Neck Tension

[DIESEL TECH]

What is the best die to use to adjust neck tension? I have some lupua brass "once fired" and full sized it but the neck tension is to tight for me. The win brass that I sized at the same time was fine but the new lupua was tight enough to shave a small bit of copper off the bullet. They seated fine just to tight for my taste.. I guess I need to tell you guys that it is a .308.

[JeepsAndGuns]

My guess would be a compettition bushing neck die. You choose the bushing that sizes the neck to the size you need it.

[earl39]

Yep a bushing die or a Lee Collet die will take care of that problem unless you want to turn the necks on your brass to fit the die you already have.

Gary

[DIESEL TECH]

I am using RCBS COMP dies in .308 like I said the win brass is fine but the lupua brass is tighter then I like. What is the deal with "Soft Seating" I shoot sierra mk and Berger's VLD 168 with a 1-12 twist. I was going to load some 155VLD Berger"s. Some guys so that Berger's don't like jump I have set the Berger's at .010 off the lands with good luck. A friend told me to try some 155 he said they shoot even better then the 168 in his 12F T/R. That is the same rifle that I am shooting.

[82boy]

Why not pull the stem out of the die, chuck it in a drill, and hold sand paper over the expander ball, polishing it and sizing it for proper neck tention. RCBS dies are one of the best.

[DIESEL TECH]

Will cutting down the expander ball make the neck tension less?

[1Shot]

Will cutting down the expander ball make the neck tension less?



...NO...The Lapua has a thicker neck...The die closes the neck down..The expander is what opens it back up...You trim that down & it won't open up as much...AKA smaller hole for the bullet to go in...Come on guy's think alittle... :-X
..Either use a bushing die or a LEE Collet die...

[DIESEL TECH]

Will cutting down the expander ball make the neck tension less?



...NO...The Lapua has a thicker neck...The die closes the neck down..The expander is what opens it back up...You trim that down & it won't open up as much...AKA smaller hole for the bullet to go in...Come on guy's think alittle... :-X
..Either use a bushing die or a LEE Collet die...


That is what I thought. cutting that expander ball down would make it tighter?

[earl39]

...NO...The Lapua has a thicker neck...The die closes the neck down..The expander is what opens it back up...You trim that down & it won't open up as much...AKA smaller hole for the bullet to go in...Come on guy's think alittle... :-X
..Either use a bushing die or a LEE Collet die...
[/quote]

That is what I thought. cutting that expander ball down would make it tighter?
[/quote]

I'll try to say it again in a different way. The ONLY way to get the same neck tension with your RCBS die is to turn all your necks to the same thickness. If you don't want to go thru that much trouble use either the Lee collet die or a bushing die with a bushing picked for the proper neck tension for each brand or lot of brass.

Gary

[GaCop]

They pretty well summed it up.

[DIESEL TECH]

Thank's guy for some it up for me. What is the best die to use for this, Redding makes a bushing die for that right or is the lee better

[Blue Avenger]

Redding will be more consistent when you get it set up, Lee is a lot cheaper

[memilanuk]

With the Lee collet die you get pretty much one setting (technically you can either order special sized mandrels or polish a little of the existing one to get a little more neck tension, but it's not really intended to be used with anything other than the size it comes with.

With 'bushing' dies, as mentioned you can pick a bushing size according to what you need. As you noticed, Winchester brass is much thinner in the neck (11-12 thou per side) than Lapua (14-15 thou per side) and the Lapua starts out sized awful tight to begin with. As an example, for loading Lapua brass in my .308 12 F/TR, I neck turn to 0.0141" neck thickness (just where it ended up for a 90% cleanup of the necks). ~0.014 *2 = 0.028 + 0.3085 (bullet dia)= ~.3365 for finished loaded round diameter - which is right about where it ends up, btw. So I pick a .334 neck bushing when sizing my cases - it sizes the neck 0.002" under the final diameter, and the floating carbide expander ball I use on my die is also about 0.002" under nominal bullet diameter, so it just 'kisses' the inside of the neck on the way out - just enough to make sure its round from the inside out.

