help: lock and load, comparator usage

[dataforce1@gmail.com]

I am getting too wide a sampling when I measure OAL using hornady thing and comparator. I must be doing something wrong. Seems simple but I worked on this for an hour this morn and variations went from 2.11 to 2.15 sometimes with same bullet.

Any easy suggestions?

 

[itchyTF]

The bullets themselves may not be consistant and, depending on neck tension, the seating depths may not be consistant.

Try measuring a decent sample of just the bullets (around 50) and see what you get for consistancy. If they're good then I'd say it was neck tension. If they're not good then I could be the combination of the two.

 

[bozo699]

Itchy is spot on, also you have to close your calipers using the force your going to be using and zero the caliper, I use a good snug closure but not enough to spring the blades, I try to be very consistent with this pressure, recheck to make sure your getting a .0000 measurement with no round in it everytime you close the caliper! if not your not using it the same. Bullets vary badly and that is not the best tool in the world to check them with but it will work and bullets do vary, sometimes more then what you are seeing, if your brass has different number of firings on them or there different brands you WILL have oal issues,...hope this helps some.
Wayne.

 

[jcampbellsmith]

I am getting too wide a sampling when I measure OAL using hornady thing and comparator. I must be doing something wrong. Seems simple but I worked on this for an hour this morn and variations went from 2.11 to 2.15 sometimes with same bullet.

Any easy suggestions?

Is the rifle barrel new or well used? If the throat is worn or dirty (or both), then it may be tricky getting consistent OAL measurements. Regards JCS

 

[bozo699]

I am getting too wide a sampling when I measure OAL using hornady thing and comparator. I must be doing something wrong. Seems simple but I worked on this for an hour this morn and variations went from 2.11 to 2.15 sometimes with same bullet.

Any easy suggestions?

Is the rifle barrel new or well used? If the throat is worn or dirty (or both), then it may be tricky getting consistent OAL measurements. Regards JCS

Hornaday thing may have thrown me, if your talking trying to find your lands for a starting point looking for seating depth then the same theory applies that I explained to you with the calipers, you have to use the exact same pressure with both the oal tool,...(not thing) and use your caliper with the same pressure, do this 10 times and if the bulk of the measurements are the same go with it or a over all average throw out any obvious real bad measurements, it takes a little practice but you can get pretty consistent with these tools.
Wayne.

 

[dataforce1@gmail.com]

Thanks guys, Barrel is new and chamber is clean. I just was inconsistent. I asked my son to do it and he got 6 reads from 2.1525 to 2.1500. he used consistent pressure and held in both the bullet rod and lock and load shaft while tightening screw. this worked well.

JR

 

[bozo699]

JR,
Glad to hear your boy figured it out, I think it will work fine for you,...take care and shoot straight.
Wayne.

 

[CaptainMal]

For what it's worth I also found a bit of inconsistancy with brand new barrels. My take is there are burrs in that throat that wear down after a few rounds.

For me, to get within a couple thousandths, is good enough for a starting measurement. After a bit of shooting and feel with the tool, it may even get better.

 

[paul223]

Glad to hear that your measurement issue is resolved. Just curious - was the rifle a Savage ?

Thanks,

Paul

 

[Martin52]

I have had a similar problem then swapped over to measuring using a Lee Collett die, this permits the case neck to be reduced in diameter sufficient to gently hold a bullet in the case mouth. Seat long then gently close the bolt on the unprimed case, the bullet will be pushed back into the case neck. At that point, gently open the bolt and extract the case taking care not to cause the bullet to move. Measure the base to ogive on your caliper with comparator and then repeat the test. I found it to be a very reliable and consistent way to measure to the lands. Be careful to size down the neck enough to hold the bullet but not too much that it sticks or too loose that it slides too easily. And be gentle opening and closing the bolt.

 

[260Ravage]

I'm with Martin on this. I cut a couple slits in the neck,clean them up well so there are no burs inside or out. Then I run that case through the FL die. I seat the bullet by hand, run it into the chamber, closing the bolt. Eject it carefully and measure the oal length with a comparator. I do this two or three times and I get very consistant readings.

 

[gotcha]

I can identify w/ Dataforce. I too, got inconsistent seating depth readings when checking seating depth w/ the Hornady tool. I found that if I looked at the base of my cartridge where it rested on the caliper jaw while holding it to a light scource, I could see a sliver of light on one side of the jaw. (case slightly cocked between comparator & jaw) by moving the base slightly to eliminate the sliver of light the measurements became much more consistent. This also had a marked effect when sorting bullets for BTO. Just my .02 cents

 

[necchi]

I just was inconsistent. I asked my son to do it and he got 6 reads from 2.1525 to 2.1500. he used consistent pressure and held in both the bullet rod and lock and load shaft while tightening screw. this worked well.

Yup, you nailed it. Good for you.
It's just a matter of getting the human variable to do the job in a consistant manner,
it boils down to a feel thing.
As you use it more, you'll become proficient and trust the measurement more an more, it's a comfort to KNOW where the bullet is against the lands.

I follow direction and will measure 3-4 bullets from the box and measure each bullet in 4 positions,,
12-3-6 and 9 O`clock in relation to the case and holder rod,, then use the average of those 12-16 measurements.