Rack or ramp to sort bullets by length en mass


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wacki
November 2, 2011, 02:18 AM
I'm getting into pistol reloading and I was wondering if anyone out there has a way to double check the length of a cartridge en mass. For instance, S&W .40 has to be 28.83 mm in length. A metal ramp with holes in it of various sizes could put the short bullets (that risk overpressure) in one pile, the perfect bullets in another and the longer bullets in a third. Just dump your bullets at the top and let the ramp sort!

Just a idea... you never can be too careful.

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ReloaderFred
November 2, 2011, 02:45 AM
You're overthinking the process. I'm also assuming that when you say "bullets", you're refering to the loaded cartridge.

What is important from a pressure aspect, is the volume of the case, not the overall length of the loaded round. Granted, the OAL will have an affect on volume, but if you measure the length of most brands of bullets, prior to loading them, you'll find some variation from one bullet to the next of the same weight bullet. Unless you're loading to the absolute maximum for the caliber, a small variation isn't going to hurt anything.

Your seating die should be setting the length of the loaded cartridge, so if you're having issues with some being shorter than others using the same weight and brand of bullet, it's probably due to the seating stem not matching the ogive of the bullet, and not allowing the tip of the bullet to bottom out on the seating stem.

If you want to check several bullets at one time, you can stand them in a row on a piece of flat glass, such as a mirror, and use a straight edge on top. That will tell you if any of them are shorter by looking under the straight edge.

Hope this helps.

Fred

bds
November 2, 2011, 07:57 AM
wacki, been there and done that myself. :D

ReloaderFred made good suggestions.

I use bullet weight to sort my bullets for consistency. For jacketed bullets, I use 1 grain variance as my match grade standard and Montana Gold bullets provide this level of consistency.

For lead bullets, I found bullet weight to be less of an issue but the bullet-to-barrel fit/proper obturation of the bullet base to be greater contributors of producing more consistent chamber pressures. Even 1-5+ grain variation won't affect the accuracy much if you have good fit/obturation.

rcmodel
November 2, 2011, 10:46 AM
S&W .40 has to be 28.83 mm in length.Americans measure ammo in thousands of an inch.
I don't even know what 28.83mm is.

As for "has to be"?

MAX OAL for the .40 S&W is 1.135", which is roughly 28.83mm, I guess?

But cartridge OAL for any specific bullet weight & profile can be anywhere from 1.080" to 1.135".

So sorting would have to be OAL specific for the bullet you were using in the loaded round.

rc

RandyP
November 2, 2011, 11:00 AM
For reloading, regardless of the brand or style mahcine you end up owning, you WILL need a caliper -I am very satisfied with my Harbor Freight $10 digital unit -

Use one and measure a random box of factory made ammo - after which I suspect you will be less concerned over OAL precision.

ranger335v
November 2, 2011, 11:54 AM
Book OAL is agonized over far more than it's worth. I've been reloading since '65 and don't recall that I've ever even looked at a book OAL. I've always set my bullets where they need to be for best cartridge function/performance from day one without reguard to what the book makers used to develop their data - because that's all the book lengths mean anyway.

gamestalker
November 2, 2011, 09:39 PM
Ranger335v has said it as best, as can be said.

Reloading gives us the edge over one size fits all by allowing us to seat bullets to the firearm being loaded for. I too don't even gander at book OAL's, they are meaningless unless one is trying to load one size fits all ammo, but why? Just find the OAL that your firearm will accomodate and is at least longer than a book OAL for that bullet, but short enough that it will fit the magazine and not make contact with the lands.

There is nothing wrong with using the book OAL as a minimum refrence point, but I don't use that number as my seating depth unless it just happens to be the same OAL that best fits my firearm.

cberge8
November 2, 2011, 09:54 PM
"Americans measure ammo in thousands of an inch.
I don't even know what 28.83mm is."

Spoken like a true American!

1SOW
November 2, 2011, 09:59 PM
Your three piles "should" all be fine for shooting unless you're loading at one extreme or the other of the load range.

When you set your seating die, "measure" a LOT of cartridge lengths until you know the range of variations your press will give. With careful die adjustments and a steady arm pull, the +/-
variations won't be significant. Once you know what you and your press can do, just periodically check for oal.
Reload enough of the same bullet/load and you'll be able to SEE .003+" (or .08mm) variations by looking at the "shoulder" of the exposed bullet.

Reloading data gives the "minimum oal" the manufacturer gives "for that max load". Longer is no problem as pressure drops when the oal is longer. Unless you are loading to absolute max load, a little shorter hurts nothing at all.

You have the right attitude. Do it right and be safe, but you don't have to be perfect.

Deavis
November 3, 2011, 05:42 PM
short bullets (that risk overpressure) in one pile

I believe you've got that backwards. Your seating die is set in height relative to your shellplate and not the bullet length. When you seat them, the distance from the top of the bullet to the shellpate can't be different between the two bullet lengths. Therefore a longer bullet is going to go deeper into your cartridge and raise the pressure.

Unless you are buying some sort of crappy bullets or are using pulldown, this is should be a non-issue. If you wanted to sort on length a vibratory bowl with dropouts by length is how pull-down bullets are sorted by "weight".

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