True 6mm-06 / 6mm-06AI velocities?

Rugerjim

Registered from Australia
Nov 6, 2018
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#1
Hi guys. New member!
Been cruising some of the threads and note that many of you own calibers chambered in 6mm-06. One person was shooting 55grn pills at 4500fps. Would love that load info!
I'm considering making my own first wildcat. I really am interested in high velocity 6mm (243) rounds. I would love to shoot a 55gr pill at 4500 or a 70gr pill at 4000fps (ballpark).
If you dont mind me asking, what velocities are your truly getting from these cartridges with 55-70gr pills?
What twist rate do you use for lighter pills? Was thinking 1:10/1:12.
Thanks for any info supplied. Much appreciate your time.
Jim!
 

sandwarrior

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Apr 21, 2007
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#2
I shoot a 6-284, which has the same capacity as the 6mm-06. I can easily get 3800 from an 87 gr. projectile. Although, to save the barrel, I typically shoot them around 3600. I have played around with lighter bullets, but since my game is reaching out farther, I stick to the heaviest projectiles that will stabilize in my rifle. But, 70 gr. are capable of 4000 out of it. It takes a tougher bullet to do that, as a thin jacketed bullet will come apart due to the high rotation.

That said, if you goal is hyper velocity light bullets, you need a slow twist. For 55's only, you want a 1-14" twist. For, 55's and 70's you need a 1-13" twist. But, you might have to sacrifice speed on the 55's so as not to blow them apart.
 
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Rugerjim

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Nov 6, 2018
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#3
If a 6mm-06 can honestly shoot a 70gr pill at 4000fps than I am totally going for it! Is there any kind of load data/reference someone can show me?
 

sandwarrior

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Apr 21, 2007
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#4
Rugerjim,

Here's a place to start.

http://www.hodgdonreloading.com/data/rifle

I happened to be looking at it when you posted back. I like Hodgdon's website as they cover a lot of wildcat cartridges like the 6mm-06 and 6.-284. But, they don't go high on the loads for liability reasons. You will have to find what your rifle likes and where you end up at max pressures. I found with my 6-284 that the top load wasn't even up to my starting load. My whole case was smoked back. Typical of a way underloaded case. I upped the powder until it quit smoking. I'm running 100 gr. BTSP's at about 3400. That's minimum pressure for that cartridge in my rifle. Again though, it's liability thing and you'll have to find max pressures in your own rifle.

As an aside, do you reload much? Sometimes with wildcats, things get sticky quickly. I'm not a fan of the 40 degree shoulder of the Ackley cases. At the top end pressure curves go way too high, way too fast. If you were interested in a 6mm-06 IMP, look up the RCBS version. it's got a 28 degree shoulder and is less dramatic when increasing loads at the top end.
 
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Rugerjim

Registered from Australia
Nov 6, 2018
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#5
Hi Sandwarrior, yeah I reload a few different calibers. I was going to chamber my own barrel on my lathe. Basically I'm trying to justify not just using a plain old 243. If I can push a 55gr pill 4500 or a 70 gr pill at 4000 than I can justify spending the money. The reason I asked about the AI cases is I figured if i'm gonna go nuts I may as well go all out and try to push it as fast as I can. But if a 6mm-06 on its own gets those figures I'll simply go with that. Still looking for decent data, most reports of velocities has been from people who own them, there doesn't appear to be listed data. So the search continues at this stage. But are we thinking a 6mm-06, (not AI) will hit those numbers? If so I'm in.
 
Nov 25, 2007
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#8
Yes, it will hit 4k. Using a slow powder (4831, RE-19 or 22) in a long barrel. As noted, you only need a 1-13" twist for those 70's.
I shoot a couple of 6BRs and both barrels are 1-14 twist. I don't hot rod them and both shoot 70gr bullets without issue.

If you are going for speed, I'd recommend the 1-14.

However, keep in mind if your goal is to blow up rodents, a faster twist increases rotational velocity and bullet expansion with light jacketed bullets.

Having a choice, I would build the 6-284 with a 8-9 twist just in case I wanted to deer hunt with it.

YMMV
 
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sandwarrior

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Apr 21, 2007
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#9
I shoot a couple of 6BRs and both barrels are 1-14 twist. I don't hot rod them and both shoot 70gr bullets without issue.

If you are going for speed, I'd recommend the 1-14.

However, keep in mind if your goal is to blow up rodents, a faster twist increases rotational velocity and bullet expansion with light jacketed bullets.

Having a choice, I would build the 6-284 with a 8-9 twist just in case I wanted to deer hunt with it.

