The 6UM

[rifletuner]

Do you mean handle as in the bullet doesn't hold together at all, or handle as in terminal performance at those velocities?
The former depends on barrel twist. An 8 twist should open up lots of options. For the latter, maybe Form or someone has some experience but I haven't seen much data on anything but the NR DTAC yet.

I understand twist rate. I am referring to terminal performance. So far I have only seen people using the nose ring DTAC bullets, but wondering if something like a Berger Hybrid or ELD-M would work. Mainly thinking about closer ranges or ate least closer to the muzzle since I already know an ELD or other bullet will hold up at the reduced impact velocity of a shot several hundred yards down range.

 

[PathFinder]

I understand twist rate. I am referring to terminal performance. So far I have only seen people using the nose ring DTAC bullets, but wondering if something like a Berger Hybrid or ELD-M would work. Mainly thinking about closer ranges or ate least closer to the muzzle since I already know an ELD or other bullet will hold up at the reduced impact velocity of a shot several hundred yards down range.

Gotcha. I think the best answer is that we don't have much data yet.
Just to parrot what Form told me: Berger hunting bullets, Barnes MB, A Tips and ELD M probably won't like the higher velocities. Might be ok out of a short barreled gun around 3250 or so. Likely fine on deer/antelope/bear, not ideal for elk.
Berger targets should be ok.
Sierra needs to make a 110+ grain TMK.

 

[rifletuner]

Gotcha. I think the best answer is that we don't have much data yet.
Just to parrot what Form told me: Berger hunting bullets, Barnes MB, A Tips and ELD M probably won't like the higher velocities. Might be ok out of a short barreled gun around 3250 or so. Likely fine on deer/antelope/bear, not ideal for elk.
Berger targets should be ok.
Sierra needs to make a 110+ grain TMK.

Yes, that was pretty much my thinking. We have very limited availability of the DTACs in Australia, so right now thats kind of the "fatal flaw" of the 6UM. I will be watching with interest for more bullet performance reports.

 

[amassi]

Yes, that was pretty much my thinking. We have very limited availability of the DTACs in Australia, so right now thats kind of the "fatal flaw" of the 6UM. I will be watching with interest for more bullet performance reports.

What are you hunting?
The 95 gr ballistic tip might be worth a look. I used to shoot them out of a 240 wby around 3350 and they were absolutely devastating from small pigs to elk
For a sleeker bullet I think the 100 tipped game king would work just fine if you can get them


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[rifletuner]

What are you hunting?
The 95 gr ballistic tip might be worth a look. I used to shoot them out of a 240 wby around 3350 and they were absolutely devastating from small pigs to elk
For a sleeker bullet I think the 100 tipped game king would work just fine if you can get them


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Potentially deer, including small elk sized deer. Our supply of bullets generally from the USA has been pretty sporadic the last few years, and sources of a lot of different projectiles can be very limited at the moment. Hornady is about the only brand that seems to be restocking over here with any kind of regularity. Sierra TMK or TGK are non-existent in popular calibres. Same with Berger and Nosler.

 

[Formidilosus]

I dont know if I missed it in the thread, but is there a match bullet or lead cored bullet other than the nose ringed DTACs that will handle 6UM velocities?

Hornady 105gr HPBT. They have done well in 6x284’s and 6mm-06’s. Though I wouldn’t be afraid to try the 108gr ELD-M or 103gr ELD-X either.

 

[rifletuner]

Hornady 105gr HPBT. They have done well in 6x284’s and 6mm-06’s. Though I wouldn’t be afraid to try the 108gr ELD-M or 103gr ELD-X either.

Thanks. I have a good supply of 108gn ELD-M bullets, so that would be worth a look.

 

[bohem]

I dont know if I missed it in the thread, but is there a match bullet or lead cored bullet other than the nose ringed DTACs that will handle 6UM velocities?

The PVA 95 and 100gr Seneca are both match bullets. They're mono's so you can shoot them to any speed and twist. They're not going to expand but they will tumble and rip things up if you're shooting them at game. They will also hold together and not grenade on impact at close range.

 

[khuber84]

The PVA 95 and 100gr Seneca are both match bullets. They're mono's so you can shoot them to any speed and twist. They're not going to expand but they will tumble and rip things up if you're shooting them at game. They will also hold together and not grenade on impact at close range.

I'd recommend the cayuga hunting bullet from PVA over the Seneca, it actually has a hollow point. They can handle speed/velocity well. I had the 122 6.5 near 3500 from a 26" 7.5tw Saum and they shot pretty dang good too.

 

[bohem]

I'd recommend the cayuga hunting bullet from PVA over the Seneca, it actually has a hollow point. They can handle speed/velocity well. I had the 122 6.5 near 3500 from a 26" 7.5tw Saum and they shot pretty dang good too.

Absolutely, I would too. He asked about a match bullet so I told him that about the Seneca. The Cayuga series are definitely the way to go for a hunting bullet that is impervious to speed and twist considerations.

 

[Tx_300wsm]

If I wanted to rebarrel my factory tikka 300wsm to a 6um, is it as simple as a barrel swap? Or will bolt/mags/bolt stop need to be changed?

 

[bohem]

If I wanted to rebarrel my factory tikka 300wsm to a 6um, is it as simple as a barrel swap? Or will bolt/mags/bolt stop need to be changed?

It’s just a swap on the barrel and I have 7 and 7.5 twist blanks on hand with the 6UM reamer too.

 

[khuber84]

It’s just a swap on the barrel and I have 7 and 7.5 twist blanks on hand with the 6UM reamer too.

I'd be running an 8 or 7.5 at the fastest(chose 7.75 for my personal build) 7tw at 3300fps is 340k rpm. That's a wee bit much.

 

[Tx_300wsm]

Is there any reason to go faster than an 8 twist? I’d probably run an 18-19 inch barrel and do most of my hunting at sea level.

Also wondering if h4831 would be too fast?

 

[amassi]

Is there any reason to go faster than an 8 twist? I’d probably run an 18-19 inch barrel and do most of my hunting at sea level.

Also wondering if h4831 would be too fast?

No a 8 will be fine, unless sierra drops a 120 tmk

Way too fast, think retumbo-N570


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[khuber84]

Is there any reason to go faster than an 8 twist? I’d probably run an 18-19 inch barrel and do most of my hunting at sea level.

Also wondering if h4831 would be too fast?

What bullet you going to run? I know my buddy has had good success with RL23 which is similar burn to H4831sc but has a lil more energy. He's running 105hyb at 3450 from a 24" 6saum with 58.5gr Rl23, that's his winter load, summer he drops it down to 3350.

I'd love to see a 6mm tmk over 105gr, would be fantastic, but it'll never happen. They can't even make 95tmk available.

 

[Tx_300wsm]

What bullet you going to run? I know my buddy has had good success with RL23 which is similar burn to H4831sc but has a lil more energy. He's running 105hyb at 3450 from a 24" 6saum with 58.5gr Rl23, that's his winter load, summer he drops it down to 3350.

I'd love to see a 6mm tmk over 105gr, would be fantastic, but it'll never happen. They can't even make 95tmk available.

I would probably run the 108 eldm or 115 dtac

 

[khuber84]

I would probably run the 108 eldm or 115 dtac

Both of those are good in an 8tw at UM velocity!

 

[Reburn]

I would probably run the 108 eldm or 115 dtac

I think the goal is to stay under 300k rpm. I would personally go a 8 unless you live on kodiak.

 

[Jimbee]

I scored a stainless 8 twist 243 tikka take off, maybe it could be rechambered to a 6um? The brass availability and expensive dies aren't very appealing though.