|
Forum Rules | Firearms Safety | Firearms Photos | Links | Library | Lost Password | Email Changes |
Register | FAQ | Calendar | Search | Today's Posts | Mark Forums Read |
|
Thread Tools | Search this Thread |
June 8, 2010, 10:24 PM | #1 |
Senior Member
Join Date: April 15, 2009
Location: East TN
Posts: 638
|
Quick question about data for lead...
Ok, so I'm new to the reloading game, and I have never loaded any lead. I just picked up some .38sp dies and I have a quick question.
If I order some bullets from, say, Missouri Bullet (or any other lead bullet supplier), can I assume that the load in Lymans 49th will work for that bullet? To clarify, if I order some 158gr lead bullets from a given supplier, will the data from any reputable source apply for that bullet (as long as It's the same weight)? Are all lead bullets of the same weight and type cast to the same dimensions (ie have the same bearing surface)? If they are all different, how can one tell what data to use? I assume that they are all close enough not to cause any safety issues due to the fact that none of the data I have read specifies the brand of bullet when it comes to lead. ETA: I will be working these up from starting loads. I know at the upper end minor differences can be much more serious, but I don't plan on getting anywhere near the max loads with these.
__________________
It matters not how a man dies, but how he lives. The act of dying is not of importance, it lasts so short a time. -Samuel Johnson Last edited by (BH); June 9, 2010 at 10:30 AM. |
June 8, 2010, 10:28 PM | #2 |
Senior Member
Join Date: December 20, 2007
Location: S.E. Minnesota
Posts: 4,720
|
In 9mm and other short high-pressure cartridges, the exact bullet can make a difference. In long low-pressure cartridges like .38 Special, not so much. Besides, that's why you start low and work up the load. HTH
__________________
"Everything they do is so dramatic and flamboyant. It just makes me want to set myself on fire!" —Lucille Bluth |
June 9, 2010, 07:04 AM | #3 |
Senior Member
Join Date: November 8, 2007
Posts: 2,001
|
The alloy makes a difference.
Not all lead bullets that are the same shape can use the same load data. The reason is that lead bullets can be anything from pure lead, which is pretty soft, to wheel weigth alloy, which is significantly harder, to linotype alloy, which is pretty hard, to heat-treated alloys, which can be even harder.
Lead bullets can leave lead in your barrel if the pressure of your load doesn't get high enough to expand the base of the bullet enough to seal the bore. On the other hand, if you make the pressure too high for the alloy's strength, you can also get leading from the extra friction created as the deforming bullet metal transmits the gas pressures through its bearing surface. Lee's reloading manual has some good information on measuring the bullet alloy's hardness and matching the load pressure to the alloy. But, most people just start with low charge weights and look at the groups on-target. As the charge weight increases, groups tend to tighten-up for a while, then get looser again when the peak pressure exceeds the compressive strength of the alloy. If you are looking for accuracy and have a reasonably strong gun, not exceeding published load data and going back to the most accurate cahrge weight when you see the groups start to open-up again will keep you safe enough. But, if you are going to try for maximum velocities with hard lead bullets, you need to study the issues involved before you start so that you don't exceed safe pressures in your gun, unless it is one of the super-high pressure models that have come-out recently. SL1 |
June 9, 2010, 08:46 AM | #4 |
Staff
Join Date: March 4, 2005
Location: Ohio
Posts: 21,060
|
The question is also how exact you are trying to be? The Lyman 49th data will be for bullets cast of their number two alloy. It's typical of the hardness of most common commercial cast bullets. As a result, if you run a 158 grain round nose commercial cast bullet or a 158 grain SWC of typical commercial casting alloys in the .38 Special, they will both work fine with one of Lyman's starting loads for that weight. Just don't expect to get the exact same velocities or the exact same pressures as you work up the two. That would depend on a combination of the bullet weight and seating depth (how much volume is in the case under the bullet) and how much crimp you apply and how far the bullet has to jump the find the throat of the rifling?
As an extreme example, even though 148 grain wadcutters are slightly lighter than 158 grain round nose bullets, because they seat all the way down in the case until their flat nose is flush with the case mouth, they leave much less powder space underneath them. That greater confinement will raise the pressure of a given load much more than the weight reduction will reduce it.
__________________
Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle |
June 9, 2010, 10:28 AM | #5 |
Senior Member
Join Date: April 15, 2009
Location: East TN
Posts: 638
|
I'm not really worried about precision accuracy here. I'm just wanting to load up some cheap plinking rounds. I just wanted to make sure that it was safe to assume that most lead data (as long as weight, type, etc are equal) is interchangeable.
I will be working these up from starting loads, so I figured there would be a little wiggle room in terms of variations, but I just wanted to make sure. I'm of the opinion that there are no stupid questions, especially when it comes to reloading.
__________________
It matters not how a man dies, but how he lives. The act of dying is not of importance, it lasts so short a time. -Samuel Johnson |
June 9, 2010, 11:17 AM | #6 |
Staff
Join Date: March 4, 2005
Location: Ohio
Posts: 21,060
|
It sounds like you'll be fine, then. And you are especially correct on that last point. Why risk bodily harm when you can just ask; and not just for your own sake, but also for that of others who may learn something from the answer? These boards typical have more lurkers than participants over time.
__________________
Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle |
Thread Tools | Search this Thread |
|
|