Bullet diameter

wash44 · May 3, 2006, 08:25 AM

I've just started reloading for my 44 mag Blackhawk. I recently picked up a box of SWC cast bullets from a company called Aardvark here in Washington. These bullets are 0.431 diameter. I've fired about 25 of these with good results mostly over 7.0 and 8.5 grains of Unique. Last week I was reading the "ABC's of reloading" and that books suggests that the bullet size should be matched to the max diameter of the rifling of the gun being reloaded for. I measured my blackhawk and found a dimension of 0.428

So my question is: Is it safe to fire these 0.431 cast bullets in this gun?

Thanks,
Greg

AlaskaMike · May 3, 2006, 09:25 AM

It's perfectly safe. The Lasercast 240 grain SWCs are also .431, and I've shot them over a wide variety of loads, including some fairly stout ones in my Anaconda with no problems at all.

I haven't been reloading for very long, so hopefully someone with more experience than I can correct me here. My suspicion is that they size them .431 because the alloy they use is so hard that it may not obturate well enough with lighter loads, and they don't want everybody screaming "Lasercast (or Aardvark) bullets will lead up your gun like crazy!!". That's just my own guess and may be way off the mark, I don't know.

Mike

cdoc42 · May 3, 2006, 10:33 AM

Wash44, did you measure the lands or the grooves? I think the only accurate way to measure bore diameter is to cast the bore. Which I've never done. I've been loading for over 30 years and I've never paid attention to it. My thought is barrel manufacturers make .44s in a range that match the bullet diameters. So if your bore is at the large end and you fire a bullet at the small end, and vice-versa, you'll still be ok. You might find better accuracy with a given brand because the diameters match better which might explain the accuracy but there are too many other variables (powder, charge, primers, seating depth, crimp, etc). If you make your own cast bullets, well, that might be a different story. A small bullet in a big bore, gas escapes, accuracy suffers. A big bullet in a small bore and pressure increases.

wash44 · May 3, 2006, 11:02 AM

I measured the grooves - bottom of one groove to the bottom of the groove opposite and measured 0.428"

Sounds like I don't need to worry too much about it.

Another question I have on these bullets, since the manufacturer does not offer any loading data, is where to find starting loads for it. The bullet is 240 grain SWC 0.431 diameter. I would like to try the 'Keith load' of about 22 grains of 2400 but I'm a bit nervous to try and not sure what load to start with.

Is there generic loads information for SWC cast bullets? I've tried to contact the manufacturer (Aardvark, Poulsbo, WA) with no reply.

Thanks for the replies!
Greg

**44 AMP** · May 3, 2006, 11:24 AM

cast bullets are intentionally .001 or .002 oversize for standard bore diameter. Since lead compresses (somewhat) this is not a problem, and also allows reasonable accuracy in slightly oversize bores.

Use any standard data for lead SWC of correct weight, and start low, working up to your desired level. Lazercast are pretty hard, I have used them, but do not load them to max in my revolvers. Only because I like something milder for plinking. Just be sure to apply a proper crimp for the load level you use.
Note, some companies (Speer, for one) sell swaged lead bullets, which are softer than Hard cast, and will lead the bore when loaded too hot. A rough rule of thumb is (oddly enough) use your thumb nail. If you can make a dent or gouge in the bullet, then the bullet may be considered "soft". A very small dent, or just a bright spot scraped on the bullet, it is "hard".

Leftoverdj · May 3, 2006, 11:34 AM

This is one time that "The ABCs" is wrong. Cast bullets need to be oversized. I suspect your measurement is wrong, too, unless you have special equipment and are incredibly good with it. Direct measurement of groove diameter is very difficult. The customary method is to drive an oversized lead slug through the bore and measure that. A .45 round ball for a muzzle loader would be a good slug.

Ideally, we match the bullet to the chamber throats. The throats should be larger than groove diameter. If they aren't you'll have little success with cast.

The old Keith load is now generally regarded as too hot. With 240 grain bullets, 20 grains of 2400 is about as high as I would go. 23.0 grains of H-110 is another popular load. I am of the opinion that either load is too much for plain base bullets. They work fine with gas checked bullets.

