Making 30 XCB cases: a quick tutorial

[Bjornb]

There has been enough interest around the Goodsteel-made 30 XCB rifles that I won't be surprised if more CB members decide to have rifles built by Tim.
There has also been quite a bit of discussion on making the brass for these rifles. The cheapest alternative is to make the cases from 30-06 brass. An easier approach is to make brass from 7x57 or 8x57 Mauser cases (the XCB cartridge is also called the 30x57), but these are not nearly as universally available and therefore they cost more.
Here I'll attempt to give a quick introduction to how I make the cases from common 30-06 brass.

I start with a W-W 30-06 case (purchased from member Monmouth, good guy)
119086
Then lube it with a little case lube, and run it through the FL custom XCB die (supplied by Goodsteel, made from an RCBS 30-06 FL sizing die). I do this initial forming without the decapping and sizing assembly:
119088119089119090
Then I do rough trim on my chop saw, using a jig that I made for expediency. I trim to 2.29 inches.
119091
Next step is another run through the FL die, now with the decapper/expander installed.
Then I expand all the necks with this K&M expander. The reason I do both these expander operations is that the FL die's expander ball goes below the shoulder and therefore opens up the entire case neck, while the K&M expander is designed so it WON'T expand the donut, leaving it on the inside of the neck so the neck cutting tool will take it out with its carbide cutting mandrel.
119092
Now I trim to length, chamfer and deburr the case mouths:
119093119094119095
Turn the necks:
119096
Continued in part 2

[geargnasher]

Thank you, Bjorn, once again a picture is worth a thousand words. BTW, your pics in the second post aren't coming up for me for some reason.

You'll be happy (maybe) to know that I spent the entire evening shopping and buying more tooling.

When I first got my barreled action back from Tim, I modified an RCBS FL die (shortened by exactly .254" by me and the neck honed out to .335" x .333"), but I still found it necessary to FL size range-pickup/fired '06 brass in a standard RCBS FL die (no decapper) to knock the bulge out of the base (any FL die will do provided the neck isn't too small). If I didn't do this, there tended to be a bulge or shaving of brass at the base, since the XCB squazzes the head a bit past '06 specs. This is actually a planned advantage of the wildcat and aids in re-centering the rim with the body of previously fired '06 brass. Once lubed and sized in both while being very careful not to get too much lube on the shoulder (dents/creases), I go cut them off in a chopsaw as well and inside VLD deburr to knock off the rough stuff. Then on to expanding, reaming, sizing again, expanding to fit the Forster turning mandrel, and a simultaneous outside turn/length trim. These last steps have proven unsatisfactory per my posts on the other thread, but we're getting to that...

Tonight's purchases included a Redding form/trim die that presumably will have to be shortened, but is larger than other brands and is designed to work with fired neck diameters, so should be perfect for rough trimming the brass. Also I bought an RCBS GM Match bushing/fl sizer die and a selection of steel bushings which I can hone to a taper if necessary for initial forming. Also, I intend to knock the shoulder back with the bushings out of the die per Btroj's method on the other thread, then squeeze the neck to just below turning mandrel size, re-expand with an RCBS cast bullet expander (I have a selection of sizes already) and outside turn.

If I still have trouble with excess taper or donuts, I'll investigate the K&M neck turning tool with the carbide donut reamer and matching expanding tool.

As an aside, after using half a dozen '06 headstamps among scads of other calibers, the best '06 cases to use have turned out to be (running for cover.........)........FEDERAL. I know, I know. But the stuff forms like a champ and doesn't leave as much of a ring near the mouth as other brands do, annealed or not. It's a little thicker there and turns to .0135" with a perfect cleanup. I have 20 of these made up and they have about eight firings on them so far, seven of them full-power, with nary a trim or anneal.

Gear

[Bjornb]

I re-did the pictures in the second half of the post:

A little 0000 steel wool, inside flashhole deburring, and primer pocket cleaning, and voila!
119126119127119128119129
Case necks mike .0125 after turning:

119130
This is the way I do it. There is nothing wrong with the ways others choose to make their cases for this cartridge, but this is what I found to be the simplest way. YMMV.

[Bjornb]

I've never had problems with Federal brass, so you won't have to run from me. I initially chose W-W brass because that's what I had in some quantity. I never experimented. I know Tim uses HXP because that's what was available to him. Run was talking about converting 8mm Mauser brass; that's an option I haven't tried yet but one that definitely SHOULD be tried.

