Neck Expander vs M Die

[straightshooter1]

Used to post on the old Shooters site, knew you guys must have gone somewhere when it shut down, found this a while ago. Always valued Buckshot, Jumptrap and so many others for their great advice on making these things shoot.

I use M dies. They are "OK" but I have heard that the RCBS neck expanders are better. At $18 plus each I wanted to make sure I was doing the right thing. I was planning to buy for 308 and 30'06 to start.

Will the same one work for both? Also, my boolits are .310, thus I would buy the .310 die, right? Or the .311? Or the ...?

Appreciate any advice you can give and if I should just stick with the M dies, that's fine, too. Just looking, as always, for a better round, better group, etc.

[fourarmed]

Just to complicate things, there is also the Lee collet necksizer. Within reason, you can adjust how much the neck is sized - from none to normal. You can adjust it up to the recommended maximum, then you can get a little more (I heard it here!) by sizing, rotating the case a little, and sizing again, and maybe again.

[David R]

If the boolit has a gas check, I just chamfer the heck out of the inside of the neck when I trim the brass. I use no M die, expander, flaring tool or anything else. The gas check expands the neck enough for the rest of the boolit to enter the case with out shaving any lead.

I trim the brass, just touch the outside of the case with an RCBS chamfer or deburr tool, then trim the inside of the case till it almost kicks up a burr on the outside. Trim off that little part if you get it and away you go. After a few cases you can see how wide the inside chamfer is and its easy. The case neck ends up almost sharpened.

I bought a LEE universal expander die, but have never used it.

David

[StarMetal]

Davidr,

A gascheck, especially an un-annealed one, springs back more then the alloy portion of the bullet during sizing. Measue it some time and see if the gascheck is larger diameter then the driving bands on the bullet. What this does then is when you're seating your bullet, the gascheck being larger spreads the case neck out farther then what the driving bands are and even though you think you have a good tight seated bullet in reality you don't. This is one reason why when you seat an un-annealed gas check bullet it seats easily after the gascheck has started into the case neck. I anneal mine. If you are a stickler about proper and consistant neck tension, then make sure your gascheck is staying sized the same as the rest of the bullet.

Joe

[StarMetal]

On those Lee collet neck sizer dies, you can also polish the diameter of the rod down some, but not alot, because alot won't get you anymore, say a .001 or so.

There is also a way to modify the Lee collet die so it doesn't size the very end of the mouth of the case and you end up with a sized case that looks like you used a Lyman M type die on it, but not as drastic. I haven't done that to mine. There is a fellow here that explained....please chime in sir.

Joe

[BCB]

Straightshooter1,

I assume you are talking about the RCBS Neck Expander Die set. It comes with 1 expander plug (whatever diameter you request) and the neck expander plug rod. The expander plug screws onto the rod and this screws into the die. You purchase the size plug you want. The die basically just holds the rod and plug in place and to the correct depth you set. I purchased the different sizes of expander plugs that I need and I also purchased extra rods. I then have one plug on each rod. I use the same die, but just screw the correct rod/plug into it for whatever application is need. You don’t need to purchase a new die for every size plug you wish to purchase. Hope this helps…BCB

[straightshooter1]

BCB
Yes that is what I am considering. I guess I must be one of the few that uses an M die to expand the case mouth. Has worked OK, but, someone said I'd do better (better groups?) with the RCBS Expander.

I guess I am a bit behind the curve here.


Thanks,
Bob

[Maven]

Bob, For what it's worth, I use the same .30cal. M-die to expand the necks of .30-06, 7.5 x 55mm and 7.62 x 53R (These take CB's @ .311" & .312") and haven't had a grouping problem at all. Also, with the .30-06 Lee Collet Die, I can skip the M-die entirely.

