243_WSSM Modified

[autoxforfun]

I talked to HillBilly Brass today regarding 243 WSSM brass.  They take a Norma WSM cartridge (270 or 300) and make a number of WSSM variants....223, 243, 25 and 6.5.  What got my attention was that they are starting with a quality piece of brass.  I walked thru what I intended to do with his brass and he was very comfortable that there should not be an issue.  I ordered some to try and he said that he would have them ready next week.  I've had good success with Norma in the past but it will interesting to see how good his forming processes are.  But if there is a source of Quality brass, that makes the potential of this succeeding much better.

[jvw2008]

Hey that's great news. Norma isn't Lapua but it's a heck of a lot better than Winchester - IMO🙄

What neck wall thickness will the brass have?

[autoxforfun]

That was the 1st question I asked....the neck thickness is set to be factory compatible so it is 0.022.  I will doing some turning/reaming.  I set the neck diameter on the reamer so that I would need a neck thickness around 0.016.

[autoxforfun]

I decided to make a die so I could bump the shoulder.  The Lee Collet die worked great for setting the neck and then a standard 243 WSSM worked for doing a full length sizing.  The problem that still remained was getting the shoulder bumped so that the bolt would close easily.  

Using the chamber reamer on a old piece of barrel worked to give me a method for bumping the shoulder.  The issue is that a chamber reamer is a bit larger than you want.  So when you bump the shoulder, you also make the case bulge some before it hits the sides of the die.  So this means I needed to bump it more than I wanted, then put it back into the full length sizing die in order to get rid of the bulge and to get the final bump.

But this should get me by until the customer Whidden die arrives in a few more weeks.

[jvw2008]

I figured you would get it worked out. 👍😊

[mnbogboy]

I've been tinkering with the 243_WSSM for a couple of years and have never been successful in making it a competitive round.  I think one of the issues is that the brass is so thick that controlling the neck tension was always a challenge.  I figured I would need to trim/ream the necks but then the chamber clearance would be too great requiring a new reamer.  So I set it aside for awhile.  Last summer I decided to continue the quest.  So I contacted Manson Reamers and ordered a custom reamer for it.  If I was going to get a custom reamer, I decided to make more changes that just the neck clearance. 
  - Increased the shoulder angle to 40deg
  - Extended the Case-Shoulder Junction
  - Increased the Free Bore
  - Reduced the total neck length
  - Reduced the neck diameter

I took my old 243 WSSM barrel and cut off the chamber and then rechambered it.  Since I had a lot of Fire Forming to do, I thought this would be a good use for the barrel.  This was the first time I've had to significantly fire form some brass so I was a bit nervous.  I loaded some bullets just into the lands so that I knew that the headspace was not a problem.  I went to the range yesterday with 50 rounds to form. 

For the first one, I put on some really good safety glasses, stood a bit to the side of the rifle and pulled the trigger.  It went off and nothing bad happened...woo_hoo.  The process went off perfectly and I now have 50 new pieces of fire formed brass.  I have a new die coming from the Whidden for the new cartridge.  Also, have a new 6mm blank that I can now chamber to get ready to do the load development.

The photo is a before and after picture.  I was pretty  pleased with myself......now, I hope it shoots better that it did before.



https://ibb.co/MkpcYPG

great job those first few fireworks to 40° always leave a sense of accomplishment!
I quoted this post and found the link add image to post! Something new?

[jvw2008]

Yes Randy. Just tap on the post image link and you can directly down load a picture from your photo files. It's been working well. 👍

[autoxforfun]

I loaded up some of the Winchester brass (2nd Firing since Fire Forming) to narrow down on a good load.  I want to shoot this rifle at our local match at the end of the month...so this work needs to get done.  I loaded 50 Berger 105g VLD Targets and 50 Berger 109g Hybrid Targets.  I had already shot these and had some idea of where I needed to be.  So I have some loaded at the mid node in the low 3000fps range and some loaded at a higher node in the low 3100 fps range.  I'll post some targets.

I also received the Norma version of the 243 WSSM.  It started out as a 270 WSM and then Bill at HillBilly Brass does his magic and turns it into a WSSM.  I still need to trim the neck length, reduce the neck thickness and fire form before I can really tell how well they will do.

[gman47564]

Bob does that case in the picture still have to be fire formed to get the 40 degree shoulder.. I assume so

[jvw2008]

Sexy!!!

[autoxforfun]

Bob does that case in the picture still have to be fire formed to get the 40 degree shoulder.. I assume so

Yes it does.  It comes as a spec compliant 243 WSSM including the 0.022 neck thickness.  So it now needs to be  neck turned and fire formed.

[DHuffman]

Fixed it for you!

[autoxforfun]

Thanks Dave.....lol   Let's hope so !!

[DHuffman]

Thanks Dave.....lol   Let's hope so !!

If nothing else you improved the looks of them.

[jvw2008]

6mm wAssIm 😊


The WSM is referred to as a Wizum
You could call the AI modified WSSM a Wassim.