View Full Version : Casting and gas checks down under.

Drummer Boy
04-15-2010, 12:23 PM
Afternoon all, I was just wodering if any one has had any experience with hard cast loads (gas checked) in either 7mm or 257. most of our reloading components come from the US and supplies are drying up a little so i thought i might give the lead a go. As I have always used jacketed projectiles, I am not sure what kind of performance is possible with cast stuff. Is it easy to make your own gas checks? any feed back is appreciated.

04-15-2010, 04:07 PM
I don't cast .25cal, but I do 7mm. I know you have access to Lee moulds and their 7mmRNGC is a good one to start with. Lyman and RCBS both make a good selection of .25 and 7mm moulds that you can choose from.

Make sure you clean ALL the copper fouling out of your barrels. I know you can get Sweet's copper solvent in OZ because that's where it's made, and it's one of the best available. (Hint: Don't use a bronze brush or you will NEVER get the blue out of your barrel. :razz: :mrgreen: )

I have been searching for a good way to make my own gas checks for over 30 years and have come up empty. Buying them is about the only viable way to go. However, for light target loads they aren't really necessary, even with bullets designed to use them.

When you have specific questions, ask away.

Drummer Boy
04-16-2010, 10:37 AM
Hi all, thanks for making me feel welcome lads.its goos to talk to people on the othe side of the shooting world. And thanks to Versifier for your response.
I would like to drive a 7mm gas checked proj. anywhere from 140 to 175gn as fast as i can safely get away with and not cause too many problems in barrel flouling. one of you lads mentioned something about slugging the barrel and that seems to make sense. I have used hard cast 405gn in my 45-70 with good results in accuracy at around 1600 fps, but i hope to do a fair bit better with gas checked 7mm fodder. any help as always is greatly appreciated.

04-16-2010, 12:34 PM
As long as you aren't going to use them for hunting, you can cast them as hard as you like. For rifle target bullets I use an alloy of 1/2 linotype and 1/2 pure lead in medium bores to pure lino in small bores. The more lino the lighter the bullets will weigh. Just remember that you aren't talking about jacketed bullets - with cast the rules are different. If you can get 2000fps from your 7mm, you're doing great - you might be able to squeeze a bit more, but the question isn't so much how fast but where do the groups tighten up, and generally the 1700-1900 range is where you'll find it in the weight range you're thinking about. With the smaller bore, you might get a bit more velocity (I can get close to 3000fps in some .224 barrels, 2500 in others), or you might not, depending on the combination of barrel, powder, bullet, and lube you use. Testing is the only way to find the "accuracy nodes". Just like with jacketed, an individual barrel can be really picky about the weight and profile of the bullet you use, too. I have more than a dozen different .30 cal rifles with at least that many moulds, and every one of them likes different bullets and/or different velocities for optimum accuracy. Every time I get a new mould it takes a year or so to see how they all like the bullets.

You definitely need to slug each barrel to determine optimum size for your bullets. A soft lead slug (oval fishing weights are great, or the next size up bullet i.e. .30cal for your 7mm and 6.5 for your .25) well greased goes through the bore and gets measured with a mic (not a caliper). I generally size .002" larger than groove diameter, but others may go with anything from groove to .003". This saves an unbelieveable amount of trial and error testing and the added expense of sizers you won't end up using and powder & primers you're wasting.

Check out this site, too:
This is one of the better mould makers in the world and right close to home for you, too.

Drummer Boy
04-16-2010, 10:41 PM
You have obviously had a lot of experience with casting and your help is already a thousand times what I would get over the counter, so thanks again. And i will check out the link you sent me.
I hear you, I fully understand the importance of accuracy over velocity as long as the velocity is usable for the task at hand as I would if loading jacketed stuff. If I could get 1800 to 2000fps I would be stoked. I would like to use the bullets for hunting as well as target so I gather i would need something a little softer than the ones you would use for target and i have heard mention of about 20-1 lead to tin.
Like I have mentioned before its all new to me, and it has only come about because of things getting harder and harder to get down here. All we hear down here is that everyone in the US is panic buying and the shelves of gun shops are empty. Rather than take the risk and wait till components dry up I just want to be prepared. i have always got great enjoyment and satisfaction from rolling my own.

04-17-2010, 02:34 AM
Well, the panic is pretty much over and the shelves are getting stocked again, but the prices are all way up. There are still a lot of back orders when you want specific things, though. I prefer to take the long view and hope the hoarders will be forced to sell very low at gun shows over the next few years. There are several dealers and quite a few individuals that tried to take advantage of the situation that I will never do business with again. You know right away who's honest and who's a crook when times are hard.

If the current administration continues to drive the economy into total collapse (25+% unemployment and getting worse despite "official numbers" around 10% and dropping), things could get pretty ugly, especially in the large cities. Here we have gardens and game to hunt, wood to heat with, but most everyone I know has a very large stash of ammunition just in case.

04-18-2010, 12:28 AM
Versifier, have you tried plain base bullets with punched out pieces of plastic or other materials for gas check?

04-18-2010, 02:36 AM
I have tried punched-out foam meat trays as over powder wads for .45-70 cartridges and for m/l shotguns. I am leery of using something like that in a bottleneck case. What kind of plastic and do you glue them to the bottoms of the bullets?

04-28-2010, 01:06 AM
As others have said " slug your barrel".
Here's my story, I was trying to get a 22 Hornet to shot --no luck, lots of leading. Slugged my barrel and it was .2235", then I sized my bullets .225, Bingo, 7/8" X 1"groups at 100 yards. I went to Bull's green lube, No leading, and bore looks like I clean it after each shot--sometimes a very small amount of powder, that's it. Always remember, what works in one gun
may not work in YOURS. good shooting
results count

04-28-2010, 03:33 AM
I have tried punched-out foam meat trays as over powder wads for .45-70 cartridges and for m/l shotguns. I am leery of using something like that in a bottleneck case. What kind of plastic and do you glue them to the bottoms of the bullets?

Rolls of plastic were (?) sold by some stores at some point for the purpose. The process was discussed at Castboolits and some shooters mentioned good results (full speed in 30-30), and variations on the process (punching discs from milk cartons, etc...).
I don't have access to my electronic notes at the time so I cannot be more accurate; I mostly wanted to know about your experience.

06-29-2011, 04:00 PM
I stopped using gas checks years ago.

I keep my velocities under 1800FPS and put a dab of lithium grease on the base of each bullet before seating it in the case. Have never had a leading problem.

07-28-2012, 06:19 PM
Maybe just me but, I've never had good luck with mounting gas checks. I try and stay with plain based bullets in my handguns.