Saco extractor

[JMP]

I don't recommend converting a factory remington bolt to a sako extractor.
When you change the location of the extractor from the middle of the left lug to ABOVE the left lug without also rotating the ejector plunger in the boltface, you are dramatically changing the ejection angle.



The ejection angle is a product of the extractor location combined with the ejector plunger location.
The 700 action was designed with the extractor in the middle of the left lug and then the ejector plunger is located to get the fired case to fly out of the ejection port.
Changing the location of the extractor is changing the design of the action.



I have seen lots of problems where the fired cases will bounce off the scope knob and end up backwards in the action.

If you want to change to a different type of extractor, the right solution is to get a whole new bolt with the extractor cut already made and the ejector rotated appropriately in the boltface.
PTG makes them to order.
Figure on having the headspace and maybe the endspace corrected on your barrel as well if you are NOT also rebarrelling when you get the new bolt.

To add, here is a factory Remington bolt next to Sako bolts. Their orientation has been designed as such (in both 2-lug and 3-lug bolts). I think it makes no sense to convert a Remington bolt to a Sako extractor unless you have a specific reason to do so.

[LynnJr]

KenDog
I have been on many forums were the Guffster got the boot for his cryptic nonsense.
It's fun watching him telling some of the top machinists in the US they don't know how to measure brass and then he brings up his 30-06 Mauser and gets the boot.

[LynnJr]

Diver
It's to show new shooters that on properly prepared brass you can't make a mistake. The flatbase bullets have a pressure ring and they will seat and reseat to the same location each time even if done by hand without dies.

[diver160651]

Diver

At our 2000+ yard matches I like to pull a bullet out of a round then re-install it and hit the gong.

I learned something.. not sure it is more than academic. But then this, really Lynn, whatever drives the need to always add that part, it's lame...

Jim

[LynnJr]

Diver
Get the powder charge spot on and seat the bullets with a comparator to within 0.001 and you will be more than happy.

At our 2000+ yard matches I like to pull a bullet out of a round by hand then re-install it and hit the gong. I show the shooters the pressure ring on the flatbase bullet and how it clicks into the neck.

[diver160651]

Load your ammo like Benchrest shooters and you will never have a problem.

LOL that is EXACTLY the true..

BR guys take it all to the edge.. obviously they push precision to what it is today. All of us benefit...but not exactly by duplicating every process.

Guys laying in the powder dirt or tank traps etc were the drill is to f with accuracy.. can not reload with many of the tolerances nor techniques like jamming with low tension. So if we try to modify what the bad *** BR guys do, but the needed jump can dick with or ES if we don't do something different for field guns.

No free lunch..

[kendog4570]

Lets take this back to the Mystery Wrench level.

[kendog4570]

Load your ammo like Benchrest shooters and you will never have a problem.

And I think we all got insulted by KenDog. Calling us Guffsters Now that is insulting.

I said I was coming off like the Guffmeister!


Bet you don't know what I am talking about...! Mere mortals cannot even begin to comprehend.

[LynnJr]

Load your ammo like Benchrest shooters and you will never have a problem.

And I think we all got insulted by KenDog. Calling us Guffsters Now that is insulting.

[MongooseV8]

Yeah Im with you on the psi vs surface area.

[ar15barrels]

And isnt the thinnest part the neck and shoulder? Wouldnt those expand the most as you point out?

I should not have said the most.
The chamber obviously limits the expansion amount as the case stops expanding when it comes to rest against the chamber.
Think of the case as a pressure activated gasket that seals up against the chamber when the pressure acts on it.

The thinnest section expands the easiest.
The amount of surface area will determine how much force is present in a given area.

Pounds PER Square Inch.

Using our 30-06 example, the inside of the case body has around 2 square inches of surface area.
At 55,000 PSI there would be about 110,000 pounds of force locking the case against the chamber.
The inside of the shoulder area would receive about 6900 pounds of force, with more than 2/3 of that force being outwards and less than 1/3 being forwards.
The base of a 30 caliber bullet would receive about 4100 pounds of force.
The inside of the case neck once the bullet has left would receive about 20,000 pounds of force.
The inside of the case head would receive about 6800 pounds of force.

