OAL and hollow base bullet

[sofbak]

Looking to load up some 200 gr HBRN bear creek bullets in .45acp, and I'm stymied by the OAL. For a 200 gr bullet using W231, my Lee manual says minimum is 1.225". But these bullets are the same length and profile as a 230 gr. solid bullet which has a minimum OAL of 1.200"

How do I account for that cavity on the back side of the bullet, or am I fretting over minutiae here?

Which would be the safer approach, go longer on the OAL than the listed value for 200 gr or shorter?

[CSACANNONEER]

Longer is safer than shorter. However, I'd question the Lee manual. I sort of doubt that it is saying to load a lighter bullet (with the same profile) out longer than a heavier one. Personally, since I don't load close to max pressure, I'd just play with the COAL until I found the right length for my guns. I've had certain profiles not want to feed with certain (premium) mags. Sometimes there are just too many possibilities to give you the one right answer for you. I will suggest ALWAYS consulting more than one reloading manual though.

[sofbak]

....... However, I'd question the Lee manual. I sort of doubt that it is saying to load a lighter bullet (with the same profile) out longer than a heavier one......

Uhm....no. Just to be clear, the Lee manual makes no distinctiion for profile-I did.

Lee manual (W231):

200 gr. lead........1.225 min OAL
230 gr. lead........1.200 min OAL

misprint???

[Bill Steele]

How do I account for that cavity on the back side of the bullet, or am I fretting over minutiae here?

For 45 Auto, yes you fretting too much. 1.2" doesn't work as well as longer in most 45's, so I would load longer anyway, but you are not going to blow anything up loading to 1.2" with the HBRN. Or maybe better said, if you do blow something up it won't be the OAL that caused it.

[sofbak]

For 45 Auto, yes you fretting too much. 1.2" doesn't work as well as longer in most 45's, so I would load longer anyway, but you are not going to blow anything up loading to 1.2" with the HBRN. Or maybe better said, if you do blow something up it won't be the OAL that caused it.

Thankyou. One more question. If I can load longer, how much longer? Seems that I read in one forum or another that "excessive" space in a cartidge from too much OAL for a given charge/powder could lead to an overpressure problem. Is there any rule or science that would indicate where the limit is?

[Bill Steele]

Thankyou. One more question. If I can load longer, how much longer? Seems that I read in one forum or another that "excessive" space in a cartidge from too much OAL for a given charge/powder could lead to an overpressure problem. Is there any rule or science that would indicate where the limit is?

Urban myth stuff. The only condition that has ever been even roughly approximated in ballistics labs is the state where you are loading a very slow rifle powder with a lot of space in the case shot out of a rifle with an extremely rough throat. The condition that has been replicated is the primer blast moves the bullet into the throat before the powder burns fast enough to get the bullet really moving (because of the extra space in the case, powder burns slower with less pressure), the bullet sticks in the rough throat and pressures spike. Pistol powders burn fast enough that the extra space in the case is not a problem. Powder puff loads of 50 BMG, maybe; 45 Auto, no problem.

You will read people swear up and down they blew their gun up with an under change with stories of flashovers, shaped charges, all sorts of nonsense. Richard Lee has a good write up regarding this very subject in his 2nd edition reloading guide, including rules of thumb for minimum load density based on relative burn rates starting with 50BMG and working up the burn rate chart. Worth the price of the book alone.

For 45 auto, I load my 200gr LSWC to 1.270", my 230gr LRN to 1.265" (for optimal feed, not pressure or powder considerations), when I am loading light with Bullseye, you can barely see the powder down in the case before you set the bullet.

Good luck, have fun.