Resizing rifle brass, and the M-die...

[Charlie98]

For those of you who use an M-die (or equivalent) for brass prep, loading cast...

Do you size your brass leaving the standard expander ball in, or do you remove it and let the M-die (or equivalent) mandrel do the neck expansion work? ...or is it better to expand the neck with the standard ball, and then finish it with the M-die?

I'm thinking of my .348WCF brass... which is pretty heavy brass. I'm trying to not work the necks any more than I have to, but it would also be relevant for something like the .30-30, which has relatively thin necks.

 

[forrest r]

I leave the standard expander ball in the sizing die.

This causes the m-die to not have to expand the cases as much. Less spring back/less work hardening of the brass

 

[Bazoo]

I do both ways. I prefer to remove the expander ball and M die only. It is easier on the brass to M die only in my opinion.

The problem I've run into with M die only is trimming cases. You size first then trim, well, if you don't neck expand your pilot won't go in the necks. You can't M die expand before trimming because it flares the case. (I guess technically you could but I didn't think it would be satisfactory).

So what I did was buy an extra trimmer pilot, and turn it down slightly to fit my necks. If I recall correctly, I took the pilot from about .306 to about .295. I just spun it in my drill and used sandpaper on it since I don't have a lathe.

Removing the expander takes a lot of work out of resizing the case. I mean it makes it physically easier to work the press handle. I use both several bench mounted presses and a lee hand press.

It has to be easier on the brass because you're not forcing it as much, even though it is moving the brass the same amount.

I chased down an extra expander ball for my Lyman 30-30 set, in 270 size, so it wouldn't touch but still hold my decapping pin. I figured I'd keep the original expander in case I ever needed to repair a case mouth that was somewhat squashed but not crease.

 

[Charlie98]

The problem I've run into with M die only is trimming cases. You size first then trim, well, if you don't neck expand your pilot won't go in the necks.

I hadn't thought of that... and, yes, trimming is the next step. Crud.

 

[Charlie98]

I leave the standard expander ball in the sizing die.

This causes the m-die to not have to expand the cases as much. Less spring back/less work hardening of the brass

Maybe I'm missing something...

On a standard expander setup, does not the expander ball 'expand' the neck (likely only marginally...) going into the case, the neck is sized, and then the expander ball sizing the neck yet again on the way out? ...and then further working the neck with the M-die? I'm not arguing, I'm just trying to sort this all out.

 

[mdi]

The only M dies I use are for handgun cartridges and my handgun caliber sizing dies don't have expanders built into the sizing die...

 

[Charlie98]

The only M dies I use are for handgun cartridges and my handgun caliber sizing dies don't have expanders built into the sizing die...

I'm talking rifle cartridges, of course. I didn't even know they made M-dies for pistol brass! ...but I guess it makes sense.

 

[AJC1]

I size, use an noe expander then trim if I need to. I want the necks as round as possible during my trim,chamfer,debur process. What type of trimmer your using may effect your process. If your trimmer indexes off the shoulder, being in the same point in the process is all that matters.

 

[Charlie98]

I size, use an noe expander then trim if I need to. I want the necks as round as possible during my trim,chamfer,debur process. What type of trimmer your using may effect your process. If your trimmer indexes off the shoulder, being in the same point in the process is all that matters.

No, I have an old Hornady (Pacific) hand cranker that indexes off the base. I hate it, but it does a good job.

 

[AJC1]

No, I have an old Hornady (Pacific) hand cranker that indexes off the base. I hate it, but it does a good job.

I use a hand crank hornaday and it doesn't give me any issues.

 

[forrest r]

Maybe I'm missing something...

On a standard expander setup, does not the expander ball 'expand' the neck (likely only marginally...) going into the case, the neck is sized, and then the expander ball sizing the neck yet again on the way out? ...and then further working the neck with the M-die? I'm not arguing, I'm just trying to sort this all out.

Don't know if your missing something or not???

With my 30cal cast bullets for example:
I use the standard ball expander that comes with the sizing dies. I can load .308" jacketed bullets or my cast .310" bullets. I takes a lot of force to seat the .310" cast bullets. So I use a m-die on the cases I want to use cast bullets in. If I use a jacketed bullet on cases I expanded with the m-die they pretty much drop in and more often then not fall into the case when trying to seat them. Hopefully there's enough powder in the case to stop the bullets from going all the way into the case.

So

I can use a standard expander with jacketed or cast.
I can only use cast with the m-die

The m-die opens the case larger
When using the m-die only the case gets expanded more, hence more spring back
When the case gets expanded more and springs back more there's well more work hardening from the massive 1 step compared to 2 smaller steps.

 

[Charlie98]

When using the m-die only the case gets expanded more, hence more spring back
When the case gets expanded more and springs back more there's well more work hardening from the massive 1 step compared to 2 smaller steps.

No, that was my question.

