Is .005 thou neck tension too much?

[270 ftw]

Had an expander ball that was only giving me .0005 difference between sized neck and loaded neck. Busted out the DeWalt and sand paper, got a little crazy and now im at .005. How much increase in pressure can I expect between the two different neck tensions?

 

[Sniper338]

Read it wrong first 2 times...

Umm. Depends what your loading for..

 

[4xforfun]

Also depends on your neck thickness. A .002 squeeze ...one piece of brass the neck is .015 thick and you sqeeze it .002...the other .008 thick and you sqeeze it .002. Is the neck tension the same? Which one has a tighter grip?

When I ran .330 neck 300 Wbys I usually ran .008. When I went to a .334 neck i went to .003 ish.

Tod

 

[270 ftw]

Just looking for the relative difference guys between 2 loads all other variables being the same just a .0045 thou increase in "neck tension". So in relative terms are we thinking barely noticeable/ a few feet per sec...or better turn my face away for the first shot?

 

[270 ftw]

Also depends on your neck thickness. A .002 squeeze ...one piece of brass the neck is .015 thick and you sqeeze it .002...the other .008 thick and you sqeeze it .002. Is the neck tension the same? Which one has a tighter grip?

When I ran .330 neck 300 Wbys I usually ran .008. When I went to a .334 neck i went to .003 ish.

Tod

Just curious...im assuming the .330 & .334 neck are chamber dimensions? Why did running a wider neck chamber cause you to change neck tension in your load? Was that just the new sweet spot?

 

[243winxb]

Bullet pull will be higher, but not dangerous. Bullet may exit the case mouth later.

K&M https://kmshooting.com/custom-diameter-expand-mandrel-kit-for-bullet-tension-main.html

 

[Bc'z]

You probably need to re test your load.
I was doing OCW aka OCD test last week.
.001 in neck tension took a .3 load to over an inch.

 

[270 ftw]

You probably need to re test your load.
I was doing OCW aka OCD test last week.
.001 in neck tension took a .3 load to over an inch.

Wow Ouch!! .001 thou taking you compleatly out of your node. Well i will certainly expect some different results. Fortunately I didn't get too dialed in with that load because the necks were getting so carbon fouled which I'm assuming (hoping) was from such light neck tension.

 

[Bc'z]

Wow Ouch!! .001 thou taking you compleatly out of your node. Well i will certainly expect some different results. Fortunately I didn't get too dialed in with that load because the necks were getting so carbon fouled which I'm assuming (hoping) was from such light neck tension.

Went from a .288 bushing to a .287.
Tighter neck tension push me to a lower accuracy node.
A difference of .5 grain of powder.

 

[270 ftw]

Went from a .288 bushing to a .287.
Tighter neck tension push me to a lower accuracy node.
A difference of .5 grain of powder.

Did you have to reduce by .5 gn? And that got you back to butter zone?

 

[Bc'z]

No I went with the lighter tension and higher powder charge.
I was in a good spot with great accuracy either side of my chosen charge.
I wasn't seeing pressure at my charge weight but would have taken a full grain of powder to get to next node.
Confined to mag length and control feed I chose to stay where I was at.
Folks were posting higher charges with the bullet powder combo were probably able to single feed and have more free bore.

 

[Murray Brook]

I don't believe you have a problem as long as your bullet isn't damaged during the seating.. Your bullet will simply expand the neck to the proper size.

 

[270 ftw]

No I went with the lighter tension and higher powder charge.
I was in a good spot with great accuracy either side of my chosen charge.
I wasn't seeing pressure at my charge weight but would have taken a full grain of powder to get to next node.
Confined to mag length and control feed I chose to stay where I was at.
Folks were posting higher charges with the bullet powder combo were probably able to single feed and have more free bore.

I got ya. So moral of the story .001 thou pretty significant pressure change. Didnt take yo

No I went with the lighter tension and higher powder charge.
I was in a good spot with great accuracy either side of my chosen charge.
I wasn't seeing pressure at my charge weight but would have taken a full grain of powder to get to next node.
Confined to mag length and control feed I chose to stay where I was at.
Folks were posting higher charges with the bullet powder combo were probably able to single feed and have more free bore.

I got ya, you went back to the .288. Well a significant result with only .001 thou difference. From the sound of it .0045 will be noticeably higher pressure but i wont blow up

 

[Bc'z]

When you develop a load that is the recipe, any deviation no matter how little will have a result on paper.
Some good some bad.

 

[243winxb]

See post #16 here. https://www.handloadersbench.com/fo...h-com-load-data/27215-neck-tension-experiment

 

[270 ftw]

View attachment 1089735

Ok now that is some cool data! .007 thou more only 7 psi difference to pull. Very very interesting. Thx 243

 

[Intheshop]

Higher tension shows up in the seating process for me..... higher tension "usually" equates to higher runout #'s.

My rigs and loads are for running rounds up through the magazines on push feed bolt guns. I have OAL constraints as well as durability issues..... so am very often .003 and sometimes a touch more tension. Forces you to get on top of the seating op.

 

[243winxb]

The bullet becomes the expander as its seated.

higher tension "usually" equates to higher runout #'s.

Makes sense to me. I never checked runout.

 

[Bc'z]

No, its the total . You missed a zero. .0007"

I think he's referring to the pull force between .003 and .010.
Hopefully he's recognizing how much force it takes with increasing tension.

 

[243winxb]

ok, i see that now. Thank you. (deleted my comment above)