AlaskaMike · May 3, 2006, 12:40 PM

Doesn't Keith's load assume Keith bullets as well? I'm almost positive that the crimp groove on most 250 grain Keith bullets is lower down on the bullet (ie, more bullet mass is outside the case when it's seated) compared to standard machine cast 240 grain SWCs (I'm thinking of Leadhead's .430 Keith bullets compared to the Lasercast SWC). This would give less pressure, and I wouldn't think the extra 10 grains of bullet weight on the Keith would be enough to cancel this out.

Leftoverdj, I'd be curious to hear your thoughts on that--you obviously have a lot more handloading experience than I, and I'm sort of pulling this theory out of you-know-where...

Mike

Leftoverdj · May 3, 2006, 01:34 PM

Mike, the difference in case volume when using the common 250 grain SWCs is not a large one when expressed in percentages. It's pretty big case, and there is only so much room for lead ahead of the case. In a short case with fast powders, seating depth is a lot more critical.

Handloading is an inexact science. The average hobbyist can do no more than make an informed guess at the pressures he is getting. Even the professional ballistics labs disagree considerably. My belief is that a variation of say .050 in the depth of the base of the bullet would get lost in all the other variables and our lack of ability to accurately measure pressure.

The classic Keith load is not going to blow up a sound gun. Too many have been fired safely (many by me) to worry about that. It is extra stress on the gun for a fairly small gain. I've quit pushing my guns to the limits, and would be more comfortable with the currently recommended 20 grain max. At this point, it's academic to me because I have a large supply of surplus AA-9.

357shooter · May 3, 2006, 04:10 PM

I shoot the 240 gr. lswc from lazer cast out of my blackhawk.My loads are 9.0 gr.of hodgdon universal under 240gr.lswc and 19.5 gr. of hodgdon h4227 under the same bullet.These loads are very acurate out of my blackhawk and I get almost no leading.Both loads will do most anything I need them for and I can shoot them all day without punishing me.Remember though these are loads out of my gun,so the rule of thumb is start out lower and work your way up .

May 3, 2006, 08:25 AM	#1
wash44 Junior Member Join Date: March 21, 2006 Posts: 2	Bullet diameter I've just started reloading for my 44 mag Blackhawk. I recently picked up a box of SWC cast bullets from a company called Aardvark here in Washington. These bullets are 0.431 diameter. I've fired about 25 of these with good results mostly over 7.0 and 8.5 grains of Unique. Last week I was reading the "ABC's of reloading" and that books suggests that the bullet size should be matched to the max diameter of the rifling of the gun being reloaded for. I measured my blackhawk and found a dimension of 0.428 So my question is: Is it safe to fire these 0.431 cast bullets in this gun? Thanks, Greg

May 3, 2006, 11:24 AM	#5
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,845	Cast bullets cast bullets are intentionally .001 or .002 oversize for standard bore diameter. Since lead compresses (somewhat) this is not a problem, and also allows reasonable accuracy in slightly oversize bores. Use any standard data for lead SWC of correct weight, and start low, working up to your desired level. Lazercast are pretty hard, I have used them, but do not load them to max in my revolvers. Only because I like something milder for plinking. Just be sure to apply a proper crimp for the load level you use. Note, some companies (Speer, for one) sell swaged lead bullets, which are softer than Hard cast, and will lead the bore when loaded too hot. A rough rule of thumb is (oddly enough) use your thumb nail. If you can make a dent or gouge in the bullet, then the bullet may be considered "soft". A very small dent, or just a bright spot scraped on the bullet, it is "hard".

May 3, 2006, 04:10 PM	#9
357shooter Senior Member Join Date: January 13, 2005 Location: upstate new york Posts: 111	I shoot the 240 gr. lswc from lazer cast out of my blackhawk.My loads are 9.0 gr.of hodgdon universal under 240gr.lswc and 19.5 gr. of hodgdon h4227 under the same bullet.These loads are very acurate out of my blackhawk and I get almost no leading.Both loads will do most anything I need them for and I can shoot them all day without punishing me.Remember though these are loads out of my gun,so the rule of thumb is start out lower and work your way up . __________________ shooter....