The ONLY step in your forming process that I'm leery about is the inside neck reaming, if that's indeed what you are doing. When reaming necks on the inside you have no countering support on the OUTSIDE (like a mandrel when outside neck turning) of the neck and thus no guarantee that you are thinning the brass evenly. I've always got it beaten into me that outside turning is good, inside reaming needs to be monitored very closely.

[geargnasher]

That's the idea, use whatever brass you have readily/cheaply available.

On the reaming, you may be thinking of the method where the case is run up tightly inside a fully-supporting reaming die that's mounted in a reloading press, then the reamer run down through the top. That method is very useful for some things, but you are correct that it doesn't encourage even thickness all the way around the neck. What I'm doing is "free reaming" using a Forster inside reaming attachment that looks just like a turning mandrel but has cutting flutes the full length and a chamfer on the business end. After expanding the necks on a .312" mandrel, they spring back .310" x .312" or so and I run the .311" reamer through them. It cuts out the excess from about the bottom 2/3 of the neck. After that, I can resize the necks in the tapered forming die and they're mostly straight on the inside and ready for outside turning. Not perfect, but decent. It's time consuming and more inconsistent than I like, and after fireforming and resizing there's still a little washboarding inside that can be felt when seating a bullet. To get better results than I've been having at really top-end pressure for the 180-190 grain bullets I'm going to have to fix these fine detail issues with the necks.

Gear

[Jr.]

Awesome write up I appreciate the explanation. I was having a hard time visualizing what exactly it was you were using in the rifles. This made things a lot more clear. I am excited to see the progress in the future.

Thanks

Aaron

[kbstenberg]

Gear could you add pic. of your inside neck reaming? PLEASE!

[Bjornb]

I believe this is the reamer Gear speaks about:
119146
A regular Forster mandrel on the right. The reamer works well; my only reservation was only that it does indeed "free ream", with no real control as to the even thickness around the neck.

[geargnasher]

Also, that's a Forster case length trimming pilot on the right, not to be confused the the outside neck turning mandrel which is even longer than the reamer Bjorn pictured. It would be futile to attempt an outside turn while using the short, undersized trimmer pilots.

I'll see about some pictures at some point.

Gear

[tomme boy]

That is exactly how I formed 8x57 brass for my target rifle when I had it. I wanted the 3006 brass as I wanted thick brass to fill the neck. I always turned the outside as well as I did not want to deal with the donut that forms from reaming the inside. The Throat was very short on the barrel so the bull was deep seated and would have run into the donut. I had to just do a light cleaning up with the outside of the necks.

The factory 8x57 brass was all over the place as far as the neck thickness. When I first built this rifle, I made my own brass. As I had it, I was able to get actual brass for it. Then all of a sudden, the groups went to heck. Went back to the converted brass and it came back again. Remington brass was absolutely useless. The bullets would just fall into the cases after sizing the necks. The best 8mm brass I found was Mitchell. I do not know who made it, but it was nice and thick in the necks.

[geargnasher]

Bjorn, what's the diameter of the outside of the neck, about 1/8" to 1/4" up from the shoulder, right after forming in the RCBS die (fourth pic)?

Gear

[Eutectic]

Interesting testing you have going on with your cast boolit bench guns!

I'm just an ol' guy that has formed thousands of cases in probably 30 or 40 different configurations over the years...

So I offer some friendly advice from that experience on forming your cases. I think.... no I know, that forming your cases in one step as you are doing will not give you a quality case much less a benchrest quality case.

When you push a shoulder back and size a new neck portion on your.30 XCB there are two major forces at work. One is the circumferential radial force to reduce neck diameter. You want this. The other is a longitudinal compressive force as you push the shoulder back to its new position. You don't want anymore of this force than is absolutely necessary!
Your 'donut' rings and other neck reaming/turning comments tell me you are doing too much in one step with your shortened .30-06 die. The new shoulder needs to be formed in steps.... at least two steps. The simplest for the .30XCB case from .30-06 would be a .35 Whelen full length die shortened as your .30-06 die is. Size your cases here first leaving the shoulder about .005" longer than final location. I would go .40 cal to .35 cal. to 33 cal then the '06 die because I have the capability and would want benchrest brass.

WHY?? Because too much longitudinal force can be a compressive force on your brass pushing it down as well as reducing diameter.

