.308, 150 and 168 gr bullets making different holes

Kayser · September 30, 2011, 01:48 PM

I've been loading Hornady 150 gr FMJ for my 308 for years now. Always shoots excellent (<= 1" groups @ 100). Today I tried out some 168 gr (Hornady, hp bt). They also shot great.

But I noticed something interesting. The 168 gr loads make perfectly circular little holes in paper. As if you were using a punch. The 150's have always made jagged holes - little rips that splay out from the hole itself. It's a very stark difference. What causes this? Velocity difference? Cannelure vs. no cannelure?

Brian Pfleuger · September 30, 2011, 01:52 PM

Different bullets make different holes.... I believe that's why the "wadcutters" were invented, to make perfect holes in targets for scoring purposes. Otherwise, every bullet is a little different.

Doodlebugger45 · September 30, 2011, 02:30 PM

Probably from the HP on the 168's. If it's a fairly wide hollow point, they will start the hole by "cutting" first. The FMJ just kind of shove their initial entrance point into the paper. I see it relly clearly comparing the holes my 44 mags make with the Keith style SWC compared to the RN bullet I shoot in .45 Colt.

FrankenMauser · September 30, 2011, 03:56 PM

Aye, it's the bullet shape.

The hollow point of the 168s is cutting a nice little hole in the center, so the rest of the bullet doesn't have to tear the paper as much as the non-cutting FMJs.

If you want to see the results of this difference first-hand, you can run an easy experiment:
Find a cheap soft point bullet with a decent sized exposed lead tip, such as the Speer Hot-Cor (Nosler ballistic tips would work well, too).
Load 10 rounds to the same specifications.
Trim the exposed lead tip off of 5 rounds (or cut the plastic ballistic tip off), so it's flush with the end of the jacket. (nice and straight)
Fire the standard bullets.
Fire the trimmed bullets. (You may lose some accuracy by trimming, but that's not the point here. -No pun intended.)
Compare the holes in the paper.

The wider meplat (trimmed) bullets will "cut" a cleaner hole.

September 30, 2011, 01:48 PM	#1
Kayser Senior Member Join Date: May 29, 2002 Location: Illinois :( Posts: 550	.308, 150 and 168 gr bullets making different holes I've been loading Hornady 150 gr FMJ for my 308 for years now. Always shoots excellent (<= 1" groups @ 100). Today I tried out some 168 gr (Hornady, hp bt). They also shot great. But I noticed something interesting. The 168 gr loads make perfectly circular little holes in paper. As if you were using a punch. The 150's have always made jagged holes - little rips that splay out from the hole itself. It's a very stark difference. What causes this? Velocity difference? Cannelure vs. no cannelure? __________________ ----------------- Box Of Truth Afficionado!

September 30, 2011, 01:52 PM	#2
Brian Pfleuger Moderator Emeritus Join Date: June 25, 2008 Location: Austin, CO Posts: 19,578	Different bullets make different holes.... I believe that's why the "wadcutters" were invented, to make perfect holes in targets for scoring purposes. Otherwise, every bullet is a little different. __________________ Nobody plans to screw up their lives... ...they just don't plan not to. -Andy Stanley

September 30, 2011, 03:56 PM	#4
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	Aye, it's the bullet shape. The hollow point of the 168s is cutting a nice little hole in the center, so the rest of the bullet doesn't have to tear the paper as much as the non-cutting FMJs. If you want to see the results of this difference first-hand, you can run an easy experiment: Find a cheap soft point bullet with a decent sized exposed lead tip, such as the Speer Hot-Cor (Nosler ballistic tips would work well, too). Load 10 rounds to the same specifications. Trim the exposed lead tip off of 5 rounds (or cut the plastic ballistic tip off), so it's flush with the end of the jacket. (nice and straight) Fire the standard bullets. Fire the trimmed bullets. (You may lose some accuracy by trimming, but that's not the point here. -No pun intended.) Compare the holes in the paper. The wider meplat (trimmed) bullets will "cut" a cleaner hole. __________________ Don't even try it. It's even worse than the internet would lead you to believe.

September 30, 2011, 02:30 PM	#3
Doodlebugger45 Senior Member Join Date: April 15, 2009 Location: Wyoming Posts: 1,717	Probably from the HP on the 168's. If it's a fairly wide hollow point, they will start the hole by "cutting" first. The FMJ just kind of shove their initial entrance point into the paper. I see it relly clearly comparing the holes my 44 mags make with the Keith style SWC compared to the RN bullet I shoot in .45 Colt.