Reloading for Accuracy

keys85 · October 3, 2008, 02:15 AM

It's been said and done that seating the bullet .010" off the lands of your rifle will probably achieve the best accuracy. Does this hold true with pistols?

I loaded up a round that was .040" longer than the cartridge's max COL for my pistol. It runs in the magazine fine. It chambers fine. My pistol seems to have a long throat so it will reliably feed and chamber rounds far longer than the factory spec max COL. By seating closer to the lands, much like in loading for a rifle, can this give an extra aid to accuracy?

The recommended load data is given for this bullet .065" shorter. Will seating my bullet this far forward lose substantial velocity or is it negligible, say, .1 or .2 grains powder difference? This is for the .40 S&W.

VaFisher · October 3, 2008, 08:11 AM

Quote:

Does this hold true with pistols?

Depends alot on the gun you are using, remember the barrels float to a degree depending on bushings. As long as it's feeding okay I don't see any wrong it but the only way to find out if it's more accurate is to shoot it.

**Unclenick** · October 3, 2008, 08:30 AM

letting the bullet actually touch the lands will help cast bullet accuracy in a pistol. It doesn't seem to do much for jacketed bullets. The purpose is to better line the bullet up in the barrel. At pistol pressures and velocities, jacketed bullets can usually find their own center pretty will. Rifles are another story. Some rifles like a load developed with bullets touching the throat, some don't. You usually have to adjust that to the rifle's individual preference. The result for a rifle is usually a bullet seated somewhere between 0.010" to 0.030" off the lands, but sometimes it is more. Don't worry too much about carrying rifle principles over to the pistol.

Seating out will cost you about 50 fps out of 1000. How much powder is needed to bring the pressure back up depends on the components used. It's not easy to generalize about. With Unique powder and a 180 grain jacketed bullet it looks like about a 7% increase in the .40 S&W. It will be less or more with other powders and bullets and may change with the primer you choose.

Alleykat · October 3, 2008, 09:01 AM

Quote:

It's been said and done that seating the bullet .010" off the lands of your rifle will probably achieve the best accuracy. Does this hold true with pistols?

Starting a thread based on a false premise just never made any sense to me. The first sentence of the above quote is a false premise.

WESHOOT2 · October 5, 2008, 11:24 AM

Easy way to discern it is to actually test for accuracy.

I know, way too logical.

wncchester · October 5, 2008, 03:00 PM

"It's been said and done that seating the bullet .010" off the lands of your rifle will probably achieve the best accuracy."

As Alley implies, that's beer hall ballistics BS, along with a LOT of other so-called "truths".

Best accuracy is where you find it. There are no valid rules and no shortcuts, only YOUR experimentation with YOUR load in YOUR rifle will let you know what works best for YOU. That's why "pet loads" are almost laughable in application, even a Ken Waters load won't apply to maybe 80% of the cartridges it tries to "help" with. That's little better than picking a load out of a loaidng book using a dart.

October 3, 2008, 02:15 AM	#1
keys85 Junior member Join Date: September 21, 2008 Posts: 199	Reloading for Accuracy It's been said and done that seating the bullet .010" off the lands of your rifle will probably achieve the best accuracy. Does this hold true with pistols? I loaded up a round that was .040" longer than the cartridge's max COL for my pistol. It runs in the magazine fine. It chambers fine. My pistol seems to have a long throat so it will reliably feed and chamber rounds far longer than the factory spec max COL. By seating closer to the lands, much like in loading for a rifle, can this give an extra aid to accuracy? The recommended load data is given for this bullet .065" shorter. Will seating my bullet this far forward lose substantial velocity or is it negligible, say, .1 or .2 grains powder difference? This is for the .40 S&W.

October 3, 2008, 08:30 AM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,743	letting the bullet actually touch the lands will help cast bullet accuracy in a pistol. It doesn't seem to do much for jacketed bullets. The purpose is to better line the bullet up in the barrel. At pistol pressures and velocities, jacketed bullets can usually find their own center pretty will. Rifles are another story. Some rifles like a load developed with bullets touching the throat, some don't. You usually have to adjust that to the rifle's individual preference. The result for a rifle is usually a bullet seated somewhere between 0.010" to 0.030" off the lands, but sometimes it is more. Don't worry too much about carrying rifle principles over to the pistol. Seating out will cost you about 50 fps out of 1000. How much powder is needed to bring the pressure back up depends on the components used. It's not easy to generalize about. With Unique powder and a 180 grain jacketed bullet it looks like about a 7% increase in the .40 S&W. It will be less or more with other powders and bullets and may change with the primer you choose. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; October 4, 2008 at 10:18 AM. Reason: Typo fixes

October 5, 2008, 11:24 AM	#5
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	ditto, alleykat Easy way to discern it is to actually test for accuracy. I know, way too logical.

October 5, 2008, 03:00 PM	#6
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"It's been said and done that seating the bullet .010" off the lands of your rifle will probably achieve the best accuracy." As Alley implies, that's beer hall ballistics BS, along with a LOT of other so-called "truths". Best accuracy is where you find it. There are no valid rules and no shortcuts, only YOUR experimentation with YOUR load in YOUR rifle will let you know what works best for YOU. That's why "pet loads" are almost laughable in application, even a Ken Waters load won't apply to maybe 80% of the cartridges it tries to "help" with. That's little better than picking a load out of a loaidng book using a dart.