Does bullet need adequate support in the neck to shoot well?

[Webster]

Thanks everyone for the replies. Seems its worth investing time and components to go ahead and test this weekend.

If you don't have a rifle and the skills to consistently shoot .250" groups, you’re probably wasting your time and components testing. If the rifle already shoots big groups you are also wasting your time. Describe the rifle and what it's used for. Good enough for what you intend to use the rifle is good enough, hunting, casual shooting ect.

 

[243winxb]

Is adequate bearing surface in the neck important?

Depends on the cartridge, components & powder, amount of jump.

Dont want bullets moving to soon.

 

[0give]

If you don't have a rifle and the skills to consistently shoot .250" groups, you’re probably wasting your time and components testing. If the rifle already shoots big groups you are also wasting your time. Describe the rifle and what it's used for. Good enough for what you intend to use the rifle is good enough, hunting, casual shooting ect.

You better have recoil......LOL What i was referring to is, if you
don't, you'll draw back the bolt spilling powder, if you don't
stand the rifle straight up.

30k of jam or so has never stuck a bullet in my experience. This is not a concern.

 

[0give]

What bullet? If there’s that much erosion in a 223, it’s barrel time. I understand if it was reamed for heavier bullets but wouldn’t it just be better to use the heavier bullets until barrel replacement.

Its 6mm.

 

[243winxb]

I'll guarantee, sooner then later you'll have an action full of
loose powder.....

I agree.
Light bullet hold/neck tension + jam = Action full of loose powder, when extracting a live, unfired round.

I have done it in my youth, firing the 40x single shot in 243 win. Neck tension .001" thanks to a Lee Target loader that reamed the case necks.

Comes down to what amount of neck tension are you using.

 

[JFrank]

Question: You have two options. Jump a bullet a lot or only have .020” or less bullet bearing surface in the neck to get into lands where it normally shoots good. Which do you go with and why?

TL;DR
Is adequate bearing surface in the neck important?

Toward the end of a barrel and im to the point where the bullet wont reach where i like to seat to anymore. Just happened to notice that i only have basically the lip of the brass holding onto the bullet. This is a new bullet to me, long heavies dont have this issue.

Are you following the tune or the lands ?

 

[0give]

Are you following the tune or the lands ?

Tune

 

[0give]

Update:
Shocked at how well long jumping works. Totally shocked actually. Velocity dropped 77 ft/s, but stayed pretty well in tune.

 

[VA_XTC_Shooter]

I've definitely gotten worse runout when the bullet was seated far out with small amount of neck holding on. When seated well into the a neck that has good concentricity, I'll get really good concentricity on the seated bullet.

If there's little neck holding the bullet and the bullet being seated into the lands, I'd think that the chambering pressure would likely straighten any concentricity issue out. And though being seated into the lands, the starting pressure will be higher than being well off the lands, but the pressure would remain pretty consistent over substantial throat wear, as long as the bullet is being seated into the lands the same.

That's if you believe concentricity of the cartridge actually makes a difference.

 

[243winxb]

long jumping works

if the cartridge is in alignment with the throat/bore.

On a standard 243 win chamber, sizing only 1/2 of the necks helps alignment & accuracy. The unsized area of the neck expands to the chamber, after a few firings.
If neck sized more, accuracy falls off.

Two other thing help alignment....
1.Tight neck chamber.
2. A jam.

Never had a tight neck.
My 40X barrels throat is shot out, so i have a very long jump. Could not jam now, even if i wanted to. When rifle was new, i could jam.

Redding type S, Fl sizing, bushing die used. Control shoulder bump, but no crush fit. Allow the neck to do the alignment.

Grandson can hit an egg at 300 yards with the old gun. Good enough.

 

[243winxb]

Velocity dropped 77 ft/s,

I have see reports that a jam can raise pressure as much as 10,000 PSI. More pressure, higher velocity?? Maybe?

(Quickload)

 

[drop_point]

if the cartridge is in alignment with the throat/bore.

On a standard 243 win chamber, sizing only 1/2 of the necks helps alignment & accuracy. The unsized area of the neck expands to the chamber, after a few firings.
If neck sized more, accuracy falls off.

Two other thing help alignment....
1.Tight neck chamber.
2. A jam.

Never had a tight neck.
My 40X barrels throat is shot out, so i have a very long jump. Could not jam now, even if i wanted to. When rifle was new, i could jam.

View attachment 1573483 Redding type S, Fl sizing, bushing die used. Control shoulder bump, but no crush fit. Allow the neck to do the alignment.

