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

 

[wysongdog]

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.

Sweet great plan. I’m impatiently waiting on my wooden rok stock. But rumor has it it’ll be done by Mother’s Day. Out of curiosity, who are you having cut your barrel?

 

[rbutcher1234]

I just went ahead and had PBB do two prefits in 6UM-40. Seems like people have had good luck with their in the past.

At least one person in this thread said theirs was good to go.

 

[wy_will]

Sweet great plan. I’m impatiently waiting on my wooden rok stock. But rumor has it it’ll be done by Mother’s Day. Out of curiosity, who are you having cut your barrel?

Straight Jacket Armory. I have used them for 4 other barrels in the past and they have always been great to work with.

 

[wysongdog]

I was wondering since you were in Wyoming. They did my 257 and did a great job.

 

[wy_will]

I just went ahead and had PBB do two prefits in 6UM-40. Seems like people have had good luck with their in the past.

At least one person in this thread said theirs was good to go.

I was going to use them but was told that they don’t have the reamer for the 6UM

 

[wy_will]

I was wondering since you were in Wyoming. They did my 257 and did a great job.

They did move to Utah, but I still chose to use them since I have had good luck in the past.

 

[Ryan Avery]

I was going to use them but was told that they don’t have the reamer for the 6UM

They made the prefits for the LS-Wild group buy. I have one; it shoots well.

 

[Bater]

I just went ahead and had PBB do two prefits in 6UM-40. Seems like people have had good luck with their in the past.

At least one person in this thread said theirs was good to go.

I was planning to order a 6UM-40 from PBB but didn't see it as a Tikka prefit option

 

[rbutcher1234]

I was planning to order a 6UM-40 from PBB but didn't see it as a Tikka prefit option

Need to contact LS Wild to do it, it’s his reamer at PBB.

 

[benconfused]

Was it noted recently on an S2H podcast that the 6UM is performing better with a 1:7 rather than a 1:7.5 twist?

If so, what was the criteria around that? Was it for both the UM30 and UM40 versions, only for DTAKs, etc? @Ryan Avery