284 to 450B cases AKA 450B LRP cases

[gunnut]

284 to 450B cases

If your new to reloading. Please Don't try this. I assume to much in this.

OK Guy’s Here’s the latest on what I’ve been doing in order to use Large rifle primers .I cut the Winchester 284 cases at the start of the shoulder and trimmed them to 1.695.No inside reaming on these. Case capacity is 54.4 Gr of beer…..just kidding H2O I got the Lee 47-70 Factory crimp die and took it to my local Gun Smith. I had him take .5 off the Die & Collet This put the crimp right at the case mouth. So, I had him take .05 off the Collet. This droped the crimp down .05. I’m using a 230gr. FMJ bullet “zero #123”and crimping them .01. Trust me! You Can over crimp a jacketed bullet. The oal is 2.149. Passed the “Thunk” test just fine. Chambered & ejected from a mag,with no problems Bullet jump was as follows 1st chambering 2.146, 2nd 2.145, 3rd 2.148, 4th 2.147. OAL. With the same dummy round. Seeing’s how the is one heck of a crimp and beats the Hornady taper crimp hands down. I started my loads at 36gr.of LiL Gun and worked up to 40 in 1gr. Steps. Hit a sweet spot at 39gr. But, I was getting soot down the side and in the extractor grove until I hit 40gr. And a little then. The Dia. Of the head just in front of the extractor grove is .494 on virgin brass and .494 on the 40grainer’s.Primers look fine. Still rounded edges. I can barely see the ejector mark and no marks from the extractor. Bore looks clean. I think I’ll work up in .5gr step from here.

All things remaining the same. The cases I did the inside reaming with did better in the bullet jump test because of the shelf on the inside left from the reaming. And a FULL Lee FCD crimp. 2.15oal then 2.16, 2.17, 2.17, 2.175. They shot just as well. But, I don’t think these will last very long because of the thinner brass at the case mouth being worked this much.

Most of what I’m doing I have picked up from reading the post from all of you and piecing it together. I thank you all Very Much!!

[BD1]

I've been loading cast boolits in my cut down .284 brass without any reaming. Just using the Hornady expander die. Not much joy with cast boolits so far as groups, but an example for a comparison of the different cases:

31 grains of Lil Gun under a 293 grain cast RNFP sized .452, using a "body crimp":
-In the hornady factory brass with Rem 7 1/2 primers gave AV of 1939 fps, ES of 52, SD of 17, group size for 10 rounds 4.8"
-In the cut down .284 brass with Fed 210M primers I got AV of 1982 fps, ES 30, SD 10.86, group 7.5"

The Hornady expander is too large in diameter. I've ordered a Lyman "M" die to play with.

I have been able to get much better ES and SD with the cast as I have a groove to body crimp into, but I'm still getting much better groups from the condom slugs.
BD

[BD1]

OK, faced with the prospect of cutting off 200 .284 cases I had to come up with something faster thn the dremel tool. So I made a jig to cut them on the chop saw. I took a scrap block of mahogany molding and drilled it clear through with a 31/64 bit on the drill press, then I followed that hole with a 1/2" bit to a depth of 1.13 This hole arrangement holds a .284 case perfectly when inserted from the 1/2" side. i used a shell holder to set the depth against the insert side, and then cut the block length so I was removing the shoulder, leaving just .05 or so to trim on the case trimmer to true them up. I screwed the block to a long piece of board so I could align it against the saw, and then screwed the whole mess down tight. This particular saw had a triple chip blade in it that we'd been using to cut copper gutter and that worked just fine. I think any 80 - 90 tooth trim and laminate blade would work as well. To trim to final OAL I took the handle off my case trimmer and chucked up a cordless drill. With this set up i think I spent a little less than 2 hours total to make the 200 cases.

[BD1]

OK, i didn't have much luck with the tiny pics routine. Hopefully these are the pictures I was trying to attach. They didn't wind up in order, but they are the block with a .284 case indexed by the shell holder and ready to cut, A case still in the block after being cut off, and the cordless drill "motorized" case trimmer
BD

[MudBug]

Cool. When I first thought of trying this I went to harbor freight and bought their mini cut-off saw and I was gonna try to make some kind of jig for it. Looks like you made it happen.

BTW, I tried the tiny pic thing and it worked for me, PM me what happened when you tried it.

[BD1]

Well, I experienced the "wedge anchor effect" at the range yesterday. I decided to try some heavier boolits in the cut down .284 cases so I could light them using large primers. The Lyman 457193, (405 grains), sized to .453 and seated to 2.255 chambered hard and would not extract. i could set them with the forward assist and fired a few, but the inability to extract them without dropping a brass rod down the muzzle led me to think that it wasn't a great idea, so I stopped.
I'll load and try some in the Hornady brass and see if that improves the situation. If it doesn't, we may have a limit on how long of a boolit is practical in this cartridge.
BD

[gunnut]

The 230gr. hard balls ".451" are working just fine in my unreamed 284 cases with 42grs. of Lil Gun. You may have found the limit as to how much weight the side crimp will hold.

[BD1]

I think the limitation is more caused by diameter and seating depth of the bullet, rather than weight itself. It's the heel of the bullet that is bulging the side of the case. A RNFP 300 grainer with a 70% meplat has a lot more of it's weight out in the nose than a 300 grain spitzer design. A bullet with a boat tail like the FTX doesn't seem to have this problem at all.

The long and short of it seems to be that the thinner, more cylindrical Hornady cases are better suited for the cast boolits of .452 and .453 diameter, while the .284 cases seem to give much better neck tension on the jacketed .451 bullets. Unfortunately this works against us on the primer pocket size as in my experience the jacketed bullets seem to like Lil Gun, (which "likes" small primers), and the cast boolits want the slower H110, (which needs the large primers to light consistently).

BD

[gunnut]

You could try reaming the 284 cases. It worked for me untill I found the side crimp., which eliminated the wedge anchor effect with jacketed bullets.

[halfslow]

BD1:
I like that chop saw setup.

I had a fine tooth bow saw that I used to cut cases in the distant past. It wandered off one day.

I saw this post this morning before going to Harbor Freight, and spotted a tool I had to get; it is a small chop saw with a 2 inch metal cutting blade. Cost is $20 on sale.
Here is the link:

http://www.harborfreight.com/cpi/ctaf/D ... mber=42307

The little vise thing is removable, so one could make one of your mahogany case holders and get to work.

Thanks for a great idea.
This will save me a lot of time.