartridge protrusion. Measure the depth of the bolt face, most are .115". Then you need clearance of at least .005".
.125" -.130" cartridge protrusion. Measure the depth of the bolt face, most are .115". Then you need clearance of at least .005".
"As long as there's lead in the air....there's still hope.."
Beat me to it.........
The Dunning-Kruger effect is alive and well.
0.125" is the standard depth of a shell holder for reloading presses as well. By no coincidence.
"They couldn't hit an elephant at this distance." Last words of Gen. Sedgwik
After reading this thread and thinking a little (dangerous)! Is it necessary for the chamber end of the barrel to be perfectly square with the chamber. There is about 1/8 inch clearance between the bolt head and the end of the barrel, Savage bolt head floats, so is a perfectly square barrel face necessary?
I have a barrel that has the chamber cut a little deep and when I headspace I am hitting the end of the barrel. I see no reason I couldn't just use a file to remove a few thous.
Redneck engineering and gunsmithing! Setting a barrel back with offset grinder and file!
You can't "clean up" an eccentric chamber by just running another reamer in.
Running another reamer into it- whether by hand, or under power- isn't going to change it. The reamer will follow the existing hole.
That problem can only be resolved on a lathe by indicating the bore with a range rod, and using a boring bar to true the chamber to the bore/lathe axis, setting back and re-cutting the chamber.
There is only .005"-.015" between the bolt head and the barrel breech face.
Use a Gage to measure the protrusion. (the problem could be your sizing process)
Like Fred said, measure the depth of the bolt face and measure protrusion. The protrusion number must be greater than .005" than the bolt face depth.
The Dunning-Kruger effect is alive and well.
This will work with no problems providing the original chamber isn't "egged" as tobnpr mentioned. I've shortened the breech with a hacksaw on numerous occasions and squared it up with a big bastard. Any craftsman can get within a thousandth or two and that will pose no problem. Just make sure the go-gauge protrusion matches the bolt head recess + your desired bolt head to breech face clearance. It usually falls in that .125 to .130 number. Some aftermarket heads like PTG may require a little bit more.
Make sure the reamer pilot matches the bore just ahead of the throat. Do all the hand reaming vertically with the barrel mounted below your work station. I have a barrel vise mounted specially for hand reaming and stand above it on a stool to provide constant equal down force on the reamer. The reamer will follow the "old" hole, as long as you don't induce side pressure. I do not recommend trying a full chamber with this method. Withdraw the reamer every .010 - .025 and clean it and the chamber & barrel. Re-lube each flutter with cutting oil each pass. Use a reamer stop for the last passes. I've only done this 10 or 12 times to create Ackleys , wildcats or simple cartridge swapping. Not for complete chambering.
Yes it works fine if you have the time. There is a learning curve.
Here is an example of a "hacksaw" rechamber quicky. Was a .260 Rem, hacksawed .250 off breech, filed square, ran 6.5 creedmoor reamer in .075 deeper than creed depth. Used 260 brass in creedmoor die to bump length...trim to 2.003. 2-1/2 grains more capacity than CM and shoots ok. Barrel did have over 1000 rounds so no break in was required.
Edit: this was 5 shots at only 100 yards with Berger 130 vlds pushed with h4350.
Also .010 off with no other load developement. Velocity was 2984 ave over 5 with sd 9.1 over mag speed.
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