Too much pain? I used to think so.... Then I compared some pre-weighed cases that were sized in two steps and finished completely to those of the same exact weigh that were sized in four steps... (A little more radical reform than .30XCB) All cases were identical externally and entire neck length reamed/turned the same.. The two step sizing brass weighed 1 1/2 to 2 grains more! That extra weight went somewhere... and you can bet it wasn't applied evenly!

Eutectic

[tomme boy]

The donuts usually show up after a couple of sizings. And then you have to ream them out. Thats what I always under stood. The brass is not tapered when it is reformed. Thats why it is happening. When the original brass is drawn, it is tapered towards the top. That is why it does not form with original brass.

Am I right on this?

[MBTcustom]

What I have seen matches Eutectics post right off the bat, but even if done right, the donut flows forward like Tommyboy describes.
Of course that is a diagnosis based on observations I have made, so I might be hammering nails into trees.
I know how aggressively you form your brass can definitely have an effect on the size of the donut, but I've also seen it get worse as the brass is fired.
Honestly, I just didn't worry about it too much though. What accuracy I was experiencing did not degrade with the presence of the donut. What I did observe was that the size of the donuts had a measurable effect, but I segregated my cases based on the size of what pin gauge would slip easily through the case necks (and the donut) and the matched cases shot consistently to their brothers. Mix them up and things went weird (obviously).
I think it's just barely possible this is being over thought just a little bit here, but what do I know?
Seems to me that the point of reaming is more a matter of making all the cases consistent, rather than getting rid of the evil donut. Just a thought.

[geargnasher]

Eutectic, no replacement for experience, is there? Thanks for weighing in.

When making 6.5x55 Swedish Mauser brass I used several steps like you say, pushing a shallow shoulder back with an 8mm Mauser die, then reducing neck diameter with a 7mm-08 die, then final sizing the neck and pushing the shoulder to the correct angle. Sounds like the same sort of thing may be needed with the XCB help some of the problems I'm having. Brad was having pretty good luck knocking the shoulder back on the XCB with no bushing in his body die, then sizing down the neck in a second step, but I'm not sure how big the hole is without the bushing installed, probably smaller than ideal, but it is working for him. The 8mm Mauser die has a sharp shoulder that was fine for the Swede, but not so much for this one, so a shortened .35 Whelen makes more sense like you say.

Gear

[Bjornb]

Interesting testing you have going on with your cast boolit bench guns!

I'm just an ol' guy that has formed thousands of cases in probably 30 or 40 different configurations over the years...

So I offer some friendly advice from that experience on forming your cases. I think.... no I know, that forming your cases in one step as you are doing will not give you a quality case much less a benchrest quality case.

When you push a shoulder back and size a new neck portion on your.30 XCB there are two major forces at work. One is the circumferential radial force to reduce neck diameter. You want this. The other is a longitudinal compressive force as you push the shoulder back to its new position. You don't want anymore of this force than is absolutely necessary!
Your 'donut' rings and other neck reaming/turning comments tell me you are doing too much in one step with your shortened .30-06 die. The new shoulder needs to be formed in steps.... at least two steps. The simplest for the .30XCB case from .30-06 would be a .35 Whelen full length die shortened as your .30-06 die is. Size your cases here first leaving the shoulder about .005" longer than final location. I would go .40 cal to .35 cal. to 33 cal then the '06 die because I have the capability and would want benchrest brass.

WHY?? Because too much longitudinal force can be a compressive force on your brass pushing it down as well as reducing diameter.

Too much pain? I used to think so.... Then I compared some pre-weighed cases that were sized in two steps and finished completely to those of the same exact weigh that were sized in four steps... (A little more radical reform than .30XCB) All cases were identical externally and entire neck length reamed/turned the same.. The two step sizing brass weighed 1 1/2 to 2 grains more! That extra weight went somewhere... and you can bet it wasn't applied evenly!

Eutectic

Eutectic, I cannot find a single item to put my finger on in your post. Being an old guy myself, I'm a brand new bench gun owner, mostly having shot WW1-era milsurps since the 1960s without paying much attention to fine detail. When I acquired Bertha (who is roughly as old as I am, close to 60), I was given a rude awakening when it came to the loading procedures necessary for precision shooting.

The tutorial I posted above was pretty much the way I figured out on my own with a little help from Tim how to make the cases. I definitely see what you are trying to say about compressing the brass and ending up with uneven case weights.
This may also be why my cases formed from 7x57 brass (a very minimal conversion) seemed to shoot better right off the bat.

This is why I like this forum; there's ALWAYS someone who knows how the better mousetrap is built.

