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SAAMI #'s question


Abominator
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SAAMI states that 40 S&W at the mouth should be .423". SNS bullets are .401". At the flare step I am only flaring to about .423"to.424". I am not scraping any of the coating off of the SNS 180grain bullet and it seats smoothly. Does this mean that I am flaring too little? In the last stage with the Factory Crimp Die, is there any de-belling needed? I can still push the bullet down in the case if I push hard enough against the table. If I crimp to .420" I can no longer do that. These is still some case mouth at this point, it is not crimped inward. Is that too much crimp? I searched some other posts about this but I didn't quite see my exact question. Sorry if this has been asked to death. 

Edited by Abominator
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Does it fit a gauge or the chamber?

 

While there may be no real problem, the fact that you can push the bullet in may be of concern.

 

Take an uncrimped round and measure it.  Then load it in a mag and drop the slide on it to chamber it.  Re-measure the length.  Repeat for a total of five chamberings, measuring each, and see what it shows you.

 

While we don't want to repeatedly chamber a round many times in normal use, this test should show you what is happening when shooting.

 

It tends to suggest the brass wall thickness may be somewhat thin, with respect to the sizing action of the sizing die.

 

If you are not seeing any shaving of the bullet when seating, and it fits the gauge/chamber, and there is little to no setback when chambering, there may be no reason to be concerned.

 

How about a 0.422" or 0.4215" crimp?

 

 

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10 hours ago, Guy Neill said:

Does it fit a gauge or the chamber?

 

While there may be no real problem, the fact that you can push the bullet in may be of concern.

 

Take an uncrimped round and measure it.  Then load it in a mag and drop the slide on it to chamber it.  Re-measure the length.  Repeat for a total of five chamberings, measuring each, and see what it shows you.

 

While we don't want to repeatedly chamber a round many times in normal use, this test should show you what is happening when shooting.

 

It tends to suggest the brass wall thickness may be somewhat thin, with respect to the sizing action of the sizing die.

 

If you are not seeing any shaving of the bullet when seating, and it fits the gauge/chamber, and there is little to no setback when chambering, there may be no reason to be concerned.

 

How about a 0.422" or 0.4215" crimp?

 

 

Thank you, I will try that out and I will fine tune my crimp die. I have a dial caliper so I'll try to get it as close to .4215 and see. Oh and yes they fit the case gauge and pass the plunk test.

Edited by Abominator
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With regards to crimp or de-belling rather. I was reading the SAAMI specs and it says .423"-.424" for the case mouth. I ran several measurements with different brass and this is what I got     ( bullets are .401" for ref)

Mixed brass: .4175" after sizing--- .4225" after flare --- the bullet seats east with no scraping of the coating using the Lee Factory Crimp Die with stem fully out. The final case mouth size is .421" with no crimp. I cannot push the bullet in against the bench. All head stamps had same measurements

I was concerned that being .002" tighter than SAAMI specs was bad but I measured some factory ammo 180
grain jacketed and it was .419"-.420" consistently

You guys think these are okay? I mean, I literally can de-bell any less. My powder charge is 10% below max for Sport Pistol and I am loaded a bit long, min OAL is 1.16" and I am 1.18" for these bullets.

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1 minute ago, Ming the Merciless said:

Case sizing controls bullet set back not crimping, if you can't push the bullet in against the bench, the sizing is fine.  As long as you're not scraping the coating off, the belling is fine.  If you're not breaking the coating, the crimping is fine.

Awesome thank you. Yeah not scraping off the coating in the seating or crimping stage. 

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9 hours ago, Ming the Merciless said:

Case sizing controls bullet set back not crimping, if you can't push the bullet in against the bench, the sizing is fine.  As long as you're not scraping the coating off, the belling is fine.  If you're not breaking the coating, the crimping is fine.

 

This is correct.  You should be sizing the case down enough that the interference fit prevents bullet setback.  The crimp is only to remove the flare or maybe .001 under.  It's not meant to hold the bullet in place (and it won't).

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On 4/8/2020 at 12:41 PM, Abominator said:

With regards to crimp or de-belling rather. I was reading the SAAMI specs and it says .423"-.424" for the case mouth. I ran several measurements with different brass and this is what I got     ( bullets are .401" for ref)

Mixed brass: .4175" after sizing--- .4225" after flare --- the bullet seats east with no scraping of the coating using the Lee Factory Crimp Die with stem fully out. The final case mouth size is .421" with no crimp. I cannot push the bullet in against the bench. All head stamps had same measurements

I was concerned that being .002" tighter than SAAMI specs was bad but I measured some factory ammo 180
grain jacketed and it was .419"-.420" consistently
 

 

.423" is the maximum SAAMI measurement for the crimp.  Note on that page it says for the cartridge "unless otherwise noted body dia. (diameter) -.008

 

That means the crimp can be .008" smaller and still be within spec. Thus a crimp between .415 to .423 is within SAAMI specs.

 

That's why the factory ammo you measured is smaller.  In fact, all factory ammo should/will be under .423".

 

 

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The SAAMI specs are for manufactures to provide a standardized cartridge. For  reloading we load what works in the application we are shooting.

 

1. The proper bell size is the one in which your bullet will sit and smoothly seat into the brass without scraping the coating off.

2. The crimp size is removing the belling and able to gauge in the barrel, i.e. "plunk test. It is not required to be at SAAMI specs.

3. If the bullet after seating and crimping can be pushed into the brass then your sizing die needs to be changed. I suggest the Lee, Dillon or Hornady, which are all slightly "undersized" and will prevent "setback."

 

 

From Eggleston Bullets:

 

1851770.png?411

Edited by HesedTech
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22 hours ago, superdude said:

 

.423" is the maximum SAAMI measurement for the crimp.  Note on that page it says for the cartridge "unless otherwise noted body dia. (diameter) -.008

 

That means the crimp can be .008" smaller and still be within spec. Thus a crimp between .415 to .423 is within SAAMI specs.

 

That's why the factory ammo you measured is smaller.  In fact, all factory ammo should/will be under .423".

 

 

 

Thanks so much. I guess I wasn't understanding that.

 

19 hours ago, HesedTech said:

The SAAMI specs are for manufactures to provide a standardized cartridge. For  reloading we load what works in the application we are shooting.

 

1. The proper bell size is the one in which your bullet will sit and smoothly seat into the brass without scraping the coating off.

2. The crimp size is removing the belling and able to gauge in the barrel, i.e. "plunk test. It is not required to be at SAAMI specs.

3. If the bullet after seating and crimping can be pushed into the brass then your sizing die needs to be changed. I suggest the Lee, Dillon or Hornady, which are all slightly "undersized" and will prevent "setback."

 

 

From Eggleston Bullets:

 

1851770.png?411

Much appreciated!

 

I loaded up about 20 test rounds and took them to the range. Made a couple adjustments and shot 30 more, everything worked great at the range. I think I have it down now for this caliber. I am not sure why but I just seemed to have more trouble than I did with 9mm. Thanks to all for the help. Loaded 800 rounds up yesterday, stockpile is starting to look good. Lots of reloading to go!

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