Neck sizing

[Smokey Joe]

I have successfully used Norma brass rifle cases in the past, and they have a deserved reputation for excellence and consistency among the reloaders of my acquaintance. Thus, the following was a surprise:

Recently I bought 200 Norma cases, in .300 WSM. Loaded a number of them and fired them without incident in my Savage Model 12BVSS. Then planned to reload them and develop a nice accurate load for the rifle.

Resized 95 of the cases in my RCBS Rockchucker, using a Lee Collet die. I discovered in measuring the resized necks that 10 of the cases' necks were greater than 0.309" inside diameter. The bullets I was loading were 165 grain Nosler Ballistic Tips, which are a consistent 0.308" in diameter. An exact 0.309" neck just holds the bullet friction tight, but the 10 cases in question allowed the bullets to slide into their necks, and slide right out again. The 50 cases I did load had necks that were at 0.309" inside diameter, or very slightly less, allowing the seating of the bullets.

I'm not sure if I did something wrong or if the Norma cases are varying in neck wall thickness or the die is malfunctioning some way, or what. As per the die maker's instructions, I tightened the die on each case, then lowered the case, turned the case in the shellholder, part of a turn, and raised the case into the die a second time. Most of the time, this worked, and the case was sufficiently neck-sized. I'm an experienced reloader, and frankly, I'm puzzled.

Any advice or suggestions?

 

[redneck2]

IIRC, the collet die squeezes the neck around a mandrel. If you haven't, you may want to be sure to clean the inside of the necks with a brush to make sure there's no powder build-up

Since the collet squeezes the brass from the outside and around the mandrel, I'd tend to think it's more of a question of the size of the mandrel.

As to why some work and some don't...well, you're talking .001. Thats 1/4th the thickness of a sheet of paper. Pretty fine stuff. In theory, a .309 neck shouldn't hold a .308 bullet, but you're way down past splitting hairs. I guess you could inside or outside turn the necks to true them up. Then again, having .001 difference from side to side in a neck probably wouldn't be unknown. Perhaps (just a guess) is that the ones that didn't size down were slightly thicker on one side and this limited the amount the collet could squeeze.

If you have a ball mike that can check wall thickness, I'd take the "defective" cases and check the neck all around. Thinking as I go here, if you outside turn it may solve your problem. Guess you'd have to try it.

I believe Lee states in their literature somewhere that they will turn down the mandrel as necessary if you send the die back to the factory. I've had real good luck talking with the tech people at Lee. I'd call them and they'll know for sure

 

[user203]

Hate to state the obvious, but did you check for that famous double bump at the end of the stroke, i.e. is the die set correctly?
I had the same issue, and just moved it a tad and voilla!

 

[redneck2]

User 203..

what do you mean be "moved it a tad"?

I've loaded a lot of pistol but very little rifle, but I'm set up and going to start. I've got some Lee collet dies, so I'm asking as something to watch for..thanks

 

[Ol` Joe]

Were these older cases? The brass work hardens over time with use and and developes "memory" problems. The collet die only sizes to a bare minimum where a regular style die over sizes then opens the neck back up. The answer to this is to anneal your brass. Thin cases walls could also be part of your problem. One other fix recommended by Lee is to polish the mandrel with fine grit emery, 400/600 and see if it helps. Don`t take more then about .001 off the mandrel, too much and you`ll wreak your die.

 

[Lennyjoe]

A buddy of mine uses the Lee Collet dies and if you dont use enough pressure to squeeze the neck it wont size all the way.

For that reason alone I went with RCBS neck sizer for my 22-250 and -06 loads.

 

[Ol` Joe]

Lenny pressure has little to do with the Lee die working properly. Once the collet has compressed the neck against the mandrel, squeezing harder does nothing for further reduction of the case neck.
The problems are case wall thickness and brass spring back. The case wall problem is addressed in the instructions, polish the mandrel, and don`t remove more then about .001" the collet travel won`t allow it to work past a certain point. Try double striking the case while turning it 180 deg. this helps with old brass that has work hardened and will aid with cases with thin walls.

