Hi all,

I need help. The depth Micrometer I have has a rounded end to the rod. It is no good for measuring the distance from the breech face to the shoulder on a barrel. I need a depth micrometer that has a flat tip to it. Any recommendations from those of you that use em? Since I'm not a pro at this less expensive would be nice if possible.

Or, is there some other way to measure that I'm over looking?

Mitutoyo is probably the best deal. This is not the equipment that you want to skimp on. You can get a set from 0-4" for about $120.00. I've used Starret, Brown & Sharpe, Fowler, and host of others, but Mitutoyo is as good as all of them, and the price is lower too.

I'll second what triggerguard said. - dan

is the barrel thread dia so close to the dia of the shank that the centerline of the depth mike rod wont make it onto the face of the shoulder? ...bob

What brand of mic are you using? The rods on most depth mics are replaceable for very little cost. I had to buy an extra rod for my Starrett set because I needed a round end for a job that I was doing. I have also made my own rods from 1/8" drill rod when I needed an extra long length. Just be sure that you have a way to calibrate the new rod. You don't need to buy a mic, when you just need a rod.

Nashcat

222blr,

That's my problem. Shoulder is too narrow. Still, I'm sure I could use a better mic. Enco has a Mitutoyo for $98. I suppose I can forgo eating for a week or so. Wouldn't hurt to lose a little weight. :-)

z1r---

Go hungry if you wish but your work will suffer from hunger worse than inadequate tools.

Has your mic got a knurled cap on the back? UNscrew that cap and pull the rod out. Go to the tool store and tell the guy you want one like it but flat on the end. They're less than ten bucks at MSC.

JBelk,

Thanks. Actually, mine will be easier to check as the rods pull out the front, it came with 4. I didn't know you could buy new rods. I'll measure mine first and see if MSC has replacements. I appreciate the tip.

z1r, if your depth mike is like mine you can reveress the end of the rod you stick in the mike. The rods that cam with my import mike have a rounded end and a flat with taper end. When I need the flat end I just reverse the rod and are careful to not let the rod fall out.
Ray

Thanks to all for the suggestions. Turns out my rod size is .177" and none of the replacement rods I saw for sale were that size.

m1carbine's idea seemed good but the taper on the opposite side is almost as bad as as the round end so that won't work.

I'd need a shoulder consistently larger than 1.200" to read.

I think I'm gonna have to suck it up and invest in a new one, a name brand. This way at least I know what rods will work if I ever need a new one.

I actually have one last option. The set came with 4 rods and I'll never use the 4" rod. If I can find a way to hold something as small as the rod I could cut and face the rod to length. Trouble is neither my 3 jaw or 4 jaw will hold something so small. (light goes on in head!!!) I just remembered that I have a small drill chuck that has a straight shank. Maybe I can chuck it into the 4 jaw. If the runout is ok then maybe this'll work. Nothing to lose I suppose.

I am sure the rods will be hardened..tough to cut , better off grinding, but it has to be square to the dia, or it will cause more trouble than it solves.....then it has to be calibrated or at least set to the face of the body....best of luck....check ebay, I bet you could find one for 10 bucks....bob

Another idea is shopping on Ebay. Ok, hold the jeers; I bought an old but like-new Starrett on Ebay for less than $40. It's still in the case and works great.

Vibe,

This is one area (headspacing) where close enough won't cut it. But thanks for the input.

Looks like the Mitutoyo will be ordered soon.

-M

[/QUOTE]Have you tried the depth guage extension on your calipers? This might not be to the same degree of accuracy as your depth mike...but it might be "close enough". Most all of those have small flat ends.[/QB][/QUOTE]

The rule of thumb on calipers, whether they be digital or dial, is never trust them with anything that must be more accurate than +/-.001", and this is based on using the standard measuring side, not the end, which is even more inconsistent. Depth mics are by far the better method to use in this instance. I use calipers everyday for checking relative measurements and such on noncritical items, but when the measurement has to be right on, it's time to get a set of mics of one variation or another.

Thanks guys. I knew all of what was said. But being unaware of the exact procedure being attempted, I could not judge what level of precision was needed. My only point was that this tool is an often overlooked feature for making relative measurements.

One more question: Would the Starrett No. 449 be suitable for ths type of work? It is the model with non rotating blade type rods.

Ok, I lied. I really have yet another question: What base size do you all prefer. I like the 2.5" but wondered if any of you used the 4" and why?

Thanks,

M

Hey,

The idea about EBay really paid off. I scored a very nice Starrett for $19.00. I guess the three rod 1"-3" set isn't so popluar. Good for me.

Thanks,

M