How Much Sleep To Lose Over Oal?

[thefish]

I am loading mostly MG 180's w/3.9 of TiteGroup in a Glock 35. My OAL is pretty consistent @1.125 give or take .003. What advantages and/or problems are there in manipulating my OAL either higher or lower? Does it affect accuracy?...does it affect recoil?...is a short OAL more dangerous b/c of higher pressures?...do lighter (i.e., 165gr) bullets behave differently?

In a nutshell...if the rounds are consistent and they fit/feed in the gun, how much should I even worry about OAL's?

Thanks in advance for your help.

[HSMITH]

You have a sound load and a good OAL. Leave it alone, it works and that is number one.

For what we do with a handgun the differences in accuracy or recoil that might come from tweaking the OAL are insignificant.

That said, I play with loads quite a bit mostly just out of a quest for knowledge whether that knowledge will help me or not. My G22 doesn't really care what the OAL is, or at least I can't shoot it well enough to see a difference. Major ammo is about all I have ever shot in any quantity from it and the gun is darn sharp no matter what I feed it. I can't tell enough difference on the timer to tell you that any powder I have tried is much better than another from the G22.

If you really want to know try changing things up. Document what you are doing and what the results were, go slow and be careful. There isn't anything to lose but a little time and a little money if you do test a few changes.

[bgary]

I'm no expert, but my experience has been that the two considerations are feeding and pressure. As a secondary issue, length *can* affect velocities, which can in turn affect accuracy.

If you're within a hundredth (.010), the gun runs consistently, and you're not getting pressure signs, and you're making your declared power factor, I wouldn't lose sleep over it. On the other hand, if you're getting feeding problems, or bulging primers, or weird accuracy issues, one of the things to look at would be OAL.

$.02

Bruce

[n2ipsc]

What advantages and/or problems are there in manipulating my OAL either higher or lower? Does it affect accuracy?...does it affect recoil?...is a short OAL more dangerous b/c of higher pressures?...do lighter (i.e., 165gr) bullets behave differently?

In a nutshell...if the rounds are consistent and they fit/feed in the gun, how much should I even worry about OAL's?

Thanks in advance for your help.

In a nutshell - don't.

YMMV, but my personal mantra has always been 1) determine OAL for dead-reliable feeding (note that this will vary by bullet type - not just weight), then 2) adjust velocities with powder charge to suit, #1 being by far the most important.

There's been a fair amount of press re. the criticality of OAL (or, more specifically, bullet seating depth) with small-capacity cases and heavy bullets (e.g. 9mm's, where a small change in seating depth/OAL, and/or military vs. commercial cases, can have large impacts on pressures), but, generally, this is problematic only at the red line, or sub-optimal combinations of too-heavy projectiles and too-fast powders. Stick with published reloading data - including OALs - and you'll be fine. If your toy wants an OAL materially shorter than published data, caution would dictate backing way off the published load and carefully working back up, but this should be a very rare to non-existent occurrence.

[bgary]

generally, this is problematic only at the red line, or sub-optimal combinations of too-heavy projectiles

Dang, those are some pretty big words for a 12-year-old!

B

[billdncn]

If you're within a hundredth (.010), the gun runs consistently, and you're not getting pressure signs, and you're making your declared power factor, I wouldn't lose sleep over it.

Bruce

.010 = ten thousandths, not a hundredth

Sorry...........someone had to do it

Edited September 7, 2006 by billdncn

[thefish]

What advantages and/or problems are there in manipulating my OAL either higher or lower? Does it affect accuracy?...does it affect recoil?...is a short OAL more dangerous b/c of higher pressures?...do lighter (i.e., 165gr) bullets behave differently?

In a nutshell...if the rounds are consistent and they fit/feed in the gun, how much should I even worry about OAL's?

Thanks in advance for your help.

In a nutshell - don't.

YMMV, but my personal mantra has always been 1) determine OAL for dead-reliable feeding (note that this will vary by bullet type - not just weight), then 2) adjust velocities with powder charge to suit, #1 being by far the most important.

There's been a fair amount of press re. the criticality of OAL (or, more specifically, bullet seating depth) with small-capacity cases and heavy bullets (e.g. 9mm's, where a small change in seating depth/OAL, and/or military vs. commercial cases, can have large impacts on pressures), but, generally, this is problematic only at the red line, or sub-optimal combinations of too-heavy projectiles and too-fast powders. Stick with published reloading data - including OALs - and you'll be fine. If your toy wants an OAL materially shorter than published data, caution would dictate backing way off the published load and carefully working back up, but this should be a very rare to non-existent occurrence.

Thanks again for taking the time to reply.

Regarding OAL's that are on the long side: can that also cause hi pressure problems b/c the bullet may be touching or almost touching the rifling, or do OAL's on the long side usually manifest themselves by not feeding?

Edited September 7, 2006 by thefish

[Steve Moneypenny]

Sleep easy a couple of thousandths doesn't make much difference. OAL in pistols doesn't effect accuracy very much in rifle cases it's a whole other story. but again your working with much faster moving projectiles.

if too short you can have too much pressure. (too little capacity) if too long you can have too much pressure ( no "jump" between rifling and the bullet) if too long or too short there are feeding issues either in the magazine (too long) or comingout of the magazine (too short)

don't stress over a thousandth

[Scott R]

If you're within a hundredth (.010), the gun runs consistently, and you're not getting pressure signs, and you're making your declared power factor, I wouldn't lose sleep over it.

Bruce

.010 = ten thousands, not a hundreth

Sorry...........someone had to do it

Then how many thousandths are equal to a hundredth?

[HSMITH]

A= 100 thousandths = one tenth........

[wide45]

.1 = one tenth

.01 = one hundredth

.001 = one thousandth

[Harmon]

if you put a zero on the end of .01, it becomes .010 which is ten thousandths.

with out the zero, its 1 hundredth.. its all about precision.

the zero was there for a reason and shouldnt be rounded off.

Back to topic...i dont like my ammo to vary more the 5 thousandths any more and there is a problem somewhere.

Harmon

Edited September 13, 2006 by Harmon