Cutting .223 for 300 Blackout

[hylomar]

I'm finally jumping on the 300 Blackout band wagon. I started trimming .223 cases with a pipe cutter. I got through 20 cases and decided that I need a better way to do this.

I took a 2x4 and drilled five holes in the end with a 3/8 forstner bit. drilled slow till I found the depth that I wanted with the first hole, then I marked the bit and drilled the rest. They are not exact, but close enough.

I then chopped the 2x4 off a little longer than the cases sit. I drilled through the back and inserted some nails for use as ejector.

Clamp the block to my miter saw and attached an abrasive cut off blade.

Insert cases, chop, lightly tap the back of the nails with remaining 2x4 to eject, remove, repeat.

Faster and easier on the finger.

 

[Dukes Defense]

Nice. That's a good idea. I'm going to look at doing something like this for my chop saw. Doing 5-10 at a whack will make short work of a 1,000 cases.

Thanks for posting.

 

[wgttgw]

Looks like you already have a workable set up. This is mine. The saw is a cheap harbor freight mini saw (IIRC around $25 on sale). The jig that mounts to it was a little pricey around $50. It uses a spring and ball bearing to index on the case rim and hold the case being cut. The next case gets inserted and pushes to cut one out. 10 to 20 case a minute is fairly easily achieved.

 

[hylomar]

Couple of thought.....case mouths have a lot of slag on them. I'm hitting the ones I've done with a chamfer, but it is one more step. I'm thinking that running the brass through the sizing die first might be the way to go.

You can probably get a more uniform cut by sizing first then building the jig to index off the shoulder. Better support for the neck might cut down on burrs. I have some ideas for this, but I need to get my dies in first......more to follow

 

[hylomar]

Looks like you already have a workable set up. This is mine. The saw is a cheap harbor freight mini saw (IIRC around $25 on sale). The jig that mounts to it was a little pricey around $50. It uses a spring and ball bearing to index on the case rim and hold the case being cut. The next case gets inserted and pushes to cut one out. 10 to 20 case a minute is fairly easily achieved.

That's what gave me the idea. I already have the saw and I'm a bit to cheap to spend $50 on the jig......I would rather spend that on having someone else convert it. Brass prep is already the bain of my reloading world.

 

[wgttgw]

I have also seen a wooden holder made by a guy on a different forum for use with the mini saw which works pretty slick as well. The $50 made me think twice too. I just don't need that much brass at one time. I am glad I did get it however. I cut the cases so the final trim is very very little. The cut is also very clean and consistent. I cut, size, trim, chamfer, anneal and load.

 

[anil]

Is annealing necessary?

 

[hylomar]

Is annealing necessary?

Your decision in the end.... information from people smarter than me can be found here: http://www.accurateshooter.com/technical-articles/annealing/

TL: DR-- Yes and No...... Not absolutely required, but it increases brass life. I anneal "normal" brass on the 6thish fire. Precision brass that I want to keep (6mmbr) I do every time. I have some 6mmbr on its 11th firing. Time consuming, but cheaper than new brass.

 

[hylomar]

I have also seen a wooden holder made by a guy on a different forum for use with the mini saw which works pretty slick as well. The $50 made me think twice too. I just don't need that much brass at one time. I am glad I did get it however. I cut the cases so the final trim is very very little. The cut is also very clean and consistent. I cut, size, trim, chamfer, anneal and load.

Not saying my way is the best... like I said "I'm Cheap". My process needs refinement. I'm thinking that I need to size first then cut. I want to redesign my jig to load from the rear with sized brass. Then trimming will take care of the slag I've encountered. With all that being said....my time is cheap when I'm doubling trials with watching the kids while the wife is out. Yours is the proven method.

 

[IndispensableDestiny]

I use a mini chop saw with a homemade jig held in the saw's vise. I chop, clean, resize, then deburr/chamfer. My friend Arne who is on here from time to time uses a drill press and a carbide end mill. The best I've seen is a Dillon Trimmer on a 650 press with a special sizing and trimming die.

 

[Winterborn]

Very nice, I like the improvisation.

