SmallCaliberCentral

Guys,

I'm trying to reduce my extreme spreads and have started to pay a bit more attention to neck tension and other things in order to do so. I just checked some brass I sized and it measured .222 (OD) at the neck. A loaded round (39 SBK) was .226. This is Remington Brass sized in a standard RCBS die. .004 neck tension seems like alot to me, so I thought I'd ask you guys what you were running.

I'm also kind of wondering if the .204 is any more or less sensitive to neck tension when it comes to accuracy when compared to larger calibers.

I'm thinking about just taking the plunge and getting a Redding Type S Bushing die (have one for my 6.5 X 47 L) but if I do, I'm also interested in what bushing to order.

Thanks!

KetelOne

I just happened to be loading some 204's this morning and have never checked neck tension. I'm using Norma brass shot once only by me. An unsized round measured .232 at the neck. Full length size with a standard Redding die brought the neck down to .225. The neck sizer part of the die (with the decapping pin) measures .204. Imagine that! After seating with an RCBS competition die it measures .226+ a tad (.2265) standard dial caliper-not digital. By doing the math it looks like my neck tension is .001+. Curious to see what the others are getting. Randy.

It seem like the Redding die is the ticket, just like it is with my 6.5, where I'm using a .289 bushing and achieving .001+ in neck tension. It shoots very well with less than a minute of vertical dispersion at distance. I had my .204 to the range last week and had 4" vertical spread at 300 yards with a 39 grain SBK. The same load that shoots into .5 MOA out to 200 yds. goes to heck at 300 with the vertical dispersion (windage is right on, however). Not surprisingly, my extreme spreads are wacked out (80 fps+) so I'm hoping this neck tension excercise will help.

Ketel... are you sure that the problem is not in your seating depth...?

or irregular primers...?

I'm using Winchester brass and my fired necks measure .231
I then size them with a Redding .226 bushing which leaves them at .225
I then run them through my Sinclair mandrel which opens them up to .226.
My loaded rounds measure .227 so it looks like I have only .001 neck tension.
I'm wondering now if it's enough.

Well, my bullets aren't falling out with .001 neck tension so I'm calling it good! I shot today what I hope is my final test load before loading up 600 or so rounds for this year's squirrel shooting. I settled on 29.5 gr. of CFE223, 32 gr. varmageddon's, 7.5 primers all seated for 2.250 overall length.

I'm thinking .001-.002 neck tension is probably ideal based on my experience with my 6.5 but perhaps the comparison is not valid? Anyway, I did seat these a quite a bit shallower (Cartridge base to Ogive (CBTO) at 2.040") with the 39 SBK. This is a change from CBTO of 2.000" and I'm still .030" off the lands! (man these throats are long). I'll test them at the range but like I said, it think that .004" neck tension is a bit proud. We shall see. It's nothing I can't drink myself through! (after the shooting, of course).

To me... 1 to 2 thou is ideal... with no need to make them tighter. Groups that pattern left to right ( horizontal) are usually the result of powder charge... and vertical groups are usually seating depth. I would seat them to the lands and start backing them out until the groups came back down to horizontal... but that's just me....LOL.

I settled on the Redding 225 bushing for my Hornady brass. After loading they measure .226. Seems perfect.

204Luver wrote: ↑Sat Mar 10, 2018 3:40 am I settled on the Redding 225 bushing for my Hornady brass. After loading they measure .226. Seems perfect.

Thanks. I'm going to pursue the Redding die with the 225 bushing myself.

You really can't get more than ~2 thousandths of neck tension. Any more than that and you're just resizing the necks when you seat the bullet, which is silly and invites things to get crooked.

I'm not a fan of bushing type dies. I like collet-type neck sizers better.

Neck tension varies like the wind. Regardless of what your calipers read the tension on the bullet will depend on the hardness of the brass. Freshly annealed cases will have different tension on the bullet than a case with 4 or 5 firings on it. This is why many benchresters anneal after each firing so as to theoretically get more consistent release of bullets.

Here's a link to an article on understanding tech tension.
http://www.accurateshooter.com/technica ... hing-size/

danielbrothers wrote: ↑Fri Mar 09, 2018 7:13 pm To me... 1 to 2 thou is ideal... with no need to make them tighter. Groups that pattern left to right ( horizontal) are usually the result of powder charge... and vertical groups are usually seating depth. I would seat them to the lands and start backing them out until the groups came back down to horizontal... but that's just me....LOL.

I find powder charge is vertical. Seating depth for horizontal.

Duker... your are absolutely correct... My Bad... I said it backwards... you are correct... powder always causes a vertical... and seating depth is usually the horizontal problem... thanks for the correction... I must have feel out of bed that morning...LOL.