So I encourage anyone who will be attempting to make these cases that you incorporate the extra steps explained by Eutectic for better end result.

There's another angle here: How far do you go into TRUE bench rest loading techniques before you say to yourself: Have I gone TOO far? There's case weighing and sorting, the physical primer pocket and flash hole improvements, bullet sorting and segregating, then checking of runout and neck tension. The list goes on.
My own thoughts? You can NEVER go to far with the small details if maximum accuracy is your true goal. Love Life sent me a list of things to check regarding my ammo, and I'm already starting to incorporate these. Seating depth can play a vital role and must be tested. Etc. etc.

Thanks to all of you who take the time to post on these threads.
Bjorn

[Bjornb]

Bjorn, what's the diameter of the outside of the neck, about 1/8" to 1/4" up from the shoulder, right after forming in the RCBS die (fourth pic)?

Gear

Gear,
here are the measurements (even though I've been chastened by Eutectic's better technique):
Taken about 1/8 inches above neck/shoulder joint.
After 1st run through die .32745
After cutting off neck and running through a second time .33780
After expanding with K&M expander (to exactly fit mandrel) .34060
After neck turned .33210
Final neck thickness .0125

[geargnasher]

What I have seen matches Eutectics post right off the bat, but even if done right, the donut flows forward like Tommyboy describes.
Of course that is a diagnosis based on observations I have made, so I might be hammering nails into trees.
I know how aggressively you form your brass can definitely have an effect on the size of the donut, but I've also seen it get worse as the brass is fired.
Honestly, I just didn't worry about it too much though. What accuracy I was experiencing did not degrade with the presence of the donut. What I did observe was that the size of the donuts had a measurable effect, but I segregated my cases based on the size of what pin gauge would slip easily through the case necks (and the donut) and the matched cases shot consistently to their brothers. Mix them up and things went weird (obviously).
I think it's just barely possible this is being over thought just a little bit here, but what do I know?
Seems to me that the point of reaming is more a matter of making all the cases consistent, rather than getting rid of the evil donut. Just a thought.

The problem I've been having is FORMING the brass, not any donut formation afterward. The necks end up about .003" thicker at the base than at the mouth, and will not expand parallel on the inside no matter what I do, so reaming is the only option I have to fix that....except to not form the taper to the inside in the first place, which is what Eutectic was getting at by changing the way the brass is moved, which should also help with any donut formation during subsequent firings because it will minimize excess brass flowing into the shoulder/neck junction in the first place. Forming the shoulder in steps instead of squeezing the neck and shoving the shoulder back all at once makes a lot of sense and should eliminate the need to ream. Any excess should be left on the outside of the neck to be turned off.

Gear

[geargnasher]

Gear,
here are the measurements (even though I've been chastened by Eutectic's better technique):
Taken about 1/8 inches above neck/shoulder joint.
After 1st run through die .32745
After cutting off neck and running through a second time .33780
After expanding with K&M expander (to exactly fit mandrel) .34060
After neck turned .33210
Final neck thickness .0125

I wanted to see if Goodsteel reamed the neck of that die, it appears he did not. The Lee dies push the neck down to .323" on the OD, most of my RCBS '06 dies put them about .327-9" depending on vintage and wear. I honed my XCB die to give brass at .333" and then tapered the base to make it about .335-6" or so, depending on if it's annealed or not and the brand. My worry was getting the neck off-center by taking it from .342-something to .320-something and then expanding again to about halfway in-between, that's a lot of working of the neck and most necks have about 1-2 thousandths thickness variation before turning, so whanging the neck back and forth can cause uneven stretch/compression. Of course we outside turn the high spots, which on an uneven neck kind of makes them off center too. Fireforming under full-pressure conditions ought to fix all that if the necks and shoulders aren't too hard.

Gear

[dtknowles]

The problem I've been having is FORMING the brass, not any donut formation afterward. The necks end up about .003" thicker at the base than at the mouth, and will not expand parallel on the inside no matter what I do, so reaming is the only option I have to fix that....except to not form the taper to the inside in the first place, which is what Eutectic was getting at by changing the way the brass is moved, which should also help with any donut formation during subsequent firings because it will minimize excess brass flowing into the shoulder/neck junction in the first place. Forming the shoulder in steps instead of squeezing the neck and shoving the shoulder back all at once makes a lot of sense and should eliminate the need to ream. Any excess should be left on the outside of the neck to be turned off.