No, I don't use the M-die to load standard jacketed bullets. I am fairly new to loading cast bullets in rifle, however. Loading jacketed, you want neck tension, loading cast, by and large, you don't want as much neck tension... I think that was part of the problem when I first started loading cast in the .348... the tight necks were swaging the cast bullet down.

 

[Bazoo]

Not all M dies are created equal. Lyman M dies are not really the correct size for many cast bullet applications. The 30 caliber die I have is not much larger than the expander ball except for the step. The step feature gives a shelf for the bullet to set on and clearance to keep it from shaving lead. However, because of the size it works great with jacketed bullets too. With cast that has a gas check, the gas check sizes the brass as it's seated. It makes loading flat base jacketed bullets much easier.

With a plain based lead bullet, the Lyman m die does not size large enough. That's where the NOE expander comes in.

RCBS uses M die expanders in their pistol sets, the new sets. They aren't suitable or much over the standard jacketed size bullets either.

I'd suggest .001-.002 below the bullet diameter. For soft lead, go .001. So if you're sizing .350 and you want .002 neck tension you need an NOE plug marked 348x352. The first number is the expander size, the second is the step size.

 

[AJC1]

Not all M dies are created equal. Lyman M dies are not really the correct size for many cast bullet applications. The 30 caliber die I have is not much larger than the expander ball except for the step. The step feature gives a shelf for the bullet to set on and clearance to keep it from shaving lead. However, because of the size it works great with jacketed bullets too. With cast that has a gas check, the gas check sizes the brass as it's seated. It makes loading flat base bullets much easier.

With a plain based bullet, the Lyman m die does not size large enough. That's where the NOE expander comes in.

RCBS uses M die expanders in their pistol sets, the new sets. They aren't suitable or much over the standard jacketed size bullets either.

I'd suggest .001-.002 below the bullet diameter. For soft lead, go .001. So if you're sizing .350 and you want .002 neck tension you need an NOE plug marked 348x352. The first number is the expander size, the second is the step size.

The thousands of 357 and 45acp bullets loaded with rcbs sets would tend to disagree. Your experience may be different but they work great for me. U had considered a cowboy set but why....

 

[Bazoo]

I have an older set of RCBS 357 and the expander plug is .356 and works fine with cast.

I have a newer set of 45 auto RCBS, that while the diameter is fine, the depth is not sufficient on the expander. I pulled a bullet and the lower half of the rear driving band had been swaged down. It was leading very very minor, but worked.

I have an 80s set of 44 mag that the expander is something like .4265. RCBS sent me the cowboy expander for 44 mag and it's at .428. You'll think that'd be okay for .430 bullets eh? Nope. It swaged them down. Why? Because 44 magnum brass is thick. Least my Hornady and starline is. Not to mention I want to load .431 bullets.

Remington brass is thinner and softer, and loads cast easier in my experience. But, you can't just use only remington brass if you're not rich.

 

[BWS]

There's right much more to this but,in some ways you need to work it out yourself. Cpl things I will share though,if you really are trying to wring out the accuracy of cast rifle loads,WRT M dies.....

You owe your self at least,two custom spuds,with three not being out of the question. Forget what Lyman "prescribes". Try around .0015, almost .003 and very occasionally what Lyman's "might" be which is around .004" interference.

You gotta get really serious here;

You need to mic the rifle's neck. Not a chamber cast,and not reamer spec. Use an adjustable small hole gage(they can be inserted into an aluminum arrow BTW,to facilitate if the barrel is still mounted). These gages come in two varieties, round and square bttm. The latter,if you only can have one. The other thing you're checking here is an out of round condition on the neck.

Still thinking M die;

Once you have the actual neck ID,now you get to play with loaded round OD..... insert "neck turning" here,but hold this thought.... You now can start recording how the interfere #'s effect accuracy when presented with a change in loaded round neck clearance. A change in neck clearance,"MAY"(don't mean "will") require a change in M spud size.

In jacketed bullets,your neck turning effects this. Cast however,we can change bullet diameter,ALONG with neck turning,giving near unlimited control over clearance. I know that was a lot of info,just think about it. Without undue cost,think $1000+..... you're gonna be stuck with a jacketed bullet's diameter. But cast? Shoot.... we have almost a .003" range to play with. This .003" can,and does have a direct bearing on the interference fit that's gonna test out the best on target.

The next thing in this area that separates cast from JB;

These same/above clearances dynamically change when running,typically.... reduced charges. It has to do with bullet release. "Most" JB accuracy loads are running on up in pressure.... not always,but generally yes. Cast however has more on the table,so the way the bullet gets it's start/release when you factor in all we have to work with,not available to JB's..... means....

You can't predict nearly as well with cast what tension to run. So,once you've decided on what range of speeds your cast is going,play with the diameter to close up the loaded neck clearance a little..... then use your jam and tension #'s to fine tune it.

Like I started with.... much more to it(bearing lengths,alloys,tapered ogives,twist rates,etc) but,those are some of the considerations with spud diameter. Keep notes and good luck with your project.

