My issues with the Berger method…..

[Litehiker]

Good info here.I'm starting to reload a bunch of once-fired Hornady brass that I've trimmed to spec (when needed) and sorted by weights.

I'm using Berger and Hornady bullets.
Eric B.

 

[Impulsive]

Bullet Jump Research: Executive Summary & Load Development Tips

This is the last post in a series of articles focused on bullet jump research that has been conduct...

precisionrifleblog.com

Really depends on what your doing with your rifle. F class, prs, hunting?

I was very interested in this article until I got to the part about having to lengthen the chamber to keep the bullet above the neck shoulder junction. That killed for me.

 

[Taylorbok]

I was very interested in this article until I got to the part about having to lengthen the chamber to keep the bullet above the neck shoulder junction. That killed for me.

You would just have the throat extended. It's not a big deal but I would say only necessary for competition use. If you have this done you likely won't be able to mag feed them unless your running a short cartridge in a long action.

 

[Tumbleweed]

All of this depends on how long your throat is and the rifle in question.
Many factory guns are not within cooey of the rifling with a mag box restriction that does not allow a .005"-.030" off seating depth….hence the Berger seating depth method.
I have a few 300's that are limited to a max COAL of 3.39", in a 300WM SAAMI chamber, this is close to .150" jump.
So, your reasoning about where nodes are at is not a constant, nodes can appear at many different seating depths, not just those close to the rifling.
I have found several LR bullets that don't like to be close to the rifling, some Sierra, Nosler ABLR and Berger Hybrids.

Cheers.

Good point. I think the same concept is valid whether you're working from zero to .035" jump or starting at .070" jump and working deeper, maybe because of mag length restrictions. For me, I've found that the deeper seating depth nodes are wider and more forgiving with equal or better accuracy than the ones typically closer to the lands. I know others have discovered the same thing.

 

[kaseyfied]

I'm actually fighting a rifle right now on seating depth. The powder node is huge... like almost 2 grains is aries like 30fps.. I've tried just about everything and it won't shoot the way my other builds have shot so far.. thinking about trying 55ish off and working deeper to see If maybe the 230otms like more jump.. I tried neck tension and they all shot like 1moa at 250yards some worse.. I'm going to test out this jump theory everyone's talking about. I usually get a rifle to shoot great from .010 off to .025 off

Kasey

 

[Bob Wright]

My (2) 7RM's, the 168 HVLD liked .090 and the other rifle liked .100 off on the 180. It's never changed. Both are SAAMI chambers, one with a custom barrel. Found them relatively quick with Walt Berger's method starting at .030 off. One can see the groups tighten pretty quick.

 

[Bob Wright]

Good point. I think the same concept is valid whether you're working from zero to .035" jump or starting at .070" jump and working deeper, maybe because of mag length restrictions. For me, I've found that the deeper seating depth nodes are wider and more forgiving with equal or better accuracy than the ones typically closer to the lands. I know others have discovered the same thing.

Yep, my Krieger barreled 7RM is very forgiving even with a higher ES. It still shoots to the same POI where other rifles would show vertical stringing. I'm at .100 off on the 180 VLDH. This is with 2 different powders. I think it likes a running start with the extra jump in my rifles and SAAMI chamber

 

[.gacton]

can you explain BTO across 100. ? some of us are not educated

He is saying that if you measure 100 Berger's, their BTO length will be within .0015".

 

[david g ranes]

He is saying that if you measure 100 Berger's, their BTO length will be within .0015".

Measuring the bullet from the base of it to the ogive. David

 

[Taylorbok]

I'm actually fighting a rifle right now on seating depth. The powder node is huge... like almost 2 grains is aries like 30fps.. I've tried just about everything and it won't shoot the way my other builds have shot so far.. thinking about trying 55ish off and working deeper to see If maybe the 230otms like more jump.. I tried neck tension and they all shot like 1moa at 250yards some worse.. I'm going to test out this jump theory everyone's talking about. I usually get a rifle to shoot great from .010 off to .025 off

Kasey

If I was having issues I would start with a coarse seating depth test. .020" increments. likely go out to .160" I would choose which one of those shot the best, add .010" to it and then work back in .003" increments. should find something that shoots.

I would also check over all your fasteners just to be certain.

 

[lancetkenyon]

can you explain BTO across 100. ? some of us are not educated

Measuring the base of bullet to the ogive of the meplat with a comparator is BTO (Base to Ogive). The Ogive is where the bullet transitions from the straight bearing surface to the start of the taper of the nose.

So, in measuring 100 Berger bullets in a box, I have found very little difference in the BTO (base to Ogive). About .0015". I have done this on occasion early one, but now usually pull 10 from a single box and check.

I actually do not measure COAL (Cartridge Overall Length-from case head to bullet tip) hardly ever. Just to make sure they will fit in a magazine.

I want my CBTO (Cartridge Base to Ogive) to be exactly the same in every round I build. At least within .0005" (not .005"). Meaning the exact same jump to lands from round to round. CBTO consistency is WAY more important than COAL, where meplats (the point or tip of the bullet) can vary as much as .010" even when the BTO is within .001". This is due to the manufacturing process of pointing the bullet.

And since the seating stem in your seating die does not support off the Ogive, but near the tip of the bullet, having consistent BTO and nose shapes makes a huge deal in getting CBTO consistent. If you load some brands, you will seat 10 bullets, and get 10 different CBTO measurements, as much as .00" in some cases....ahem....ELD-X). Berger is usually within .0005" or exact, with maybe one in 10 at .001" different that needs a tweak to the die (if you are that anal about it....which I am). I try to keep all my loaded rounds with .0005" CBTO. 5/10000ths (or half a thou as some call it). Not 5/1000ths.

 

[lancetkenyon]

I'm actually fighting a rifle right now on seating depth. The powder node is huge... like almost 2 grains is aries like 30fps.. I've tried just about everything and it won't shoot the way my other builds have shot so far.. thinking about trying 55ish off and working deeper to see If maybe the 230otms like more jump.. I tried neck tension and they all shot like 1moa at 250yards some worse.. I'm going to test out this jump theory everyone's talking about. I usually get a rifle to shoot great from .010 off to .025 off

Kasey

Have you tried a primer change? I have had amazing differences with a simple primer swap.

A Fed GM215M is not always better than a Fed 215 Mag or CCI250, or even a Rem 9 1/2 Mag in some circumstances.
Same with a Fed GM210M or CCI BR2 over a CCI200, Fed 210, or Win WLR.

 

[bamban]

Have you tried a primer change? I have had amazing differences with a simple primer swap.

A Fed GM215M is not always better than a Fed 215 Mag or CCI250, or even a Rem 9 1/2 Mag in some circumstances.
Same with a Fed GM210M or CCI BR2 over a CCI200, Fed 210, or Win WLR.

Lance, you are right. On my 280AI swapping the 215 match with CCI 250 magnim tightened rhe group at 200.

 

[kaseyfied]

Yeah I'm using cc250s currently.. I'll try some with different primers