Arisaka key holing at 20 feet?

[swheeler]

Slug the throat, size to that, use some of his 2400 powder or slower if available, h2o drop the bullets. Most importantly check those calipers with a standard, something smells fishy. I've a couple of those Lee c.312/185, one had a .297 nose, it got lapped, sure wish I hadn't since I got a K31

[MBTcustom]

Hey there link, not to jump on you with everybody else about your calipers but I am a machinist and I know tools really well. what you have is a set of digital calipers and they measure .0005 at a time. I dont trust that last digit except on the best quality sets, even then, using calipers takes feel and practice and even I miss it sometimes. a micrometer takes the feel out of it but you have to be careful that you dont use it like a C-clamp and crush the boolit you are measuring with it. You can order a 0-1" micrometer from MSC industrial supply for $25. Its a good investment. Keep an eye on the pawn shops when your in there browsing, usually they keep 'em under glass next to the jewelry, you can get a good deal that way.

[303Guy]

no mine say like .3155

Mine too. The resolution is .0005 but that's not reliable. I've used my calipers to measure relative alloy hardness. I zero the caliper on the boolit then squeese the jaws and take a reading of the impression depth.

It's like Chargar says;

When measuring a round object this can be enough to give false measurements.

[Wayne Smith]

Link, where are you in school? Larry offered to send you gas checks, I'll do the same. There is probably one of us within reach as well.

[chaos]

I have a set of Mitutoyo Calipers that read to .0005 or 5 tenths. I have no clue as to why they would make calipers read to this increment. graduated in half a thousandth........

For accurate readings, use a true Mic.

[Link23]

im up at school in Rexburg Idaho right now, im From Ashland KY the Tri-state of Ohio and Wv

So how do you slug the throat? just push it up through the chamber that way and then knock it back down?

[MtGun44]

Please take this as education, not attack. Resolution is the number of digits reported,
but accuracy is the actual correctness and repeatablility of the readings. They are not the
same, and I can keep adding resolution (more digits) without doing anything to make
the unit actually more accurate. Resolution can be an inexpensive sales tool as many
do not distinguish between resolution and accuracy, assuming more resolution means
more accuracy. Not necessarily so.

So, I would suggest that you assume that the unit is, like most calipers +/- .001 or
.002 on accuracy, regardless of the resolution of the readout. If you have a machinist
that you know, you may find it interesting and useful to take your calipers and measure
some of his gage pins and see what you get. Gage pins are very precise, close enough
to dead on ( minus gage pins are the marked reading minus 0.0002" with a very tiny
tolerance) to let you check out both your caliper and your skills in using it.

Get a mic when you can afford it, I was a student myself and my outlook at that time
was "poor folks got poor ways" and I regularly did things that were the best I could afford,
even when I knew it was a bad way to do whatever it was. You'd be surprised at some of
the junk cars that I drove around, engines patched together with literally parts I pulled from
the junkyard because I had to have a car to get to school and work, and could NOT afford
new repair parts, just junkyard rings and pistons, etc.

Bill

[madsenshooter]

Since he's probably using the same instrument to measure the slug as he is the boolit, they're no doubt accurate enough to say, "The boolit is bigger than the bore." Provided he smashed the slug into the rifling rather than simply push it through.

[Wayne Smith]

im up at school in Rexburg Idaho right now, im From Ashland KY the Tri-state of Ohio and Wv

So how do you slug the throat? just push it up through the chamber that way and then knock it back down?

Best way is to take a case and fill it most of the way with lead. Place that in the chamber and lock the bolt. Now take a slug that will be long enough to fill the rest of the case and the throat, run it down the muzzle of the rifle with a brass rod, and give it a good pounding. Do this with soft lead. The lead will fill the rest of the case and expand to fill the throat. Once you've done this open the bolt and drive the throat slug and case out of the chamber. Now you have a permanant record of the throat.

The other way is to get some Cerrosafe and make a chamber/throat cast.

Check your PM's.