Seating depth- picture

WhelanLad

WhelanLad

CGN Ultra frequent flyer
Rating - 0%
0   0   0
Location
Australia AU
Howdy guys- winters well an truly here now, Snows up on the hills an the deer are down in the valleys!

I took this photo today after I wanted to check how far out I could seat a bullet until it touched the lands.

This is what I came up with, Left- obvious . Middle- seated out far an pushed in slightly. Right- a ready to fire hunting round.


Can this photo tell you guys anything about the seating depths, am I in the right area- seems like a jump from ogive to the lands with my hunting rounds... is this OK?


Ask some questions you need answers too.

cheers
WL

DSCN0390-35WhelenSeat.jpg~original
 
Seating depth be damned, your first consideration is whether or not the round will cycle effortlessly through your rifle. Any benefit in accuracy that you may or may not achieve by seating the bullet long, cannot be exploited in the field except under exceptional circumstances. But for the sake of argument, lets say that a long seated bullet does cycle through your rifle. The upside down round gives you the length to the lands. Now if you take a bullet and press it nose down into the muzzle of the rifle, and turn it, the line scribed on that bullet will indicate the forward edge of the bearing surface, which should be slightly forward of the cannelure. If you seat the bullet so this scribed line is equal to the length of the cartridge with the upside down bullet, it will be just touching the lands. From this point on you can increase the jump, or jam as you prefer, and those two dummy rounds provide a reference for later consideration.
 
Hi boomer thanks for the reply.

First off- The middle round has been put in long, with enough tension so as it could slide forward once it hit the lands, an a few faint markings just before the Cannelure told me that was that?

Which is in the same area as the upside down one. So im confident that is the distance until the ogive meets lands.

My reload on the Right, is one ive been using forever in the Whelen, an came about from putting a factory Corlokt round in the seating die. As it also was around the Cannelure I left it at that.

Since reading some more tech tips in a magazine, I went an done this test today with the black marker.


Sounds like there isn't much to worry about for hunting accuracy, an to be honest I don't think this load would be MOA- but its shot a lot of deer...... I just wanted to make sure my RN wasn't stuck up in the lands to create excess pressure, But it looks as if I have a fair gap.

bare with me

WL
 
Boomer said:
Now if you take a bullet and press it nose down into the muzzle of the rifle, and turn it, the line scribed on that bullet will indicate the forward edge of the bearing surface, which should be slightly forward of the cannelure. If you seat the bullet so this scribed line is equal to the length of the cartridge with the upside down bullet, it will be just touching the lands. From this point on you can increase the jump, or jam as you prefer, and those two dummy rounds provide a reference for later consideration.
Click to expand...

Ok I re-read this- Makes sense!

Although I think that is what happening on the Middle case- its been pushed in whilst loose. Soooo

I think what your saying is that all my loads should be seated out like the middle one(in some instances) an that seating depth played with to find 100% accuracy
But if you look at the middle one, there really isn't anything left of the projectile in the case??

thanks
 
its a Ruger Hawkeye mkII BTW

just don't the bullet in the barrel trick, with the loaded hunting round to get a comparision... If you draw a line from the Base of the Left upside down bullet across to the Middle round. that is where the Ring comes up on the Loaded round (Left) Use the black horizontal lines from the pc screen behind bullets

So, this is mostly just confusing me but since im this far I may aswell find out what all this means an if its good/ bad

WL
 
WhelanLad said:
Howdy guys- winters well an truly here now, Snows up on the hills an the deer are down in the valleys!

I took this photo today after I wanted to check how far out I could seat a bullet until it touched the lands.

This is what I came up with, Left- obvious . Middle- seated out far an pushed in slightly. Right- a ready to fire hunting round.


Can this photo tell you guys anything about the seating depths, am I in the right area- seems like a jump from ogive to the lands with my hunting rounds... is this OK?


Ask some questions you need answers too.

cheers
WL
Click to expand...

G'day,

A friend of mine at work (sniper) made me a little tool for my 308. He took a piece of brass, and sawed 2 incisions into the next with a hack saw. He then put a projectile in it and chambered it a few times. He took the measurements from each chambering (Rem700AACSD) and cal;culated the average. The neck is tight enough to hold the projectile in place when you chamber it and you can still pull it out with your fingers so you can calculate using different projectiles.

From here just sacrifice one piece of brass and one projectile, take your time and seat the projectile exactly how you want it. Write the measurement right on the round (if you have multiples like me) and all you do when setting up your seating die is take your desired template round, put the die in your press, back the seating part off (pardon the term, im new to reloading). Pull the press handle, and screw down your seating die thingy until it touches....and there you go.
 
Hm thanks mate but it isn't what im looking for.. i'm not sure what im looking for though

maybe someone will catch my drift an shout out :)

cheers
WL
 
Like the middle round was once fired an has a shot primer in it, all I did was put It up the sizing die & seating die about 1/8 inch for enough resistance to pop the butt of the pill into.... after that I carefully put it in the mag, just half to not let the bullet be forced as the CRF feeds its way.... without the bullet getting caught I slid the bolt all the way closed and being careful to feel for slight tightness expecting the projectile to be pushed in More atleast.
I closed the bolt and slowly slid it back out...

I had some little marks just above the cannelure (although nothing showing a lot of pressure) marks coinciding with the results of the upside down bullet..... So..... I figure that is the Length..

BUT

the bullet is literally only just inside the case, So it seems that's what is confusing me. I figure the cannelure is there for a reason and with this projectile it seems my rifleing is very far away.. and would like to know what is the go with that, an is it ok, or what should I do

:)

Thanks
WL
 
In the next month or so I will be able to chrony the loads I use, which is on the right. to give me more idea of things.

ive been reloading this rifle for about 3 years, same load an lengths etc.
 
This jump/no jump start has been an argument for years.
That middle one is just barely seated in the neck.
For hunting, a no no.
At the range, maybe?
Sometimes studying too much causes eyes to cross.

If you decide to do the no jump start, keep your brass on the long
side of long.

That's all eye got to say 'bout this.............:wave:
 
Looks like you are in the right range. Generally speaking you should let the cartridge/rifle tell you what works. Go shoot it.

Big game hunting ammo doesn't need to be bench rest qualityaccurate. A 2" group at 100 yards is still plenty accurate for deer and larger game up to 300 yards easily. If you shoot over 300 yards then the extra accuracy starts to become more important.

There's still a lot of people that spend hundreds of hours developing a sub MOA load for their hunting rifle, which is fine but people need to learn shooting from positions other than just bench resting and i wonder sometimes if too many of us get hung up on getting the last 1/4 inch of accuracy off the bench wehn we should be using the time practising field shooting.
 
Last edited:
I'l leave it with this last comment-

from my researching of the past few hours it sounds like it not going to effect my accuracy in the field - pressure must be ok with the jump as is and seems unreasonable to seat it any further out.

Would be worth looking at different 358 bullets in the flesh to make any more judgement, as every projectile is going to vary as the weight goes up.

as some have said the only way to improve the load is to do another run of load testing + seating depths- which im not interested in doing for now.


feel free to throw any info up, im just not chasing the reasons :)

Cheers fellas!
WL
 
You must log in or register to reply here.
Back
Top Bottom