Paging Varminterror: can you break down the 6mms for us?

[gotboostvr]

but the reality is my primary deer hunting rifles for the past several years has been a MK12 clone in 223 Wylde and a CZ527 in 7.62x39. And I can best be described as a "big fella" at 6' and a fit 250ish pounds from spending more time at the gym than most people do.

I very rarely break out the bigger guns for whitetail anymore.

I hesitate to call it a clone, but I'm just finishing up a 223 wylde Mk12 mod0 "inspired" build for general hunting purposes myself.

Although, if I come across a deal on an similar 6.5G barrel, I might switch it up a bit. I already have a few other 5.56's.

 

[JmacD]

I still say that, along with adding, “men of small stature”

You gotta have thick skin to hang hang around my hunting buddies

Haha. One of those groups where the right of passage is to fire a 300 mag with the butt against your nose? No, I have never done it. And I won’t. But…

 

[zdc1775]

I hesitate to call it a clone, but I'm just finishing up a 223 wylde Mk12 mod0 "inspired" build for general hunting purposes myself.

Although, if I come across a deal on an similar 6.5G barrel, I might switch it up a bit. I already have a few other 5.56's.

Mine isn't a true clone either as I never cared for the PRI handguard when it was issued to me so I went with a MI one instead, but I am beginning to think doing a similar build in 6ARC will be in the near future and will replace the current rifle.

 

[rdnktrkr]

If you load a 6creed to the magical 2930fps would it have as good a barrel life as the 6GT? Would I have issues finding an accurate load? I was looking at a 6creed at a LGS and my friend brought up that it burns barrels about like the 243win, I've been looking for a 6mm bolt gun and all they had was the Creedmoor and 243win. I've looked locally for a Howa or Bergara donor chassis for a custom build but prices are still elevated.

 

[gotboostvr]

If you load a 6creed to the magical 2930fps would it have as good a barrel life as the 6GT? Would I have issues finding an accurate load? I was looking at a 6creed at a LGS and my friend brought up that it burns barrels about like the 243win, I've been looking for a 6mm bolt gun and all they had was the Creedmoor and 243win. I've looked locally for a Howa or Bergara donor chassis for a custom build but prices are still elevated.

Keep an eye on brownells. They have barreled Howa actions in many varieties and they go on sale pretty frequently.

 

[12Bravo20]

Too bad those Howa barreled actions are not available in left handed versions.

 

[Varminterror]

If you load a 6creed to the magical 2930fps would it have as good a barrel life as the 6GT?

No. Not even if you load it down even slower. I loaded one of my 6 creed barrels never exceeding 2800fps and it has been the worst barrel life I’ve ever had from any of them. Also, the best barrel life I have had so far in 6 creed was also my fastest barrel I have ever had, ~80fps faster than any of my others with the same load, including 2 other identical barrels from the same maker during the same run and chambered by the same smith, running 3165 for its stable life, and outlasted any of my others by ~500 rounds.

Would I have issues finding an accurate load?

No. I’ve had no trouble at all finding multiple nodes in 6 creed from 2800 to over 3200fps. I don’t really buy the “magic speed” stuff; Ken Wheeler and Erik Cortina did a video recently that SPJ posted which largely debunked and dismissed speed nodes as coincidental to the bullet weights and case capacities competitors are all using, acknowledging the unsubstantiated nature of universal "magic speeds." I can slide the 105 Hybrids over 500fps between different cartridges and barrel lengths and find nodes with each barrel which shoot very well out at 1000yrds all along the way.

I was looking at a 6creed at a LGS and my friend brought up that it burns barrels about like the 243win,

Eh, 6 creed burns barrels quickly, but the 243win is more, and does more quickly. I used to expect ~750-900 rounds from a 243win barrels, but reliably get ~1100-1200 rounds on 6 creed barrels. Might not seem like much, but it's a third to half again more than 243win. Things move pretty quickly when we change case capacity for these cartridges - shrink from the 243win down through the 6 Creed and you pick up more than twice the barrel life with the 6GT, and thrice by the time we get down to the BR based cases.

 

[rdnktrkr]

Thank you for your reply, I think looking for a donor action will be my best option and rebarrel as a 6gt, we punch paper out to 1200 but mostly out to 600, I figure I shoot about 4 or 500 rnds yearly out of my target guns and would like to see more than 3 years of accuracy out of anything I buy/build and if I decide to try a competition I would like to feel every miss is my fault not my equipment.

 

[Nature Boy]

No. I’ve had no trouble at all finding multiple nodes in 6 creed from 2800 to over 3200fps. I don’t really buy the “magic speed” stuff; Ken Wheeler and Erik Cortina did a video recently that SPJ posted which largely debunked and dismissed speed nodes as coincidental to the bullet weights and case capacities competitors are all using, acknowledging the unsubstantiated nature of universal "magic speeds."

