Seating Depth
- Thread starter savageshooter86
- Start date
Elkbane--- measure some bullets using 30 cal insert and got same readings. Then put in the 22 cal insert. And got same readins on all the bullets with this comparatorl. Using both inserts I got the same max variation of 0.0005 at most. So initially that seems that bullet profiles are consistant
Die should be here by Friday I hope
Die should be here by Friday I hope
Lot of good responses here.
Funny, no one has mentoned that seating will be inconsistent if you are using compressed loads (especially with light tension). The pressure of powder against the bullet base, will tend to push them up.
Attaining perfect OAL to the ogive is difficult, even with some of the best custom bullets. I try to stay within .003" using the Davidson base and nose piece attached to my caliper. I learned early in this game that the hex nut comparator is very difficult to use for consisency.
Funny, no one has mentoned that seating will be inconsistent if you are using compressed loads (especially with light tension). The pressure of powder against the bullet base, will tend to push them up.
Attaining perfect OAL to the ogive is difficult, even with some of the best custom bullets. I try to stay within .003" using the Davidson base and nose piece attached to my caliper. I learned early in this game that the hex nut comparator is very difficult to use for consisency.
indeed a lot of helpful posts. I did notice awhile back compressed loads seated longer even on same setting. 44.2 is barely compressed since my OAL is close to 2.890“. I barely feel powder when seating and I feel powder moving inside case if I shake a loaded round
my biggest variation comes when i can feel a different resistance to bullet seating (due to a difference in neck tension for what ever reason). loaded some 22 brs last night. my forster bullet seater is very sensitive and i could easily feel 3 that seated much easier than the others. from experience i knew they would measure deeper and indeed they were .003 deeper that those that resisted the seating stem. close inspection showed the stem ring on the forward ogive of the harder to seat and this is where the .003 goes. right on re being sure primers are seated below base.
tenring or anyone else: how consistant is the davidson measuring tools? I just looked at them on sinclair and look interesting
I am having issues with the hornady bullet comparator lighty cutting into the bullets when try to measure the ogive. I have polished with fine grit paper and steel wool and cleaned them and did not improve much. My method is i insert and lightly close calipers then apply slightly more pressure and spin the case with my fingers until the caliper settles on a reading. This according to others and Hornady takes the play out and gives more accurate reading. But I get nice little shiny rings on my bullet ogive when doing this
I am having issues with the hornady bullet comparator lighty cutting into the bullets when try to measure the ogive. I have polished with fine grit paper and steel wool and cleaned them and did not improve much. My method is i insert and lightly close calipers then apply slightly more pressure and spin the case with my fingers until the caliper settles on a reading. This according to others and Hornady takes the play out and gives more accurate reading. But I get nice little shiny rings on my bullet ogive when doing this
Savageshooter86 – The best way for me is to insert the bullet into the comparator, lightly close the caliper and then just giggle the base of the bullet until it sits flat against the other edge of the caliper. No real force should be applied as the bullets are pretty soft or you will change the reading by denting the bullet. There is no need to spin the bullets; all you are trying to avoid is having the base of the bullet sitting cockeye on the other edge of the caliper. There should not be any markings on the bullet from doing a measurement.
Have not seen the Davidson tool but you should be able to get consistent reading of around 0.0005†to at most 0.001†lengths with a good quality caliper like a Mitutoyo and the Hornady bullet length/headspace tool combo.
On the topic of greatest variation from hard seating – that is absolutely true. That is one reason why it is important to have consistent neck tension and consistent resistance to seating. For example, if your brass have donuts in them, you will ge variation in seating depth.
Have not seen the Davidson tool but you should be able to get consistent reading of around 0.0005†to at most 0.001†lengths with a good quality caliper like a Mitutoyo and the Hornady bullet length/headspace tool combo.
On the topic of greatest variation from hard seating – that is absolutely true. That is one reason why it is important to have consistent neck tension and consistent resistance to seating. For example, if your brass have donuts in them, you will ge variation in seating depth.
Elkbane , can u please repost your first post again on this topic cause I think they missed it ....maybe in a different context this time .
savageshooter86 said:
I have the hex comparator, the Hornday OAL tool and neither is as accurate as the Davidson. The big advantage of the Davidson, is that you buy the base with correct nose piece. The base sits your brass rim in exactly the same place each time. Once lined up with the nose piece it is very accurate, but remember bullet ogives do vary.
"Elkbane , can u please repost your first post again on this topic cause I think they missed it ....maybe in a different context this time ."
I think they understand it - if not, go back and re-read post 16. The controlling logic of physics still stands. Case contacts the dies/press in two places - the base of the case and the nose of the bullet at seating stem ID datum line. The distance the dies are set between those two points are the only factors that determine seating depth, assuming the dies are tight in the press and the seating stem threads are locked in (no slop).
If the seater stem digs into the bullet nose due to excessise seating force, you have effectively changed the bullet dimension at one the contact points and the result will express itself as variability in seating depth as measured base to ogive. If the primer is proud of the case base, that produces a measurement error in my way of thinking, as you are not affecting the true seating depth (base to ogive). But it can affect the MEASUREMENT of seating depth.
If you spin the bullet and the comparator digs into the bullet, that also affects the measurement of seating depth as you are changing the dimension of the ogive - unless you spin each one to deliver a "groove" of the same depth. I just slip the cartridge into the comparator and jiggle the case base a little until when doing it twice I get the same measurement....with light, even pressure on the caliper. Keep in mind - we're using a caliper - they're better than using a yardstick, but +/- .001 is about as good as you can get with them.........
Elkbane
I think they understand it - if not, go back and re-read post 16. The controlling logic of physics still stands. Case contacts the dies/press in two places - the base of the case and the nose of the bullet at seating stem ID datum line. The distance the dies are set between those two points are the only factors that determine seating depth, assuming the dies are tight in the press and the seating stem threads are locked in (no slop).
If the seater stem digs into the bullet nose due to excessise seating force, you have effectively changed the bullet dimension at one the contact points and the result will express itself as variability in seating depth as measured base to ogive. If the primer is proud of the case base, that produces a measurement error in my way of thinking, as you are not affecting the true seating depth (base to ogive). But it can affect the MEASUREMENT of seating depth.
If you spin the bullet and the comparator digs into the bullet, that also affects the measurement of seating depth as you are changing the dimension of the ogive - unless you spin each one to deliver a "groove" of the same depth. I just slip the cartridge into the comparator and jiggle the case base a little until when doing it twice I get the same measurement....with light, even pressure on the caliper. Keep in mind - we're using a caliper - they're better than using a yardstick, but +/- .001 is about as good as you can get with them.........
Elkbane
got die back and gonna load some up tonight. Made on dummy round and seems to be alot better. They replaced the spring in the die with a stronger one? Measured the cases they sent back and I got the same readings for the difference in seating depths. They sent me 3 different seating depths. So I measured them using my comparator and method and got the same change they had marked on the package. Think they sent me (2)2.226,(1)2.228,and(2)2.2275". I got the exact change in seating in time I measured the cases
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