Again too much pressure and it`s a fine line, camming the press over may be too much, will simply shatter the die. Don`t ask how, but believe me I know
The dies work fine and give the lowest run neck run out I`ve been able to consistantly achieve but they don`t give super tight neck tension and do take some playing around to get use to. I`ve neck sizers by Redding, Forster, and RCBS in addition to Lees collet dies (5 different cartridges for the Lee). All are excellent dies and work as promised but for ease and for quick use the Lee gets as much as much if not more then the others.

Here is a link to Lees` Q&A pages and their instructions on the collet die.

http://www.leeprecision.com/cgi/faq/index.cgi

 

[Rockstar]

Ol' Joe's technique of rotating the case and restriking is included in Lee's instructions. When I'm precision loading using Lee collet dies, I always rotate the case and restrike.

It is possible to not adjust the die so that SUFFICIENT pressure is put on the case neck by the collet, in which case, the neck won't be sized sufficiently. I'm always able to get about .002" neck tension, using Lee collet dies.

 

[Smokey Joe]

More puzzlement

First off thanx to all for their thoughts.

Ol' Joe--Back when Lee Collet Dies were brand new I bought a set for my .30-'06. I too found out the hard way that there is such a thing as too much pressure on a case in this type of die. Lee was nice and replaced the broken parts for me, and have since changed their instructions to say that with a press like a Rockchucker that toggles over center, you screw the die in so far that the press CAN'T toggle, thus preventing the disastrous overpressure. That was my first experience w/Lee's customer service--nothing they have done since has changed my high opinion.

I too like the accuracy the Collet Die engenders.

OJ and Rockstar--I have been rotating the cases and second-striking the cases since I started using the collet die. Did so with the cases here in question. (I said this originally.)

Variations in neck wall thickness?? With NORMA brass?? I'd expect this with maybe Winchester white-box ammo, or some no-name stuff from Wallmart. But Normas??? Well, I'll measure.

The brass is new--shot once fresh out of the box and this was their first resizing. So no question of over-worked brass. (I said as much originally.)

I will try polishing the mandrel and cleaning the insides of the case necks. Will report results.

(Sigh of frustration) :banghead:

 

[ocabj]

I'm not a fan of the collet die. I bought the Lee set for .308 and I didn't like how the amount of sizing is directly related to the amount of pressure exerted when running the case into the die.

I prefer just regular neck dies for basic neck sizing. For match ammo, I like Redding S-Type dies with the bushing (and the expander mandrel removed).

 

[Vern Humphrey]

There are four keys to the Lee Collet Die:

1. Set it up properly. To work, the collet itself must bottom out on the shell holder and be pushed up slightly into the die in order to be squeezed close.

2. Use clean brass -- especially inside the neck. Fouling buildup in the neck can work against you.

3. Apply pressure. It takes a bit of pressure beyond the point where the motion stops. Not too much, but a bit more than with other types of die.

4. If all else fails, check the diameter of the mandrel -- it should be about .001" smaller than the final internal neck diameter. If it is too large, chuck it in a drill press and polish it with abrasive cloth.

 

[Smokey Joe]

Thx for further input

Ocabj--does the redding S die work like a regular neck-sizing die or how, if it is not a collet? You get xlnt results w/yrs? I'm always interested in xlnt results!

Vern--Sounds like you got it in a nutshell. Will try that; will report back.

Again thanks to all for yr. thoughts!

 

[ocabj]

The focus behind using the Redding S-Type dies is that you neck size to have just enough tension to hold the bullet. You basically measure the diameter of the neck of one of the cases seated with the bullet you are using. Subtract .001"-.002" from this number and that should correspond to the bushing size that you will want to use.

I've been using the Redding S-Type die in .308 (and now the Hornady bushing neck die w/ shoulder bump) for a long time.

 

[Smokey Joe]

Redding-S

Ocabj--Fascinating! Thank you!

 

[Delmar]

Once you set the die up properly in your press-as mentioned, do not let the press snap over center, put your case in the shell holder and raise the ram.

You should feel the ram handle stop, and if you apply a bit more pressure, you should feel the collet squeeze the case neck around the mandrel.

 

[flashhole]

Screw it in an additional 1/4 turn....1/2 turn....3/4 turn until it forms the neck to the proper diameter. It's easy to put unequal pressure on the ram and end up with a mixed bag of results. Usually screwing the die in a little further solves the problem.