case neck expander die ?

[cjmac]

So i load a lot of flat base bullets. I was thinking a lyman case neck expander die would make life easier. Is this a good idea or a bad idea ? If it puts a flair on the case mouth how would it be straighten again ? Seems like it works the brass a lot

 

[Lapua40X]

How much the expander die works the brass is relative to how much the case is sized before it finds its way to the expander. I don't have any expander dies that flair the case neck. I just have to slow down and carefully align the rounded corners of the square base bullets in the neck before running then up to the seater stem. Your seater die should align the bullet with the case mouth as the bullet runs up into the die.

 

[jonbearman]

Use a VLD chamfering tool for easier seating of flat base bullets.

 

[BoydAllen]

What you have described is a Lyman M die. I have used one extensively for cast bullets. One thing about that I found on my particular expander was that the steel part that does the expanding, was attached to the aluminum piece that secures it in the die body slightly cocked. I found this with a V block and indicator. Fortunately the thread fit was loose enough so that I was able to touch up the face of the aluminum piece, so that the assembly was straight.

If you have a sizing die that is sizing cases so much that pull exerted when the expander ball passes through the neck causes the case to become crooked, you may see less runout by not using the ball, and using an expander die. The M die may be adjusted so that there is not enlargement of the case mouth beyond the expansion the rest of the neck, and for jacketed bullets, if the chamfer is adequate to trap the base of the bullet, that is all that is needed. Of course, the potential for loaded round straightness that a given sizing die gives is best preserved by a closely fitting seating die, especially when seating FB bullets. These days I just use the expander die and mandrel that came with with my neck turning outfit, when I run into one of these situations when loading for a field rifle with unturned case necks, and a one piece FL die.

 

[Juma]

Use M Die for loading Barnes projectiles .Brilliant tool as it stops the shaving of the long copper shank when you seat.For the heretics it also helps grouping because the release seems so much smoother at least in out T3's and X Bolt.

 

[BoydAllen]

One reason that you were getting that shaving is that it is pretty common to get a burr at the bottom of your chamfer. I cut them out, with the very tip of a knife blade. The part of the blade that does the scraping sticks out from my grip on the blade (Wrap the blade if it is very sharp.) about a half inch or less, and the edge is almost parallel with the ID of the neck. You can feel the burr as you turn the case, and feel when you have eliminated it. This goes back to the days when I was using crimped primer pocket military brass to load with a Lee Loader, for my .308. I learned to scrape the crimp out by hand, because I did not have anything else. By turning the case, and going slow, it worked fine. The brass was from loaded ammo that I had fired in my rifle. The reason that I was using it was that it was the cheapest, and at that time, buying brass, was not even on my radar. That was over 30 years ago.

 

[Tzed250]

I use the Lyman M die when loading .30 Carbine. Works wonderfully. You can tweak it to get exactly what you need.

 

[DHD]

So i load a lot of flat base bullets. I was thinking a lyman case neck expander die would make life easier. Is this a good idea or a bad idea ? If it puts a flair on the case mouth how would it be straighten again ? Seems like it works the brass a lot

Just a suggestion. Try Buffalo Arms. They make an expander does what you are describing. I don't know if they make the size you are looking for, but I think they will make a custom size. The expander does not "bell", there are 2 different diameters on the shaft.

I use a few of them for my BPCR's and they work as advertised. These rifles use only lead bullets and those bullets are lovingly made one at a time and are soft. If the expanders did not work well, I would not use them.

 

[nicholst55]

CH-4D at least used to offer custom diameter 'M' die expander plugs for a nominal fee. There is at least one member of the Cast Boolits forum who offers a similar service.

http://castboolits.gunloads.com/index.php

 

[bigedp51]

The Lyman type M die is associated with softer cast rifle and pistol bullets and creating a step inside the case for the bullet to rest on before seating. And as stated above it can shorten case life by causing the case mouth to split.

If you use a M type die then you will need to crimp the case mouth to some degree to get rid of the flare. And flaring and crimping is just adding two more things to the reloading equation that can go wrong and effect accuracy.

Using the VLD chamfering tool and a inline seater like the Forster should solve your problem, you could also spin the case and hit the case mouth with some steel wool to remove any remaining burs.

 

[cjmac]

Sounds like i need a Wilson seating die . Been wanting one with a arbor press to take to the range.take my primed brass, press and die , powder measure .and have at it.. cant forget bullets. Haha

 

[rox]

So i load a lot of flat base bullets. I was thinking a lyman case neck expander die would make life easier. Is this a good idea or a bad idea ? If it puts a flair on the case mouth how would it be straighten again ? Seems like it works the brass a lot

The Lyman M die's stepped mandrel is designed to expand the neck and create a slight flare to aid seating. If you're worried about working the brass you can order mandrels for the M die in a wide range of dimensions from Buffalo Arms or get a custom one made. For example, I sometimes use a 0.304/0.312 mandrel to put a tiny flare on 0.308 brass without touching the rest of the neck.

I've heard of people who use a taper crimp to close the flare after bullet seating, but I've never tried this.

 

[Juma]

I dont agree with the notion that the M Die may shorten case life.If you anneal you overcome or reduce case hardening. Annealing avoids those stretching issues of the case mouth. The related issue is not to use full power loads.Lyman makes a quality product in this die. Bought all of them for the calibre's we load. Great service from Lyman to New Zealand. 8)

 

[BoydAllen]

Back in the day, when I was casting my own bullets that were shot in a bolt action 30-06, I used a M die for all of my loads. My cases had a generous chamfer, and I would set the die so that while there was a parallel sided enlargement at the case mouth, there was no flare. I seated lots of gas check problems this way, and used the same set of cases over and over, without the slightest hint of a work hardening problem, or any case failures. The back of the bullet fit in the segment that was opened up slightly, perfectly, and bullet heels rested on the small step that the expander created in the end of the case necks. I always have thought that this was a distinct advantage over other designs, because the bullets were centered and coaxial with the case as they rose into the seater. I did not crimp any of my loads, and felt that the slight enlargement at the end of the necks contributed to improved centering.

