The 6UM

[Holt stewart]

Very nice!

I went to 730 round with the first 6UM, it was toast. As you probably already know 66g and 60 off seem to be the pet load for the DTACs.

I started at 30 off and 66gr and it shot good enough on once fired brass that I didn’t really mess with it after that. I am a little puzzled how I lost 150fps, I’m no doctor but I would imagine it’s got to be tied to the throat growing and it’s more than likely the cause for the accuracy problems I was seeing. After I added a grain and a half of powder bringing them back up to 3120fps they shot ten in 2.1” at three hundred yards.


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[bow_dozer]

Another batch showed up today. Will have the gun put together tomorrow and go get the first rounds down the pipe on Friday.

 

[bow_dozer]

I’ll get some groups in ballistiX later, but did simple load development copying coal from Ryan and Form. Most likely will land on 66.5. 3 shot group I know.. Gun weights 9.6lb with can on. Pumped with how it shoots and feels. I’ll get some photos and specs later.

 

[PathFinder]

First bear for me with the 6UM. 4-5 year old boar, so fairly average sized. Shot was 445 yards with a slight L-R wind. Dialed up 1.2 and held on the bear's shoulder (it was facing left). Impact 3" behind the shoulder, exit just behind mid body as it was quartering away. The base of the jacket is the portion of the bullet that's visible in the picture, that was the only part I found. Upset started immediately, the wound channel was about golf ball sized through the rib cage on the entrance side. The bear only made it maybe 20 yards.
This was a 115 DTAC deep cut. Impact would have been around 2900 fps. I'd say the deep cuts upset plenty fast for use on black bears.
At fairly low magnification I was able to watch everything through the scope even while racking the bolt. Watching impacts and never wondering what happened at the shot is priceless.
2nd pic is the exit, 3rd is the entrance.

 

[Formidilosus]

First bear for me with the 6UM. 4-5 year old boar, so fairly average sized.

Good job on the bear.

This was a 115 DTAC deep cut. Impact would have been around 2900 fps. I'd say the deep cuts upset plenty fast for use on black bears.

At that impact velocity, yes. Above 2,400-2,500fps impact they upset quickly. Below that, they tend to produce a long neck length, and I personally would not suggest them for bear.

 

[PathFinder]

Good job on the bear.




At that impact velocity, yes. Above 2,400-2,500fps impact they upset quickly. Below that, they tend to produce a long neck length, and I personally would not suggest them for bear.

Thanks!
That makes sense. Sometimes I forget they're starting out at 3400+ in this cartridge.

 

[slowelk]

At that impact velocity, yes. Above 2,400-2,500fps impact they upset quickly. Below that, they tend to produce a long neck length, and I personally would not suggest them for bear.

Because bears aren't as wide as deer or elk? or?

 

[Formidilosus]

Because bears aren't as wide as deer or elk? or?

Relatively narrow through the chest and overall just “soft”. I have not seen hundreds of dead bears, but the ones that I have including a couple of 6 footers, I’m not sure a DTAC at lower impact velocities would have upset at all inside the chest.

I could be wrong in this and they might be great in bears somehow, but NR DTAC’s even in deer are only starting to upset in the far side lung at lower impact velocities. For deer and bear, I prefer immediate upset of the bullet. I was using deep cut NR DTAC’s last year for a hunt, came back to camp and a bear had been shot by another- it wasn’t a huge bear and it wasn’t a cub- an average bear, but once I started looking at the body and measuring it, I immediately went and switched all my mags to ELD-M’s.

 

[6.5x284]

Relatively narrow through the chest and overall just “soft”. I have not seen hundreds of dead bears, but the ones that I have including a couple of 6 footers, I’m not sure a DTAC at lower impact velocities would have upset at all inside the chest.

