Overal Length question

[adriel]

I'm slightly confused about overal length. I know that Barnes triple X bullets are long, so I measured the length of a loaded cartridge with one, and it seemed wayyyy too long.
300 Win Mag
180 grain Triple X bullet

The picture below shows the bullet at the max overal length as given from "Modern Reloading". It looks ok to me, but from measurements, the bullet base is far extended into the case, which seems weird.

Can anyone set me straight on these?

 

[Boomer]

The bullet shank extending into the body of the case is a problem when you use heavier bullets in cases like the .300 Winchester, which are cursed with short necks. I prefer to have the bullet seated so that it does not extend below the shoulder of the case, but sometimes this is not possible.

When considering OAL in a hunting rifle, the first criteria is that the rounds are short enough to feed through the magazine without hanging up. Target rifles can be single loaded, so the OAL is determined by the amount of jump you want from the bullet's ogive to the rifling.

The length of the bullet extending into the body of the case may effect your choice of powder. It is better, in my opinion, that the powder column is not heavily compressed. The best accuracy is often realized when 96-98% of the case capacity filled with powder. If seating the bullet on top of coarse extruded powder requires effort, choosing a ball powder might be an advantage.

 

[python357]

Oal

I'm not a rifle reloading expert,but I presume that reloading manuals have to take into consideration the thousands of different rifle models and actions "out there". Also, seating the bullet to be at the max distance YOUR rifle lands or mag configuration permits to reduce bullet "jump" is fine, but as soon as you change the type, size, weight, shape etc. of your projectile, you have to make sure that that OAL is STILL valid,otherwise, svere pressure problems can develop.

With all ammunition reloading procedures, SAFE is BETTER than SORRY !

 

[K98ACTION]

I'm not a rifle reloading expert,but I presume that reloading manuals have to take into consideration the thousands of different rifle models and actions "out there". Also, seating the bullet to be at the max distance YOUR rifle lands or mag configuration permits to reduce bullet "jump" is fine, but as soon as you change the type, size, weight, shape etc. of your projectile, you have to make sure that that OAL is STILL valid,otherwise, svere pressure problems can develop.

With all ammunition reloading procedures, SAFE is BETTER than SORRY !

You touched on a point that I wanted to CLEAR UP too. Regarding the OAL, I have been reading Lee Richards latest version of his handloading book. And I must say if I am reading him correctly, he is constantly contridicting himself in his book.

Regarding OAL, at one point he writes, it's ok to seat your bullet far enough out of the casing so that it just touches the rifling when the round is chambered. Ok, so I set a bullet into an empty 8mm casing way out and chamber it carefully so that the bullet is pushed back into the casing when making contact with the rifling. When ejected you now have a custom to your chamber bullet seating to just contact the rifling. (This technique was also in his book)

Anyhow, now when I measured the OAL it came to 3.091". The Hodgons load data for all the loads I wanted indicate an OAL of 2.9xx shorter anyway not by much but the contradiction comes in to play when I read on and pressure is discussed.

Lee writes, that if a bullet is seated out farther than load data specifies, the extra empty volume left behind in the casing as a result, can allow the pressure to build up more than what the data says possibily resulting in an over pressure situation??

Of course he does not go on to say by how much more extra empty case volume this would be. But non the less, now I have some doubt, and when in doubt YOU MUST ASK.

 

[K98ACTION]

I'm slightly confused about overal length. I know that Barnes triple X bullets are long, so I measured the length of a loaded cartridge with one, and it seemed wayyyy too long.
300 Win Mag
180 grain Triple X bullet

The picture below shows the bullet at the max overal length as given from "Modern Reloading". It looks ok to me, but from measurements, the bullet base is far extended into the case, which seems weird.

Can anyone set me straight on these?

Adriel, just a point. Is that a crimp grove on your bullet that I can just see above the casing mouth?? Cause if it is your bullet can be seated even further into the case so that the crimp grove is just past the mouth. There for your bullet maker designed it correctly so that it indeed does set way into the casing. But now this contradicts what other writings say about better accruacy by having the bullet out far enough to contact the rifling, which would probably result in that crimp grove being no where near the case mouth.?? HELP

 

[dan belisle]

If it's a hunting rifle adjust your col so that the round wil cycle through the magazine. If you're trying to wring maximum accuracy from your rifle, adjust the col to give you slight (0.005", 0.010", etc) clearance off the lands. Having the bullet into the rifling is not uncommon in benchrest loading, but NOT a good idea in a hunting rifle. If you set the bullet way out to hit the rifling, you do in effect give the case more internal capacity (the base of the bullet doesn't take up as much room in the case). I would worry more about over pressure caused by jamming the bullet into the lands then I would overpressure from the extra case capacity. Try to use loads that approach 100% of case capacity whenever you can. - dan

 

[woodchopper]

I am using 200grn noslers in my 300WM, they are seated at 3.500" OAL, they are not hitting the lands yet but the mag has problems feeding if I set the bullets out far enough to touch the lands. Anyways for hunting as mentioned above you don't want the bullets engageing the lands, it also makes it hard to extract an unfired round from the chamber

 

[Andy]

The Barnes X bullets are pure copper which is only 80% as dense as copper clad lead. This means that they need to be 25% longer to be the same weight. As a result they have a very long bearing surface, which means more friction (and pressure), and they intrude into powder space which both limits the amount of powder and increases pressure as well. That needs to be taken into account when developing loads. Furthermore, their greater length can impact on the ability of your barrel to stabilize them if you are not careful - in other words if your barrel is just able to stabilize one 180gr bullet (e.g. with a 1:12 twist), it might not stabilize a Barnes X of the same weight.

I always seat my bullets 0.050" from the lands, or max mag length, whichever is longest,as long as I have at least one bullet diameter of bullet gripped by the neck.

With lead bullets I want to have the bottom of the bullet about flush with the bottom of the neck to avoid gas cutting, but with jacketed, i haven't seen any negative effects.

 

[blargon]

Anyhow, now when I measured the OAL it came to 3.091". The Hodgons load data for all the loads I wanted indicate an OAL of 2.9xx shorter anyway not by much but the contradiction comes in to play when I read on and pressure is discussed.

Lee writes, that if a bullet is seated out farther than load data specifies, the extra empty volume left behind in the casing as a result, can allow the pressure to build up more than what the data says possibily resulting in an over pressure situation??

If seating out further, reduce loads to account for pressure changes and work back up. In the LEE manual I believe the loads are "minimum overall length" not maximum. The max for your gun would be where the bullet touches the lands, OR where the cartridge won't fit/feed in your magazine.