Bullet seating question

[absolutchris]

Hey guys, I finished my first batch of hand loads and it was awesome.

I am using a Redding type s micrometer seating die. Got it dialed in, started seating and was checking length to ogive using Hornady comparators.

It was very consistent and so I stopped measuring. Finished 50 rounds and then measured the last one and it was off by 0.003". It was long. So I adjusted on the micrometer and resat the ones that were off.

How often are you guys checking when seating bullets? I thought you could set and forget? How hard are you screwing in the die/lock ring?

Thanks in advance

 

[spife7980]

I check enough to figure out what my average is at the beginning and then leave it alone and trust it to work. Usually I have a spread of +/- .001 but the occasional .003 gets in there. I dont fret over it because I cant really ever tell down range.

When I am doing a seating depth test I go in .005 increments and I will worry about it more specifically but thats just so my testing is perfect but when I load up lots of the same thing I dont worry about it. If its longer or shorter it just goes in to the next group it fits into.
I sure as hell dont measure each one and reseat it to fall in line and then go back to the original setting and see the result and do it all over again.

 

[ShtrRdy]

Congrats on your reloading session! It sounds like you did well.

There are at least two things that I've found which can cause this sort of inconsistency. ( and 0.003" isn't too bad ) The first is inconsistent neck tension/friction. If it takes different amounts of force to seat a bullet, there can be some push back thus causing some cartridges to be longer than others. The second thing is that the seating stem contacts the nose of the bullet in a different place than the Hornady Comparitor tool. To check this theory out remove the seating stem from the die and measure some bullets. Measure from the base of the bullet to the top of the seating stem. Also measure from the base of the bullet to the Hornady Comparitor on the same bullet. Notice that the Seating Stem and the Comparitor contact the nose of the bullet in different places. Repeat this on a sample of bullets to see how consistent they are.

 

[Steel head]

I check enough to figure out what my average is at the beginning and then leave it alone and trust it to work. Usually I have a spread of +/- .001 but the occasional .003 gets in there. I dont fret over it because I cant really ever tell down range.

When I am doing a seating depth test I go in .005 increments and I will worry about it more specifically but thats just so my testing is perfect but when I load up lots of the same thing I dont worry about it. If its longer or shorter it just goes in to the next group it fits into.
I sure as hell dont measure each one and reseat it to fall in line and then go back to the original setting and see the result and do it all over again.

This.

 

[spife7980]

Congrats on your reloading session! It sounds like you did well.

There are at least two things that I've found which can cause this sort of inconsistency. ( and 0.003" isn't too bad ) The first is inconsistent neck tension/friction. If it takes different amounts of force to seat a bullet, there can be some push back thus causing some cartridges to be longer than others. The second thing is that the seating stem contacts the nose of the bullet in a different place than the Hornady Comparitor tool. To check this theory out remove the seating stem from the die and measure some bullets. Measure from the base of the bullet to the top of the seating stem. Also measure from the base of the bullet to the Hornady Comparitor on the same bullet. Notice that the Seating Stem and the Comparitor contact the nose of the bullet in different places. Repeat this on a sample of bullets to see how consistent they are.

A visual example

 

[65shootmoor]

You can also get a variance in length due to inconsistent hand pressure on the handle. Even on heavy, metal benches and everything torqued down, I can usually get around 0.003" difference in pressure applied from just touching the stop or giving it a squeeze. I installed a bolt to act like a stop against the bottom of my handle to give me feedback of when I hit bottom. A wooden bench will give a little when you flex it even if you have everything else tight.

 

[absolutchris]

Ok thanks guys, makes me feel better.

I forgot to mention, it was virgin brass and so the neck tension was definitely variable because I didn't neck turn etc. I just ordered the bushing for the sizing die etc

The other information is really good info also

thanks again

 

[MarkLeupold]

As you get better at reloading, you'll become more consistent, as will your equipment. I used to measure every other case/seated bullet, then I checked every fifth. Now I check the first three. If they're good to go I load until the middle of my batch and check those three. If they're good, I load the rest and check the last three. Leaving them segmented like that helps me pinpoint where something went wrong if it does change. My seating depth is pretty much always +/- .001" nowadays.