YMMV
I agree, I bought this rifle with the 1-10" twist and have now set it back twice. It'll kill varmints to 1k, but gets pretty iffy past that. Next time is gonna be a tight twisted barrel.:cool: I may go through barrels, but I want good ballistics at one mile.:p;)

So, with that said, Rugerjim, as Mike said, he's stabilizing the 70's with a 1-14" twist, and all-out speed is what you're after that would be the way to go. I would say, that if you had to wait on a 14" vs. a 13" or one was higher than the other, I wouldn't go the harder route. Get a good barrel at the best price and go for it.
 

Rugerjim

Registered from Australia
Nov 6, 2018
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#10
Thanks for the info guys, on monday I'm calling the smith and asking what barrel blanks he has available in 6mm- 12/13/14 twist. I think its about $720AU for the barrel and then I'll base it off a weatherby/howa action. Plan was to neck down 6.5-06 brass.
Truth be told I want a rocket ship, since I have to set up and call for feral dogs some of the shots I'll need to take might be 400 yrds. I really hope I can get those kinds of figures. Right now I'm shooting my 223 with 40gr vmax at 4000fps with a 1/8 twist and a really hot 2207 charge. Bullets aren't separating yet. I'm curious as to the why the 6-284? Looking at reloading info it's not quite as fast as what I hear can be achieved with the 6mm-06. I have someone pressuring me to just got 243AI, but I don't think it seems worth it when the 6mm-06 seems so much faster. Thanks for your time gents!
 

sandwarrior

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Apr 21, 2007
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#12
Rugerjim,

The 6-284 came along as the "littlest" brother to the .284 Win. When new cartridges came out, everything got necked up and down. Those that did the 6.-284 found with the then relatively high BC's and fast speed it was a great 1k gun. As long as there wasn't a ton of wind. Along came uber high BC projectiles. About the same time everybody figured out that "more room, was just really only more boom". Meaning, smaller more efficient rounds could push bullets nearly as fast without eating barrels nearly as fast. In a given neck/case diameter ratio, increasing the powder, decreases efficiency proportionately. Meaning an efficient case like the 6mm BR can be doubled in size only to get a few hundred feet more per second. Vast amounts of powder only eat barrels as they make marginal gains in velocity. They don't contribute to awesome velocity as much as we wish. The smaller the cartridge diameter the more pronounced this phenomena is.

If it's worth anything, one of my mentors, Skip Talbot, set seven 1k NBRSA records in a day with one back in 2000. Thus why years after his passing, I gave in to the urge and honored him with getting a 6-284.

Which brings me to ask, Why 4000? That is a magic barrel eatin' sumbitch number! You can get a lot of varmint killing out of a 3k medium to moderate weight 6mm bullet. Use an efficient bullet and you can kill varmints as far as you can see them! None of the long range shooters go 4k on their loads. They use efficient bullets pushed in the upper 2k's to lower 3k's. It's one thing if you are competing, but in varminting it's worth saving barrels. Even for competition, the 6-284 eats barrels too fast.

IMO, you'd be better off getting a 6XC, .243 Win, 6mm Creed. or a 6mm Rem. Stick with a short action in doing so. AI's, as noted above, have some advantages, but IMO, the disadvantages outweigh them.
 
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308220

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Jul 19, 2014
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#13
If youre set on a 6mm, go with the 6-284. Get an 8 twist. Shoot 100gr + bullets. Get double the barrel with not shooting 4000 fps. If your intent is "long range" varminting, this is your ticket. I would never limit myself with a slow twist barrel.

Run the numbers on a 103/108 eld at 3200 fps vs 55gr Nosler at 4000 fps. Especially at longer ranges. 600-700 yards+......youll see.
 

Rugerjim

Registered from Australia
Nov 6, 2018
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#14
Good question: why 4K? Because when looking at ballistic charts the 243win as standard can shoot a 55 gen bullet at 4K with very little drop. I just like the low drop rates of fast projectiles last 200 yards. It hits hard at extended ranges. Make it a 70gr pills and the improvement is massive. I already have a 223, 308, 270 and 243. I just want a build a dedicated night vision/thermal long range flat shooting dog gun. Run a 55 to 70 grain flat out, if I burn barrels... well I burn barrels. Dogs are worth a bit of coin to me so it’s important I have a good rig. Maybe a plain 6mm-06 is the ticket, when it’s done, i can ream it to make 6mm-06 AI brass ? I can get cheap 24” 1:10 243 barrels. Then maybe ream it just out, or get a 26” made for 720... hmmm.
 
Feb 27, 2014
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#15
I run an 8 twist 6-284 w a 26.
I run 105s at 3140-3150. There’s more but no need for it.
While I agree barrels are consumables, the speeds you’re talking will eat barrels. If you don’t mind that then carry on.
Don’t forget though that the lighter pills are going to let the wind dick with you since you mentioned extended range.
 
