How do we get a heavy (120+ grain) 6mm bullet made?

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I read it as him guesstimating at a BC. I would think if the DTAC is already there and you add 7 grains but keep the design the same the BC would be higher, but it’s theoretical until someone builds one and tests the BC I suppose. I can’t find anywhere that his were ever tested for the actual real world BC.

He used litz calculations applying modifications to an existing known BC which i've seen referenced as being pretty dang accurate in the past. My takeaway/assumption is that it just wasn't a high form factor design. Even the DTAC isn't a "peak" form factor type design but was clearly better than this custom bullet.

I also wonder if some of these completely optimized form factor bullets dont end up pickier. Seems like lots of people have reported struggles with the 110 SMK for example and that's a pretty sleek mofo.
 

JBahr

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Alright I’ve now officially got skin in the game with a 6 PRC on order from UM. Based on all the replies it seems like Hornady is our best bet… anyone got an in with Hornadys ballistician(s)? 😝

I did find this interesting post from nearly a decade ago with some relevant info. Link
I also ordered a 6-6.5 PRC on 3/1 from UM. Blaine seemed confused, "I feel like I already entered this order today..." HAHA. Tikka, Rok Stock, 22" Ace 7.5 twist
 
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Dobie07

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I also ordered a 6-6.5 PRC on 3/1 from UM. Blaine seemed confused, "I feel like I already entered this order today..." HAHA. Tikka, Rok Stock, 22" Ace 7.5 twist
Great minds think alike @JBahr! I went with a 20” barrel tho… let’s hope we don’t get mixed up!
 

ddowning

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He used litz calculations applying modifications to an existing known BC which i've seen referenced as being pretty dang accurate in the past. My takeaway/assumption is that it just wasn't a high form factor design. Even the DTAC isn't a "peak" form factor type design but was clearly better than this custom bullet.

I also wonder if some of these completely optimized form factor bullets dont end up pickier. Seems like lots of people have reported struggles with the 110 SMK for example and that's a pretty sleek mofo.
I am not an aerospace engineer. I can only speak from my anecdotal observations. I have shot several thousand dtacs. While lot to lot variation is a complaint I have, they are not picky. I can get them to shoot better than most bullets and occasionally as good as Bergers. I think this is a product of manufacturing qa/qc, not the design itself. I have had lots where every group was sub 3/8 moa for 5 shots, pretty much regardless of load. Others were a struggle to get 5/8 moa for 5 shot across several groups. I have had bcs true out from .585 to .635 at speeds from 2950 to 3190. I have never had situations where groups were consistently over 3/4 moa for 5 shots like I have with questionable lots of Hornady bullets.

I have had the best luck with easy accuracy with length sorted 105 bthp, 107mk, 108 berger, dtac, etc. Secant ogive bullets have been more of a struggle. I would personally give up bc for significantly better precision (and I have done this many times.)

It is possible that an optimized form factor 117 or 120 could be tamed by experimenting with reamer dimensions. It is likely this bullet would be a niche bullet for large 6mm cartridges. I doubt it will go fast enough in anything smaller than 6 creed to take advantage of the bc, and even that is questionable. Given that the big 6s are completely custom jobs at the moment, it would be nothing in the grand scheme of things to do the r and d on the reamer to make it work.

Ther is also the possibility that the easy button of no cleaning ect would not also mesh with the best reamer design for accuracy, so there is that trade-off.

Also, for Hornady to make an accurate optimized form factor bullet, I think they would need to run the lots like the a-tips, but use the polymer tips. That seems to be the way to get consistent bullets. When watching Berger factory tours it appears all of their bullets are done in a similar manner. They probably also do more testing, they don't sell seconds, and their bullets are less $$$. I'm not dogging on Hornady. I shoot their bullets for hunting, or if I want a cheaper bullet. However, if they could figure out a way to be price competitive on a premium line of bullets with Berger, they would own the market. I understand what's in play with cost of marketing, r and d, production capacity, etc.

