Seating stem for 153.5 gr Berger Hybrid

[Overclok79]

What seating stem do I need for the 153.5 berger hybrid? I am currently using the ELD stem in a Hornady match grade die. This stem has worked great for 140 ELDs. I have done some additional polishing with steel wool and even attempted to lap the stem to the 153.5 gr hybrid with 80036 valve grinding compound by chucking it in a drill. Even after all of that, I still here a loud popping noise after seating when the bullet disengages with the stem and a ring is left around the nose of the bullet.

Should I buy the 135/153 A Tip seating stem? I have been unable to find any information on if the 153 A tip has a similar profile to the 153.5 berger hybrid. Bergers says I need a "VLD seating stem", but this doesn't seem to correlate to anything in Hornady's product offering.

Here are some pics of the mark on the nose of the bullet and the inside of the stem. Oddly enough, the vertical marks are present on the bullets from the factory. The stem is leaving that horizontal ring. You can see a build up of copper in the stem after I seated about 40 rounds.

 

[straightshooter1]

What seating stem do I need for the 153.5 berger hybrid? I am currently using the ELD stem in a Hornady match grade die. This stem has worked great for 140 ELDs. I have done some additional polishing with steel wool and even attempted to lap the stem to the 153.5 gr hybrid with 80036 valve grinding compound by chucking it in a drill. Even after all of that, I still here a loud popping noise after seating when the bullet disengages with the stem and a ring is left around the nose of the bullet.

Should I buy the 135/153 A Tip seating stem? I have been unable to find any information on if the 153 A tip has a similar profile to the 153.5 berger hybrid. Bergers says I need a "VLD seating stem", but this doesn't seem to correlate to anything in Hornady's product offering.

Here are some pics of the mark on the nose of the bullet and the inside of the stem. Oddly enough, the vertical marks are present on the bullets from the factory. The stem is leaving that horizontal ring. You can see a build up of copper in the stem after I seated about 40 rounds.

View attachment 8308852View attachment 8308853

I don't uses a VLD seating stem, just the regular stem that comes with my L.E. Wilson seating die. Though I did do a little lapping with a bullet to get rid of a faint ring it was producing. Now all is good. And I even use this same seating stem on my 153 A-Tips with no issues. I think some of this success I have with this seating stem has to do with my case prep where neck tension isn't too great and enough lubrication.

Based on my experience, I really don't think you should use a VLD seating stem on a Berger 153.5. Just be sure whatever stem you use, make sure it's not sitting on and pushing on the meplat.

You said you're seating into virgin ADG brass and often virgin brass will have lot of seating resistance that'll result in such rings on you're ogive. Usually, it's because of the ID being somewhat tight, then in addition to that the clean interior of the neck also adds to that resistance. To mitigate the clean neck issue, you need to use some sort of lube, like a molly lube or Imperial's Dry Neck Lube. Once they've been fired, if you don't clean the inside of the necks, that residue will act as a lube on its own.

 

[R_A_W]

Based upon where the bullet is making contact, it does not look like there is a problem with the profile of the seating stem. It's how rough the interior is. You can see copper deposition on the ring that is cutting into the jacket. Seating stems are usually super cheap, I'd just replace it.

Those grooves are so deep I'm not sure you'll be able to get rid of them easily. Was the inside of the stem always that rough or did that happen after you honed it w/ steel wool & valve lapping compound?

 

[R_A_W]

The Berger 153.5 LRHT has a longer nose length; it's ogive is about 0.1" further back from the meplat.

Again, I don't think the profile of your current seating stem is the actual issue here.

 

[Overclok79]

Based upon where the bullet is making contact, it does not look like there is a problem with the profile of the seating stem. It's how rough the interior is. You can see copper deposition on the ring that is cutting into the jacket. Seating stems are usually super cheap, I'd just replace it.

Those grooves are so deep I'm not sure you'll be able to get rid of them easily. Was the inside of the stem always that rough or did that happen after you honed it w/ steel wool & valve lapping compound?

I'm unsure if those grooves where always present. I am also suspicious of them and feel like they may have been caused by the lapping compound. I'll go ahead and get another stem.

I don't uses a VLD seating stem, just the regular stem that comes with my L.E. Wilson seating die. Though I did do a little lapping with a bullet to get rid of a faint ring it was producing. Now all is good. And I even use this same seating stem on my 153 A-Tips with no issues. I think some of this success I have with this seating stem has to do with my case prep where neck tension isn't too great and enough lubrication.

Based on my experience, I really don't think you should use a VLD seating stem on a Berger 153.5. Just be sure whatever stem you use, make sure it's not sitting on and pushing on the meplat.

You said you're seating into virgin ADG brass and often virgin brass will have lot of seating resistance that'll result in such rings on you're ogive. Usually, it's because of the ID being somewhat tight, then in addition to that the clean interior of the neck also adds to that resistance. To mitigate the clean neck issue, you need to use some sort of lube, like a molly lube or Imperial's Dry Neck Lube. Once they've been fired, if you don't clean the inside of the necks, that residue will act as a lube on its own.

Hmmm. I've previously seated 140 ELDs in virgin Lapua brass with this same stem. And I've seated 115 DTACs in virgin Alpha brass with my Whidden die. Both were set to .002" neck tension, I didn't lube either of those necks, and all I did to the respective stem was polish it with some steel wool for about 5 minutes. I'll give some neck lube a try and report back.

 

[Bobby Ball]

FWIW,
I lapped my stem to the bullet 190lrht that I shoot pretty much exclusively. Very simple, and inexpensive.

 

[Overclok79]

I just bought the 135/153 A Tip stem and it worked like a dream. I polished it for about 5 minutes with a drill and steel wool. It gave me no fuss seating the 153.5 Bergers.