Making Progress with my Dillon SDB. Need more knowledge, though.

[HossMan]

Sorry, not "giving me a bulge at the base", but having a natural bulge at the base that then tapers to the crimp. He showed me one of his reloads. It had a bulge at the base of the bullet, but the thickness of the bulge didn't go all the way to the case mouth. My reloads have the bulge that is even in thickness all the way from the base to the case mouth. Thanks.

Pardon my French, but this guy is an idiot if he doesn't understand that different brand dies will size and crimp in highly different ways. There is always more than one way to skin a cat.

Some dies size with a tapered case, as per the SAAMI spec for 9x19 Luger. Some dies size with a (easier to manufacture) straight wall sizing die, so of course the base of the bullet will show up much more clearly in the finished product. Then some fall between these extremes. Each method has good points and bad.

So is he saying that all factory ammo with the tapered case is loaded incorrectly ?? What are his credentials for making such a statement ?? Some investigation will probably reveal that while competent, he's used only one brand of die his entire career, has no background in design or engineering to understand the various methods and options, and has a closed mind about new ideas.

Historically speaking, this closed mind "my way or the highway" just never seems to hold up.

I'm off my soap box now.   

Yeah, I see where you guys are coming from. I picked up and looked at a couple  handloads that shooters racked out of their guns when they were finished shooting stages. They looked pretty much like mine in terms of crimp. I will leave my crimp die alone for now.

[IDescribe]

Here's my question:  what was increasing your crimp supposed to fix to begin with?  What problem was he responding to?

[HossMan]

Here's my question:  what was increasing your crimp supposed to fix to begin with?  What problem was he responding to?

I was meaning to call him and ask him that today. Hahaha

[IDescribe]

Okay, you don't have to, then.  He was trying to be helpful by encouraging you to make a "correction" to your ammo so that it would look exactly like his, which isn't going to happen and shouldn't happen.  Feel free to ignore his suggestion.   

[Wobbly]

Feel free to ignore his suggestion.   

I already have !! 


Hoss is using a Dillon SDB, which has only one set of dies available in the entire Free World. What was he supposed to do, go to his local machine shop and start ordering up made-to-order parts based on a casual conversation ??

I also work a lot with vintage motorcycles. On those forums there's always some Yahoo suggesting that you MUST install a new $500 such-and-such, contrary to the evidence of the bike running just fine for the last 60 years on what it already has. Amazing how ready others are to spend your money !

 

[RenegadeDave]

Hoss you weren't talking about the IDPA match at GA Firing Line were you?  There was a new guy at the match shooting a P01 with what looked like acme 124s. 


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[HossMan]

Hoss you weren't talking about the IDPA match at GA Firing Line were you?  There was a new guy at the match shooting a P01 with what looked like acme 124s. 

That's me. Mr Hoss.

[Wobbly]

So why not put your locale in your profile ?

Heck, if I'd have known that I would have ridden over and we could have tweaked your machine together.

 

[Wobbly]

After shooting IDPA last night, the gun wasn't all that dirty. I'm still loading a hair under minimum power factor according to Hodgdon data. I didn't inspect my brass this time, because I forgot to.

One of us is confused.

Hodgdon doesn't list their load data by Power Factor. They simply have a Starting Load and a Max Load. If you mean you are loading under the Starting Load, then no wonder you're having trouble.

I need my coffee !

[HossMan]

After shooting IDPA last night, the gun wasn't all that dirty. I'm still loading a hair under minimum power factor according to Hodgdon data. I didn't inspect my brass this time, because I forgot to.

One of us is confused.

Hodgdon doesn't list their load data by Power Factor. They simply have a Starting Load and a Max Load. If you mean you are loading under the Starting Load, then no wonder you're having trouble.

I need my coffee !

Sorry, you're right. I should not have alluded to Hodgdon data containing anything about Power Factor. I've just been experimenting with everything from the starting load to a tenth or couple tenths of a grain above starting load. I have yet to load anything with a 4.1 powder charge or above. I need to order more Acme bullets before I can start doing that. Thanks for your help, Wobbly.

[Wobbly]

I've just been experimenting with everything from the starting load to a tenth or couple tenths of a grain above starting load.

Ah ! Now it's clear. Thanks. 

[copemech]

Sorry, not "giving me a bulge at the base", but having a natural bulge at the base that then tapers to the crimp. He showed me one of his reloads. It had a bulge at the base of the bullet, but the thickness of the bulge didn't go all the way to the case mouth. My reloads have the bulge that is even in thickness all the way from the base to the case mouth. Thanks.

Pardon my French, but this guy is an idiot if he doesn't understand that different brand dies will size and crimp in highly different ways. There is always more than one way to skin a cat.

Some dies size with a tapered case, as per the SAAMI spec for 9x19 Luger. Some dies size with a (easier to manufacture) straight wall sizing die, so of course the base of the bullet will show up much more clearly in the finished product. Then some fall between these extremes. Each method has good points and bad.