Also, a lot of the market that is interested in this bullet is going to want to play in NRL Hunter. A lot won't, but a rule change could sell a lot of these bullets. Currently, a lot of 25 cal bullets are being sold to the nrl hunter crowd and those copycatting what they are doing.
 

z987k

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It would get really long, but the Swiss lathe copper guys could make them with a few flicks of the keyboard.
No, in copper at 120gr in 6mm, they'd be so long, they just wouldn't stabilize. If you talk to the guys making high bc monos, the limit appears to be around 6x diameter in length.

I think the best bc mono in 6mm is the 100gr SBD-2 with a .6G1. It's 1.420" long, up next to the theoretical 1.458 limit.
 
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It is possible that an optimized form factor 117 or 120 could be tamed by experimenting with reamer dimensions. It is likely this bullet would be a niche bullet for large 6mm cartridges. I doubt it will go fast enough in anything smaller than 6 creed to take advantage of the bc, and even that is questionable. Given that the big 6s are completely custom jobs at the moment, it would be nothing in the grand scheme of things to do the r and d on the reamer to make it work.

Good stuff. If a DTAC is run successfully in Dashers and such why would you need a much bigger case for a 117-120 that has the same or possibly even shorter bearing surface length putting the extra weight in a longer nose compared to the short one the DTAC has? I wouldn't think a same or shorter bearing surface and + 2 to 5 grains bullet weight would be that huge of a velocity difference?
 

hereinaz

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I have always wondered why a heavier 6mm hasn’t been made. The 115 DTAC has been around a long time without more coming along. There are a lot more 6 mm shooters out there. It surprised me that Berger made the 133 and 135 in .257 first.

I think the Dasher runs the 115 at slower velocity to really take advantage of the high BC. Tubb designed it for his 6xc which predated and is essentially the same as the 6.5 creed case.

The 25 cal .133 in the SST (Saum derived) is quite a bit of recoil, more than a heavy 120+ 6mm would be. You can see it for sure in the reticle. I can see and feel the difference between the 133 .25 at 3050 fps and the 143 6.5 at 3050.

For my purposes, the recoil isn’t enough to make me wish for or wait for the high BC 6mm to come out. But, if it does come out I might build a 6 mm mag of some sort.

If I am shooting inside 500 yards, there are plenty of 6mm bullets out there to shoot with a 6 creed. At farther distances, time and opportunity give me the chance to build a solid position to shoot the .25.
 
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Dobie07

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Sharing an update with the group. I contacted Hornady asking if they would consider bringing a heavier 6mm bullet to market and got the following reply. Maybe we need to have a few (hundred) more folks submit requests…
 

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hereinaz

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Sharing an update with the group. I contacted Hornady asking if they would consider bringing a heavier 6mm bullet to market and got the following reply. Maybe we need to have a few (hundred) more folks submit requests…
Check with Berger?
 

ACHILLES

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Would a 25UM or 25-7prc solve the BC issue with only a minimum increase in felt recoil?
For me specifically it does.

9lb rifles/26” bbls

6UM 66gr n570 115gr 3400 21.6 lbs recoil
25sst 61gr n570 131gr 3270 21.2 lbs recoil

2% less recoil I get more barrel life and the 25 shows to have .45moa (almost 2clicks) less wind drift at 1000 yards in a 10mph 3cl wind.
I know you can’t get the 131 ACE’s anymore but when you could I bought several thousand. And despite them being pointed I’ve had good results with them on several deer and hog harvest as long as you ensure the hollow point is free of debris.

Like form said in light rifles a small increase in recoil can have a significant difference. My 22creed is 8.25lbs and when I shoot 90s instead of the 80gr bullets I can easily feel the increased recoil even though it’s only a 4% difference.

