.243 win reloading neck size question

[kawsam62s]

Hi
If a loaded round neck diameter is correct to the chamber diameter upon firing ,should a bullet drop into a fired case?
Thx for the help!

 

[GLShooter]

Maybe. Some chambers are only about 0.001-0.002 bigger than the loaded neck. On firing the neck expands but then contracts. You may well not be able to get a bullet back in there. Most factory rounds will be find done to SAAMI but a custom reamer or wildcat not so much all the time.

The "tight neck" bench guns require you to turn the necks so you can get the round chambered. You may well not be able to get them in the chamber period without that step. When turning they don't take it down much below the chamber neck size. They resize them very little.

Greg

 

[kawsam62s]

Maybe. Some chambers are only about 0.001-0.002 bigger than the loaded neck. On firing the neck expands but then contracts. You may well not be able to get a bullet back in there. Most factory rounds will be find done to SAAMI but a custom reamer or wildcat not so much all the time.

The "tight neck" bench guns require you to turn the necks so you can get the round chambered. You may well not be able to get them in the chamber period without that step. When turning they don't take it down much below the chamber neck size. They resize them very little.

Greg

Thx for the help
I’m thinking I have a tight unmarked chamber that’s pinching the bullet
I turned lapua brass down to .014 wall and a bullet won’t drop thru the case after firing, accuracy is dismal ,trying to figure if I need to turn a little more.

 

[GLShooter]

I'd turn to 0.012 and see.

Greg

 

[mikecr]

So then the real question is 'what is my chamber neck diameter?'.
Why did you choose 14thou to turn necks to?

With necks that thick, chamber neck is close to 1thou over fired neck ODs.

 

[kawsam62s]

So then the real question is 'what is my chamber neck diameter?'.
Why did you choose 14thou to turn necks to?

With necks that thick, chamber neck is close to 1thou over fired neck ODs.

Hi
The brass started out with .015 wall.
So I figured moving .001 per side on a few case was worth trying ,dismal performance,
Using n160 and .105 vld bergers@3000 fps
Tried seating adjustments and powder charges so started thinking’s out side the box.

 

[Coyotefurharvester]

That bullet requires a faster twist 1-8.25, if you have a 1-10 your probably not stabilizing the bullet.

 

[243winxb]

The outside diameter of a 243 Win. loaded rounds neck should not be larger then .276" for a factory chamber.

If the loaded round doesnt chamber freely, stop.

Slow powders of starting loads may not fully expand the necks on firing.

 

[kawsam62s]

That bullet requires a faster twist 1-8.25, if you have a 1-10 your probably not stabilizing the bullet.

Hello
1-8 twist

 

[kawsam62s]

The outside diameter of a 243 Win. loaded rounds neck should not be larger then .276" for a factory chamber.

If the loaded round doesnt chamber freely, stop.

Slow powders of starting loads may not fully expand the necks on firing.

Hi
32 inch bartlein 1-8 barrel loaded round measures .2715 does chamber with no resistance

 

[dhagerty40]

I am going to add with Lapua brass because of how soft it is, The ejector sometimes dents the neck when the case is being ejected and a bullet may not go into the neck of a fired case. this happens with my 6BR brass.

Also, N160 is a little slow for a 243W

 

[kawsam62s]

I am going to add with Lapua brass because of how soft it is, The ejector sometimes dents the neck when the case is being ejected and a bullet may not go into the neck of a fired case. this happens with my 6BR brass.

Also, N160 is a little slow for a 243W

Thx for the replying.

 

[mikecr]

So what is the fired neck OD?

 

[HTSmith]

https://www.brownells.com/gunsmith-...0&cnxclid=16304475520285581729410090302008005

This stuff could help. It would be easier if you could screw the barrel off.

 

[kawsam62s]

So what is the fired neck OD?

I believe it was .272
I could actually just seat a bullet, no sizing required

 

[JFrank]

I believe it was .272
I could actually just seat a bullet, no sizing required

What does a loaded round OD measure ?

 

[kawsam62s]

What does a loaded round OD measure ?

.2715

 

[Capt. Oblivious]

With those measurements id say your chamber is close to .272 or a hair bigger and that .2715 on your loaded round is imo not enough clearance. On a clean chamber yes but unless you clean the whole time your going to run into problems, N160 is a clean burning powder but not so clean that id run that sort of fit/clearance

On a side note N160 is just about perfect for a long barrel 243 size case with a 105gr bullet

 

[painter]

Thx for the help
I’m thinking I have a tight unmarked chamber that’s pinching the bullet
I turned lapua brass down to .014 wall and a bullet won’t drop thru the case after firing, accuracy is dismal ,trying to figure if I need to turn a little more.

The brass neck may be getting a ding if the ejector spring is causing it to be forced into the side of the chamber when being extracted.

 

[mikecr]

If your loaded is .2715 OD, then fired .272 OD would allow bullets to freely fit in necks (at least to donut depth).