Feb 20, 2017
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#16
Good question: why 4K? Because when looking at ballistic charts the 243win as standard can shoot a 55 gen bullet at 4K with very little drop. I just like the low drop rates of fast projectiles last 200 yards. It hits hard at extended ranges. Make it a 70gr pills and the improvement is massive. I already have a 223, 308, 270 and 243. I just want a build a dedicated night vision/thermal long range flat shooting dog gun. Run a 55 to 70 grain flat out, if I burn barrels... well I burn barrels. Dogs are worth a bit of coin to me so it’s important I have a good rig. Maybe a plain 6mm-06 is the ticket, when it’s done, i can ream it to make 6mm-06 AI brass ? I can get cheap 24” 1:10 243 barrels. Then maybe ream it just out, or get a 26” made for 720... hmmm.
When you say you want a dedicated night vision/thermal long range flat shooting dog gun, what exactly do you mean by long range? Like how far?
 
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Rugerjim

Registered from Australia
Nov 6, 2018
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#17
Probably 400 yards. Problem is the doggies are really smart, often in packs, so follow up shots must be quick, bullet needs to get there quick, maybe even on the run. They typically turn and look back for a fleeting moment before hitting cover giving you just the smallest moment to get a second one. If I could get a 55 going 4500 or a 70grn going 4000-4100 I’d be in top shape. I’m not fussed about barrel life, happy to ream and chamber my own. Looks like the 6mm-06 might be the easiest to achieve, there are no 6-284s around. Even 257 WM isn’t available as standard. We are kinda limited that way here in aus.
 

sandwarrior

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Apr 21, 2007
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#19
Rugerjim,

What is available down in AUS? Reason being, the .270 Win you mentioned will push 100 gr. bullets VERY fast! If you can get 100 gr. .270 bullets down there. something to think about before you go all in on a new wildcat cartridge.

As to the 4k, I get you want the flattest shooting cartridge available. It would seem to me also, you have access to 6mm bullets where others aren't so plentiful? For me the problem is past 400-500 light bullets are iffy. The drops inside are pretty spectacular, but beyond, pretty unpredictable. If you don't see taking long shots, it's a moot point. Everyone needs a lazer, and mine is the 6-284. I laugh with chagrin when I've set the barrel back prematurely, but I smile when I can point and shoot as far out as I can.

If you ever do look at going longer with a more efficient cartridge, a little scope work can really help. Even just a duplex reticle gives you three elevations dead hold to use. And, you can vary off of those for longer or shorter shots. Zeroing at the point of the upper duplex, then graphing where you hit at the crosshair and the lower duplex point. Meaning you use a 100m zero for the upper duplex, and in your scope, say it's a 2moa drop so it hits dead on at 200m. Then say the lower duplex hits just low at 300m. Those are examples, not what your 6mm-06, or the scope you put on it, would be capable of.

You can get this flexibility out of any duplex scope, which is common, without having to dial. As you mentioned fast shots are going to be the norm, so that's kinda out. Quick, "known" holds is your best option. Might as well figure them all out now before you get all set to build the superduperloudnboomin'combustionchamber dogaroo nightmare.
 
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Rugerjim

Registered from Australia
Nov 6, 2018
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#20
I’m running an ATN 4K atm. Great bit of kit. Will get a Thor when available in 640. The question is now, what action do I want. Options are Ruger, Remington, weatherby Vanguard/ Howa, or browning Abolt3. My plan now is to buy a 270 and Rebarrel it shortly after. The 06 cartridge is easy to get as is the long action. It’s also much easier to get a chassis/stock for rem, howa, ruger, but not for browning. I like the short bolt throw on some of them but am a fan of vanguards quality. Probably a 26 or 28 inch barrel. Might be a little while till it’s all done. Any thoughts on action?
 
Apr 21, 2007
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#21
All good actions. I'm not a fan of the chassis stocks, but many do like them. Personally, I tend to like wood/laminate stocks that are contoured to be more ergonomical in their handling.

Long action cartridges can give a bit more speed and versatility for long range shooting. Short actions with the right set-up are all you need though. Recoil is a major issue in follow-ups. So, stock fit is crucial and since you want a fast cartridge, you might also think about threading the end for a muzzle brake. Noting quite like watching the entire firing process from squeeze to bullet impact, without ever moving off target.

I'm assuming since you are going to turn your own barrels, you might also have access to a mill where you can hog your own stock style out? make your own chassis?
 
Apr 21, 2007
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#22
So I had some spare -06 rounds and thought I would make a dummy round for comparison. 6-284 on left, 6mm-06 on right. I found I had to "three-step" the neck as the brass wanted to crumple with that big of a size change.
IMG_20181117_080340933.jpg
 
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