Since I’m probably guilty of perpetuating this let me say in my defense that I was not saying this ~2,930 fps was “magic” or “universal”.

What I am saying is with 6BR and variants (not 6 Creed BTW), there tends to be a node around that speed and I’ve seen it repeated enough in my own experience, with those I shoot with, including testimonials from some of the nations top shooters and gunsmiths.

I view it more as a curiosity than I do some mystical artifact of load development. At the end of the day every rifle/load/shooter is a discrete event. They have to test for what’s best in their system, regardless of what I say, what you say, and what Cortina and Wheeler say.

 

[Varminterror]

What I am saying is with 6BR and variants (not 6 Creed BTW), there tends to be a node around that speed

Exactly this - Wheeler and Cortina said it well in the video: when we’re all shooting the same cartridge, using the same few powders and same few bullets, it’s pretty reasonable to expect similar performance nodes to reveal themselves.

Maybe another way of thinking about it - if we’re roofing a house, we’d never expect anyone to show up with a sledge hammer to do the job, nor a ball peen hammer. So when we're standing across the street, hearing the sound of the roofing crew, we can't really tell the difference between a 16oz hammer with a wooden handle or a 14oz with a fiberglass handle, and we can't really tell the difference between which one is swung by the 200lb dude on the crew or the 140lb dude, or driving into OSB or plywood, or driving galvanized or stainless nails, rubber washers or poly - we just hear the same repeating "thok, thok, thok" of hammers falling on nails. Or maybe another way - when we've tuned them, full size and half size violins, even full and half sized violas playing the same note will make the same note - resonate with the same frequency. I think putting about the same mass of powder into about the same case capacity with about the same bullet masses in about the same barrel material ends up about the same, in the end.

 

[JFrank]

I’ve shot my best groups on a low node, my buddy won the Nationals shooting a low node. The trick is to follow the clues during load development. I’ve been guilty of straying off course a couple times chasing a high node/ super group but I don’t recommend it with out a willingness to suffer some defeat.

 

[JmacD]

Since this thread started, I’ve been thinking about a 6mm pretty hard… anyone hunted deer with a GT?
My apologies if that’s not in the scope of the thread…

 

[Varminterror]

Since this thread started, I’ve been thinking about a 6mm pretty hard… anyone hunted deer with a GT?
My apologies if that’s not in the scope of the thread…

You can interpolate 6GT performance between the photos of dead deer in my post on page 2. The 6GT falls dead between the 6 Dasher and 6 Creed I posted. All we're talking about throughout this thread is the same bullet moving a little faster or a little slower for every incremental change in case size. Several of my buddies hunt now with GT's, it's a 6mm pushing 105/108 class bullets around 2950-3050fps, it's well within the known - thoroughly familiar - realm of hunter experiences. Another way of saying it - I wouldn't know the difference based on game killing performance if you rechambered either of my rifles pictured in that post to 6GT instead of Dasher or Creed. I'd just have a new velocity point and a slight shift one way or the other in trajectory.

 

[JmacD]

You can interpolate 6GT performance between the photos of dead deer in my post on page 2. The 6GT falls dead between the 6 Dasher and 6 Creed I posted. All we're talking about throughout this thread is the same bullet moving a little faster or a little slower for every incremental change in case size. Several of my buddies hunt now with GT's, it's a 6mm pushing 105/108 class bullets around 2950-3050fps, it's well within the known - thoroughly familiar - realm of hunter experiences. Another way of saying it - I wouldn't know the difference based on game killing performance if you rechambered either of my rifles pictured in that post to 6GT instead of Dasher or Creed. I'd just have a new velocity point and a slight shift one way or the other in trajectory.

That is just about the conclusion that I had to come to I think I’m going to have to start collecting parts for another build how is brass availability? It seems like it is kind of pointed a little bit towards competition side. I’m just curious if you know anyone with experience along that line. Probably all I would do is handload for it. So I’m not necessarily worried about finding factory.

 

[Varminterror]

how is brass availability? It seems like it is kind of pointed a little bit towards competition side.

GT brass is available, there are basically two flavors, budget-friendly stuff from Hornady at 75¢/case or Alpha OCD brass at $1.25/case. So it’s less specialized than everything else on the list I mentioned in my first post, save 6 creed, which does have broader availability, pricing options, and manufacturing base.

 

[JmacD]

GT brass is available, there are basically two flavors, budget-friendly stuff from Hornady at 75¢/case or Alpha OCD brass at $1.25/case. So it’s less specialized than everything else on the list I mentioned in my first post, save 6 creed, which does have broader availability, pricing options, and manufacturing base.

Ok. My research hasn’t failed me. That’s just about exactly the conclusions I had come too. I do like hearing it from someone “in the trenches” so to speak. I seem to have a knack for liking cartridges that are becoming obsolete, and then the brass and ammo hunt is non stop. Lol. Thanks again. This thread has answered a lot of questions I’ve had.