The inside of the primer cup ends up with about 5900 pounds of force.
This backs the primer out of the case head against the breech face until such time that the case body yields and lets the case head slide back against the breech face.

Low pressure loads will often show a protruding primer after being fired.
This is because the pressure was not high enough to yield the case body and the case head did NOT slide back.
The primer cup will be sticking out by the amount of headspace present in the chamber with that particular case.

Because of the much larger surface area, the case body will elongate and yield long before the bullet moves forward out of the case neck, allowing all the pressure to reach the case neck.
Once the bullet moves out of the neck, the neck is also contributing to holding the case forward in the chamber though.
It's just a much smaller piece of the overall pie.

[kendog4570]

You guys should get a room...
At the risk of coming off like The Guffster, one can also "stretch" bottleneck cases with an improperly adjusted FL sizer.

[diver160651]

Lets use a 30-06 as our example.
Look at the surface area of the inside of the case.
This includes the case neck, shoulder, body, case head and the base of the bullet.
The internal surface area of the case body GREATLY exceeds the surface area of the neck as well as that of the case head or the base of the bullet.
The pressure from the burning powder acts on ALL of these surfaces.
Since the case body has the most area and the pressure acting on the area is equal in all areas, the case body will
be most susceptible to elongation and deformation.

The thinner areas of the case will have the most elongation and the thickest areas will have the least.
That's just the basics of how metal behaves under pressure.

The case NECK can not actually expand until the bullet moves forward and lets the pressure act upon the inside of the neck.
The pressure acts outward on the inside of the case though long before the bullet moves forward.

I can't help you if you choose to believe that the case BODY is not expanding and that just the neck is expanding and holding the case into the chamber as that sort of belief defies rational logic.

Thanks everyone. I think I understood most the process of expansion -- hardening etc.

Sorry I took me sooo long to get the explanations.

Except honestly, was thinking of this backwards.. Thinking the bolt face was ground zero..

FWIW, I seldom need to trim brass ~

Talking about (1)-brass sealing the chamber.. or being a "gasket" and (2)-Lynn's mention the wrong round in a chamber, is exactly what (1)-didn't and (2)-did happen.. Funny how there is only so much elasticity in the brass when you put a long thinner round into a fat chamber... I was calling wind on the gun and without lifting my head felt for my round and single loaded the wrong round.

[MongooseV8]

Well obviously the case body expands, I never said it doesnt. And isnt the thinnest part the neck and shoulder? Wouldnt those expand the most as you point out? And the bullet can move out of the way pretty fast exposing the neck to the building pressure.

Like I said this isnt something I made up on my own, but at the end of the day this whole topic is speculation anyway. We cant exactly stand inside a chamber and watch in slow motion.

[ar15barrels]

After ignition the neck expands and locks into the barrel/chamber, then the case head slams rearward into the boltface, then the walls expand to the chamber.

Lets use a 30-06 as our example.
Look at the surface area of the inside of the case.
This includes the case neck, shoulder, body, case head and the base of the bullet.
The internal surface area of the case body GREATLY exceeds the surface area of the neck as well as that of the case head or the base of the bullet.
The pressure from the burning powder acts on ALL of these surfaces.
Since the case body has the most area and the pressure acting on the area is equal in all areas, the case body will
be most susceptible to elongation and deformation.

The thinner areas of the case will have the most elongation and the thickest areas will have the least.
That's just the basics of how metal behaves under pressure.

The case NECK can not actually expand until the bullet moves forward and lets the pressure act upon the inside of the neck.
The pressure acts outward on the inside of the case though long before the bullet moves forward.

I can't help you if you choose to believe that the case BODY is not expanding and that just the neck is expanding and holding the case into the chamber as that sort of belief defies rational logic.