[felix]

The very best way is to use a straight line seater die that fits just right for the diameter of the boolit, after using a die that just closes the neck just tight enough. I have dies that do this only for my "accurate" rifles because of the expense of having them made for that "perfect" fit. ... felix

[sundog]

Joe, about the neck being expanded too much. EXACTLY what I've been pondering alot lately.... Here's the deal. 30-180-SP is a .310 boolit. No reason to put it thru a .311 die to check & lube because the GC is not getting squeezed enough, thus expanding the neck on seating and reducing tension (and increasing runout!). BUT, if you 'beagle' the boolit to .311 then no problemo, if that's what you need to fill the throat -- otherwise, find another fatter boolit. Sometimes, I think to much... sundog

btw, that 30-180-SP works real good in a 12 twist .308W with 21.0/IMR4227.

[sundog]

Joe, about the neck being expanded too much. EXACTLY what I've been pondering alot lately.... Here's the deal. 30-180-SP is a .310 boolit. No reason to put it thru a .311 die to check & lube because the GC is not getting squeezed enough, thus expanding the neck on seating and reducing tension (and increasing runout!). BUT, if you 'beagle' the boolit to .311 then no problemo, if that's what you need to fill the throat -- otherwise, find another fatter boolit. Sometimes, I think to much... sundog

[JSH]

A bunch of good info on this subject in this thread already.
My for instance pertains to a 30-30 barrel for the most part, but other 30's now also. I was just slightly belling the mouth of ALL the cases with a polished center punch. Well after developing a wrist the size of popeyes, I had to try a 3M die. Long story short, my groups shrank a bunch. So now I am wondering if that may pertain to Joe's thoughts on the GC springing back.
But to those of you using the collet die, are you still belling with somthing else? The dies I had used in the past had caused me to shave a lot, or I should say the biggest part of the bullets, not a good thing.
I am curious as to what the RCBS die looks like, any one have a link to a good view of this?
If Lyman would offer just the sizer slug for theirs I wouldn't even consider the RCBS.
I am just trying to get as much knowledge as I can on this subject. I am going to build a BR gun to shoot CB's only. I have ran across several non believers and just feel the need to prove the point. The success I have had using plain old WW sweetend with a bit of lino has turned me way around. With bulk bullet alloy I have no doubts what so ever that I will be able to hold my own and best most of them. Oh, BTW have already picked the caliber, it will be a 30BR. Specs are still up in the air, this will be a some what long term project, have the action but am still up in the air as to what barrel mfg, leade angle, throat length, etc...........
Jeff
Jeff

[StarMetal]

sundog,

You annealing your gaschecks? If not try doing it. They don't have as much springback.

Joe

[Slowpoke]

If Lyman would offer just the sizer slug for theirs I wouldn't even consider the RCBS.
Jeff

They do or did, I have bought just the plugs in the past.

Another better option IMO is hire Buckshot to make the plugs for you.

Good luck

[straightshooter1]

I am afraid you fellows are way beyond me on this subject. I think I will, however, buy one of the Lee Colletts and give it a try. I didn't mean to suggest the groups I get using the M dies are bad, only that this fellow who is apparently very well versed in CB shooting, says I will get better groups with the RCBS method.

BTW, I am really glad I found this site. I got so much out of the old Shooters and have been just stumbling along since it went away.

Thanks,
Bob

[9.3X62AL]

Good to see ya back in the fold, SS.

I have both and use both the RCBS and the Lyman M-die. I usually set a small flare at the case mouth with both tools to ease seating hangups. I like the short expanded portion of the case neck provided by the M-die, although I really can't see a difference in accuracy between the two systems. I think the RCBS gives a longer range of depth than does the Lyman system--I use the RCBS for the 25-20 and 250 Savage, while the Lyman M-die works on the 25-35. The "rods for each spud/plug" is a fine idea--they back out with use from their settings on the threaded rod, and the flares get pretty big when that occurs.

A toss-up, in my view.

[Shepherd2]

I think they are a toss up too. I started out with a .30 cal RCBS die and at some point bought a .35 cal plug for it. Some where along the line I started buying Lyman M dies and like them a bit better than the RCBS. I use both and can't say that I can see any difference in accuracy between the 2. You could try both and sell the one you don't like here on this board or eBay.

