Tweaking gun data in QuickLoad

azar92 · June 5, 2010, 11:00 AM

I have recently acquired QuickLOAD 3.6 and need a bit of help adjusting the input values for my 6.5x55. It lists a grove diameter of 0.265 which I believe to be incorrect for my rifle. If I change it to 0.264, it asks me to recalculate the cross sectional bore area for my rifle.

I have a CZ 550 American, purchased in April of 2005. Does anyone know of the proper values to input for:
Groove caliber (0.264, I believe)
Bore caliber (0.2565?)
Width of grooves (?)
Width of lands (?)
Number of grooves (I could probably figure this one out by looking, eh?)

**Unclenick** · June 5, 2010, 02:17 PM

Azar92,

This is what slugging a barrel is for. Once you learn how, you'll be glad you did and will find it useful.

Get a 3 foot length of 1/4" brass rod from Lowe's or Home Depot or from a hobby shop and cut off a 4" piece. Get a pure lead slug (alloys, such as wheel weights or other cast bullet alloys are too springy) or buy a box of Hornady swaged round balls in .32 caliber, then roll one between a couple of flats until it is is elongated and around .270" in the middle. Next, run a lightly oiled patch through the bore. Lightly oil the lead slug, then, using a plastic hammer or mallet, gently tap the slug most of the way into the muzzle. Then use the 4" length of brass as punch together with the hammer or mallet to get it the rest of the way in.

At this juncture you have two options. One is to use the remaining 32" of brass rod to push the slug slowly down the length of the bore from the muzzle. Doing this lets you feel for constrictions or rough spots that might want lapping? Alternately, you can remove the bolt and push the slug back out from the breech end, to get muzzle-only dimensions.

You can measure a slug with a caliper, and they are the easiest for measuring land or grove marks on the slug and are accurate enough for that. But they can be off a thousandth or even two, pretty easily, so you do better to use a thimble micrometer with ten thousandths resolution to measure across the land and groove marks. Enco usually has one for under $20 that is adequate to this task.

Pure lead is almost totally inelastic, which is why this works. In the end you have the exact dimensions of your particular barrel, just as getting the water weight capacity of your fired cases gets you the exact case volume you need to use in QuickLOAD's calculations for best accuracy.

When you have the information you need, you can save the file with a new name, you can save the specifics as your individual gun file, or you can copy the QuickLOAD cartridge file and edit the text directly and save the copy as your own cartridge file version to load it to use.

I don't know why that error in bullet diameter is there, but I've found a few in the QL data files over time. I think it's just that the database is so large that typo's get by over time.

azar92 · June 5, 2010, 06:52 PM

Thanks Unclenick. I've actually slugged two guns before using standard lead sinkers. One was an old milsurp Mosin Nagant that was my test run and the other was a Springfield XD9 that was getting leading issues with lead reloads.

I think the sinkers were a little bit too hard I believe and I think I will just go grab a box of the Hornady .32 lead round balls one of these days.

I guess I was kind of hoping that someone else with the same rifle had already done the measurements so I wouldn't have too.

June 5, 2010, 11:00 AM	#1
azar92 Senior Member Join Date: April 16, 2009 Location: Utah Posts: 187	Tweaking gun data in QuickLoad I have recently acquired QuickLOAD 3.6 and need a bit of help adjusting the input values for my 6.5x55. It lists a grove diameter of 0.265 which I believe to be incorrect for my rifle. If I change it to 0.264, it asks me to recalculate the cross sectional bore area for my rifle. I have a CZ 550 American, purchased in April of 2005. Does anyone know of the proper values to input for: Groove caliber (0.264, I believe) Bore caliber (0.2565?) Width of grooves (?) Width of lands (?) Number of grooves (I could probably figure this one out by looking, eh?)

June 5, 2010, 02:17 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 9,153	Azar92, This is what slugging a barrel is for. Once you learn how, you'll be glad you did and will find it useful. Get a 3 foot length of 1/4" brass rod from Lowe's or Home Depot or from a hobby shop and cut off a 4" piece. Get a pure lead slug (alloys, such as wheel weights or other cast bullet alloys are too springy) or buy a box of Hornady swaged round balls in .32 caliber, then roll one between a couple of flats until it is is elongated and around .270" in the middle. Next, run a lightly oiled patch through the bore. Lightly oil the lead slug, then, using a plastic hammer or mallet, gently tap the slug most of the way into the muzzle. Then use the 4" length of brass as punch together with the hammer or mallet to get it the rest of the way in. At this juncture you have two options. One is to use the remaining 32" of brass rod to push the slug slowly down the length of the bore from the muzzle. Doing this lets you feel for constrictions or rough spots that might want lapping? Alternately, you can remove the bolt and push the slug back out from the breech end, to get muzzle-only dimensions. You can measure a slug with a caliper, and they are the easiest for measuring land or grove marks on the slug and are accurate enough for that. But they can be off a thousandth or even two, pretty easily, so you do better to use a thimble micrometer with ten thousandths resolution to measure across the land and groove marks. Enco usually has one for under $20 that is adequate to this task. Pure lead is almost totally inelastic, which is why this works. In the end you have the exact dimensions of your particular barrel, just as getting the water weight capacity of your fired cases gets you the exact case volume you need to use in QuickLOAD's calculations for best accuracy. When you have the information you need, you can save the file with a new name, you can save the specifics as your individual gun file, or you can copy the QuickLOAD cartridge file and edit the text directly and save the copy as your own cartridge file version to load it to use. I don't know why that error in bullet diameter is there, but I've found a few in the QL data files over time. I think it's just that the database is so large that typo's get by over time. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Patron Member

June 5, 2010, 06:52 PM	#3
azar92 Senior Member Join Date: April 16, 2009 Location: Utah Posts: 187	Thanks Unclenick. I've actually slugged two guns before using standard lead sinkers. One was an old milsurp Mosin Nagant that was my test run and the other was a Springfield XD9 that was getting leading issues with lead reloads. I think the sinkers were a little bit too hard I believe and I think I will just go grab a box of the Hornady .32 lead round balls one of these days. I guess I was kind of hoping that someone else with the same rifle had already done the measurements so I wouldn't have too.