 

[Brians356]

Re: case neck expander die ? (Lyman "M" die)

Back in the day, when I was casting my own bullets that were shot in a bolt action 30-06, I used a M die for all of my loads. My cases had a generous chamfer, and I would set the die so that while there was a parallel sided enlargement at the case mouth, there was no flare. I seated lots of gas check problems this way, and used the same set of cases over and over, without the slightest hint of a work hardening problem, or any case failures. The back of the bullet fit in the segment that was opened up slightly, perfectly, and bullet heels rested on the small step that the expander created in the end of the case necks. I always have thought that this was a distinct advantage over other designs, because the bullets were centered and coaxial with the case as they rose into the seater. I did not crimp any of my loads, and felt that the slight enlargement at the end of the necks contributed to improved centering.

Boyd et al,

[Sorry for bumping this old thread, but I couldn't find a more recent thread where I thought I had engaged in discussing this Lyman Expander M Die. Anyone recall that thread?]

I obtained a Lyman Nexk-Expanding "M" Die (Short) in 25 caliber. In measuring the button, I found these diameters:

Step 1: 0.2547"
Step 2: 0.2593"

I was interested in using it for easing the neck entry of flat-based bullets. The moly-coated TNTs I load are 0.2574" in diameter. I was a bit surprised to find that Step 2 was nearly a full 0.002" larger than a 25-cal bullet - more than just "slightly larger" as Lyman describes it. (Perhaps cast lead bullets tend to be larger in places than nominal?)

So I suppose I need to adjust it to barely flare the mouth to just shy of bullet diameter, sort of a "super chamfer" as it were. The mouth would ride about 1/2 way up the slope between Step 1 and Step 2.

Comments?

 

[CatShooter]

Re: case neck expander die ? (Lyman "M" die)

Back in the day, when I was casting my own bullets that were shot in a bolt action 30-06, I used a M die for all of my loads. My cases had a generous chamfer, and I would set the die so that while there was a parallel sided enlargement at the case mouth, there was no flare. I seated lots of gas check problems this way, and used the same set of cases over and over, without the slightest hint of a work hardening problem, or any case failures. The back of the bullet fit in the segment that was opened up slightly, perfectly, and bullet heels rested on the small step that the expander created in the end of the case necks. I always have thought that this was a distinct advantage over other designs, because the bullets were centered and coaxial with the case as they rose into the seater. I did not crimp any of my loads, and felt that the slight enlargement at the end of the necks contributed to improved centering.

Boyd et al,

[Sorry for bumping this old thread, but I couldn't find a more recent thread where I thought I had engaged in discussing this Lyman Expander M Die. Anyone recall that thread?]

I obtained a Lyman Nexk-Expanding "M" Die (Short) in 25 caliber. In measuring the button, I found these diameters:

Step 1: 0.2547"
Step 2: 0.2593"

I was interested in using it for easing the neck entry of flat-based bullets. The moly-coated TNTs I load are 0.2574" in diameter. I was a bit surprised to find that Step 2 was nearly a full 0.002" larger than a 25-cal bullet - more than just "slightly larger" as Lyman describes it. (Perhaps cast lead bullets tend to be larger in places than nominal?)

So I suppose I need to adjust it to barely flare the mouth to just shy of bullet diameter, sort of a "super chamfer" as it were. The mouth would ride about 1/2 way up the slope between Step 1 and Step 2.

Comments?

I use "M" dies on many of my calibres - It takes some delicate adjusting, but I slowly adjust the expander so it just kisses the mouth of the case enough so the flat based bullet will sit on top, maybe 2 or 3 thou into the mouth.

When seated, there is no scoring of the jacket from chamfer tool chatter marks, and the tiny bit of flair does not interfere in any way.

 

[Brians356]

Re: case neck expander die ? (Lyman "M" die)

I use "M" dies on many of my calibres

CatShooter (or anyone):

Could you possibly do me a small favor? I'd like to know the diameter of the Lyman 'M' Expander Die mandrel for any 6mm cartridge (the small portion, not the "bell" portion.) If you have a micrometer, to the nearest .0001".

I would greatly appreciated this!

 

[BoydAllen]

Heck...just chuck that thing up by its nose in a drill motor, spin it up and fine stone a teensy bit off of the step diameter by hand. The detail that I may not have told you about my M die is that when I laid the threaded stem in a V block, and put the indicator tip on the end of the steel expander mandrel, there was quite a bit of runout. It was not parallel, but rather angular, so I figured it out, stoned (actually a flat diamond lap) the face where the shoulder of the mandrel contacted the aluminum stem. Problem solved. Your are probably right about the part being designed for cast bullets. I used to size mine .309.

 

[dedogs]

One thing that was never mentioned in any of these answers is that all the brass must be exactly the same length or you get different results. I use the Lee universal expanding die. It has a plug that is tapered to a cone on both ends which is flipped around 180* depending on the size of the case you want to flare. I love it. Use it on my .30 BR brass and no more shaved bullets. Learned this trick from CatShooter who is a pretty smart guy even if he is a bit testy at times. dedogs

 

[Brians356]

Re: case neck expander die ? (Lyman "M" die)

I use "M" dies on many of my calibres ...

FYI and FWIW one can order additional expander "plugs" (mandrels) for Expander M Dies direct from Lyman for $6.99 each. Avoids buying a whole die for each diameter, if you don't mind readjusting the die when switching catridges.