min/max oal

[bach]

I'm reloading 30-30 using lee data and 150 grain bullets and win760 powder.

The max oal is the same as the min oal. I'm not sure how to handle this.

 

[Wreck]

I use hodgdon/ winchester ( free pdf) load data for my 30-30. Most loads only state a COL 2.550"

 

[Nanook]

If min OAL and max OAL are the same number, it stands to reason that should be the OAL you should load.

To loosely quote Monte Python: "If the number is three, than three shall it be." Jump to 1:26 or so.

 

[alucard0822]

You have to understand where the numbers come from. Min OAL is actually an airspace spec, or when the bullet is seated, how much volume is there for powder and air in the case. It's important because case volume for a given charge relates to pressure, volume for a given charge decreases, pressure increases. This is also why you want to make sure you have good neck tension and a good crimp if needed to prevent setback, or the bullet getting pushed deeper in the case when chambering. The number is a spec though, usually the OAL that the velocity and pressure data was obtained for with that load, and that pressure may be under the max SAAMI spec, so you may be able to load shorter, and still be "safe", not a big deal with 30-30 as much as it is when fitting a particular round in a box mag.

The MAX OAL is purely related to bullet design and chamber specs. The idea is to place the bullet in a position that it engages the rifling quickly when fired for better accuracy, but the bearing surface is not so far out as that would jam into the rifling or cause setback on a dirty rifle, and in some models mag length is an issue. Bullet shape can give you a long tapered bullet that might load to a much longer OAL than a short fat round one, and for this reason you have to watch using specs for a bullet of the same weight, but different brand or model. COL or cartridge overall length is a simpler measurement, it is simply the OAL tested for that given load with that particular bullet, and should be copied directly, but if you have a need to load longer or shorter, you may be able to, although will end up with different pressure numbers as a result. In the case a book has a chart formatted with the min/max OAL, but they had a single COL spec, they probably would put the same number in both spots.

 

[bach]

Great info, thanks.

The bullet I'm using has a cannelure, it may be outside the case to get 2.55. Is that an issue?

I am using a lee crimp die, and these are just for target shooting.

 

[Pinecone]

.30-30 is typically crimped into a cannelure (groove) on the bullet. So for a given bullet there is pretty much one proper length.

 

[bach]

So I think my issue is that the once fired Remington cartridges are coming up short. The max trim length is 51.79 mm, and mine, after full length resizing, are measuring around 51.60 to 51.65. I can't get 64.77 mm (I switched to mm ... 64.77mm = 2.550") when I seat the bullet to the cannelure.

Is it possible the cartridges were manufactured at the minimum case length?

 

[Biggfoot44]

In this particular situation, it's kind of simple.

Use a bullet intended for .30-30 usage . Crimp into cannelure (crimp groove) .

The .30-30 ctg , and the feeding requirements of the teo overwhelming Iconic platorms are well know to component mfgz, and they figured out the issues 100 years ago.

If yoiu were to use .30-30 bullets in other ctgs , or load pointed bullets for single loading in a lever , then you would have to deal with C.O.L. issues.

 

[Pinecone]

I agree, just load them and crimp to the cannelure and stop obsessing.

 

[bach]

I agree, just load them and crimp to the cannelure and stop obsessing.

I didn't think I was "obsessing". I've loaded and fired 30-06 and 8mm mauser and haven't seen this issue before. I was concerned about the reduced case capacity in combination with the fact that my 13 year old son will fire these loads.

 

[bach]

In this particular situation, it's kind of simple.

Use a bullet intended for .30-30 usage . Crimp into cannelure (crimp groove) .

The .30-30 ctg , and the feeding requirements of the teo overwhelming Iconic platorms are well know to component mfgz, and they figured out the issues 100 years ago.

If yoiu were to use .30-30 bullets in other ctgs , or load pointed bullets for single loading in a lever , then you would have to deal with C.O.L. issues.

I am using a 30-30 usage bullet.

Could you please explain what "the teo overwhelming Iconic platorms " means?

 

[Biggfoot44]

The means my fingers slipped. The OAL for proper cycling in Win 94s , and Marlins was established from the start , every subsequent repeating .30-30 since was designed to be compatable with industry standard specs. Any component mfg would marketed a flat nose .30 bullet w/ a cannalure that didn't work in a .30-30 so seated would have had huge recalls and mega bad press.

If you are loading spitzer bullets for a single shot , then you have to pay attention to min OAL , throating , etc.

 

[Pinecone]

I didn't think I was "obsessing".

That was why the was there.

Unless you are running a max load, it is unlikely to have any pressure problems.

And if you are running a max load, without working up from a minimum load, you are asking for trouble in ANY gun.

 

[bach]

Just starter loads for me.

And thanks to both of you for the patience with my questions.