Slightly less OAL any feeding advantage ?

[Road_Clam]

Hello gents,
Quick question for those of you who have been loading 10mm, do you see any feeding advantages by loading the OAL slightly shorter than the typical 1.260 ? I loaded about 24 rounds at 1.250 and seemed to feed excellent.

[erdyalx]

I adjust based on feeding. Some bullet profiles need a shorter OAL to function.

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[The_Shadow]

Most all the 10mm offerings usually are loaded to SAAMI specs of 1.2500" - 1.2600", the exceptions being those wide nose flat points MEPLAT >0.300", where the tipping angles are affected and they usually are seated slight shorter 1.2420".
I load most all of mine to 1.2500"

[tommac919]

read thru this thread....
http://10mm-firearms.com/reloading-10mm-ammo/bullet-feeding-design-issues/

[sqlbullet]

The post tommac919 linked, which was created by The_Shadow is an excellent read.

I have found for best compatibility across my particular guns I should not exceed 1.250" in most bullet designs.  But, it should be noted that this limitation is imposed by my 1911's in 10mm.  The Glock's and Witness guns eat 1.260" ammo all day long without issue.

[The_Shadow]

Another benefit to loading to 1.2500" for the 10mm is that is where the pressure of a loading is usually best served...meaning that the space in the case is usually the optimum.  One 100th of an inch / 0.0100" doesn't seem like much, but it can help with case to bullet tension, providing a better hold on the bullet to allow powder to burn more efficiently before the clears the end of the casing to traverse the chamber to bore. 
The case volume can vary from case manufacture slightly.  Measuring various casings from the pull-downs has shown the lengths vary from 0.9880" (0.0040" shorter) - 0.9770" (0.0150" shorter), whereas SAAMI shows cases at 0.9920", if they were this long could hit the end of the chamber cut, which is also the chamber minimum length and a maximum length of 1.0040" measured from the breech face.

But as handloaders holding to specifics can improve performance overall in our own ammo!

[Road_Clam]

Thanks for all the excellent feedback!

[Ethang]

I unknowingly posted up a question about this on a FB forum... 

Semi autos headspace on the extractor.... prove me wrong...

Hi Wade...

[The_Shadow]

Yes it was a good discussion...