6mm Turbo 40 Improved

sititunga

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Just curious to know if there are any other forum members on the hide running an AR15 in a Grendel wildcat called the 6mm Turbo 40 Improved?
 

Blackhawk95

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Re: 6mm Turbo 40 Improved

Im not running the Whitley 6mm turbo 40, but im running his .22 AR.

so far its run like a champ with no problems whatsoever. Robert builds a great wildcat AR.

good luck
 

dieselten

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Re: 6mm Turbo 40 Improved

I shoot a 6 turbo 40 imp. varmint upper with 24" barrel. I like it a lot. The whole system is very well engineered, by this I mean the dies, brass, ... everything is one slick well oiled machine designed to work together. It is very user friendly to set up and shoot. The ballistics match very closely with a 6BR. And the quality of his builds (or the company he contracts) is unbeatable.
 

sititunga

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Re: 6mm Turbo 40 Improved

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dieselten</div><div class="ubbcode-body">I shoot a 6 turbo 40 imp. varmint upper with 24" barrel. I like it a lot. The whole system is very well engineered, by this I mean the dies, brass, ... everything is one slick well oiled machine designed to work together. It is very user friendly to set up and shoot. The ballistics match very closely with a 6BR. And the quality of his builds (or the company he contracts) is unbeatable. </div></div>

What sort of distances have you shot it out to? Also can you share some of your load data and velocities. Also do you have any pics?
 

steve123

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Re: 6mm Turbo 40 Improved

We've already talked about the 6mmART40 so i won't rehash but I'm still liking it.

A friend and I used it during a night shoot last weekend. Pulled off a 2cnd place and he finished up there as well.

I'm thinking of building a 18" lightweight barreled version next. Maybe even in 22AR.
 

dieselten

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Re: 6mm Turbo 40 Improved

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sititunga1</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dieselten</div><div class="ubbcode-body">I shoot a 6 turbo 40 imp. varmint upper with 24" barrel. I like it a lot. The whole system is very well engineered, by this I mean the dies, brass, ... everything is one slick well oiled machine designed to work together. It is very user friendly to set up and shoot. The ballistics match very closely with a 6BR. And the quality of his builds (or the company he contracts) is unbeatable. </div></div>

What sort of distances have you shot it out to? Also can you share some of your load data and velocities. Also do you have any pics? </div></div>

I use loads straight from the web site, 28.8 H4895 Sierra 107 in the winter and drop to 28.5 in the hot Texas summer. I do not have a chronograph but my come up to 530 yards from 100 yards is a little over 10 moa, so I am close to 2800 fps. Sorry, no pics, but it looks just like the one on Whitleys web site.
 

.308mk4

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Re: 6mm Turbo 40 Improved

I'm still experimenting with my loads. I was trying a powder I had a bunch of , but it was to temperature sensitive for my liking. For my blasting ammo its fine , but not for this rifle , although accuracy was not to bad.Then I tried 8208. I do not recommend IMR 8208 XBR for this caliber unless you don't mind your bullets traveling a lot slower than desired. It will destroy your brass and maybe blow you up. I should have just stuck with the powders listed on his site.
 

steve123

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Re: 6mm Turbo 40 Improved

I tried R15,AA2520,varget,R-17,N140 and H4895. H-4895 gave the best velocity and overall performance out of a 26" Krieger. My rifle likes a warm load of 30.2 grains of H-4895 which produces 2915 fps with a 105Amax at 2.245 OACL. Yes that length works out of a C products mag.

AA2520 is way too temp sensitive but good for throwing charges out of a powder measure to fireform brass.
 

.308mk4

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Re: 6mm Turbo 40 Improved

I originally was using 748. My average velocity dropped 70-80 fps with approximately 30 degree temperature change. The 8208 was only one powder faster than h4895 on the burn rate chart, and is supposed to be super insensitive to temperature change. But it ruined my brass. 29.1 grs got me an average of 2820 fps. It also got me blown primers , deep ejector marks , and lopsided bases. So I will not be using it anymore.
 

sititunga

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Re: 6mm Turbo 40 Improved

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 308mk4</div><div class="ubbcode-body">I originally was using 748. My average velocity dropped 70-80 fps with approximately 30 degree temperature change. The 8208 was only one powder faster than h4895 on the burn rate chart, and is supposed to be super insensitive to temperature change. But it ruined my brass. 29.1 grs got me an average of 2820 fps. It also got me blown primers , deep ejector marks , and lopsided bases. So I will not be using it anymore. </div></div>

