help with consistent seating depth ?

[rebs]

Thank you guys for all the replies. To sort my bullets what is the best way to do it?
I am mainly using Berger 80.5 full bore and a few 80 gr SMK's on occasion.

 

[Bill Norris]

Base to Tip

 

[6Creed73]

I don’t think it’s incorrect if he’s using run of the mill bullets like Hornady, Sierra or Nosler CC.

He said you will "never" get consistent seating depth unless you sort bullets. That's just not a correct statement. Sort them by what? The only way sorted bullets will give you more consistent seating depth is if you sort by where the seating stem contacts the bullet, because the comparator used to sort them won't contact the bullet in the same place the stem will. And the stem is typically tapered and contacts more of the bullet than the comparator will.

With that said, yes, non-match bullets can have slight variations in ogive. So even though the seating stem is consistently seating the bullet's depth, the CBTO measurements with the comparator can vary due to the ogive variations. So sure, you can sort your bullets by your comparator's measurement which will give you consistent readings on the caliper, but it doesn't mean the seating depth isn't consistent. At that point you aren't really talking about consistent seating depth anymore, you are talking about consistent jump to the lands.

For the OP to have 5 thou in variation, I highly doubt that's due to variations in ogive. If it is, my suggestion would be to never use those bullets again because the quality control sucks. In my experience, It's much more likely that variation in neck tension is the cause.

 

[JEFFPPC]

Incorrect. I only sort my precision rifle rounds and I get consistent seating depth with everything I load. And precision rifle I sort by weight, which will have no affect on seating depth.

Even if you sort your bullets by ogive to base, the tool you used to measure is not going to contact the bullet at the same spot that the seating stem will. Even between different dies and stems, they won't contact the bullet in the exact same spot.

First step to consistent seating depth is brass prep. If you have different neck tension from case to case or the neck is rough from trimming, it absolutely will affect seating depth.

Thanks you have helped me reach a decision I have been pondering for some time. Good luck with your reloading.

 

[RabbitSlayer]

I am no expert but on my forester coax i found i could vary seating depth by at least .006 between light pressure and firm pressure at the bottom of the stroke. Dont remember now exactly, but the last time I loaded 53gr vmax with hornady seater almost all were within like .001 BTO. A few out of 50 were within .002 or .003. i just use those for fouling. I measured all of them cuz it was a seating depth test.

 

[Dave M.]

case head to ogive with comparator on my caliper

Check to make sure all primers are under flush. Shoulder bump has zero to do with it if you are measuring in the above manner (which is correct)

 

[Dave M.]

I am no expert but on my forester coax i found i could vary seating depth by at least .006 between light pressure and firm pressure at the bottom of the stroke. Dont remember now exactly, but the last time I loaded 53gr vmax with hornady seater almost all were within like .001 BTO. A few out of 50 were within .002 or .003. i just use those for fouling. I measured all of them cuz it was a seating depth test.

This is why I don’t seat using my presses. I only seat with Wilson dies and a K&M Arbor Press.
Dave

 

[Dave M.]

Thank you guys for all the replies. To sort my bullets what is the best way to do it?
I am mainly using Berger 80.5 full bore and a few 80 gr SMK's on occasion.

I sort my long range bullets into .002” groups by overall length.

 

[RabbitSlayer]

This is why I don’t seat using my presses. I only seat with Wilson dies and a K&M Arbor Press.
Dave

I know. On my list but that is a very long expensive list of upgrades lol. Amp annealer next...

 

[6Creed73]

I sort my long range bullets into .002” groups by overall length.

I'm curious at what distance you see a difference between sorted bullets by OAL vs no sorting. I'm asking because I used to sort by OAL because it's logical that bullets that are alike will fly similarly and group together tighter.

However, I didn't see results unless I was shooting beyond 600 yards. Also, at the time I was shooting PRS, not BR, and the difference between sorted and unsorted was too small to matter in my application...so I stopped due to diminishing returns.

I'm just curious how much of a difference you experience and at what distance.

For the OP, I think it's important to note that sorting by OAL won't make any difference in his seating consistency...but could help with grouping performance.

