Bullet weight variations from the mean

chucko · August 22, 1999, 04:15 PM

I'm current looking into reloading. I've just bought a scale and was weighing some pulled bullets of various makes and manufacturers. and noticed some inconsistancies.

What is an acceptable tolorance from the designed weight of a bullet?

For example:

.308 168gr Sierra Match King

What is generally accepted as the maximum deviation from the designed bullet weight.

2.0gr? 1.0gr? 0.5gr? .25gr?

Thanks,
Chuck

Geoffreyt · August 22, 1999, 05:19 PM

Dude, Im not exactly sure of the mean, etal, but if one samples bullet variation by weight, I would think 1 to 1.5 % of the intended weight would be norm. No more. Also, lead bullets may vary more than jacketed. And as bullets become more expensive, variation should deminish!

Art Eatman · August 22, 1999, 08:01 PM

Match bullets oughta be pretty close to perfect, I'd guess. Maybe 0.1 to 0.2 grains?

Is there a web site for the bench rest guys? I just thought of this, posting to Joe Portale's questions, and haven't searched, yet...

Have you asked any of the bullet-makers, via their web sites?

Note that for ranges out to 200 yards or so, it will only matter in top BR competition--but they are trying for one-hole perfection. Even a 1% deviation should give a ragged one-hole group at 100 yards, all else being close to perfect.

I've shot as tight a group with deformed-nose soft-points as with pristine ammo, but this is hunter's accuracy around 3/4" at 100 yards.

FWIW, Art

Later: Okay. http://www.benchrest.com is the place to browse. I didn't get into forums or loading...

Nighty-bye...

[This message has been edited by Art Eatman (edited August 22, 1999).]

swifter... · August 22, 1999, 09:40 PM

I've found that "premium" bullets, like, say, Berger MEF's, will vary no more than 0.1 or 0.2 gr. from their stated weight.

Hand cast lead pistol bullets I sort at about 2% of "oughta-be" weight. That's the weight on the mould, and 2% in either direction. I can't hold close with a pistol like I can a rifle, tho.

But if you're looking at a 150 gr .308 bullet, 1%= 1.5 gr. That may get you deer rifle accuracy, but not varmint or benchrest accuracy.
Most factory ammo does not use premium bullets, BTW...
Hope this helps!

------------------
The Bill of Rights, and the Golden Rule are enough for civilized behavior. The rest is window dressing. Shoot carefully, swifter...

chucko · August 22, 1999, 10:34 PM

Thanks Everyone!

This is exactly what I was looking for. I was trying to figure out how anal I needed to be about my bullet weights. Now I know that the couple tenths of a grain variation I was seeing is just fine.

Chuck

Cheapo · August 23, 1999, 04:27 PM

Yeah, I seem to remember people getting 1 MOA out to 600 yards using USGI 173-gr. match ammo. Those can run up to +/- 1 full grain.

August 22, 1999, 04:15 PM	#1
chucko Senior Member Join Date: May 20, 1999 Posts: 151	I'm current looking into reloading. I've just bought a scale and was weighing some pulled bullets of various makes and manufacturers. and noticed some inconsistancies. What is an acceptable tolorance from the designed weight of a bullet? For example: .308 168gr Sierra Match King What is generally accepted as the maximum deviation from the designed bullet weight. 2.0gr? 1.0gr? 0.5gr? .25gr? Thanks, Chuck

August 22, 1999, 05:19 PM	#2
Geoffreyt Junior Member Join Date: August 21, 1999 Posts: 5	Dude, Im not exactly sure of the mean, etal, but if one samples bullet variation by weight, I would think 1 to 1.5 % of the intended weight would be norm. No more. Also, lead bullets may vary more than jacketed. And as bullets become more expensive, variation should deminish!

August 22, 1999, 08:01 PM	#3
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	Match bullets oughta be pretty close to perfect, I'd guess. Maybe 0.1 to 0.2 grains? Is there a web site for the bench rest guys? I just thought of this, posting to Joe Portale's questions, and haven't searched, yet... Have you asked any of the bullet-makers, via their web sites? Note that for ranges out to 200 yards or so, it will only matter in top BR competition--but they are trying for one-hole perfection. Even a 1% deviation should give a ragged one-hole group at 100 yards, all else being close to perfect. I've shot as tight a group with deformed-nose soft-points as with pristine ammo, but this is hunter's accuracy around 3/4" at 100 yards. FWIW, Art Later: Okay. http://www.benchrest.com is the place to browse. I didn't get into forums or loading... Nighty-bye... [This message has been edited by Art Eatman (edited August 22, 1999).]

August 22, 1999, 09:40 PM	#4
swifter... Senior Member Join Date: March 16, 1999 Location: So. CA Mountains Posts: 540	I've found that "premium" bullets, like, say, Berger MEF's, will vary no more than 0.1 or 0.2 gr. from their stated weight. Hand cast lead pistol bullets I sort at about 2% of "oughta-be" weight. That's the weight on the mould, and 2% in either direction. I can't hold close with a pistol like I can a rifle, tho. But if you're looking at a 150 gr .308 bullet, 1%= 1.5 gr. That may get you deer rifle accuracy, but not varmint or benchrest accuracy. Most factory ammo does not use premium bullets, BTW... Hope this helps! ------------------ The Bill of Rights, and the Golden Rule are enough for civilized behavior. The rest is window dressing. Shoot carefully, swifter...

August 22, 1999, 10:34 PM	#5
chucko Senior Member Join Date: May 20, 1999 Posts: 151	Thanks Everyone! This is exactly what I was looking for. I was trying to figure out how anal I needed to be about my bullet weights. Now I know that the couple tenths of a grain variation I was seeing is just fine. Chuck

August 23, 1999, 04:27 PM	#6
Cheapo Senior Member Join Date: November 19, 1998 Posts: 986	Yeah, I seem to remember people getting 1 MOA out to 600 yards using USGI 173-gr. match ammo. Those can run up to +/- 1 full grain.