Inconsistent seating depth

[Conaso]

Since you're using Lee dies, have you thought of swapping out the Lee lock rings, with rubber o-rings, with cross-bolt split rings, e.g., Hornady, Forster, etc. Also, how you set up your dies and lock them down can be a factor, e.g., cartridge in die when locked down.

 

[wkdickinson]

FWIW - I have measured and chased this issue with Berger 105 Hybrids many times. Ultimately, what I came to understand is that the the problem is "ogive consistency" or inconsistency as it were. The bullet seating stem is significantly small in diameter than the Hornady comparator. Consequently they are referencing at different places on the bullet. To prove this, I made a custom insert for my Hornady comparitor that was sized as close to the diameter of the die's seating stem as I could make it. When I checked my loaded rounds using the smaller diameter insert, their length was very consistent.

 

[girish]

Any problem with the 77smk?

No issues with the 77 SMK.

 

[girish]

The Lee tech is correct, the hybrid shape of the Berger doesn't play well with the seater. You did adjust the seater stem for when changing bullets(I hope).

Adjusted seating depth separately for Sierras and Bergers for .020 from jam.

 

[girish]

Some time ago, I started buying a VLD seater stem with every Type S Redding setup I have (same idea as the Lee "custom plug" setup you mentioned). The VLD stems work just fine with bullets that have a relatively short and blunt nose, but they also work with the very long and pointy VLD-type bullets I find myself using more often these days. So I simply replace the standard stem straight out of the gate. Only in one case do I know with certainty that the bullets I was using were actually "bottoming out" in the standard stem, but with the VLD stems, it's simply no longer a concern, even if it wasn't a necessity. They're not stupidly expensive, so it may be worth it to you to swap out the stem, although that isn't necessarily guaranteed to fix this seating issue you're having.

Depending on how many times you've fired the brass, not annealing it could be part of the issue. It is usually possible to feel the difference in seating force necessary with brass that has not been annealed after as few as 3-4 firings. Regardless of what some may think, annealing with a torch setup to dull cherry red in a darkened room does not "ruin" the brass in any way, shape, or form. That is complete disinformation. If you decide to begin annealing your brass, there are torch-based setups available for much less than an induction annealer. In fact, some use the old standby of a simple torch and a socket wrench to hold the piece of brass while it is annealing. I believe the available machines will make the process much easier and more consistent than doing it by hand with a socket wrench, but if you just want to try annealing a few pieces, the socket setup should work well enough with costing a lot of money. Just be warned that there are almost as many opinions about how to properly anneal brass as there are people doing it, so be prepared to filter through the information that is out there if you decide to start annealing your brass.

I'll order the custom seating plug if I can't figure out the problem soon. The brass has been fired 5 times, some of them 6. I've been reluctant to try torch annealing, partly due to the differences of opinions I've read. I might have to reconsider that though.

 

[girish]

so I have had this issue with a Lee dead length seater once, the threads for the knurled knob (that controls seating depth) were cut way oversize, when the floating seater plug would contact the knob it would rise (because the slop in the threads) and dependent on the amount of neck tension variation would give in inconsistent seating depth

Thanks. I'll check that next time.

 

[girish]

Mark the bullet and case on a long and short example. Pull both bullets and powder. Resize brass. Swap bullets between cases and reseat and measure. If the short condition moves to the other case - bullet issue. If it stays with the case - brass problem. Not a cure, but may help narrow the fault.

That's a great idea. Thanks.

 

[girish]

Since you're using Lee dies, have you thought of swapping out the Lee lock rings, with rubber o-rings, with cross-bolt split rings, e.g., Hornady, Forster, etc. Also, how you set up your dies and lock them down can be a factor, e.g., cartridge in die when locked down.

I haven't tried that. If it could make a large difference, it would be worth it. I have wondered if the rubber o-rings would change the setting change each time screwing it into the press. I do verify each time I put it in the press and I haven't noticed a problem. I did think it odd that Lee decided to use a squishy rubber part in something you are trying to get highly repeatable.

 

[longbow]

I drilled out a seating stem almost 30 years ago when i started shooting 1K BR Waxed the bullet and filled the stem with epoxy for the VLD bullets...Sierra 104 and 220 gr. 30 cal back then. Made all the difference. We have come A LONG ways since then.No computer then. I was one of the first to join 6BR.com ,then to become this Forum. Guys starting out now just need to take the time and SEARCH...you can pretty well find it all now. Good shooting.Pete

 

[girish]

FWIW - I have measured and chased this issue with Berger 105 Hybrids many times. Ultimately, what I came to understand is that the the problem is "ogive consistency" or inconsistency as it were. The bullet seating stem is significantly small in diameter than the Hornady comparator. Consequently they are referencing at different places on the bullet. To prove this, I made a custom insert for my Hornady comparitor that was sized as close to the diameter of the die's seating stem as I could make it. When I checked my loaded rounds using the smaller diameter insert, their length was very consistent.

