Watch your caliper zero!

[1Shooter]

If you're using a caliper that isn't electronic, always check your zero before you start measuring c.o.a.l. I started reloading for my .22-250, and realized that the c.o.a.l. was longer than I had written down from this spring. I figured it was just because the bullets I use were recently replaced with a different part number and are now made longer. Besides, my seating die is still set the same as it was in the spring, so I should be fine.

Then I started trying to work up a load for my .30-06. The book tells me that for the bullet I'm using, the c.o.a.l. should be 3.200". I measured my c.o.a.l. for the .30-06 to be 3.23", so was trying to load for that. I started to seat my first bullet so I could set the depth on the die to where I wanted it. Took my calipers and measure the c.o.a.l. to be 3.91". It looked a little long, so I adjusted my die accordingly. Tried it again, got it down to 3.75". This looks about right, but it's not even close to 3.23" Well I get the c.o.a.l. all the way down to 3.5", but now it looks like the bullet is about ready to fall into the case. After some pondering on what the @#$% is going on here, I found out that I lost the zero on my calipers by about .40". WOW .

I now own an electronic caliper

[Tim Anderson]

You can re-zero your dial caliper by turning the outside ring, loosen the set screw first and turn dial to zero and then tighten set screw.
If you switch bullet weights, style like h.p. or soft point or what have you the seating depth reading willbe different from each and your seater stem will seat them differently as well......

[Coyotehunter]

yep you need to keep this stuff calibrated. it is best to measure off of the ojive for consistant measurements.

[1Shooter]

If you switch bullet weights, style like h.p. or soft point or what have you the seating depth reading willbe different from each and your seater stem will seat them differently as well......

I didn't switch bullet types, it's still the same 52 gr. Berger hollow point I was shooting, I just think that it's maybe a little longer than the previous 52 gr. hollow point I was using from Berger. They discontinued the "Match Grade" version and now just make a "Varmint" version that has a slightly smaller B.C. due to a different jacket, the G1. If I remember correctly, when I bought these bullets I called Berger because I wasn't finding my bullets, and they told me they replaced them with this new G1 jacketed Varmint grade bullet, and I believe the ogive is the same.

This caliper I have that lost it's zero doesn't have a set screw, and when I try turning the outside ring, the reading arm doesn't move That's why I went and picked up the new caliper.

[Coyotehunter]

http://www.larrywillis.com/bullet-shape.html

interesting article.

I understand wht you are saying about the caliper. glad you got a new one. made me think for a moment about overall length. that is why I made the comment about were to measure from to get a consistant overal length.

[1Shooter]

Interesting read Coyotehunter. It's nice to have more accurate readings from the electronic caliper anyway. This week I'll see if silverdog will help me measure off the ogive of these new bullets to see if there are any changes.

[leadbiscuit]

I've got a dirty little secret.... I don't own a caliper attatchment for measuring off the ogive. When I start working with a gun I normally fiddle with the seating depth until I get a square mark on the bullets from contact with the rifling. Then I try several different powder charges with this seating depth. After I find the powder charge that shoots the best I'll start seating the bullets deeper 0.020 at a time. When I find the seating depth that shoots the best I make up a dummy round that stays in the die box and gets used to set the seater die when it's time to load more ammo.This system hasn't given me much trouble....yet.

have a good one
lead

[Coyotehunter]

I had a old time gunsmith show me the same thing and I have been doing it that way for years and years. I also do not screw with my stuff much anymore. other then a few new barrels and this .243 WSSM I just got I have not had a new gun in years. So I just do not try anything new these days, been shooting the same load on the .22-6mm for 12 years. I do think that a guy needs to know all the ins and outs for trouble shooting purposes. That article I posted was very interesting to me, makes sense. dies wear out and things change.

[leadbiscuit]

It is the right way to do it (measuring off the ogive). I won't argue with that. I guess I just enjoy being a little backwards. I am a redneck after all... It is nice to have a few gadgets around when the shit hits the fan. I remember reading somewhere that inconsistant bullets cause far more problems with fliers when a person is trying to seat bullets to just barely touch the rifling. The reason for this is that you end up with some bullets touching the rifling and some that don't. It causes fliers and "double groups". In other words two rounds touching and three rounds touching a short distance away. I have found that to be true when trying to run bullets seated like that. I just had it happen with one of my 22-243's. I seated the bullets another 0.020 deeper and it's shooting like a champ. An 80 grain berger going 3450 and shooting in the threes at a hundred yards. I don't think the coyotes are gonna dig it much. I'm not sure what it's gonna do on fur though. I guess if Chris is chasing me around with his skinning knife at Minot I'll have to rethink things.

have a good one
lead

[lyonch]

You wont be the only one being chased leadb There are a few guys that think the only good coyote is one that has a basketball size hole in them I should have anyone who blows a hole in a coyote sew it up for me on the spot

[leadbiscuit]

I can't sew a button on shirt let alone a hole in a hide!!! Is there some sort of treat that would buy my safety? A cold beer maybe?

lead

[lyonch]

I don't know what it is about a cold beer, but it sure gets a guy out of a lot of trouble and sewing Can't wait to meet you fella!!

[Jerry Hunsley]

The old way will work, but still boils down to one thing. To get accurate readings when measuring your bullet ogive with any gauge , you have to have your barrel super clean especially with an older gun that has a lot of rounds through it. I found this out a long time ago. Sometimes , I think a guy overlooks a real good cleaning of his rifles and it will effect your consistency of oal. You got to get all that fouling out to get consistent readings. Most of you probably know that already. It is the little things a person has to pay attention to. It will make a big difference in your accuracy. I think the Stoney point Oal gauge is pretty good. I still have a problem with that gauge trying to get the inserting pressure the same everytime, but not that much of a problem .