 

[243winxb]

Use a fl size standard die, with expander. Trim, chamfer and deburr. Open case mouth with Lyman "M" die. The step part should be about 1/8" below/in the case mouth.

The Over working brass part starts with the sandard fl die sizing the neck smaller then needed. This is before any expander gets near it.

Bushing dies give full control of how much the neck is sized.

 

[AJC1]

There's right much more to this but,in some ways you need to work it out yourself. Cpl things I will share though,if you really are trying to wring out the accuracy of cast rifle loads,WRT M dies.....

You owe your self at least,two custom spuds,with three not being out of the question. Forget what Lyman "prescribes". Try around .0015, almost .003 and very occasionally what Lyman's "might" be which is around .004" interference.

You gotta get really serious here;

You need to mic the rifle's neck. Not a chamber cast,and not reamer spec. Use an adjustable small hole gage(they can be inserted into an aluminum arrow BTW,to facilitate if the barrel is still mounted). These gages come in two varieties, round and square bttm. The latter,if you only can have one. The other thing you're checking here is an out of round condition on the neck.

Still thinking M die;

Once you have the actual neck ID,now you get to play with loaded round OD..... insert "neck turning" here,but hold this thought.... You now can start recording how the interfere #'s effect accuracy when presented with a change in loaded round neck clearance. A change in neck clearance,"MAY"(don't mean "will") require a change in M spud size.

In jacketed bullets,your neck turning effects this. Cast however,we can change bullet diameter,ALONG with neck turning,giving near unlimited control over clearance. I know that was a lot of info,just think about it. Without undue cost,think $1000+..... you're gonna be stuck with a jacketed bullet's diameter. But cast? Shoot.... we have almost a .003" range to play with. This .003" can,and does have a direct bearing on the interference fit that's gonna test out the best on target.

The next thing in this area that separates cast from JB;

These same/above clearances dynamically change when running,typically.... reduced charges. It has to do with bullet release. "Most" JB accuracy loads are running on up in pressure.... not always,but generally yes. Cast however has more on the table,so the way the bullet gets it's start/release when you factor in all we have to work with,not available to JB's..... means....

You can't predict nearly as well with cast what tension to run. So,once you've decided on what range of speeds your cast is going,play with the diameter to close up the loaded neck clearance a little..... then use your jam and tension #'s to fine tune it.

Like I started with.... much more to it(bearing lengths,alloys,tapered ogives,twist rates,etc) but,those are some of the considerations with spud diameter. Keep notes and good luck with your project.

You need a light in that rabbit hole... I appear to have lucked into a lot of success, but when I fail your on speed dial.

 

[AJC1]

Use a fl size standard die, with expander. Trim, chamfer and deburr. Open case mouth with Lyman "M" die. The step part should be about 1/8" below/in the case mouth.

The Over working brass part starts with the sandard fl die sizing the neck smaller then needed. This is before any expander gets near it.

Bushing dies give full control of how much the neck is sized.

I like the forester option

 

[Charlie98]

I have an older set of RCBS 357 and the expander plug is .356 and works fine with cast.

I wonder if some of you are confusing 'flare' with 'expand'? All of my pistol dies, all RCBS or Hornady, have a 'flare' die to open the case mouth for any type bullet. I've loaded cast (and jacketed) bullets in handgun cartridges for years without anything fancy. I do not have any handgun 'cowboy' dies, which may or may not include a expander die... I don't have any, so I don't know. I do have one set of RCBS Cowboy dies in .45-70... it has their version of the M-die, and works very well. It took me a while to understand the differences between standard and 'cowboy' dies.

Without undue cost,think $1000+.

Not happening. We are talking a Browning 71 lever-action in .348WCF... not a benchrest rifle. My intention is to not overwork my precious .348 brass. I have other cartridges I load cast for, but those are common cartridges and the brass is easily replaced.

In the end, both Forrest and Bazoo answered my questions. Bazoo in particular was right... I have to use the standard expander if I have to trim, as I verified last night.

I DO need to evaluate the diameter of the M-die I'm using, however, to see if I can make a change there that might be beneficial.

Thanks, gang!

 

[BWS]

Sorry to have wasted your time.

 

[Bazoo]

For 348, I'd be annealing often, to not lose any cases. I have 7-8 loads on a couple batches of 30-30 brass. No losses yet and I'm thinking of annealing next empty cycle.

I did a test on only one case, where I loaded it with my batches and shot it every time I shot my rifle. It lasted 20 loadings with no annealing. It might be of interest to you.

https://www.thehighroad.org/index.php?threads/30-30-case-life-test.896133/

 

[Walkalong]

Size with a bushing die, expand with a Century or Brownells expander.

Wilson now makes nice expanders as well

 

[Bazoo]

I didn't know brownells or Wilson made expanders. I've never heard of century. I'll have to do some research to catchup.

 

[Charlie98]

Sorry to have wasted your time.

Not at all... in fact, I learned quite a bit from your post, but in this instance it's not really applicable. I would say there is another member here that will probably soak up what you wrote like a blotter...