HF Cutoff saw to make 300 BLK brass from 5.56 brass

[Cullen]

This is my first posting, so I may screw it up while trying.
I have started converting some 5.56 brass into 300 BLK brass by cutting them off and re-sizing to a .308 neck. This is for a .300 AAC Blackout round. I found a cheap ($35) chop saw at Harbor Freight that (with a few mods) works great for this purpose. It has a 2" diameter blade (0.022" thick) that produces a clean cut with practically no burrs. I took the vice off that came with the unit and threw it away and made a small clamp that indexes the brass and clamps it for the cut-off. I cut mine at 1.350" length and tne necking action grows the length to 1.358 (0.010 less than the SAAMI spec for maximum length). I will attempt to attach a Word document which has pictures.
Cheers, Cullen

 

[igluit4u]

That's a cool idea! I have one of those, I shoot competitive archery and bowhunt, so I build a lot of arrows and started out with that to cut the carbon or aluminum shafts, worked great, but I eventually upgraded to a better arrow cutoff saw.. Now I have a reason to bust it out again! LOL

 

[Blackhawk]

That is a great idea, do you have the dimensions for the clamp you made? I would like to see if I can make it.

lanham

 

[Cullen]

I did not make a drawing when I made it (sorta free-handed it) but I will sketch up something (with dimensions) this weekend and post it here.
Cheers, Cullen

 

[Blackhawk]

thank you kindly sir

lanham

 

[Cullen]

I'm not sure how to attach this new addition except to reply to my original posting, but with a new document (same name, but with a number 2 attached). This one has a sketch of the clamp added and some dimensions. Most of the dimensions are good enough, but some were difficult to measure without dismantling the entire saw and I didn't want to loose the setup. It cuts the brass to perfect length the way it is right now. Anyway, it will give you something to start with. I will retain the rights to any commercial reproductions of it (any "home use only" reproductions are fine with me).

The only part of the clamp that requires some "fiddleing with" is the tapered hole that actually clamps the brass. I did a lot of scrape-ing and filing to get a good fit so that it could not wiggle while being cut. The aluminum is soft and can be shaped pretty easily. Be sure to keep the brass square to the blade.
Cheers, Cullen

 

[OnyxSkyDV]

There is a nice jig being sold on the 300blk forum for using on that mini chop saw. I replicated one for my use on my bridgeport pretty quickly. Just had to order the ball detent from Reid.



Onyx

 

[squidly87]

Excellent idea and it can easily be modified for other cartridges. Thank you.

Randy

 

[Cullen]

There is a nice jig being sold on the 300blk forum for using on that mini chop saw. I replicated one for my use on my bridgeport pretty quickly. Just had to order the ball detent from Reid.

View attachment 45460

Onyx

Hey, that's way cool. There are lots of ways to "skin that cat" for holding the brass. I believe the central focus is how appropriate this saw is for doing the "work" once presented with the brass. The old KISS principal always wins out in the end. Cheers