Gear

I am hesitant to jump in here as I hate to think about adding more steps to the laborious process but you might think about annealing the brass before you do the final expanding of the necks. The thick brass at the base of the neck might be springing back more than the rest because it is harder and thicker and was moved a bunch during forming.

Tim

[runfiverun]

Tim. Beat me to it
i like my brass to have a little hardness to them but once the forming is done and its
just some re-shaping an anneal step might prove useful

[geargnasher]

UPDATE: Per Eutectic's comments, I rummaged around in my spare parts/miscellaneous drawer and produced an RCBS .358 Winchester form/trim die that I picked up at a gunshow a while back (for ten bucks, hard to go wrong). After setting it about 1/16 turn off the neck of a formed XCB case, I took several '06 cases and pushed the shoulder back a little. They came out perfect, the sharper shoulder of the .358 is of zero consequence here, in fact I think the shape it makes is actually more desirable than a 17.5 degree shoulder. Not having a .33 anything, I went ahead and relubed and put a case through the XCB form die a little at a time, checking to see where the metal went. It all did pretty well, but remember I tapered my form die neck pretty severely. After a trim, expansion, and a resize, it's only about a thousanth tapered on the inside, MUCH better and NO reaming required. I can feel with inside calipers that the very base of the inside of the neck is actually larger than nominal, so there actually is a "negative donut" at this point. After an outside trim and check, the case walls are the same thickness from base to mouth, and there is a superficial overall cone to the neck. A quick trip through a .308 neck die and expand on a .308" mandrel put the necks back right and ready to load. I think I'm in business now, I'm wondering if the '06 trim die I have coming might be even better for a second step than the XCB form die since it will size the neck less and act as an intermediate step to form the shoulder without pushing the neck all the way back to loading outide diameter before the trim. More to play with, but doing the shoulder and neck to a .35 caliber FIRST helped a whole bunch. Thanks Pete! You get the care package yet? Tracking shows it's been bouncing around in your local PO since Friday.

Gear

[btroj]

I wonder how a 8 mm Mauser form die would work? Pretty good I bet.

i won't be doing any testing for a bit, work has been hell lately and I have a major new project getting installed Friday.

[Bjornb]

Making and shooting cases from 8mm Mauser brass is my next project. I have a good stash of PPU and Remington, and I'll be using whichever brand that shows the most even neck thickness. I would expect them to be similar to the 7mm cases, but only testing will tell. R5R also mentioned trying this avenue.

[btroj]

I was inking more about using an 8mm form die used for making 8mm cases from 06 brass as an intermediate step. Would this be enough to reduce the forces on the brass and give me better brass in the end?
Dont know but I can easily borrow the required die from my FIL.

[MBTcustom]

You could feasibly go 358 Winchester, then the 8mm Mauser, then finish with the 30XCB. That would be a pretty gentle path to the end result.

[geargnasher]

My only concern about the 8mm die is that unless it is shorter than a FL size die (and I think some of them are) it won't push the shoulder back near far enough (shy by about .200"), and the body is .010" smaller at the shoulder/body junction. You could push it up into the die with a quarter across your ram instead of a shellplate holder and tap the case back out with a punch. Not much effort would be required to eject them, really, I think you could push it out with a #2 Phillips screwdriver or maybe bop it out with your palm on the handle. I think it would work fine if you did that, but stop about .010" short of fully knocking back the shoulder. When you form the rest in the XCB die, the stress of forming the neck and final shoulder might push the body back out nearly to the right size again near the shoulder. Worth a shot, anyway. This .358 Winchester form/trim die has worked wonders for me, and required no modifications.

Gear

[MBTcustom]

My only concern about the 8mm die is that unless it is shorter than a FL size die (and I think some of them are) it won't push the shoulder back near far enough (shy by about .200"), and the body is .010" smaller at the shoulder/body junction. You could push it up into the die with a quarter across your ram instead of a shellplate holder and tap the case back out with a punch. Not much effort would be required to eject them, really, I think you could push it out with a #2 Phillips screwdriver or maybe bop it out with your palm on the handle. I think it would work fine if you did that, but stop about .010" short of fully knocking back the shoulder. When you form the rest in the XCB die, the stress of forming the neck and final shoulder might push the body back out nearly to the right size again near the shoulder. Worth a shot, anyway. This .358 Winchester form/trim die has worked wonders for me, and required no modifications.

Gear

That seems like a pretty straight forward way to go. Is it cutting down on the neck taper for you?

[geargnasher]

That seems like a pretty straight forward way to go. Is it cutting down on the neck taper for you?