That's a good observation. As I mentioned I noticed the Lee plug contacts the bullet closer to the tip than the Hornady comparator. I checked some bullets with the plug as a comparator and they were a little more consistent than the Hornady measurement. I did not use the plug as a comparator on loaded rounds. Hard to imagine .030 or more variation based on datum placement, but I'll try it.

 

[girish]

That's a good observation. As I mentioned I noticed the Lee plug contacts the bullet closer to the tip than the Hornady comparator. I checked some bullets with the plug as a comparator and they were a little more consistent than the Hornady measurement. I did not use the plug as a comparator on loaded rounds. Hard to imagine .030 or more variation based on datum placement, but I'll try it.

I just tried this. I took the seating plug out of the die and used it like a comparator for the loaded rounds. Equivalent results to using the Hornady comparator. Short ones are about .030 shorter than others.

 

[Conaso]

May not be an issue - I found Hornady and Lyman shell holders inconsistent, I only use then for decapping, for me a separate process after cleaning brass. For precision sizing and seating I only use Redding shellholders. I don't care to use Lee products, although I have LFC dies for ARs and I like the Supreme (?) powder measure for short-dropping cylinder-type powders, doesn't cut them.

 

[JFrank]

I just tried this. I took the seating plug out of the die and used it like a comparator for the loaded rounds. Equivalent results to using the Hornady comparator. Short ones are about .030 shorter than others.

Are you saying you have .030 base to seating stem difference in loaded ammunition ?

 

[girish]

May not be an issue - I found Hornady and Lyman shell holders inconsistent, I only use then for decapping, for me a separate process after cleaning brass. For precision sizing and seating I only use Redding shellholders. I don't care to use Lee products, although I have LFC dies for ARs and I like the Supreme (?) powder measure for short-dropping cylinder-type powders, doesn't cut them.

Thanks for the suggestion. I use the Lee shell holder that came with the die set. I guess trying another shell holder could be an option. I still wonder why there has been no problem so far with the 77 Sierras, only with the 85.5 Bergers.

 

[girish]

Are you saying you have .030 base to seating stem difference in loaded ammunition ?

Yes, 15 to 20 percent of the rounds using the 85.5 gr Bergers are seated around .030 or more deeper than the norm, regardless of whether they are measured BTO with the Hornady comparator or with the seating stem.

 

[girish]

My son in law had a weird seating issue similar to your variance, he tracked it to the two piece seater die bottoming out iirc he could adjust the micro stem but nothing was changing to the depth of the round beyond inconsistency. It’s been awhile but I recall him taking the die apart and re assembling.

I've had the Lee seating die apart a number of times. The seating plug floats in the cap. I'm not sure how it could sort of short stroke, but thanks for sharing.

 

[girish]

Mark the bullet and case on a long and short example. Pull both bullets and powder. Resize brass. Swap bullets between cases and reseat and measure. If the short condition moves to the other case - bullet issue. If it stays with the case - brass problem. Not a cure, but may help narrow the fault.

I have done this test now. Disassembled long (normal) and short rounds. The powder charges were the same as expected. Re-necksized, put the powder back in, swapped the bullets and reseated. Measured both rounds CBTO with the Hornady comparator and they were the same. Both normal length. Neither one was short.

I guess this means that I don't have to chase bullet variation as the cause. I have ordered a custom seating plug for the 85.5 gr Bergers. Lee says there is a 4 week backlog.

 

[Silo1616]

I have done this test now. Disassembled long (normal) and short rounds. The powder charges were the same as expected. Re-necksized, put the powder back in, swapped the bullets and reseated. Measured both rounds CBTO with the Hornady comparator and they were the same. Both normal length. Neither one was short.

I guess this means that I don't have to chase bullet variation as the cause. I have ordered a custom seating plug for the 85.5 gr Bergers. Lee says there is a 4 week backlog.

I hope that cures it for you. I hate these "fantom" variances that show up from time-to-time.

You could also try twisting the bullet in the neck after seating. I've had neck tension too light before and was actually moving the bullet when measuring.

 

[girish]

I hope that cures it for you. I hate these "fantom" variances that show up from time-to-time.

You could also try twisting the bullet in the neck after seating. I've had neck tension too light before and was actually moving the bullet when measuring.

Thanks. I'll try that too.

 

[Conaso]

I don't know if there is an impact but when I seat a rifle bullet I seat it about half-way. Then I rotate it 90 degrees and seat it all the way. Then I rotate it yet again 90 degrees and seat it for the final time. Extra steps and slows reloading, can't prove if an improvement but it placated by anal retentiveness.