6mm Fat Rat project

[502Chevelle]

Well, here is my next project. The 22 Grendel didn’t shoot up to my expectations. It’s ok, I went out on a limb and ventured into experimental territory. I gave it a whirl, didn’t like the results, so we are trying a new gig. 6 FR from Lee Wells. 24” 8 twist Bartlein. 936 from the gas block on. I got the whole kit, dies etc. The only thing I don’t like, is I requested a threaded muzzle. I’m sure it’s just an oversight on his part. The barrel is pretty heavy, and the FR is not a big cartridge, so I don’t think I’m really worried about it not having a brake on it. My life is crazy right now, and I’ve got to pull the other rifle down for the new build, so it may be a little while, but I expect to give you guys the full story when I get her running. Have fun out there!

 

[Brasscow]

Lee is a great guy and he builds a shooter. The 6 fat rat sings.

 

[502Chevelle]

I emailed him about the muzzle, and he got back to me pretty quick to send it back and he would take care of it. It’s boxed up and ready to go. I’m usually ready to jump on a project hard once I have the parts, but right now it’s not hurting me one bit to have a little delay. Looking forward to this one.

 

[bigjake83]

I emailed him about the muzzle, and he got back to me pretty quick to send it back and he would take care of it. It’s boxed up and ready to go. I’m usually ready to jump on a project hard once I have the parts, but right now it’s not hurting me one bit to have a little delay. Looking forward to this one.

Which fat rat chamber did he choose?? He does the standard chamber and then the varmint chamber.

I had one of his barrels as well, Lee is an outstanding guy to work with but the fireforming process got old real quick, and it was absolutely brutal on the brass. Makes sure to run a H2 buffer, Full Mass BCG and Adjustable gas block and if I were to do it all over again I would have done a +1 or +2 gas system on the 22"barrel I had.

 

[502Chevelle]

This one is a 24” varmint chamber. He said it would be better since it was mag fed. It is a +2gas system. Looking forward to it. Anyone have load data that has worked out well for them? I have AR Comp, CFE 223, and Varget on hand, but I am willing to try others.

 

[bigjake83]

This one is a 24” varmint chamber. He said it would be better since it was mag fed. It is a +2gas system. Looking forward to it. Anyone have load data that has worked out well for them? I have AR Comp, CFE 223, and Varget on hand, but I am willing to try others.

CFE is a good one, I used R15 and easily achieved 1/2 MOA but its pretty dirty. I would also look at XBR 8208.

I'd look into what is the preferred powder for the 6mm ARC and try that one.

 

[357Max]

CFE is a good one, I used R15 and easily achieved 1/2 MOA but its pretty dirty. I would also look at XBR 8208.

I'd look into what is the preferred powder for the 6mm ARC and try that one.

That would be Lever.
It’s pretty forgiving on upper end loads i.e. won’t trash your fire formed brass. This would also be a good choice IMO for fire forming since it’s a slow BR. I used 8208 & Lever to form a bunch of 24Nosler into 224 Valk. lever worked the best for that.

Staball Match is showing decent results albeit @ 50-75 less than Lever. Not much data yet, but it & Lever are what I’d work with.

RL 15.5 looks good on paper, but it gets testy real fast near upper end loads. I gave up on it for AR’s cause it’s recked brass trying to find loads. Great in bolt guns, not so much in AR’s.