I have around 1000 blackout cases already made that I got in trade, so I have yet to set something up to convert cases. When I do, I like your idea.

Thanks for posting.

 

[GUNSnROTORS]

Fantastic idea!

Been using a Proxxon KGS 80 Micro Chop Saw.
http://www.amazon.com/Proxxon-37160-KGS-MICRO-Chop/dp/B001AT5H1C
Pricy, but quiet and cuts quick and clean. Slow, maybe 8-10 rounds/min. I tell myself it's therapeutic, to justify the time.

 

[Sticky]

The $50 made me think twice too. I just don't need that much brass at one time. I am glad I did get it however. I cut the cases so the final trim is very very little. The cut is also very clean and consistent. I cut, size, trim, chamfer, anneal and load.

Same here.. it is worth the money.. quick and clean cuts and I already had the HF mini chop saw from old archery endeavors just collecting dust, so.. my 300 brass converts quickly now..

 

[IndispensableDestiny]

Been using a Proxxon KGS 80 Micro Chop Saw.
http://www.amazon.com/Proxxon-37160-KGS-MICRO-Chop/dp/B001AT5H1C
Pricy, but quiet and cuts quick and clean. Slow, maybe 8-10 rounds/min. I tell myself it's therapeutic, to justify the time.

I have one too. I made a length jig that clamps to one of the vise jaws. I took off the fence and feed them from the right side. I use a metal cut off disk. Not the ones Proxxon sells, but from the hardware store. The Proxxon ones are too thin and bend, giving a slanted cut.

 

[IndispensableDestiny]

Couple of thought.....case mouths have a lot of slag on them. I'm hitting the ones I've done with a chamfer, but it is one more step. I'm thinking that running the brass through the sizing die first might be the way to go.

I deburr the newly cut cases. I tried running them straight into the die, but the metal gets pressed into the neck. It doesn't always fall off during final trimming.

You can probably get a more uniform cut by sizing first then building the jig to index off the shoulder. Better support for the neck might cut down on burrs. I have some ideas for this, but I need to get my dies in first......more to follow

You can index off the .223 shoulder and then cut behind it. Of course you'd have to set the cut depth to do so without chopping through the jig. I had thought of doing this with a block of plastic.

 

[GUNSnROTORS]

I have one too. I made a length jig that clamps to one of the vise jaws. I took off the fence and feed them from the right side. I use a metal cut off disk. Not the ones Proxxon sells, but from the hardware store. The Proxxon ones are too thin and bend, giving a slanted cut.

Same here. Great minds ... ?

 

[hylomar]

So I made a couple of refinements....

I abandoned the idea of indexing off the shoulder. The test runs I ran produce the same result with burrs on the mount and it was hard to push the case out backwards through the jig.

I took the orginal jig and mounted it to a larger block to better clamp it and attached the jig to the saw fence with a screw. Block is now solidly set.



The burrs from cutting.



I run the outside of the case mouth on a bench grinder to knock off the burrs.



Form the case. Decapping/sizing rod removed. Burrs as still inside the case mounth.



Trim. Case is now free of burrs.



Once more through the sizing die, this time with the rod inserted.

Processs is fairly quick and pain free. Hope this helps someone.

 

[ScottR]

If you use a fine toothed carbide finishing blade you wont get all the slag on the cut cases. A friend showed me this while cutting a couple hundred aluminum ballusters for my new deck railing. I was using an abrasive metal cutting disk and getting the slag, but the carbide tipped wood blade cut them clean and fast, and didn't dull the blade either

 

[hylomar]

If you use a fine toothed carbide finishing blade you wont get all the slag on the cut cases. A friend showed me this while cutting a couple hundred aluminum ballusters for my new deck railing. I was using an abrasive metal cutting disk and getting the slag, but the carbide tipped wood blade cut them clean and fast, and didn't dull the blade either

Thanks! I 'll have to go looking for one.

 

[IndispensableDestiny]

I run the outside of the case mouth on a bench grinder to knock off the burrs.

Don't use a bench grinder. Just like decapping with a ball peen hammer and punch works, it's gross overkill. Just use a deburr and chamfer tool.