I could be wrong in this and they might be great in bears somehow, but NR DTAC’s even in deer are only starting to upset in the far side lung at lower impact velocities. For deer and bear, I prefer immediate upset of the bullet. I was using deep cut NR DTAC’s last year for a hunt, came back to camp and a bear had been shot by another- it wasn’t a huge bear and it wasn’t a cub- an average bear, but once I started looking at the body and measuring it, I immediately went and switched all my mags to ELD-M’s.

Where do the 110 Sierra Match King fall into your list as far as speed of upset? I have gone through a lot of this thread and have mainly found Sierra mentioned with regard to making the DTAC. I have a pile of 110’s on hand.


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[Ryan Avery]

Where do the 110 Sierra Match King fall into your list as far as speed of upset? I have gone through a lot of this thread and have mainly found Sierra mentioned with regard to making the DTAC. I have a pile of 110’s on hand.


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They are a pointed bullet VERY inconsistent expansion IME.


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[bow_dozer]

Shot 21 out of the UM and she popped the can…
Never was able to find the rest of the can/baffles. Weird experience, shot hit true at 900, recoil was noticeably stiffer and louder, looked down and 2/3 of the can is missing!

OAN, I am at shot 21 out of the UM. Velocity is 3300 with an ES of 6.
66.5 N570. Fed 210

 

[The Fish Box]

@bow_dozer what is your barrel length?

 

[bow_dozer]

@bow_dozer what is your barrel length?

20

 

[Holt stewart]

I’m running 67.5 grains of N570 out of an 18” barrel and so far the silencerco omega has held up for about 550 rounds but I was certainly concerned I was gonna end up in the same boat as you. I blew one of them up on my 28 nosler with 22” barrel and they fixed it so I did it again just to prove I’m stupid lol. Bummer man, hopefully they can repair it!


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[bow_dozer]

I’m running 67.5 grains of N570 out of an 18” barrel and so far the silencerco omega has held up for about 550 rounds but I was certainly concerned I was gonna end up in the same boat as you. I blew one of them up on my 28 nosler with 22” barrel and they fixed it so I did it again just to prove I’m stupid lol. Bummer man, hopefully they can repair it!


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Rex Silentium MG7 is the can. They say they have a lifetime no bs warranty. I guess we will see.

 

[bow_dozer]

I’m running 67.5 grains of N570 out of an 18” barrel and so far the silencerco omega has held up for about 550 rounds but I was certainly concerned I was gonna end up in the same boat as you. I blew one of them up on my 28 nosler with 22” barrel and they fixed it so I did it again just to prove I’m stupid lol. Bummer man, hopefully they can repair it!


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6UM?

 

[Holt stewart]

Rex Silentium MG7 is the can. They say they have a lifetime no bs warranty. I guess we will see.

I know it’s not the same manufacturer but I was amazed at what they could do to fix mine. The second time I blew it up was a real doozy. I couldn’t find any of the guts and the sleeve was bulged in several places. They said they have a press to reshape the outside where the serial number is located and the inside is all replaceable so you can keep your tax stamp. It makes sense and I would imagine most companies would use the same sort of system.


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[wind gypsy]

They are a pointed bullet VERY inconsistent expansion IME.

Makes a guy wonder if you couldn't just nose ring them and get similar performance to dtacs.

 

[Cameron.25]

Rex Silentium MG7 is the can. They say they have a lifetime no bs warranty. I guess we will see.

Im a dealer for them and I've never had a customer have an issue, but I've heard to are great to deal with. Keep us posted on how it goes please

 

[Holt stewart]

6UM?

Hey man, sorry I missed your question somehow, It is indeed a 6um. I also just noticed you’re using a 210 primer for your load. I tried using 210’s while I was fire forming and had pressure spikes high enough to ruin the primer pockets on my brass but the velocities were still low even for fire forming loads. I think the primer didn’t have enough pop to ignite the powder fast enough causing a double burn. I wonder if that primer is allowing some of your powder to make it into the can before it ignites and that’s what made it blow? All my issues cleared up once I went to a 215. Food for thought anyway


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