[BCB]

straightshooter1,

I just thought of another tool to just flare the case mouth and not expand the neck. It is a Lee Universal Case Expanding Die. The name is a bit misleading, in that, it only flares the case mouth. It is actually a neat little item. It can be set to flare the case mouths of anything up to 45 caliber, and cases up to 3 inches in length. I use mine occasionally if I don't want to redo and adjust my RCBS expanding die. Just a thought...BCB

[Junior1942]

My M dies are gathering dust since I bought a Lee Universal Case Expanding Die.

By the way guys, the Lee Collet Die set comes with a free Dead Length Bullet Seater Die which is more useful than the collet die. You can make a micrometer seater out of the Dead Length Die simply by putting a mark on the seater screw and regular-interval marks around the top of the seater die. The seater screw is threaded 5/8 x 18 so 1 turn = .056", 1/2 turn = .;028", etc.

Mine, in 30-30, is marked for 1/8 turns, .007", around the top of the die. I picked the "0" setting as the seating depth of a 311041 bullet. Then, I noted the depth setting for other bullets and keep that data in the die box. IOW, the setting note for the Lee 113F soupcan bullet might read, "113 soup can = -1 1/4 turns."

To adjust for a different bullet, soup can, for example, I'd screw the seater screw in or out to zero. Then I'd screw it in, minus, 1 1/4 turns, and it'd be adjusted to seat the 113F. And the sucker was free!

[straightshooter1]

Thanks to all for the info/advice. I think I'll start w/the Lee collet and then progress to the others. Always looking for perfection and continually trying to convince my wife how much $ I am saving over the cost of those silly metal wrapped bullets.
Thanks again,
Bob

[Char-Gar]

I have an expander plug for an M die made by a friend with a lathe. This plug as steps from .307 to .316, in .001 steps. You really can't see these steps, but they are there and a micrometer will verify their presence.

In use, I run the case up in the plug until the gas check will just fit inside the case mouth. At that point, the inside of the case neck is sort of a funnel with the mouth of said funnel the same size as the sized bullet with gas check. The bullets seat with very little work and no problems.

Yes, I anneal all of my gas checks.

[Bass Ackward]

Good thread.

I have this cheap concept that is measured in thousanths too. It's called a bullet.

[castalott]

If you get desperate...or maybe not ..

a round of 8mm ball will flare a 30 cal neck just fine....push the pointy end of the 8mm round in the 30 cal neck and 'waller' them around together ( hold one in the left hand...and one in the right hand)....you will be amazed what you can do with this simple setup....

Oh...if you can find or make a dummy round without primer or powder...it would be a lot safer....

Dale

[scrapcan]

Just purchased some different caliber plugs.

as of 11/22/05 the plugs are $3.00 each
extra stems are $2.00 each, two sizes short cases and long cases

plus shipping and handling of course.

by the way can you tell watch pitch and diameter the plugs are where they tread into the stem? and the Stem thread and pitch?

not close to the m-die or any dies at the moment. But a lathe may be closer at hand.

thanks

[Frank46]

Straightshooter1, I found myself in the same delima as you. Neck size brass then expand with the M-die. At the time I was using hansen brass for my model 27 finnish moisin nagant in 7.62x54R. I found a place that sold 7/8x14 screw stock and bought three 3 foot long pieces. I measured the loaded neck size and fired neck size. I made up a shorty neck die that ellimenates the M-die altogether. Just run through the shorty die and seat the bullet. The shorty neck die is only about 1 1/4" long. Never hardened it and ten years later still works like a charm. I take no credit for this idea as it was published in a gun magazine some years back. The bullets seat easily and do not come out when pulled. Frank

[Ramsmacker]

SS, I don't know if this will work for you but I don't neck expand at all. Shooting a 38-55 and 32-20 using RCBS cowboy dies. I neck size just to the depth of the seated bullet then use a lee universal case expander to flair the mouth just enough to not shave lead,after seating bullet I crimp with a Lee factory crimp die just enought to take out the flair out. Don't know if this will work for higher velocity gas check loads. For 1,400fps plain base it works great.
Mick

[7br]

Does anyone know where I can get a .22cal expander for my Lyman M-Die? I called MidSouth,Midway, and Graf's and no one had one. Couldn't get through to Lyman.