Not hating on the big 6s at all and I was torn for months before deciding between the 6&25. But as for a 120gr+ 6mm bullet will be a simular situation as the 22cal 95smk. When your run a proper twist rate even on the minimal end you are restricted by rpm’s and can’t run the bullet at full speed without over spinning it in something like a 6UM. But as is a 6UM with 115s is an amazing combination of external ballistics and minimal recoil for a hunting rifle in my opinion.
 

hereinaz

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For me specifically it does.

9lb rifles/26” bbls

6UM 66gr n570 115gr 3400 21.6 lbs recoil
25sst 61gr n570 131gr 3270 21.2 lbs recoil

2% less recoil I get more barrel life and the 25 shows to have .45moa (almost 2clicks) less wind drift at 1000 yards in a 10mph 3cl wind.
I know you can’t get the 131 ACE’s anymore but when you could I bought several thousand. And despite them being pointed I’ve had good results with them on several deer and hog harvest as long as you ensure the hollow point is free of debris.

Like form said in light rifles a small increase in recoil can have a significant difference. My 22creed is 8.25lbs and when I shoot 90s instead of the 80gr bullets I can easily feel the increased recoil even though it’s only a 4% difference.

Not hating on the big 6s at all and I was torn for months before deciding between the 6&25. But as for a 120gr+ 6mm bullet will be a simular situation as the 22cal 95smk. When your run a proper twist rate even on the minimal end you are restricted by rpm’s and can’t run the bullet at full speed without over spinning it in something like a 6UM. But as is a 6UM with 115s is an amazing combination of external ballistics and minimal recoil for a hunting rifle in my opinion.
I reached the same conclusion, and I run the 25 SST too. But only started once Beeger dropped the 133. I was too late to get in on the blackjacks.

I hadn’t run the recoil numbers between the 115 and the 133s. Surprises me a little.

I love my 25 SST and will rarely spin my 7 SS barrel back on unless I really want to reach past 800.
 
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IF hornady came out with a 6mm eldm with the same BC as the .257 134eld…I’d be in for a 6 creedmoor. Until then my 25 creedmoor strikes a perfect balance between recoil, terminal performance, and external ballistics for my uses.
 

ACHILLES

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I reached the same conclusion, and I run the 25 SST too. But only started once Beeger dropped the 133. I was too late to get in on the blackjacks.

I hadn’t run the recoil numbers between the 115 and the 133s. Surprises me a little.

I love my 25 SST and will rarely spin my 7 SS barrel back on unless I really want to reach past 800.
Of course the extra case capacity of the 6UM bridges the gap in recoil though it has a lighter bullet weight.

My example with the 131s is using a .351 bc also. They list a .331 bc but for 2 rifles I’ve had to use a .351 to get everything to line up and talked to others who have had to do the same at around .345

With the berger 133s wind drift and recoil at 1000 shows to be almost identical to the 6UM.

As much as I want some company to drop a 120gr + 6mm bullet I don’t see it happening anytime soon. It’s such a niche bullet there’s no profit in it for bigger bullet manufactures, it’s going to require custom twists, and it would only appeal to a handful shooters in the market.
If you look at all the heavy for cal high bc bullets in the past you’ll see they’re were mostly put out from small company’s out of passion for long range shooting and usually don’t last unfortunately and some options can be expensive. Examples Richard Graves aluminum tipped rbbt bullets (Wildcat), ACE, Black hole, Rocky Mountain bullets, Matrix, Alco, Warner, GS customs, Cayuga, and JLK.

But you never know, just look at how far bullets & cartridges have come in the past 20 years.
 

hereinaz

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Of course the extra case capacity of the 6UM bridges the gap in recoil though it has a lighter bullet weight.

My example with the 131s is using a .351 bc also. They list a .331 bc but for 2 rifles I’ve had to use a .351 to get everything to line up and talked to others who have had to do the same at around .345

With the berger 133s wind drift and recoil at 1000 shows to be almost identical to the 6UM.

