338 Lapua bullet question

one.shot.one.kill · January 23, 2010, 02:05 AM

New member, first posting. I guess there's no such thing as a dumb question when it comes to handloading so here goes: why are 338 bullets designated "Lapua" actually 0.339" diameter? Is it not good practice to shoot 0.338" bullets in a 338 Lapua such as the Armalite 30M338?

Jim Watson · January 23, 2010, 07:49 AM

Must have something to do with European practice. I know that at one time Speer sold .30 cal Lapua bullets at .309". A thousandth of an inch makes little difference in internal ballistics. Shoot .338" Sierras and .339" Lapuas and see which is the more accurate.

one.shot.one.kill · January 23, 2010, 12:57 PM

I wonder if anyone has any data that compares pressure/velocity/accuracy of the two diameters??

cali92rs · January 23, 2010, 05:44 PM

Or:
44 Magnum = .430"
454 Casull = .452"
460 S&W Mag = .452"
480 Ruger = .475"

one.shot.one.kill · January 24, 2010, 11:31 PM

I'm only trying to establish the ramifications of using the bullets that are 0.001" over spec. I understand bore diameters and cartridge naming conventions.

K.W. · February 5, 2010, 06:33 AM

For details tables of several densities to different bullets does not succeseed, because the individual weapons.

O, my...was it in English, I wrote?

char923 · February 6, 2010, 11:06 AM

0.001" over spec. = 0.0005" on both sides in turn = a better seal in the barrel and less gas leakage by the bullet in turn better velocity.

wyobohunter · February 6, 2010, 12:17 PM

As others have said, try working up loads for both and see which one your gun likes better.

January 23, 2010, 02:05 AM	#1
one.shot.one.kill Junior Member Join Date: January 23, 2010 Posts: 8	338 Lapua bullet question New member, first posting. I guess there's no such thing as a dumb question when it comes to handloading so here goes: why are 338 bullets designated "Lapua" actually 0.339" diameter? Is it not good practice to shoot 0.338" bullets in a 338 Lapua such as the Armalite 30M338?

February 5, 2010, 06:33 AM	#6
K.W. Member Join Date: April 16, 2008 Location: Finland Posts: 87	No way? For details tables of several densities to different bullets does not succeseed, because the individual weapons. O, my...was it in English, I wrote?

February 6, 2010, 12:17 PM	#8
wyobohunter Senior Member Join Date: August 22, 2008 Location: Back in Wyoming Posts: 1,125	As others have said, try working up loads for both and see which one your gun likes better. __________________ Insanity: doing the same thing over and over again and expecting different results

January 23, 2010, 07:49 AM	#2
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 19,188	Must have something to do with European practice. I know that at one time Speer sold .30 cal Lapua bullets at .309". A thousandth of an inch makes little difference in internal ballistics. Shoot .338" Sierras and .339" Lapuas and see which is the more accurate.

January 23, 2010, 12:57 PM	#3
one.shot.one.kill Junior Member Join Date: January 23, 2010 Posts: 8	I wonder if anyone has any data that compares pressure/velocity/accuracy of the two diameters??

January 23, 2010, 05:44 PM	#4
cali92rs Member Join Date: July 8, 2009 Posts: 38	Or: 44 Magnum = .430" 454 Casull = .452" 460 S&W Mag = .452" 480 Ruger = .475"

January 24, 2010, 11:31 PM	#5
one.shot.one.kill Junior Member Join Date: January 23, 2010 Posts: 8	I'm only trying to establish the ramifications of using the bullets that are 0.001" over spec. I understand bore diameters and cartridge naming conventions.

February 6, 2010, 11:06 AM	#7
char923 Senior Member Join Date: February 18, 2000 Location: Anchorage AK Posts: 237	0.001" over spec. = 0.0005" on both sides in turn = a better seal in the barrel and less gas leakage by the bullet in turn better velocity.