Bullet Deformation Upon Seating

[getsum]

On the bench to load some .300 B/O subsonics using Hornady FL 2 Die Set and Nosler 210gr Accubond LR High BC projo's as shown in the pic on the far left. Upon seating the die leaves a deformation ring on the projo...second from left. Call Hornady and was told that the dies are set up for Hornady projo's and I may have to smoothen out the seating head in the die. So I do that, see next from left. Deformation only gets worse. The customer service guy from Hornady was nice enough to send me a free seating head for the die at the time of our conversation so I went at it again with the dremel. Far right in pic...time to stop the nonsense.

Kind of hard to believe that you would have to buy the same manufacturers projo's to work in their dies properly. So I guess if you use RCBS dies you're screwed.

Anyone else with this issue or have a cure for this problem?

 

[Old Jeff H]

Is this the only bullet you've had this kind of issue with?

Although a better fitting seating stem would certainly help, how about other things like neck tension? Compressed powder?

Do you happen to have a Lyman M die? That might alleviate at least some of it. Pretty sure their M1 Carbine model works for 300BO.

ETA: I found this after doing a search for a Accubond Long Range seating stem - https://faq.nosler.com/index.php?action=artikel&cat=3&id=82&artlang=en

 

[Flash]

I agree with what Jeff said. It takes quite a bit of force to get that much deformation of a jacketed bullet.

 

[deanq]

Your bullets are too long. You are trying seat it deeper than it can physically go. It is bottoming out on the powder. Get a shorter bullet.

 

[lostdog99]

It can be pretty common. On match bullets where the lead is below where the deformation takes place it actually does not take that much force.
RCBS actually provides a service where you can send them (for a fee) 5 bullets from the same lot of bullets. They will then custom grind a seat plug for that bullet profile.
We (as a company) have to do this regularly so that we don't marr the ammo that we want to sell. We are constantly switching between VLD bullets with second ogives and back to tangent ogives. Each are different enough that using the incorrect seat plug during seating (even if we don't compress the propellant) will leave marks/deformation on the projectile.
Or if you have Redding dies you can order a VLD seat plug or a stud seat plug. Using the correct plug for the correct projectile will eliminate or drastically reduce problems.

 

[getsum]

There are only 11gr of powder in the case. Definitely not a compressed load. While the new seat plug is on it's way I'll play with a couple other ideas. Thanks

 

[TheAccountant]

I don’t use Hornady dies - can you post a pic of the stem from the bullet’s point of view?

 

[getsum]

Sounds like a gay pic...um, no.

 

[TheAccountant]

Ok, keep trashing seating stems and ruining bullets. :handgestures-thumbup:

 

[Old Jeff H]

From the link I posted:

"Because of the long ogive and soft nose of the AccuBond® Long Range bullets, standard seating stems in certain dies may leave a ring indentation at the nose after being seated. In some cases, it may even cause rippling in the nose and/or bullet run-out (banana shape) which causes inaccuracy. Forester, Redding and RCBS all provide specially designed seating stems that accommodate long ogive bullets such as the AccuBond® Long Range."

 

[delta6]

Silicone spray and hot glue could make a quick fix.

 

[getsum]

I truly appreciate all of your feedback. And when I find the cure I will post it. Thanks again

 

[TheAccountant]

Bed the stem. It’s not uncommon.

 

[getsum]

Bed the stem. It’s not uncommon.

Here's the best pic I could get that you were asking for. One is a new backup stem and the other is the one I was taking the dremel to.

 

[TheAccountant]

Like Jeff H mentioned above, the ABLRs are meant to expand at lower velocities and are softer. Relieving the shoulder like you have done helps distribute the force some, but it’s the internal diameter of that stem that’s letting the bullet ride up into it, so you’ve basically created a funnel. Get some bedding compound, or even JB weld, and bed the bullet to the stem (you can use the one you’ve been grinding on). Then take a 3/16 or 7/32 drill to relieve the bedding in the center so the meplat isn’t contacting the bedding. I would also double check your neck tension. You may have to use a little less neck tension and then apply a light taper crimp.

 

[getsum]

Thanks again. New technique to me but will certainly give it a try. Never too old to learn a new trick I guess.

 

[getsum]

Well I took your advice (The Accountant) and bedded the stem. Being an older guy and not real techno savvy this was a new adventure. I did, however, just use hot glue as the bedding compound just for the sake of being able to remove it at a later date or have to use this process on a different projo. As the pic shows, the projo is still not perfect but a hell of alot better than the original and I'm good with that. These are just sub loads out of a .300BO AR Pistol. From what I've read even the original ring really didn't affect accuracy, but it did on BC. My intent and application is definitely not long range.

Thanks for your help.

 

[TheAccountant]

Looks like you’re getting closer. The hot glue might be compressing some vs. an actual bedding compound, but it’s definitely improved. What neck tension are you running? Are you using new 300BO brass or brass formed from 5.56?

Also, are you hunting with those, or what made you choose that bullet? I suspect you’ll be nowhere near the advertised BC with the velocity you’re running them and they probably won’t expand all that well either.