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Diagnosing bullet seating issue (Frankford Arsenal Universal die making loud click when seating, inconsistent depth)

yakimanoob

Member
Joined
Oct 10, 2021
Messages
59
Hey folks,

I am new to reloading, and I'm trying to figure out why I'm getting very inconsistent CBTO measurements (+/- 0.010 in some cases) when seating bullets. I'm working on three loads right now:
  • Hunting load option #1: 150gr Nosler E-tip over H4350
  • Hunting load option #2: 131gr Hammer Hunter over RL-16
  • Practice load: 140gr Sierra SPBT over Accurate 2460
All use new Hornady brass that I've been fire-forming in the load development stages; after my next range trip everything I have will be once-fired and I'll go from there. CCI #34 primers on everything.

Sizing is being done with my FL RCBS die, and I'm using the Frankford Arsenal Universal bullet-seating die. When seating bullets, the bullet seems to be grabbing inside the seating stem and pulling it down as I lower the round out of the die. This causes a loud snap/click as the spring returns the die to its original position. This doesn't happen at all with the Sierra SBT, only happens a little but mostly not at all with the E-tips, and it's very dramatic with the Hammers. So I assume it has something to do with the flatter ogive profile of the bullets?

I don't have the means of checking bullet runout, but I have to assume it's bad given how inconsistent my CBTO measurements are. (btw, I'm using the Hornady comparator attachment and have verified the measurements on two different sets of calipers).

Any ideas on what to change to get better results? I'm almost done with my ladder testing, and it's going to be pretty hard to test seat depth and fine-tune my charges by group size if I can't get my bullets seated consistently...

Thanks in advance for the advice.
 

BuckRut

Well-known member
Joined
Jan 8, 2019
Messages
219
Location
Montana
Pull your seating stem and see how well if fits the bullet. If you bullet is getting stuck in the stem it will definitely pull the bullet back out of the case a little as you retract your ram.
 

cahunter805

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Joined
May 27, 2014
Messages
2,216
This issue is pretty common especially with many of todays long sleek non conventional shaped bullets.

Remove the seating stem from the die and chalk it in a drill. Take some lapping compound and take the hammer bullet and lap the stem until it fits easily.
Also check the etip fit. It may be getting stuck on the plastic tip. You can drill the stem out so the tip isn’t making contact.
 

yakimanoob

Member
Joined
Oct 10, 2021
Messages
59
The seating stem seems to fit properly and does not contact the tip of the bullet.

My good friend who is an aerospace engineer and amateur machinist recommended I try adding a touch of case lube to the bullet before seating, to keep it from binding on the stem.

I loaded a few dummy rounds and the "snap" issue went away entirely, and all 5 rounds were dead on CBTO.

So maybe it's as simple as that? I'll see how it goes next time I load up a batch of actual rounds.
 

Caseknife

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Jul 1, 2012
Messages
353
Location
NE Washington
From the reviews I read, sounds like the VLD seating stems may be your issue. Is there a line around the bullets where the stem is contacting? If so, do as @cahunter805 suggested and lap the sharp edge of the seater stem. If lubing the exposed surface of the bullet prior to seating eliminates the catching problem, it is a an interference issue for sure.
 

yakimanoob

Member
Joined
Oct 10, 2021
Messages
59
Yes there is typically a line around the bullets, especially noticeable on the hammers.

I will try lapping the stem and see if that eliminates the need for the lube. Thanks!
 

Mthuntr

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Oct 9, 2009
Messages
5,252
Location
In the Sagebrush of SW Montana
FWIW most seating stems put a ring on Hammer Bullets. On my bullets, it seems to be very minor visual marring and hasn't affected bullet performance though they're not aesthetically pleasing
 

cahunter805

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Joined
May 27, 2014
Messages
2,216
FWIW most seating stems put a ring on Hammer Bullets. On my bullets, it seems to be very minor visual marring and hasn't affected bullet performance though they're not aesthetically pleasing
Do you use a VLD stem or a stem that has been lapped?
 

cahunter805

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Joined
May 27, 2014
Messages
2,216
Yes there is typically a line around the bullets, especially noticeable on the hammers.

I will try lapping the stem and see if that eliminates the need for the lube. Thanks!
Just looked up the die you are using. It stated it comes with 3 VLD seating stems. Have you tried another stem? Lapping the stem will work though.
 

oxn939

Active member
Joined
Sep 21, 2017
Messages
114
OK calling myself out here- I've seen them but never heard of anyone using a universal seating die versus dies that are caliber specific. Would the reason for that just be to keep from buying a bunch of two die sets if you already have sizing/ neck tension dies of some kind, and just want one seating die to do everything? Do they usually have these issues?
 

winmag

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Joined
Jan 3, 2018
Messages
777
Location
Colorado
That might work. Never heard it called that before.
It is a more precise way to refer to bullet seating depth, as OAL varies based on meplat [tip] shape/length differences from projectile to projectile.
 
Last edited:

winmag

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Joined
Jan 3, 2018
Messages
777
Location
Colorado
This issue is pretty common especially with many of todays long sleek non conventional shaped bullets.