Yes, it completely cured the issue, provided I still form in my taper-necked XCB die. When I get my new bushing/body die and shorten it I'll try a few and see how it works with a parallel bushing. Anyway, there's no trace of donut at all when using the .358 Win die as the first forming step.

Gear

[runfiverun]

Fired 8 Mauser straight into the xcb die will give little wrinkles around the
neck shoulder junction
win brass seemed less prone to this happening than remington
i'll have to try pushing things part way with a 358 win die and see
what happens

[detox]

Wrinkles are usually caused by using too much lube. Wipe out die and use less lube...if any. Remington brass is softer which dents easier, but avoidable with less lube.

[geargnasher]

Fired 8 Mauser straight into the xcb die will give little wrinkles around the
neck shoulder junction
win brass seemed less prone to this happening than remington
i'll have to try pushing things part way with a 358 win die and see
what happens


Hmm. I went from fired, unsized straight through my XCB die with some ancient Turkish 8mm cases, worked fine but the necks were very malleable and thick. We use a similar case lube. I'm supposing Tim didn't open up the neck on you XCB die either? They work a lot better when opened to .333" or so.

Gear

[Eutectic]

Yes, it completely cured the issue, provided I still form in my taper-necked XCB die. When I get my new bushing/body die and shorten it I'll try a few and see how it works with a parallel bushing. Anyway, there's no trace of donut at all when using the .358 Win die as the first forming step.

Gear

Seems to me that this is a good step that is working then. The .35 Whelen FL die shortened is even better as it forms right to the '06 body taper and shoulder angle. Keeping all your sizing on the center line yields the very best cases.

Starting with 8mm brass would be a pretty good idea. I wouldn't want the undersize body to shoulder area forming from '06 brass pushing into an 8mm die if it was me.... Could cause concentricity problems at final .30XCB stage.

Annealing.... Don't let your press handle trick you! Do all your heavy forming first. Remember about the longitudinal compressive force I mentioned earlier. Softer brass during the heavier forming can increase some of the brass pushing down where we don't want it. The original problem we are trying to eliminate. Just before your final sizing of the last few thousandths for your chamber fit; that is the time to anneal.

Eutectic

[runfiverun]

I'm using 2 parts lanolin to 1 part castor oil with a little neatsfoot oil mixed in to thin it out some
it's the same lube I use to swage bullets.

[geargnasher]

Ahh. I'm using 5 parts lanolin, one part castor, and something like 20 parts 91% isopropyl alcohol. I used to keep a limited-slip diff additive bottle (like LLA, but black) full of just lanolin, castor, some GY-HTO polymer additive, thinned with mineral spirits for the case lube pad, but I used all that up and now just hose my case lube pad with the spray bottle and let the alcohol evaporate when I use the pad at all, which is usually only when forming brass. Normal resizing gets the spray/shake/spray/massage-in-a-bowl treatment.

Eutectic, I found no issues at all with the .358 shoulder, I'll take some pics at some point and you can see what I mean. The sharper angle doesn't show up at all due to the slight amount that the case diameter is reduced by it. There's just a sort of radius there that blends perfectly when the final shoulder is formed. Keep in mind I'm stopping about ten thousandths short of final shoulder location when I use it and finishing with the XCB die. I'm sure a shortened Whelen die would be as good or maybe even better, but I'm not inclined to bother. Someone purchasing a dedicated form die might choose the Whelen if they don't mind cutting it down a quarter-inch.

My goodies came in from Midway tonight, but I spent a rare and unexpected evening with my dad instead of fooling with with brass. The brass will be there forever, he won't be.

Gear

[MBTcustom]

My goodies came in from Midway tonight, but I spent a rare and unexpected evening with my dad instead of fooling with with brass. The brass will be there forever, he won't be.

Gear

Well said.

[Bjornb]

I formed a few XCB cases from 8X57 brass (R-P) this morning. With just a minute amount of Imperial grease on the case they formed like butter, with no hint of creasing in the neck/shoulder area. I'm running late for work right now (as always), but when I get a few minutes I'll take pictures, turn the necks, mike the results and post it here.

[RED333]

My $0.02 on case lube
http://www.neverseezproducts.com/regulargrade.htm
I repair cooking equipment, lot of stainless steel bolts and nuts as well as sheet metal screws.
Working on steam gear it will not melt out, and years from the time you
put it on the fittings still come apart.
Just a dab will go a LONG way, I have not had a case stick after I started to use it.
Now I just resize 223 to 300 BLK for now, but I use it for all case resizing when I reload.
Yall just might like it for case lube, I do.