So is he saying that all factory ammo with the tapered case is loaded incorrectly ?? What are his credentials for making such a statement ?? Some investigation will probably reveal that while competent, he's used only one brand of die his entire career, has no background in design or engineering to understand the various methods and options, and has a closed mind about new ideas.

Historically speaking, this closed mind "my way or the highway" just never seems to hold up.

I'm off my soap box now.   

I think I may be offended! Let me check.

[HossMan]

So, for those of us that were curious, I asked the gunsmith why I should have the crimp that he has. His response was proper feeding and ensuring that the bullet does not push back into the casing, shortening OAL and increasing pressures. Not that it matters, because I'm not near max load, but I was fairly certain that the resizing of the case provides the most case neck tension that keeps the bullet at a consistent OAL during the firing and autoloading process. I will continue to load with the SDB with the crimp die crimping to .378" at the very edge of the case and just enough to remove the case flare and allow good feeding. I have yet to have a hiccup after hundreds of handloads *knock on wood*

Thanks for all your help, guys. 

[Wobbly]

So, for those of us that were curious, I asked the gunsmith why I should have the crimp that he has. His response was proper feeding and ensuring that the bullet does not push back into the casing, shortening OAL and increasing pressures.

Proper feeding comes from having a dimension smaller than the maximum dimension of 0.380" which is sited in your reloading manual. You are presently 0.002" smaller than that. The only true test is "does your ammo feed well ??" I suspect it does.

If it does indeed feed good, then 'don't try to fix what ain't broke' !!

Not that it matters, because I'm not near max load, but I was fairly certain that the resizing of the case provides the most case neck tension that keeps the bullet at a consistent OAL during the firing and autoloading process. I will continue to load with the SDB with the crimp die crimping to .378" at the very edge of the case and just enough to remove the case flare and allow good feeding. I have yet to have a hiccup after hundreds of handloads *knock on wood*

Close, but not quite. Think about this....

The Sizing Die does indeed reduce the exterior diameter of the brass case. But, each case has a different wall thickness. Wall thickness varies from brand to brand, but might also vary within lots of the same brand. So how can you squeeze the outside of the brass and know for sure where the inside diameter (which does all the bullet holding) will end up ??

Answer: You can't possibly know.

Therefore, the Sizing Die takes the exterior of the brass case smaller than needed !! Then in a secondary action, the Expander Die comes along and expands the interior of the case to the correct internal diameter. You can't possibly get correct bullet holding ability without the correct internal diameter.

In a lot of die sets the Expander Die is a separate die or die station. On all Dillon equipment, including the SDB, the Expander function for pistol brass is built into the lower portion of the Dillon Powder Funnel.

[img]http://ultimatereloader.com/wp-content/uploads/2011/12/expanders-side-by-side-500.jpg[img]

The object is to size the interior of the case to 0.002" smaller than a jacketed bullet. It's that "press fit" of the bullet into the case that does all the holding. In other words 0.355" - 0.002", or 0.353". Now if you'll carefully measure the tip of your Powder Funnel, I think you'll find that it measures 0.353" and that's why.

? So if you're using lead bullets, it's an even tighter fit! This because you're pressing a larger bullet into the same size case mouth.

? If you're bullets aren't being held very well, then check the size of your Expander Die and not the Taper Crimp setting.


Follow all that ?

 

[IDescribe]

Good. 

First, crimping past zero, by which I mean you have done more than just remove the flare of the case mouth for bullet seating, does not provide more case tension.  That sort of crimp works as a mechanical lock.  There's a groove in the bullet that the case mouth is bowed into.  The bullet won't move forward or backward because the case mouth is in its way.   This is a good thing when you're dealing with heavy recoiling rounds where the bullets might slip forward or backward in their cases under recoil.  If you'll imagine a .357 magnum or .44 magnum revolver, which headspace on the case rim, when those rounds go off, the stout recoil knocks the gun back, and the cylinder yanks back on the other cartridges by the case rim at the rear.  That massive bullet resists being moved (thanks, Isaac Newton) when the case is yanked backward away from it.  If there's only a taper crimp, and you're relying on case tension to hold the bullet in place, that bullet may slip the case tension for a fraction of a moment, and move forward in the case.  After five shots, that sixth round may have had the bullet slip all the way out, or far enough forward that it pokes out of the front of the cylinder and binds the cylinder.  So for those sorts of loads, you want a roll crimp, which crimps past zero, literally puts the case mouth in the way, so the bullet can't move forward or backward.

Second, in a pistol that is supposed to headspace on the case mouth, like most of your automatic pistol rounds, there is a lip/rim/shoulder in the chamber upon which the casemouth is supposed to catch and headspace.  If you crimp past zero, it screws up the headspacing by effectively shortening the case length.  The case mouth is still there, but it's been bowed inward where it won't catch on that lip the way it is supposed to. 

So, again, GOOD.  Don't listen to that guy.