Help, Case Neck Tension

[piutemike]

I finished loading my first rounds and the bullets did not seat easily and I had a lot of copper shavings from the Barnes TSX 180's. Checked my seating die and lots of shavings in there too? 300 SAUM
Runnout was all over the place .002 one cartridge most were around.003 to .005, two were .007-.008. Case necks were all within .001 before seating.
I then took some fired cases took some measurements, resized them and measured again. Here is what I got.
Case neck OD before sizing .347 after .337
Case neck ID before sizing .310 after .304 and some .303
Case length before 2.006 after 2.10

Took my sizing die apart and measured the expander it measured .308, RCBS Full length sizing die.

I'm lost, also can already tell I want a better seating die, what is the best one, not the cheapest one. I already have that one.

Thanks Again, Mike

 

[Varmint Hunter]

I'm not sure how you can get an inside neck diameter of .303"-.304" after bulling a .308 diameter expander ball through them. ?? Some spring back is likely but .005" seems unlikely. It also sounds like you are working the brass quite a bit with each reload.

To answer your question - personally, I like the Redding bushing dies. Tjhere are a few different types, competition, neck, FL, all with changable bushings. These dies do not have, nor do they need, expander balls. The idea behind the bushing is that you can resize the necks/cases "just enough" and no more.

Typically, all you have to do is measure the neck diameter of a dummy round (using the intended brass & bullet) and subtract .002"-.003" to determine which bushing size you need. If you order the Redding catalog, it is all explained in better detail and gives you a full description of all of their dies.

Since you're upgrading your dies, let me suggest that you get a set with a micrometer seating adjustment. This will allow you to EASILY make seating depth adjustments for several different bullets and return to any previous setting without guessing or remeasuring a thousand times. They cost more but will make life much easier for as long as you continue to load. I would never buy a set without it.

 

[rotorhead]

I'm not sure how you can get an inside neck diameter of .303"-.304" after bulling a .308 diameter expander ball through them. ?? Some spring back is likely but .005" seems unlikely. It also sounds like you are working the brass quite a bit with each reload.

To answer your question - personally, I like the Redding bushing dies. Tjhere are a few different types, competition, neck, FL, all with changable bushings. These dies do not have, nor do they need, expander balls. The idea behind the bushing is that you can resize the necks/cases "just enough" and no more.

Typically, all you have to do is measure the neck diameter of a dummy round (using the intended brass & bullet) and subtract .002"-.003" to determine which bushing size you need. If you order the Redding catalog, it is all explained in better detail and gives you a full description of all of their dies.

Since you're upgrading your dies, let me suggest that you get a set with a micrometer seating adjustment. This will allow you to EASILY make seating depth adjustments for several different bullets and return to any previous setting without guessing or remeasuring a thousand times. They cost more but will make life much easier for as long as you continue to load. I would never buy a set without it.

I agree about the redding dies. I might suggest that the brass could be a problem as well If your useing win. brass I have got some in the past that was just plain hard. I would go to Norma and or lapua. More expensive but alot less trouble.

 

[James H]

RCBS Gold Medal full length bushing die and seater. Measure a loaded round and get a coated bushing .002" smaller than the loaded round neck dia.
I have both Redding competition seaters and RCBS Gold Medal and I prefer the RCBS.
James

 

[J E Custom]

Tension

I shoot for .008" smaller than a case fired in that chamber.

This will give you .004" on each side.

I polish the expander ball/plug to accomplish this fit.

Some use less tension and some use more( in the case of
a dangerous game load without a cannelure I go with .010"
smaller after it has been fired.

Also no matter how much or how little neck tension is present
you will shave the bullets if you have not de'burred the inside of
the neck prior to loading.

Hope This helps
J E CUSTOM

 

[Winchester 69]

If you don't want to spring for a micrometer head, the standard Forster seater is the same design and of equal quality.

A VLD (long taper) de-burring tool will also help.

 

[piutemike]

Thanks for all the replies, lots of information. Like I said that was the first time I had hand loaded a round. I do know I want a micro seater die as I can tell the one I have will be a pain in the *ss for changing the seating depth.

1. The brass is Remington and what is overworking the brass? To much pressure on the case while full length sizing?

2. A neck sizing die does sound good, I'll order one and the bushings for that round and a couple others.

3. After I sized the dies I ran the brass through my rcbs power prep station, flash hole de burred, primer pocket cleaned, inside case neck beveled, and outside neck chamfered. Also prior to this I tumbled my cases.

4. Think I need a micrometer too. All the measurements I took were with a cheap set of 6" calipers. Maybe I'll buy a pair of digital. What do you think? I'll look up the VLD de burring tool too.

Thanks for everything, up to this point everything I have done has been from info at this sight. No teacher here, just you guys.

Mike

 

[piutemike]

One more Question, what is acceptable in bullet run out? I bought the sinclair concentricity guage because Buffalo Bob recommended it. I just don't know what acceptable tolerances are on case neck and bullet run out.

 

[piutemike]

still looking for an answer on runnout?

 

[Brain]

The amount of runout acceptable to your situation greatly depends on what you're trying to accomplish and what your rifle is capable of.

Zero runout is the goal, but you may never see the benefits of it depending on your rifle. If the variables in your rifle are of such loose tolerances, zero runout in your cartridges will help, but not to the degree to show drastic improvement over .001-.003 or maybe more.

You have to consider all of the variables. Control the ones you can and work around the ones you can't. Also, if you're gonna split hairs...sort your loaded rounds into runout groups and test them. You may find a runout threshold that trying to get under won't show a marked improvement in accuracy. That will be YOUR acceptable runout.

 

[piutemike]

thanks Brian, guess I need to head to the range with a note book.

 

[overbore]

Piute mike

please look up the in-depth post I did on total runout. It is all you need to know except what tool but you should have the ability to QC your reloads and to sort for purposes / ranges. Send me a pm if you can not find the post. We are here to serve the new shooters.
Overbore

 

[indiansumer]

Just want to make sure I have this right....I'm loading a .300 RUM. Before resizing my i.d. is also .310. After resizing it is .304. My Berger 210VLD's measure .308. Will this give me enough neck tension? I see that JE Custom said he would shoot for .300 or .008 less than the bullet. I just figured that the size of the expander ball on the RCBS FL die was giving me the proper size and neck tension.

 

[Varmint Hunter]

Just want to make sure I have this right....I'm loading a .300 RUM. Before resizing my i.d. is also .310. After resizing it is .304. My Berger 210VLD's measure .308. Will this give me enough neck tension? I see that JE Custom said he would shoot for .300 or .008 less than the bullet. I just figured that the size of the expander ball on the RCBS FL die was giving me the proper size and neck tension.

Inside neck diameter is difficult to measure accurately unless you have special gauges. Caliper blades are flat and shouldn't be used to measure concave surfaces. Outside neck measurements will be fine.

How much neck tension is NEEDED? - IMO about .002" of neck tension is adequate for most hunting rifles. BR guys often use less and autoloading rifles would benefit by more. Either way, .002"-.003" is a good range. More tension isn't really going to hurt anything except the life of the overworked necks. However, .008" would require much more setting pressure than I would like.