Now if I wanted to do that with Winchester brass, say @ 0.011" neck thickness (after a light clean-up neck-turn)... we're looking at 0.011 * 2 = ~ 0.022 +0.3085 = ~0.330-0.331" and I'd select either a 0.328 or 0.329" bushing to get the same results as with the Lapua cases.

That is the one beauty of the collet die... since the brass is being squeezed down against a solid mandrel, instead of being squeezed under size and then expanded back out like a traditional F/L die, the inside neck tension tends to be pretty consistent, if a bit on the light side (thats where the custom mandrels I mention come in). The down side is the buggers can develop a taste for brass and wreck a case in the blink of an eye, too.

There are other styles of bushing dies on the market. The Redding Type 'S' bushing die comes in either a full-length sizing die, a neck-only die, and they also make a 'Competition' seater that has some (in my opinion) un-necessary features - like a micrometer to control how *much* of the neck is sized ::) Wilson makes a hand die (works in an arbor press, or by hand with a mallet) that only sizes the neck from the outside with a bushing, no expander at all on the decapping rod - very common in short range Benchrest competition and surprisingly in-expensive. Bushings for Wilson and Redding dies are basically interchangeable. Forster also makes a shoulder bump bushing die, which sizes the neck and bumps the shoulder back without doing a complete full-length size (which affects the body taper, etc.) but their bushings are not compatible with the other two.

Monte

[GaCop]

I get good results with the Lee collet die sizing my Winchester 223 brass. I just shot some loads yesterday with collet sized Win brass that was weighed and averaged 92 grain wt. 80 grain A-Max bullet was pushed by Varget. Average for four five shot groups at 100 yards in 36 degrees with a 12 to 14 mph head wind varying between 11 o'clock and 2 o'clock was 2881 fps, Avg group of .704" with an SD of 4.3 and an ES of 20.1. The Winchester brass has been loaded four times and is trimmed to 1.750". I think it may be about time to anneal the brass before the next loading.

[DIESEL TECH]

memilanuk you hit it right on the nose. What are you using to turn your brass with? I found that seating to bullet soft made my groups a lot tighter. I have some 3 time fired WIN brass and it was lightly sung and I shot a five shot group .228 with 42gr Reloader 15, BR2 Primers, bullet seated at 2.210 that puts it .010 off the lands with sierra 168gr MK. Did the same load but used lupua brass that was new and the 5 shot group was .779. Maybe the next reloads will yield better results?

[memilanuk]

What are you using to turn your brass with?

K&M stuff as found @ PrecisionReloading.com


Maybe the next reloads will yield better results?


If you didn't expand the necks on the Lapua brass on a mandrel or at least run them thru a sizing die with an expander to open that neck up, then yes, the next firing will likely be a little better. One five-shot group doesn't tell you much... statistically in may be the outlier, and the 'average' groups size may be a bit bigger.

[BowElkStalker]

memilanuk you hit it right on the nose. What are you using to turn your brass with? I found that seating to bullet soft made my groups a lot tighter. I have some 3 time fired WIN brass and it was lightly sung and I shot a five shot group .228 with 42gr Reloader 15, BR2 Primers, bullet seated at 2.210 that puts it .010 off the lands with sierra 168gr MK. Did the same load but used lupua brass that was new and the 5 shot group was .779. Maybe the next reloads will yield better results?


What is seating the bullet soft?

[memilanuk]

Given the context of the post, I'm guessing its some form of 'light neck tension'. Kind of 'lightly sung' ;)

[Rifleman51]

You can also use the Foster case trimmer. With the inside neck cutters, you can take material out of the inside of the neck and get to the tention you need when nothing else works.
I prefer to use collets, but the Foster inside neck trimmer works pretty darn good when needed. Trim and then re size.

John K