May 3, 2006, 09:25 AM	#2
AlaskaMike Senior Member Join Date: September 26, 2005 Posts: 941	It's perfectly safe. The Lasercast 240 grain SWCs are also .431, and I've shot them over a wide variety of loads, including some fairly stout ones in my Anaconda with no problems at all. I haven't been reloading for very long, so hopefully someone with more experience than I can correct me here. My suspicion is that they size them .431 because the alloy they use is so hard that it may not obturate well enough with lighter loads, and they don't want everybody screaming "Lasercast (or Aardvark) bullets will lead up your gun like crazy!!". That's just my own guess and may be way off the mark, I don't know. Mike

May 3, 2006, 10:33 AM	#3
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	Wash44, did you measure the lands or the grooves? I think the only accurate way to measure bore diameter is to cast the bore. Which I've never done. I've been loading for over 30 years and I've never paid attention to it. My thought is barrel manufacturers make .44s in a range that match the bullet diameters. So if your bore is at the large end and you fire a bullet at the small end, and vice-versa, you'll still be ok. You might find better accuracy with a given brand because the diameters match better which might explain the accuracy but there are too many other variables (powder, charge, primers, seating depth, crimp, etc). If you make your own cast bullets, well, that might be a different story. A small bullet in a big bore, gas escapes, accuracy suffers. A big bullet in a small bore and pressure increases.

May 3, 2006, 11:02 AM	#4
wash44 Junior Member Join Date: March 21, 2006 Posts: 2	I measured the grooves - bottom of one groove to the bottom of the groove opposite and measured 0.428" Sounds like I don't need to worry too much about it. Another question I have on these bullets, since the manufacturer does not offer any loading data, is where to find starting loads for it. The bullet is 240 grain SWC 0.431 diameter. I would like to try the 'Keith load' of about 22 grains of 2400 but I'm a bit nervous to try and not sure what load to start with. Is there generic loads information for SWC cast bullets? I've tried to contact the manufacturer (Aardvark, Poulsbo, WA) with no reply. Thanks for the replies! Greg

May 3, 2006, 11:34 AM	#6
Leftoverdj Senior Member Join Date: October 15, 2004 Posts: 934	This is one time that "The ABCs" is wrong. Cast bullets need to be oversized. I suspect your measurement is wrong, too, unless you have special equipment and are incredibly good with it. Direct measurement of groove diameter is very difficult. The customary method is to drive an oversized lead slug through the bore and measure that. A .45 round ball for a muzzle loader would be a good slug. Ideally, we match the bullet to the chamber throats. The throats should be larger than groove diameter. If they aren't you'll have little success with cast. The old Keith load is now generally regarded as too hot. With 240 grain bullets, 20 grains of 2400 is about as high as I would go. 23.0 grains of H-110 is another popular load. I am of the opinion that either load is too much for plain base bullets. They work fine with gas checked bullets.

May 3, 2006, 12:40 PM	#7
AlaskaMike Senior Member Join Date: September 26, 2005 Posts: 941	Doesn't Keith's load assume Keith bullets as well? I'm almost positive that the crimp groove on most 250 grain Keith bullets is lower down on the bullet (ie, more bullet mass is outside the case when it's seated) compared to standard machine cast 240 grain SWCs (I'm thinking of Leadhead's .430 Keith bullets compared to the Lasercast SWC). This would give less pressure, and I wouldn't think the extra 10 grains of bullet weight on the Keith would be enough to cancel this out. Leftoverdj, I'd be curious to hear your thoughts on that--you obviously have a lot more handloading experience than I, and I'm sort of pulling this theory out of you-know-where... Mike

May 3, 2006, 01:34 PM	#8
Leftoverdj Senior Member Join Date: October 15, 2004 Posts: 934	Mike, the difference in case volume when using the common 250 grain SWCs is not a large one when expressed in percentages. It's pretty big case, and there is only so much room for lead ahead of the case. In a short case with fast powders, seating depth is a lot more critical. Handloading is an inexact science. The average hobbyist can do no more than make an informed guess at the pressures he is getting. Even the professional ballistics labs disagree considerably. My belief is that a variation of say .050 in the depth of the base of the bullet would get lost in all the other variables and our lack of ability to accurately measure pressure. The classic Keith load is not going to blow up a sound gun. Too many have been fired safely (many by me) to worry about that. It is extra stress on the gun for a fairly small gain. I've quit pushing my guns to the limits, and would be more comfortable with the currently recommended 20 grain max. At this point, it's academic to me because I have a large supply of surplus AA-9.