# Oal



## Wandering Man (Jul 9, 2006)

How far should/could you back off the Over All Length listed in the reloading manuals when loading your own. Should you get as close as possible without going over, or is it a good thing to make the round a bit shorter?

WM


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## Baldy (Jun 21, 2006)

Hi Wandering Man. There is no set number as some bullet are made longer than others. I set most all my .45s at 1.225" and the book calls for 1.227". But they are using ball and I am using a semi wad cutter. You'll get the feel for it. I have gone as low as 1.221" with a short made bullet. Good luck.


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## Bob Wright (May 10, 2006)

Overall Length is relative. It is of primary concern in autoloaders where feeding/chambering is a prime consideration. And, as Baldy points out, bullet lengths vary.

Using maximum charges, seating the bullet too deeply will result in reduced space in the loaded cartridge and increased pressure. Too long, and the round may fail to chamber, or, in the case of revolvers, stick out the front of the cylinder, which I've had happen in guns with short cylinders, such as the Colt Python.

With revolver bullets, there is a crimping groove which pretty well dictates seating depth. But auto pistol bullets have no groove. Some cases have a cannelure to mark the base of the seated bullet.

Bottom line: Trial and error. Work up your loads carefully to find out which works best for you, and your gun.

Bob Wright


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## TOF (Sep 7, 2006)

What the others said +:
The barrel of your gun and shape of bullet may dictate shorter OAL than some charts indicate. Not all bullets come with powder charts to match.

The XD9 service model I had required more setback than my M&P9 with some bullets because the rifling started very close to the chamber in the XD. My M&P has .150 inch from end of chamber to beginning of rifling.

Some Berry 124 grain hollow points I bought had to be set way back to prevent running into the rifling before the XD was in battery. 

If you are trying to use max-min load charts for bullets other than what you are using, greater setback can yield disasterous pressures increases. Using OAL shorter than chart values for a specific bullet will also yield increased pressure.

The key is to determine what effective case volume your powder charge chart is based on. Any decrease in volume due to setback will result in higher pressure than expected.

I have confused the issue enough so will just say be carefull and have fun.:mrgreen:

:smt1099


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## Wandering Man (Jul 9, 2006)

I was just trying to figure out if there is an ideal lenght.

Right now I've got a .380 round in my Kel Tec that I can't eject. I think there might have been some creeping forward, as it is the only round that I've been aware of that has had that problem.

I better take another look at my crimps ... and my OAL's.

WM


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## TOF (Sep 7, 2006)

WM
If you are dealing with a stock pistol, as opposed to custom race guns, you will not want to exceed design maximuim OAL. The main reference I use for design max is the Lee manual.

Enjoy :smt1099


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## mactex (Jan 23, 2007)

To all the great information above, I'd like add that reloading charts should also include a minimum overall length for each type/style of bullet. If you find a spot between the minimum and maximum that works with your gun all will be well.

Another issue I keep in mind when looking at seating depth is the tolerances of my press. My Lee O-frame press has enough variance between rounds that I shoot for somewhere in the middle to ensure I don't go over the max or under the min.


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