Gas check expander

[Tomme boy]

I need to make a gas check expander. I had to lap a mold and now the gas check shank is just a hair big to get the checks on.

Anyo e have any guesses as to the diameter and the tapor I should go? I have not measured the base yet but how hard they are to get on the base is bigger than before. A firm push with your thumb is all it used to take.

It is for 350 legend with bullets to a final size of 0.356". Conventional lubes and checked with a 0.358" die in my rcbs lubes. Then final sized in my Lee app push through to 0.356"

I want to try conventional lube bullets in the ruger bolt gun now that I don't have to worry about the gas system of an ar15.

 

[Ben]

I made all of mine " trial and error ".
Not so very scientific, since I wasn't measuring angles, etc.
However, it certainly worked out well for me.

https://www.artfulbullet.com/index.php?threads/trouble-seating-gas-checks.1687/

 

[Tomme boy]

Thanks Ben. I just went downstairs and made 2 of them. First one was too short. So I made another one.

I have a adapter that NOE makes I used to hold the flair tool. The adapter is like a shell holder that takes top punches for sizing. I made it so it fits the adapter with a 0.25" shank. It then snaps into a Lee die for the app press to hold anything withe the shell holder cut. I then took one of the Lee style pushers for sizing bullets and dropped that into the sizing die to give me a flat base to open the check.

It works well. I will try to get a couple pics tomorrow to show what i am talking about.

 

[Ben]

Pics would be great.
Many others may want to make something similar.

Ben

 

[Tomme boy]

 

[Tomme boy]

Doing it this way you can make different mandrals for each caliber. All you have to do is loosen the set screw and swap out the mandrel you need. It has a little rough finish. But it works fine. The steel is extremely hard. I will make another one when it is not 3 in the morning and pissed off.

 

[Tomme boy]

Here we go. A lot better. I have one more idea going off of @Ben longer punch and hammer. I am going to make a long punch and drill it to change out the smaller ends. His method is a lot faster than this way I have it now.

I have a bunch of 1/2" mild steel rod. It will work perfect for this.

.

 

[Ben]

I think you have it going your way.
Great !!!!!!!!!!

Ben

 

[fiver]

your angle up there looks about the same angle I ground on the one I made from a screw driver, but with a bit more taper.
they tend to stick on mine so I gotta knock them off with a little scraper I made from a piece of sheet metal.
I still lose 1 in 8-9 or so, but that's better than mashing all of them.
anyway I for sure feel your pain.

 

[Rockydoc]

Looking good, Tomme boy. I bought the NOE tool to expand gas checks. It expanded the checks ok but I couldn't get the checks off the tool. I got out my dental polishing tools and polished it with some jeweler's rouge and it worked fine after that.

I think tools like the NOE expander should be able to do their job right out of the box and not have the end user to be the quality control.

 

[Ian]

The tool needs to be polished, and also very hard so it stays polished.

 

[S Mac]

I understand the need to sometimes expand checks, but the original problem was an undersize mould that required lapping. It's a pain to do, but I have always taken a utility knife and shaved the edge of the lapping bullet gas check shank, no lapping occurs there.

 

[Brad]

Looking good, Tomme boy. I bought the NOE tool to expand gas checks. It expanded the checks ok but I couldn't get the checks off the tool. I got out my dental polishing tools and polished it with some jeweler's rouge and it worked fine after that.

I think tools like the NOE expander should be able to do their job right out of the box and not have the end user to be the quality control.

Some of that is lack of polishing. They also need to be at an angle specific to the check size.
I found that as I went either way from 30 cal I needed a steeper angle of the checks stick.

I polished mine well. Lots of trial and error. With tool still in lathe I tapped a check on and wanted it to fall back off.

NOE is likely depending on good surface finish from the tool to be enough. No way they can make money with hand polishing.

 

[Ian]

Or they could make a tool that works and charge accordingly.

 

[Brad]

The concept works. My checks always fall right off.

 

[358156 hp]

The concept works. My checks always fall right off.

Yes they do. At least all the ones I've tried so far.

 

[Tomme boy]

It might not look it but I used 2000 grit sand paper and a fine polishing compound on just the tip. The light is not showing it but the end is like glass. The rest is not important if it is polished. This was made with a small piece of 1095. I have just enough to make one for my 223 bullets. I don't have any problems with any of my 30 cal molds.

It's not perfect. The checks stick a little but you rub your finger across it and they pop right off.

It will end up perfect for size on the powder coat bullets.

 

[Brad]

I also broke the corner on the end. I didn’t want it biting into the check which could easily make it stick. Not a huge radius but certainly not a sharp shoulder.