 

[rdnktrkr]

I've heard about the 2930 node in multiple places, I also heard about a node above 3050, but I was thinking about barrel life being better around 2930. I've shot both 243win and 6ARC and found both accurate and was thinking when I get another rifle it will be a 6mm something.

 

[mavracer]

Following this thread is making the want of a 6mm ARC bolt gun for calm days very real, even though I don't shoot enough to really be concerned with burning the barrel on my 6 Creed.

 

[Nature Boy]

Following any of these threads can lead to a bad case of the “wants”

I have a gun closet full of proof.

 

[mavracer]

I have a gun closet full of proof.

Yeah I'm already gun poor and don't get out to the long range range enough.

 

[JFrank]

The NBRSA nationals were held last week in Medford Ore. Although poorly attended, 4 new HG records were set by Jeff Locke, here’s the equipment list.
https://forum.accurateshooter.com/attachments/2023-nbrsa-lr-nationals-equipment-list-pdf.1436696/
https://forum.accurateshooter.com/attachments/2023-nbrsa-lr-nationals-equipment-list-pdf.1436696/

 

[Walkalong]

Must be logged in

 

[12Bravo20]

Following any of these threads can lead to a bad case of the “wants”

I have a gun closet full of proof.

Ohhhhhh so true!

I've been considering changing the barrel on PSA PA10 from 308 to 6mm anyway but threads like this makes the choice of which 6mm a little harder.

 

[rld405]

Shooting rifles burns up barrels - some cartridges just do it more quickly than others. There are a lot of contributing factors to this science, and among them, I think expansion ratio is likely the only "big knob" in the picture; but powder composition, powder charge, pressure, and velocity all contribute to barrel wear - I'm convinced these much less than expansion ratio.

The leade is eroded forward, but we see firecracking within the rifled bore for a few inches, erosion of the lands for several inches... Empirically, we tend to see 5-7thou of leade erosion per hundred rounds, more for cartridges with greater "over bore ratios," and less, naturally, for less "overbore" cartridges.

Also calibrating here - when I talk about barrel life, I'm talking about stability of performance. Once broken in, after 150 rounds or so, barrels typically will offer VERY consistent group size and velocity with a given charge for a long time, and it's this period that I consider to the "life of the barrel" for PRS use (and did for benchrest and Service Rifle competition as well). I'm 11 barrels deep into 6 creedmoor, and every one of them so far has lost speed by 1200 rounds, so asking them to survive to 1400-1500 rounds means I'm tolerating gradual velocity loss, and my barrels behave differently by the last shot of a 2 day PRS match than they were on the first shot ~220 rounds earlier. That's pretty serviceable for 1 day PRS matches where we're only shooting 80-100 rounds, but for a 2 day match, ESPECIALLY any dirty/dusty match location or suppressor only match where we might need to push a few patches between Day 1 and 2 to ensure the rifles keep running right on Day 2. Generally, I've seen barrels start giving up around 15fps per hundred rounds when they start slipping, and that accelerates pretty quickly - one of my 6 Creed barrels was giving up over 30fps per 100 rnds by the time I pulled it off of the rifle. Conceding, even these "burned out barrels" will still shoot ridiculously small groups at 100yrds, any of them still holding well under 1MOA, and usually often still hanging onto about 1/2moa for 3-5 shots at 100. But they're not reliable at long range throughout 100-200 rounds - and when I consider each 2 day, Pro Series match costs me ~$1000 and each 1 day Regional Series match costs me ~$300, I don't really have interest in milking an extra few hundred rounds out of a barrel which might take a dump and cost me a lot of ranking places at a match... But those barrels will generally still shoot better than any factory rifle on the market, but we pull them off and stick them in the garden to hold up tomato plants.

I never dreamed that many rounds were shot at a match.

 

[Nature Boy]

The NBRSA nationals were held last week in Medford Ore. Although poorly attended, 4 new HG records were set by Jeff Locke, here’s the equipment list.
https://forum.accurateshooter.com/attachments/2023-nbrsa-lr-nationals-equipment-list-pdf.1436696/

Interesting to see he was shooting a Lederer barrel chambered in 6BRA.

The year I was planning my 6BRA for use in F Class was also the same year Bart Sauter was campaigning his 6BRA in Bench Rest, seemingly winning everything and breaking a few records records along the way.

I decided to try copying everything he did. I was fortunate that a lot of the matching pieces all came together. He was using a Panda action and I happened to come across a used one for sale. The heavy varmint J. Lederer barrel he was using was going to be tricky as the maker had an extraordinary long lead time. I lucked out there too when one of my contacts had an extra one he was selling. I had it cut at 28”, just like Bart.

The only thing I haven’t done is use his custom made bullets. I’ve been beaten enough times by guys using “Bart’s Hammers” that I ought to invest in them but at this point it’s more about my reading conditions better and less about equipment and components.