The 6UM

[rbutcher1234]

Has anybody experienced brass growth needing trimming before the brass dies? Getting everything set up to start loading for 6UM.

Is anybody checking headspace with gauges as well for prefits?

 

[IrkedCitizen]

I bought a go guage for 30 and 40 for prefits

 

[wy_will]

Just ordered a barrel for my 6UM-30. Actually 2 barrels. Been sitting on the brass since it originally came out and had preordered the dies, so this has been a long time in the making. Not going the usual route of UM cutting the barrel. Ordered the reamer and go gauge for my smith to do it himself. I have more trust in him and he gave me a much better price and better lead time. Not a knock on UM, just my preference.

I have 500 dtacs ready and 200 116 TMKs.

 

[Ryan Avery]

Has anybody experienced brass growth needing trimming before the brass dies? Getting everything set up to start loading for 6UM.

Is anybody checking headspace with gauges as well for prefits?

I average five shots per piece of brass and trim only once after the first firing.

 

[rbutcher1234]

I average five shots per piece of brass and trim only once after the first firing.

That’s very useful. What are you trimming to for inform length after first firing?

 

[Clarktar]

I was an early adopter with the 6 UM. What is the deal with this 40 degree shoulder? I'm guessing mine is 30 degree since I jumped in early....?

 

[Ryan Avery]

That’s very useful. What are you trimming to for inform length after first firing?

Super Scientific.. I measure 10ish cases, find the shortest, and trim to that.

 

[IrkedCitizen]

I was an early adopter with the 6 UM. What is the deal with this 40 degree shoulder? I'm guessing mine is 30 degree since I jumped in early....?

The original 6um is 40° shoulder. The headstamped brass comes standard with 30° shoulder so they made a 30° reamer

 

[wy_will]

I was an early adopter with the 6 UM. What is the deal with this 40 degree shoulder? I'm guessing mine is 30 degree since I jumped in early....?

40 degrees was the original 6UM. 30 degrees requires no fireforming.

 

[Clarktar]

Ah, got it. Thanks guys. I'm sure I will ask again in a year or so