Remove the seating stem from the die and chalk it in a drill. Take some lapping compound and take the hammer bullet and lap the stem until it fits easily.
Also check the etip fit. It may be getting stuck on the plastic tip. You can drill the stem out so the tip isn’t making contact.
This will fix it. I’d try just polishing it first before lapping, but the lapping method will definitely fix it.

I polish the seater stem on all my dies as soon as I take them out of the box to prevent the issue you’re having.
 

yakimanoob

Member
Joined
Oct 10, 2021
Messages
59
Yeah CBTO = base to ogive length.

The Frankford Arsenal universal die was actually the cheapest seating die I could find that gave me micrometer adjustment and came with VLD stems. (Obviously, there are others on the market, but I couldn't find them in my price point when I was shopping for them).

The 7mm-08 is compatible with both the shorter and medium-size stems; it seems to make no difference on this particular issue.
 

Qubo

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Joined
Nov 27, 2019
Messages
135
Location
Longmont, CO
I have this similar issue with my Forster Micrometer die and Hammer bullets on my 300wm. I don‘t have CBTO problems cause I back out before every bullet and slowly adjust in. But I do get the ring on the ogive and the sliding lower collar sticks and pops on the first stroke. Didn’t have that problem with other bullets. Since still get good accurracy and seating depth I went ahead and just ordered a new Forster die and some Hammers for my new 6.5prc.
This will fix it. I’d try just polishing it first before lapping, but the lapping method will definitely fix it.

I polish the seater sI have this similar issue with my Forster Micrometer die and Hammer bullets on my 300wm. I don‘t have CBTO problems cause I back out before every bullet and slowly adjust in.
Could you explain how you polish it. I’m not having seating issues but it’d be nice to get rid of the ring and pop. Polishing shouldn’t affect my established load should it?
 

winmag

Well-known member
Joined
Jan 3, 2018
Messages
777
Location
Colorado
I have this similar issue with my Forster Micrometer die and Hammer bullets on my 300wm. I don‘t have CBTO problems cause I back out before every bullet and slowly adjust in. But I do get the ring on the ogive and the sliding lower collar sticks and pops on the first stroke. Didn’t have that problem with other bullets. Since still get good accurracy and seating depth I went ahead and just ordered a new Forster die and some Hammers for my new 6.5prc.

Could you explain how you polish it. I’m not having seating issues but it’d be nice to get rid of the ring and pop. Polishing shouldn’t affect my established load should it?
Polishing won’t effect established load. You’ll have to disassemble and reassemble the die, so you’ll just have to re-setup the die.

Disassemble the die. Chuck the seater stem into a drill. Wrap a strip of sandpaper around the end of a qtip, start the drill, work the qtip in and out of the seater stem where it would contact a projectile. I usually do 400 grit, then 600, then 1200. Then polishing compound on a qtip. Or just 0000 steel wool then polishing compound if you don’t have a bunch of different grit paper laying around.

The alloy that Hammers uses does seem to stick more than other projectiles. Lucky for me, the sliiiiiiight visible rings I still get don’t bother me at all. If your OCD really can’t take it then lap like @cahunter805 mentioned. Which I believe would be using a projectile with valve lapping compound on it instead of the qtip with sandpaper. Then polish it after lapping. This is more aggressive as you’re actually trying to change the shape of the projectile bearing surface of the seater, not just polish it.

And if THAT doesn’t work then stick the tip of each projectile into some Imperial dry neck lube before loading and it won’t stick or ring anymore.
 
Last edited:

HONEYBADGER

Well-known member
Joined
Aug 24, 2013
Messages
428
Hey folks,

I am new to reloading, and I'm trying to figure out why I'm getting very inconsistent CBTO measurements (+/- 0.010 in some cases) when seating bullets. I'm working on three loads right now:
  • Hunting load option #1: 150gr Nosler E-tip over H4350
  • Hunting load option #2: 131gr Hammer Hunter over RL-16
  • Practice load: 140gr Sierra SPBT over Accurate 2460
All use new Hornady brass that I've been fire-forming in the load development stages; after my next range trip everything I have will be once-fired and I'll go from there. CCI #34 primers on everything.

Sizing is being done with my FL RCBS die, and I'm using the Frankford Arsenal Universal bullet-seating die. When seating bullets, the bullet seems to be grabbing inside the seating stem and pulling it down as I lower the round out of the die. This causes a loud snap/click as the spring returns the die to its original position. This doesn't happen at all with the Sierra SBT, only happens a little but mostly not at all with the E-tips, and it's very dramatic with the Hammers. So I assume it has something to do with the flatter ogive profile of the bullets?

I don't have the means of checking bullet runout, but I have to assume it's bad given how inconsistent my CBTO measurements are. (btw, I'm using the Hornady comparator attachment and have verified the measurements on two different sets of calipers).

Any ideas on what to change to get better results? I'm almost done with my ladder testing, and it's going to be pretty hard to test seat depth and fine-tune my charges by group size if I can't get my bullets seated consistently...

Thanks in advance for the advice.
I had this exact issue with Hammers. No other bullet I have used had this problem. Switched because of it. I'm not that invested in any certain bullet so it wasn't worth the trouble to me to try and fix it. If I were going to fix it, the lapping trick does seem the way to go.
 
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