[MBTcustom]

My $.02 is, I buy Frankford Arsenal case lube. Its cheap and it works really well. Just me.
http://www.midwayusa.com/product/204960/frankford-arsenal-case-lube-8-oz-pump

[Bjornb]

OK I shouldn't have been so sure of myself a couple of posts ago. I finished making 55 XCB cases from once fired Remington brass today. Of the 55, 8 had neck striations from the XCB die. I used just a hint of Imperial, and the die was cleaned inside prior to use. The surprise: All the necks miked at .011, very evenly, with my RCBS ball mike (calibrated by Goodsteel). This after necking them down.
I have loaded all the cases with 33 grs. IMR3031 for fire forming, using various cast bullets on hand. You can never get too much trigger time.
119728119730119731

[tomme boy]

Wouldn't be better to use a jacketed bullet to fireform the cases. That way you can up the PSI to form them better? Or just run the full PSI loads you are already running with the normal loads? I think they would fill out much better than a lower PSI load you are going to use. You might have to load them a couple of times to fill out with the lower loads.

[dtknowles]

Wouldn't be better to use a jacketed bullet to fireform the cases. That way you can up the PSI to form them better? Or just run the full PSI loads you are already running with the normal loads? I think they would fill out much better than a lower PSI load you are going to use. You might have to load them a couple of times to fill out with the lower loads.

Jacketed bullets will foul the bore and require cleaning and reseasoning.

Tim

[Bjornb]

The 3031 loads will be in the 27k range, and if it's not enough to iron out the necks I'll just pull them and do it again. I've got the time.

[geargnasher]

I think Tomme said the Remington 8mm Mauser brass had such thin necks as to be pretty much useless, it appears you have proven him right. I'm looking for .0135" minimum. Got .0145" easily with Turkish headstamped 8mm brass, but only had two examples of it.

Gear

[MarkP]

The screenshot below is part of what you are seeing, final draw punches are tapered such that there is a thickness transition in the shoulder junction. Your neck is now located in the former shoulder area. When the diameter is decreased the walls will thicken (constant volume) and you should see a slight increase in length, and just the opposite when necking up brass, thinner wallsand slightely shorter in length. In addition, a family of cartridges will share the same cup (the brass part that is blanked from strip and formed into a cup and annealed) 1st draw, 2nd draw, tooling. The third draw or last draw punch will be different for each cartridge. For example a 358 W will have a different final draw punch as compared to a 338 Federal, 308 Win, 7-08, ect. There can be some overlap such as a 260 Rem may use the same final draw as a 7-08. A 243 final draw punch would have the largest diameter (thinnest walls at mouth of final draw) within that family of cartridges. Tapering usually occurs with 3 or 4 dies, first die sets the body taper, latter dies form shoulder and neck.119852119853

[Bjornb]

I think Tomme said the Remington 8mm Mauser brass had such thin necks as to be pretty much useless, it appears you have proven him right. I'm looking for .0135" minimum. Got .0145" easily with Turkish headstamped 8mm brass, but only had two examples of it.

Gear

I checked out some other headstamps after I saw your post. I also have a good stash of PPU 8mm cases, and they miked .0115-.0125, none over .0125.
I have a few hundred Berdan-primed cases, 1942 Adolf-era 8x57 brass, it all mikes .015-.016.
So if you're ready to go Berdan let me know! At least 80% of the primers go bang!

On a serious note: I'll fireform these and try them out alongside the 7x57 and 30-06 cases. I can't hurt to try every combination.

[btroj]

Send those Berdan cases to Tim, for a few bucks apiece he can make them boxer primer ready!

[btroj]

Bjorn, have you tried any of those cases with the thinner necks? Would be interesting to see if .003 necks clearance or so makes any difference if shot with same load as a closer fitting neck.

[Bjornb]

I'm fire forming 55 cases this Saturday or Sunday (some had neck striations from forming and weren't uniform enough in the neck/shoulder area). Then I'll load them up immediately and post the results.

[tomme boy]

I think if I was going to do this cartridge, I would be using the 3006 brass. I would also spec the reamer for the neck for the 3006 brass so the only thing I would have to do is a very very light cleaning of the neck on the brass.

