Fire forming 303 to 410

jongun

jongun

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Just curious as I wanted to use a powder I already have to fire form the 303 whilst I wait for an order of more powder to come in. Think I could use HP-38? If not I'll just wait and use what has been recommended in some of the articles I've read on the subject. Also got some rifle powders varget,4198 and CFE. I think I'm just gonna have to be patient but still figured I'd test the waters ;)
 
I used some 2400 I had on hand. I can't remember the amount but topped it off with cream of wheat and then glue gun. About 50% were destroyed. Next time I would load lighter and maybe have to do it twice. Make sure the 303 brass chambers before loading them. I used a belt sander to thin the head so they would fit in my SG.
Good luck, let us know how it turns out.

Edit: Forgot to mention that I had annealed the brass first.
 
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I was surprised that the cases actually fit in my gun as is without any filing. One of the articles I read the fellow was using H110 so should be able to replace that with the 4198 as they have very similar burn rates. Will get out to form these puppies on Sunday and report back. Of course it will take a couple goes so it'll be multiple reports.
 
Not 100% sure yet but was wanting at least .5oz load of 7.5-8 shot and maybe Lil Gun for powder. By the way what do you guys think about my powder substitute logic? Does it make sense?
 
I suspect that fireforming results would be better if the cases were appropriately annealed. Found it pretty hard to blow out the thicker tapered portion closer to the head.
Easier to start with .444 Marlin, if it will chamber.
 
Don't have any 444 cases had a few 303s so figured may as well try them out and yes don't worry they are properly annealed. Ended up with what I believe to be a moderate loading of 4198 at 10gr packed down with TP and topped with UHU glue. We'll see how they turn out after the first forming. I suspect I may be a bit low on the powder levels but dont want to split the cases.
 
When I made mine I heavily annealed the top 2/3 of the case (till it slightly glowed red) to soften it up. It's far more annealing than for bottleneck rifle cases but this isn't being done for the same purpose. Only ended up with 30% splitting. I had to file down the bases but since pistol primers are recommended for loading them it makes sense to shorten the primer pocket.

4198 and 110 are actually quite different. They are somewhat close on the burn rate charts but there isn't a set difference between two adjacent powders. Two powders that are spaced five apart could be closer in burn rate than two powders beside each other elsewhere in the chart. They also have hugely different densities; 4198 takes up around 30% more volume per weight than 110.

I tried cream of wheat topped with hot glue and paper towel topped with hot glue, both over 5gr of Reddot, and found the cream of wheat gave much better results. The cases loaded with cream of wheat had to be fired twice while those I tried with paper towels had to be fired three times before they where straight. The shells loaded with paper towels where far more entertaining to shoot though as they threw shredded paper towels all over and caused a lot of turned heads and funny looks at the range.

Personally I would try 5gr of the HP-38 you have; should work much better than 4198 or 110.
 
I would be using Bullseye, Unique or Red Dot powders for this purpose.
The others listed are all a bit slow for proper fireforming, IMHO.

I fireformed a bunch of 30-30 cases to make 38-55, without a single loss.

10 grains of Bullseye, fill with COW, put a small plug of tissue wadded up to hold it all together.

Annealing first is a good idea, particularly if the cases have been previously fired..

Regards, Eagleye
 
At least nothing dangerous can happen so I'll just fire these cases I have loaded with the 4198. If I don't like the results I'll try out the HP-38 and go from there.
 
Making 38-55 from 30-30 I have heard of, but 410 from 303 Brit or 444?!? NOW I am interested!!! Must find some reading material on this and give it a go!!


I love these forums.....
 
Well tried out the cases I had prepped for fire forming but didn't exactly think this through as I was using my H&R 410/45Colt which has a larger diameter chamber than your regular 410. Surprisingly 2 of the 5 cases I tried out came out pretty straight. Interested to see if I could work up a load using a powder I have on hand in conjunction with punched cards and the #8 lead shot I have or maybe get the proper gun for this project Laugh2 Well sh!t those little Boitos are cheap and seem handy enough :p
 
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