Grandson can hit an egg at 300 yards with the old gun. Good enough.

In my F-T/R rifle, I'm only sizing about half of the neck. Getting really good accuracy, consistent velocity, and the loads are very straight.

 

[Straightshooter1]

I have see reports that a jam can raise pressure as much as 10,000 PSI. More pressure, higher velocity?? Maybe?

(Quickload)

Certainly, more pressure results in move velocity. The thing I find interesting about jamming is that it results in little, if any, blowby (gasses escaping ahead of the bullet). It's that aspect that I think leads to more consistency.

 

[Lucky Shooter]

I have a 222 and a 22PPC----relatively long necks----both chambers require turned necks.

These necks were turned for zero neck clearance----the entire neck-----and then the front portion
of the neck was turned for a more typical .002" to .003" clearance.

The big question for me was how much of the neck was needed to grip the bullet. I still don't
have that answer.

Partial neck sizing was done with a modified collet and ZZ pin gages.

The targets seem to show some improvement but nothing definite.

A. Weldy

 

[gunsandgunsmithing]

Update:
Shocked at how well long jumping works. Totally shocked actually. Velocity dropped 77 ft/s, but stayed pretty well in tune.

View attachment 1573472

I don't call that staying in tune. I see distinct group shapes that I look for to occur and repeat, but at much smaller increments is all. I would take that middle group, the .230 with mostly vertical and move .003 at a time on both sides of it, for at least 4 three shot groups on both sides of that. You'll see a progression of group shapes that are predictable and that repeat. That info can be used to tune on the fly. I'd bet .003 one way or the other of that group shoots smaller and with less vertical, just based on what I'm seeing in the pics.

 

[0give]

I have see reports that a jam can raise pressure as much as 10,000 PSI. More pressure, higher velocity?? Maybe?

(Quickload)

Id say that's about right. However, GRT models showed pressures increasing as bullet is seated into the case more which did not prove true in my testing. Velocity only dropped and stayed dropped, actually normalized, from .055-.105 away from the touch point.

 

[0give]

I don't call that staying in tune. I see distinct group shapes that I look for to occur and repeat, but at much smaller increments is all. I would take that middle group, the .230 with mostly vertical and move .003 at a time on both sides of it, for at least 4 three shot groups on both sides of that. You'll see a progression of group shapes that are predictable and that repeat. That info can be used to tune on the fly. I'd bet .003 one way or the other of that group shoots smaller and with less vertical, just based on what I'm seeing in the pics.

That's not going to work for me. This is a field match rifle, matches could be a few hundred rounds at a time, so the strategy I wanted to test was to park the seating depth and find something that will be good for the life of the barrel. Im sure there are ups and downs along the way, but I tested three distinct spots (start, middle, and end of total erosion) to get a big picture view of what's going on. I found something that will work for this. Prior to this effort, I would constantly chase, which worked well too, but I had to stay on top of it. Running out of neck is a new problem to me.

 

[0give]

In my F-T/R rifle, I'm only sizing about half of the neck. Getting really good accuracy, consistent velocity, and the loads are very straight.

Are you seating to a depth where all of the half sized neck is gripping the bullet? Or is just a small sliver of the half sized neck doing the gripping? I would venture to guess that half a necks worth of grip is more than enough to keep things straight. I think this would have worked for me as well. My issue was that I ran out of neck. Thus dosent really matter if half or all of it was sized, only basically the lip was grabbing the bullet.

 

[0give]

Update #2 for those interested. Followed up with bit more powder to get up over 3,000 ft/s to see what would happen. Still a bit surprised things hold together so well jumping this much. For this testing in general, I would say that jumping a long way, at least with Berger hybrids, is no more or less precise than where I'd usually jam to. Really, this rifle is probably not capable of resolving differences. It clearly ebs and flows like you'd expect. Jumping a long way maybe dampens velocity variation a bit. But it did get me out of this bind of running out of neck to grip with, which is a win I suppose. Preciate everybody's input.

 

[gunsandgunsmithing]

That's not going to work for me. This is a field match rifle, matches could be a few hundred rounds at a time, so the strategy I wanted to test was to park the seating depth and find something that will be good for the life of the barrel. Im sure there are ups and downs along the way, but I tested three distinct spots (start, middle, and end of total erosion) to get a big picture view of what's going on. I found something that will work for this. Prior to this effort, I would constantly chase, which worked well too, but I had to stay on top of it. Running out of neck is a new problem to me.

Ime, it just does work that way, but if your happy and it's good enough for the application, then enjoy!