Bullet length differences between brands

[Timothy]

I understand the relationship between cartridge OAL, seating depth, and pressure. Many posters here warn that care should be taken to not seat bullets too deep to avoid dangerous pressure conditions.
Bullet manufacturer’s load data provide OAL numbers for their particular bullets so there is no problem. Powder manufacturer’s load data provide charge information for bullet types by weight....230gr. RN, 180gr. JHP, 220gr. JSP, and so on. Some provide OAL but not all.
So here is the question: Is there a manufacturer’s length standard for each type/weight bullet? If not, it seems to me that if you seat to the powder manufacturer’s suggested OAL the seating depth and accompanying pressure would vary between bullet manufacturers. I assume with lead bullets it’s anyone’s guess.
Yes! I always start on the low end and work up. I am just curious about the effects of different brands of bullets.

 

[P95Carry]

Ya know - I have never really looked into this too much! I guess in most cases, once I have found a good bullet and then load ... I stick to it ..... too lazy to mess with other combinations!

I am very fastidious re OAL .. rifle particularly ...... but would reckon in most cases that length will broadly be a function of bullet weight ... instance my .243 105 grain spitzers ..... very long .. and so when I worked up my load I allowed for this.

Having said that .. the reload tables must also take this into account to a degree .... because as one would expect the charge weight is reduced for the heavier bullet ...... and perhaps does also make allowance for the potential for higher pressure.

Interesting subject.

 

[blades67]

I can offer my experience with Berry's Bullets.

The first bullet I tried was their plated 200 grain SWC with a 1.250" C.O.L. This worked fine in all of my magazines, but not in a friend's Mec Gar for his P220. The nose of the bullet would hang up on the front of the magazine.

The second bullet I tried was their plated 200 grain flat point. The flat point was shorter in overall length, but the base to shoulder measured the same. Using my calipers I measured (using ten randomly selected cartridges) from the case mouth the the flat of the shoulder of the SWC, then set my seating die so that the sloulder of the flat point was at the same overall length. C.O.L. was shorter, but pressures, and velocities, were about the same.

 

[stans]

So here is the question: Is there a manufacturer’s length standard for each type/weight bullet? If not, it seems to me that if you seat to the powder manufacturer’s suggested OAL the seating depth and accompanying pressure would vary between bullet manufacturers.

No, there is no standard, so you are correct, different seating depths will alter pressure. This is why you start over with load development when you switch brands or styles of bullets.

 

[Swamp Yankee]

Why Guess?

Most of the bullet companies such as Hornady, Speer, etc. will give you information as to powder charge weights and cartridge OAL if you call and ask. I have done this many times any found them to be most willing to help.
Take Care

 

[cola8d8]

remove the bolt

put the bullet you want to use in the gun so it touches the rifleing

hold it in with a pencil (from behind)

run a rod down the barrel until it touches the bullet, make a mark on the rod

remove bullet, replace bolt, put a rod in the barrel, make another mark

measure the difference between the 2 marks. That is now the max OAL for that bullet. Now you can deceide how far "off the lands" you want to seat that bullet. Have to do this for every different type of bullet and/or weight.

 

[dodgestdshift]

Use an old deprimed case. Size the neck so it will lightly hold the bullet you are interested in. Seat the bullet very long. Making sure that there is no primer or powder in the case, chamber the round (easily don't jam it in) allowing the rifling to seat the bullet as far as it will go. Carefully remove the cartridge, you now have the max cartridge lenght for that bullet. Shorten the length about 1/16 - 1/8 in. and you are in business.

 

[WESHOOT2]

NOT JUST LENGTH

but material, too; assume NOTHING.

 

[dongun]

IIRC, the OAL listed in the reloading manuals is a standard maximum length established by SAAMI so factory ammo will feed properly in any firearm. This is more critical for autoloaders than for manual feeds. So, for example, on bolt action rifles, it is often possible to use a longer OAL, as long you maintain minimum seating depth.

When establishing a maximum length for a specific rifle, keep in mind that the finished cartridge must also fit in the magazine. On my .308 M700, if I use the maximum length determined by closing the bolt on a extra long test cartridge, it will be too long to fit in the magazine.

 

[blades67]

cola8d8, that's a nifty tip, thanks!