Overall length

[NJM15]

My Lee reloading book shows max OAL for each caliber
what do you set at ? I measure a new round and go from there,
a new round is considerably shorter than the max shown in the book Revolvers are not as critical as semi's. I load 9,40's
.223's and .357 sigs.

 

[Vortec MAX]

Each bullet will have it's own specific recommendation. I have a reloading manual from almost every manufacturer. I refer to these when deciding on the OAL I will use for a specific bullet.

Mike

 

[Nevada Ed]

Company spec's and manual data is nice...................

but I also like a OAL that works my action without any problems
jams, stove pipes etc.......... even if +/- the data.
Some Pistols do better with shorter or longer OAL

Almost anything works in a Revolver................as long as one does not get "Stupid".

Second, that these "Different OAL are safe and if lucky enough...
accurate.

 

[Twoboxer]

My Lee reloading book shows max OAL for each caliber
what do you set at ? I measure a new round and go from there,
a new round is considerably shorter than the max shown in the book Revolvers are not as critical as semi's. I load 9,40's
.223's and .357 sigs.

Reloading data includes the COL at which the testing was done. So the COL FROM YOUR RELOADING SOURCE is a good starting point.

Make a dummy round at that COL, and check to see if it feeds.

Make a few rounds (like 5) and test for functionality at the range.

 

[H Richard]

The COL Max is usually set per specific bullet Mfg/design as the max length that will function in the action. Very often a different Mfg. bullet will be set at a different length to accommodate either the max length, or the "minimum" length which can relate to pressure Max (internal space available for powder burn). Either can give yo problems, but if you stay below the max length and above the minimum length you should be O.K. Pay particular attention with revolver bullets, some are RNFP (flat point) and they will normally be shorter than a plain RN bullet.

 

[mikld]

Max. OAL means just that; maximum length, can be no longer than. Normally a dimension like that will have a minus .020" tolerance. So, you can't (shouldn't) go any longer than the max. listed, but you can go up to .020" shorter. Your gun is the final say so on good OAL (magazines, chambering [plunk test], distance off lands, etc.).

I'm not a fan of the Lee Modern Reloading manuals, and much prefer a Lyman 49th for general use and for specific jacketed bullet loads I'll go with the bullet manufacturer's manual (I shoot a lot of Hornady bullets, so I use a Hornady manual). As a new reloader, just stick with the dimensions in your manual unless there is a specific problem.

 

[SMSgt]

I completely disregard the published COL and set my own.

 

[uechikid]

I completely disregard the published COL and set my own.

So if you use a COL that is shorter than the tested and recommended COL wouldn't that cause the pressure inside the case to be greater than the tested load? Might that cause a potentially dangerous situation?

 

[rwsmith]

Yes it would....

So if you use a COL that is shorter than the tested and recommended COL wouldn't that cause the pressure inside the case to be greater than the tested load? Might that cause a potentially dangerous situation?

But large cases like the .38 (from black powder days) are MUCH more forgiving than smaller semi auto cases. I never used a caliper loading .38, just put it where it 'looked good'. With bullets that you can find nowadays instead of bullets you want, you have to come to a reasonable OAL from the data that you do have. Similar bullet profiles, weight and all that. And if you're not sure with a semi auto cartridge, make it a little longer rather than a little shorter.

 

[fredj338]

There really is no book max oal. There is a saami max, but as always, oal is gun & bullet specific, always. Every barrel Is diff & there are far too man diff bullet styles to some up with a true max.

 

[Engineer1911]

Your AR will work with a COL = 2.250" . That does not mean that same cartridge will fit in a bolt gun chamber. I have learned that painful lesson the hard way. I won't bore you with the MISERABLE details.

 

[mikld]

So if you use a COL that is shorter than the tested and recommended COL wouldn't that cause the pressure inside the case to be greater than the tested load? Might that cause a potentially dangerous situation?

I've seen this type of reply to many OAL questions. But, how much shorter can an OAL go before it gets dangerous? Is there a percentage or ratio of pressure rise per .010" of case capacity loss? Or are those answers just what has been repeated, without facts, on reloading forums? Please no "I saw a set back in a 45 ACP that blew up a 1911..." type retorts...