Wouldn't it be easier this way? Maybe contact Tim to see if you could open the neck a little? Or speck the reamer for the 8mm brass? I know this is a on going learning for this new cartridge so just asking ???'s

[Bjornb]

Here's what I'm learning: with the necks turned to .125 so I have about .0015 nominal clearance with a .311 bullet, the fired brass will not accept a bullet. So all I've had to do is reprime, charge and seat a new bullet. The fired cases will let me enter about a gas check's worth of bullet. I'll be curious to hear if Gear and Btroj have similar chambering issues.

[btroj]

I do size but minimally. With my cases I use a .333 bushing, this lets me seat a bullet with just a very slight flair. I use an M-die for that, the spud doesn't expand the neck at all. I tried a .335 bushing and it was too loose, I could spin seated bullets by hand.

I haven't measured but I'm sure I am sizing cases around .003 at the present. As brass hardens with use that will change too as the cases will spring back on firing and sizing.

I may make some more cases and see what happens if I go to a thinner neck. Only problem will be that I will need a smaller bushing to get any bullet tension at all. Might order a .330 and give it a go.

[geargnasher]

With hotter loads and soft necks, mine need a resize. I measured my 1x fired necks tonight, they're all .3370" on the money, the harder, 9x fired necks that were never annealed and hard to begin with come out about .3373". I'm using a .333 bushing and the new batch of softer stuff is finishing at .3350", the harder necks at .3355" or so, some larger.

Going .3095" with the bullets makes the .333 bushing BARELY enough, the military brass still doesn't clean up 100% even then, it would be much better with .310" or larger bullets, which is what I originally intended to use and was discussed when we spec'd the reamer.

If I were to do an '06 reamer for cast, I'd go .337" with a standard '06 throat, but I'd go .336" or less with a longer, shallower throat and smaller throat entrance, like .3095" tops. I have a very tight .308 barrel to test that theory with, it has a super-long, shallow throat and .3095" throat entrance. If that works out (who knows), I might just get a similar throat cut and a .335" neck on my next '06. Only problem with that is getting a gunsmith willing to do it, most of them balk if going below .337" due to pressure excursions if anyone else gets hold the the rifle and tries to shoot factory jacketed ammo in it. The XCB won't chamber .308 OR 06 factory ammo, so no worries, we could have gone tighter but I suppose didn't know better, it was a learning experience and that's why we did it in the first place.

Gear

[Bjornb]

Yeah once I got my necks squared away (turned to .0125) I've been able to chamber .311 bullets without forcing the bolt. Tim was afraid I would shave lead above .310 but I've extracted several rounds and there are no signs of force applied to the bullet. Evidently the throat is large enough to fit the NOE bullet as cast.

[geargnasher]

Mine start to shave at .3105". It was the first chamber cut, should have been the largest throat I would think. A slug shows .3106", surprisingly right on spec.

Gear

[MBTcustom]

Mine start to shave at .3105". It was the first chamber cut, should have been the largest throat I would think. A slug shows .3106", surprisingly right on spec.

Gear


Gear, when using good quality Reamers with stone sharpened edges, you would be surprised how consistent the diameters are.
I just cut two more chambers last week, and carefully measured the throats on them. It will surprise you to know that the measurements I took are nearly identical to those you just posted.
I had cautioned Bjornb to be careful going anything over .310 because at that point you are a mere .0005 away from max diameter. That's getting real close.

[runfiverun]

those are the same neck striations I get with fired Remington brass.
I'm gonna try bumping the shoulder first with a 358 win die on the next go-round.

[Bjornb]

those are the same neck striations I get with fired Remington brass.
I'm gonna try bumping the shoulder first with a 358 win die on the next go-round.

Yep. That's what I'm using. Fired Remington brass. 358 die it is. Got an RCBS one.

[kbstenberg]

I was thinking the other day about how you ream out the inside of the neck (the doughnut) and were having problems with consistency. Would it help if you put the case to be reamed into some kind of a case length gauge and left the length gauge on to support the outside neck/shoulder when trimming the inside of the neck.
Like most novists their trying to help is old news, or unworkable.

[Bjornb]

This tool is what I have found to be excellent when it comes to removing the "donut" and turn the outside neck at the same time:
122977
The mandrel, which supports the outside cutter, has its own cutter that ONLY cuts to the diameter of the mandrel itself, thereby only removing inside neck material that is in excess of the desired ID.

[NoAngel]

Curious.
What differentiates this wildcat from the .30 Blake which is nothing but a rimless 30/40 Krag? It's of similar capacity and has a nice long neck as well.
Looks a LOT alike.