The 6UM

[ID_Matt]

32 5/8

 

[Moose83]

36 3/8

 

[Moosehunter]

35 6/8

 

[AM3]

34 4/8

 

[IrkedCitizen]

Can we not clutter up this thread with a game?

 

[Big_wals]

Can we not clutter up this thread with a game?

Your name, together with your comment made me actually lol

 

[Reburn]

Can we not clutter up this thread with a game?

I hate to be a fun sponge but I agree.

 

[longrange13]

Neither, I'm using HCA mags in factory bottom metal. Feeds perfectly and holds 3 down in the mag. 300 WSM mags would probably work well and be plenty long.

Right on, are you able to use the short action bolt stop for the 6um or does it need a long action bolt stop?

 

[PathFinder]

Not sure, this action already had the long stop. As long as you can fit 2.880", it will work. I can't remember what the max for an SA bolt stop and WSM Tikka mags is.

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[Ryan Avery]

At 2.95 it won’t fit in a SM mag

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[tito_zako]

We are gonna have a real conversation with Peterson and ADG real soon.

I have about 20k pieces sold already to some gun builders if we can make it happen.


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would this make 6UM brass available to us to buy also?? After spending too much time online trying to find a 6mm cartridge that didn't require fireforming that can still shoot a 6mm 115 grain bullet fast out of a short barrel (20 in) and finding none, the 6UM continues to meet two out of three requirements...btw, good work in developing this wildcat!!! I just don't want to use a short-lifed barrel to fire form brass, our buy fireformed brass at 5 dollars a piece, if I could

 

[amassi]

would this make 6UM brass available to us to buy also?? After spending too much time online trying to find a 6mm cartridge that didn't require fireforming that can still shoot a 6mm 115 grain bullet fast out of a short barrel (20 in) and finding none, the 6UM continues to meet two out of three requirements...btw, good work in developing this wildcat!!! I just don't want to use a short-lifed barrel to fire form brass, our buy fireformed brass at 5 dollars a piece, if I could

If you don’t want to Fireforming do a straight 6 SAUM. Your velocity drop probably won’t be appreciable


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[Clarktar]

We are gonna have a real conversation with Peterson and ADG real soon.

I have about 20k pieces sold already to some gun builders if we can make it happen.


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Well I just bought some 6.5 saum gosh darn it

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[tito_zako]

If you don’t want to Fireforming do a straight 6 SAUM. Your velocity drop probably won’t be appreciable


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I'll look into that, thanks for the rec!!

 

[sierracharlie338]

34 7/8

 

[lak2004]

And a fun game for the guys following the 6UM thread…. Guess the width (inches and eighths, ie 20 3/8s), first one to guess or gets the closest by 12/14 at 8pm gets a Procision Arms $50 gift card!View attachment 638551

View attachment 638550View attachment 638552View attachment 638560

I'm gonna throw out 33 3/8", really nice buck!

 

[amassi]

I'm gonna throw out 33 3/8", really nice buck!

Maybe they can make a guessing game thread and not clog this one up.


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[lak2004]

Maybe they can make a guessing game thread and not clog this one up.


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Good call, sorry for bumping

 

[Kurt]

I have had this rifle for a few weeks now, it is a 6 UM put together by Jake at UM. Below are the specifics on the rifle.
View attachment 596378
Tikka T3 Lite 300 WSM Action
Proof Research 24” Sendero
MDT HNT 26 Folding stock
NF NX8 2.5-20 F1 Mil
CGS Hyperion K Suppressor

Weight is 9.1 pounds. I have had it in another config without the can, one of Ryan’s brakes, non-folding stock, and a NF 2-10 NXS. While I was able to reduce weight by approximately 1.2 pounds in this set up, I have found I shoot it much better in the current configuration. I know you could also save weight with a lighter/shorter barrel if that was a priority.

Load development was fairly quick, I started with Ryan’s data using N570 powder and Dtac 115 HBN. I worked loads from 64 up through 67.5, settling on 66 grn at 2.95 coal. Velocity is 3430 as validated at range and Lab Radar. Jake at UM was kind enough to set me up with fire formed brass to get me going, and dies are on order expected any day. So far there is 170 rounds though the barrel. For those interested in the specifics of the load development, I will make a post on the 6 UM reloading page as well.

While there may be more options for mags, I have been using several MDT styles. The 7 round short action magnum mag was a little longer than I preferred in a hunting situation, so I have a couple of the 3 round mags with 2 round extenders on them. The spring has shown to be slightly weak with the 4th and 5th rounds not feeding consistently. I took them apart and stretched the spring a bit, now they feed well. I then modified a 10 round 308 MDT mag to fit, which was very easy by simply opening the top jaws slightly with a set of pliers. It does not take much, open approximately .035 using a caliper and needle nose pliers, it is a couple minute operation. They become a 6 round mag for the 6 UM. Given this is the same size mag I use on a 6 and 6.5 CM, I am leaning towards these mags for hunting. Both mags are approximately 1 oz per round.

Using the short magnum magazines, you are limited to 2.95 coal for a clean feed. This puts me .060 off the lands, it has proven to shoot very well with this jump.

Let me know if there are any questions. Overall I am very pleased with the rifle and greatly appreciate Jake at UM for putting the rifle together for me, and Ryan for his expertise on the loading and parts side.

After a season of hunting with this 6 UM, just wanted to circle back with an update. I am shooting the 115 Dtac with nose ring, velocity is 3440. I took 4 animals with it, two of which were elk. Both elk were at 500 yards plus, both one shot through the ribs and very quick kills. The Dtacs performed very well on all shots, with one being through the offside shoulder on a bull at 640.

My kids and I have taken 7 animals with a 6 CM and 108 ELDM in the last two years. While all were efficient kills, I have found I prefer the 115 to the 108 as the performance has shown itself to be more predictable when we hit bone. This being said, the 108s have performed well, but I will be switching the kids 6 CM over to 115 next fall based off my experience. with the 115 in the 6 UM.

Overall I am extremely pleased with the 6 UM, I did not change any load data or set up on the rifle during the season. It will be the rifle I use next year, and I don't have any plans of any additions other than hopefully buying some factory brass when available

Best
Kurt

 

[85zero17]

Final verdict on the super short barrel?
Going to say the safe min is 18 suppressed?