As much as I want some company to drop a 120gr + 6mm bullet I don’t see it happening anytime soon. It’s such a niche bullet there’s no profit in it for bigger bullet manufactures, it’s going to require custom twists, and it would only appeal to a handful shooters in the market.
If you look at all the heavy for cal high bc bullets in the past you’ll see they’re were mostly put out from small company’s out of passion for long range shooting and usually don’t last unfortunately and some options can be expensive. Examples Richard Graves aluminum tipped rbbt bullets (Wildcat), ACE, Black hole, Rocky Mountain bullets, Matrix, Alco, Warner, GS customs, Cayuga, and JLK.

But you never know, just look at how far bullets & cartridges have come in the past 20 years.

With recoil and 1000 yard data being essentially the same, I’d rather land an extra 18 grains on target, but that is personal preference.

It’s the bullet construction that matters.

You are right, high BC bullets have been niche, but Berger surprised me with the 133 after the 131 disappeared.

I think a 118/120 is possible, but I think the .257 has far more legitimacy as a hunting caliber than the 6 mm so that might be why it made more sense. The Blackjack showed enough support for all the .25 cal long range wildcats.
 

Axlrod

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Of course the extra case capacity of the 6UM bridges the gap in recoil though it has a lighter bullet weight.

My example with the 131s is using a .351 bc also. They list a .331 bc but for 2 rifles I’ve had to use a .351 to get everything to line up and talked to others who have had to do the same at around .345

With the berger 133s wind drift and recoil at 1000 shows to be almost identical to the 6UM.

As much as I want some company to drop a 120gr + 6mm bullet I don’t see it happening anytime soon. It’s such a niche bullet there’s no profit in it for bigger bullet manufactures, it’s going to require custom twists, and it would only appeal to a handful shooters in the market.
If you look at all the heavy for cal high bc bullets in the past you’ll see they’re were mostly put out from small company’s out of passion for long range shooting and usually don’t last unfortunately and some options can be expensive. Examples Richard Graves aluminum tipped rbbt bullets (Wildcat), ACE, Black hole, Rocky Mountain bullets, Matrix, Alco, Warner, GS customs, Cayuga, and JLK.

But you never know, just look at how far bullets & cartridges have come in the past 20 years.
All good points. But even though ACE was a small company, they didn't make the Blackjack's, Sierra did. Just like Sierra makes the Dtacs. If a "small" company (@Unknown Munitions) could order enough, a 120+ TMK could happen.
 

ACHILLES

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I doubt it will be long before Sierra drops a .25cal bullet that’s a refined version of the ACE bullet. It’s only natural now with berger and Hornady’s versions released.
That would be awesome if UM put in a bulk 120TMK order. They’ve been carrying the ball a lot lately and I appreciate it especially being a tikka fan.
I still think it will be hard to get the most out of a bullet like that with the bigger 6s since the speed will have to be limited. It’s probably going to require a 6.5-6.8 twist.
That’s 317k RPM at 3000fps with a 6.8”
 

eric1115

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I cannot figure out what I am missing in Hornady's reluctance to this. There are .285-.300 SD ELDM offerings with .600-.650 G1 in .257, .264, .277 (lower bc and ELDX but not many rifles twisted for long bullets), .284, and .308 that are all extremely popular.

The 108 ELDM has a .261 SD and .536 G1.

115 would have a .278 SD and if it follows a similar formula G1 in the low .600's I would think. They would sell a boatload of those, especially if they could be stabilized in an 8" twist.
 

stan_wa

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I messaged burger they have a product suggestion option on there contact pages.
My 6 cm is currently running at 108 Berger at 3100 and I would estimate that if Berger made a 120 ish a 22-24” cm creed would still push about 2900-2950 which is a great speed imo.


If they could get a g7 over .3 with a from factor about .9 it would be my go to for sure.

It would fit well in there existing eol line


I think making a bullet that can run in the creeds and fast twist .243 would have al out of market potential.
 
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Or.... Just get a 6.5
Love me some 6 for comp shooting but the minimal recoil advantages are totally lost when you start looking at bullets in the 120+ range pushed by cartridges big enough to make them make sense.
 
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