Is there a safe procedure for substituting a different powder for ones we find in the published recipes? I'm pretty conservative when it comes to loads, and don't really know much about experimenting, but am having difficulty (like everybody else!) in finding the powders called for in these recipes. Also, is there a rule of thumb limit on the velocity we push cast lead bullets with gas checks. I really enjoy reading your comments on everything. Thanks.
Substituting powder and gas checks
- Thread starter bkwynn
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Lefty7mmstw
Well-Known Member
The gas check isn't the problem here; it is the strength of the alloy. I'm getting to 2000 fps with my 375 h@h with a 280grain gas checked pill and getting just over moa with it. I don't know how much further I want to push the alloy I'm shooting as it is simply melted magnum grade bird shot. You want to get the lead to obdurate(fill the bore) but not overcome the strength of the alloy as it will deform the bullet and lead the bore.
When you are shooting a lead bullet(especially a gas checked pill) in any cal with a shoulder you don't want to drop the heel of the gas check below the base of the neck proper. If you expose lead you may either blow the check loose or gas etch the lead itself and the group will be blown.
As far as using another powder it is often best to ask for data on reputable sites like this, and cross reference with other powders with similar burning ranges that you do have data for. I've done a good bit of working up loads with mil surp. powders and often wring out a powder or cal. before data comes out. Watch your butt and start 15% to 20% below where you think you will land if you can get by with that low of a start. If not (as in a really overbore round where 10% down is a low start) I'd grab a flak jacket and rubber undies for your first trip to the range as you will likely need both.
When you are shooting a lead bullet(especially a gas checked pill) in any cal with a shoulder you don't want to drop the heel of the gas check below the base of the neck proper. If you expose lead you may either blow the check loose or gas etch the lead itself and the group will be blown.
As far as using another powder it is often best to ask for data on reputable sites like this, and cross reference with other powders with similar burning ranges that you do have data for. I've done a good bit of working up loads with mil surp. powders and often wring out a powder or cal. before data comes out. Watch your butt and start 15% to 20% below where you think you will land if you can get by with that low of a start. If not (as in a really overbore round where 10% down is a low start) I'd grab a flak jacket and rubber undies for your first trip to the range as you will likely need both.
You've helped me put together a plan for substitution, unless it has a serious defect that I'm not aware of right now. I'll select an available powder as close in burn rate to the one that I want to use as I can get, then use bullets that are alike or similar in type and weight, or lighter. I will start half way between start and max loads and stay there for a while with my shooting if I don't encounter problems. I've found I gain much more in accuracy with my shooting practice than I do my hand loads for now. As soon as I retire (very soon), I will begin the real sport of chasing precision with my hand loads, and wringing the best I can from each of my firearms, one at a time. The issue of gas checks is also preparation for my retirement. I've acquired a good set of tools and guns for "pouring my own", and hunting in the piney woods.
I don't shoot very well, but it is not my fault. Before I got married, I could see well, hear well, run fast, jump high, and I didn't shake. I don't remember having arthritis before marriage, either!
Thanks very much for your help.--Bill Wynn
I don't shoot very well, but it is not my fault. Before I got married, I could see well, hear well, run fast, jump high, and I didn't shake. I don't remember having arthritis before marriage, either!
Thanks very much for your help.--Bill Wynn
Lefty7mmstw
Well-Known Member
You are very welcome Bill!
You can do very well working on marksmanship with mild loads; it'll be easy on the gun and your shoulder and the target will hardly notice the difference.
For load work ups there is a lot of info here on the site but I'll toss a couple of more important ones out to start with.I would start a bit lower than midway up. I'll reiterate that I like at least 10% down or more if I don't have actual data for that powder with jacketed.
With lead start way down the ladder and work up until groups close and then start to open again, then back off to where the accuracy was best. That will be the max. load for that alloy. If you swap out alloy, you have to back up and do it again.