 

[TTE]

As mentioned above make sure the bullet tip is not bottoming out in the seating die. If the bullet is touching the powder when seating it you will find more consistent measurements by allowing dwell time at the bottom of the press stroke.

Also maybe seat the bullet 1/2 way and rotate the case in the shell holder 180' then finish seating

 

[David Christian]

I'm curious at what distance you see a difference between sorted bullets by OAL vs no sorting. I'm asking because I used to sort by OAL because it's logical that bullets that are alike will fly similarly and group together tighter.

However, I didn't see results unless I was shooting beyond 600 yards. Also, at the time I was shooting PRS, not BR, and the difference between sorted and unsorted was too small to matter in my application...so I stopped due to diminishing returns.

I'm just curious how much of a difference you experience and at what distance.

For the OP, I think it's important to note that sorting by OAL won't make any difference in his seating consistency...but could help with grouping performance.

IMO, it only matters beyond 600 yards (assuming I am using quality bullets).

 

[David Christian]

I am reloading for my Tikka 223 bolt gun using a Redding bushing die to size the case and neck. I am using an RCBS competition seating die to seat the bullets. I have-not been able to get consistent seating depth. I am loading Berger 80.5 full bore bullets and some 80 gr SMK's. The seating depth will vary by about .005 with both. I am only bumping the shoulder by .001 to .002. I have read that the Redding bushing die does not size the entire neck, could that be a problem ? Could another problem be the brass not being trimmed to the proper length ?
Is there anything you guys could suggest for me to be doing ?
I forgot to mention I am using Lapua once fired brass. Some have been fired 4 times and some 6 times

The bushing die should not play a roll in this issue, nor should the trim length. Assuming one is measuring seating depth by the ogive my most likely area for inspection is the seating stem—bullets bottoming out…

 

[Clancy]

Lots of opinions and heat in this thread, but I’ll share my experience and break it down into what I think helps and hurts.

The “hurt” category includes crappy seaters, seating on a press without consistent handle pressure, compressing loads, work hardened brass, incorrect stem, cheap bullets, dirty case necks and less than perfect chamfering and deburring.

The “helps” category would include shooting custom or sorted bullets, using an arbor press to seat, cleaning case necks with a nylon brush and annealing.

There are a lot of steps in my case prep and I don’t know which ones help the most and which help the least, but I know I can seat a batch of Bart’s bullets and see practically no variance in BTO, so I’m going to keep doing what I’m doing. I enjoy time at the bench even more than shooting.

 

[jimmymac]

I’d buy an arbor press and a Wilson seater die and call it good. Minimal investment to achieve great consistency.

 

[Fuj]

I do this on only one particular rifle....Anybody else load long
then let the bolt closure do the final seating ?? I experimented
doing this with unsorted bullets, which I normally sorted base
to ogive. First groupings of sorted bullets and loaded at .006
jamb, the rounds shot in the two's. The rounds loaded long
with unsorted bullets shot about the same. This was tested
at 100 yards and both were single digit SD's.

 

[OMW57]

Rebs, as I read your question, I noticed you said some cases were fired 4 times & some 6 times, this might or will will cause a difference in case "hardness" and can affect seating depth issues, also, I found when I experienced this issue, Polishing the seater stem using a bullet & some fine abrasive paste will get the seater stem to match the contour of the bullet nose better, thus help in seating more consistantly!

 

[JMayo]

I was seating 6mm the other day with a Wilson seater. Things began to get weird on depth.....
The darn stem had become loose. I retightend and problem went away.....

I may one day pay for putting purple lock tight on it but that isn't the first time it's come loose in 7yrs.

 

[TTE]

I would say to find out what is giving you problems, you need to look at things mentioned here and eliminate things as you go step by step.

I would start here -

Check to make sure all primers are under flush.

 

[K22]

Sounds like you're in the benchrest game.

While I am not and never have been or never will be but if I was, I would ask your fellow competitors, the ones that are winning the most, what kind of variation in seating depth they are experiencing. If it is substantially less than yours and they believe it contributes to winning scores find out what they are doing.