Bullet to case neck contact vs. long jump…300 prc 215 Berger

[Colin78]

Hey guys, in my 300 prc the Berger 215's are jammed with only .138 of the bullet bearing surface in the case neck. If I seat them so that there is .308 of contact, like the old saying say, that will be 170 thousandths jump. Seems pretty excessive. What would y'all do? Go with the big jump or not seat them to one caliber of surface contact?

 

[Dmagna]

Never heard of too much jump, or the bearing surface thing. Load them and send em, see how they do.

 

[lancetkenyon]

Shoot them where they shoot best. All the advice I have.

 

[Colin78]

Well y'all are no help. lol

I'm gonna seat them a little shy of 308 deep which will give 130 jump and see how it does.

 

[Mike D Texas]

I would follow Berger's instructions. Start at .015 off and work back.

 

[Colin78]

Never heard of too much jump, or the bearing surface thing. Load them and send em, see how they do.

The old saying is to seat a bullet one bullet diameter into the neck not counting the boat tail, especially for hunting ammo. It just ensures it stays concentric while feeding, bullet doesn't move under heavy recoil, ect. It's just an old saying.

 

[Colin78]

I would follow Berger's instructions. Start at .015 off and work back.

That would only have the bullet seated .153 into the neck. In other words it's would be barely held in place.

 

[Buttermilk]

0.138" of contact with the neck is likely not sufficient to properly support the bullet during a hunting scenario. Would work for target shooting perhaps.

The 300 PRC has a long throat and is really designed around the Hornady bullets which are longer than Berger bullets of similar weight.

I would seat the bullets so that the bullets get proper support and see how the gun shoots.

 

[Mike D Texas]

That would only have the bullet seated .153 into the neck. In other words it's would be barely held in place.

I understand. It may not shoot at .015. It may not shoot until .090. That's just where Berger recommends to start.

Even if it did shoot at .015, there will be another deeper depth where it shoots.

 

[Mikecr]

Optimum seated CBTO is so important to accuracy that no other numbers matter.
You should do Berger recommended full seating testing, and go with what your barrel tells you.

 

[243winxb]

No idea. But seat so these match. Will it fit magazine/chamber? If not adjust. https://www.gunsandammo.com/editorial/review-hornady-300-prc/358208

OR Go with the bullet that was designed for the cartridge, Hormady 225

Length of different bullets- https://jbmballistics.com/ballistics/lengths/lengths.shtml