I'm beginning to think this is just internet lore. Yes a major bullet setback can cause dangerous rises in pressure, but how far must a bullet be seated "short" to really raise pressure to a dangerous level?

 

[ChiefStealth]

I've seen this type of reply to many OAL questions. But, how much shorter can an OAL go before it gets dangerous? Is there a percentage or ratio of pressure rise per .010" of case capacity loss? Or are those answers just what has been repeated, without facts, on reloading forums? Please no "I saw a set back in a 45 ACP that blew up a 1911..." type retorts...

I'm beginning to think this is just internet lore. Yes a major bullet setback can cause dangerous rises in pressure, but how far must a bullet be seated "short" to really raise pressure to a dangerous level?

Nope! I've never seen data, or charts, or graphs, or anything else that verifies that you get X increase in pressure for every Y change in OAL. Never seen that. We know it does happen. We know we need to be careful when we get near a max load. We know that we have to stay within certain guidelines. But, just how much is bad? Ehhh... who knows? And, if ya never get near a max load, is it even an issue? However, speaking as the guy next to you at the range... please keep it between the lines.. will ya?

 

[fredj338]

I've seen this type of reply to many OAL questions. But, how much shorter can an OAL go before it gets dangerous? Is there a percentage or ratio of pressure rise per .010" of case capacity loss? Or are those answers just what has been repeated, without facts, on reloading forums? Please no "I saw a set back in a 45 ACP that blew up a 1911..." type retorts...

I'm beginning to think this is just internet lore. Yes a major bullet setback can cause dangerous rises in pressure, but how far must a bullet be seated "short" to really raise pressure to a dangerous level?

No, too many variables; powder burn rates, bore size, bullet type. Oal matters, just not as much with some powders in some calibers. Unless you are putting the bullet into the rifling, oal variations +/- 0.010" means nothing to any caliber, any powder.
How much is dangerous? As little as 0.060" can be dangerous in high pressure/small volume rds like 9mm, 357sig & 40, IF you are already running max loads. If you are at midrange & below, it's harly noticeable, even seating deeper than that.

 

[moxie]

Factory is a good start

Factory OAL is a good reference provided the bullet you are using is the same weight and profile.

 

[aurora40]

Is there a percentage or ratio of pressure rise per .010" of case capacity loss? Or are those answers just what has been repeated, without facts, on reloading forums?

I'm beginning to think this is just internet lore. Yes a major bullet setback can cause dangerous rises in pressure, but how far must a bullet be seated "short" to really raise pressure to a dangerous level?

No one can show me the percentage rise for each 10 flakes of powder I add. Does that mean that increased powder amount causing increased pressure is just Internet lore?

Almost no one owns pressure measuring equipment to tell you an exact amount. Plus the percentage would depend on many variables, including how much capacity there was to start with. However pressure and volume being related is pretty well established. Just like gunpowder and pressure.

 

[mikld]

I guess what I'm pointing out is an awful lot of posted warnings are just repeats of prior posts; something someone saw on another forum. I cast my own bullets and there is a lot of un substantiated "facts" and warnings nearly every day and I have found mebbe 25% contain any facts, and many of those facts distorted to make the poster sound like an "expert". I believe the same happens when warnings are given about "load too short and you'll blow up yer gun!" type responses. Yes, it can happen, but how many times does it really happen (if a 230 gr. 45 ACP is pushed back into the case an additional 1/2" I'd say there's a good chance of an over pressure situation).

Jes an old guy thinkin' about forum "facts"...

 

[fredj338]

It's easy to see for yourself, just run some chrono tests. All things being equal in a load, changes in vel = changes in pressures.
I ran some tests in 9mm & 45, using WST & Unique. With upper midrange loads, changing oal 0.020" each time, no significant increase in vel occurred until I passed 0.060". Obviously the 9mm with faster WST, showed the greatest increase.
Load a slow enough powder, stay well off max, even seating 0.120" isn't going to show much vel/pressure increase in something like the 45acp. Certainly not taking a gun apart.