That velocity drop makes quite a bit of difference, as I've discovered with my Grendel, at extended ranges. The Grendel, with either the 108 or 123 Scenars, is barely supersonic in colder weather at 1000 yds.
 

leadbullet

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Re: 6mm Turbo 40 Improved

I have a 6MM AR in a 26 inch barrel, with 105 scenars I get 10 shots in 4 inches at 600 yds consistently.
 

c_bass16

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    Re: 6mm Turbo 40 Improved

    I still run the .243WSSM with 105 Amax and just started playing with 105 HPBT's and I'm getting right around 3165 in a 24" with no pressure problems. I've hit 3206 without pressure problems but didn't get the accuracy I wanted so I backed down.

    I do a mag mod that lets me seat and function with an OAL of 2.390" or so, but I know of at least one other guy getting similar results, (but not quite as fast, more like 3000) seating 105 Amax to 2.26...but he's using Varget. I'm running RL17 and Gold Medal Match 215's.
     

    sititunga

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    Re: 6mm Turbo 40 Improved

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: attherange</div><div class="ubbcode-body">I have a 6MM AR in a 26 inch barrel, with 105 scenars I get 10 shots in 4 inches at 600 yds consistently. </div></div>

    What's the furthest you've shot it to?
     

    Blackhawk95

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    Re: 6mm Turbo 40 Improved

    the thing i really like about Whitleys builds are they are top quality and run like a charm. my 22ar ballistics wise is like a semi auto 22-250.

    He is also a great man to deal with no matter what chambering you go with.

    if you look on his 22ar page i developed the brass neck down proceedure..
     

    sititunga

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    Re: 6mm Turbo 40 Improved

    Are you running the 90gr Berger's? What distance have you taken it to?
     

    lwrkeysfisher

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    Re: 6mm Turbo 40 Improved

    I like the 22ar idea. Harrison over at AR Performance spun up a couple Krieger barrels for a 6.8 based .224 using the 75 Amax. He was hitting 3000fps out of a 22" barrel---not quite 22-250 territory, but it would work well to 1000yds and 6.8 brass, bolts, and mags are easy to come by.
     

    sititunga

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    Re: 6mm Turbo 40 Improved

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lwrkeysfisher</div><div class="ubbcode-body">I like the 22ar idea. Harrison over at AR Performance spun up a couple Krieger barrels for a 6.8 based .224 using the 75 Amax. He was hitting 3000fps out of a 22" barrel---not quite 22-250 territory, but it would work well to 1000yds and 6.8 brass, bolts, and mags are easy to come by.
    </div></div>

    He`s was also making a 6mm BRX that was pushing he claimed a 108 gr Berger at 3100 fps. But apparently for what ever reason he`s no longer making the BRX.
     

    lwrkeysfisher

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    Re: 6mm Turbo 40 Improved

    Yeah, he keeps talking about the BRX but sold all the barrels and hasn't made any more. It's hard to nail him down on wildcats; seems like he thinks something up, makes it, and then moves on. However, I know he has a couple of these .223-6.8 barrels kicking around---and the 3000fps velocity seems pretty reasonable given case capacity and barrel length. I've been tempted to pick one up, but have decided to focus on other things right now.
     

    sititunga

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    Re: 6mm Turbo 40 Improved

    Messing around with wildcats can be real time consuming. The T40i looks pretty simple to set-up though and has the good name of Whitley behind it - that`s what I`m looking at.
     

    sititunga

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    Re: 6mm Turbo 40 Improved

    It`s always worth looking at options - there`s a lot out there now. I was seriously looking at the BRX before, but couldn`t get Harrison to commit.
     

    Blackhawk95

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    Re: 6mm Turbo 40 Improved

    Im the 22Ar it a 7.7 twist and the heaviest bullet ive shot is 80gr's

    and really i get the best accuracy out of the 75's be it Berger VLD or the Amax bot almost shoot the same. I run the 75gr VLD at 3100fps with 28gr Varget and its super accurate.

    But i will say this a AR is harder to shoot accurately than a bolt gun, whole different learning curve.
     

    sititunga

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    Re: 6mm Turbo 40 Improved

    Should probably ask Whitley at 6mmAR. Might be easier just to get a new barrel and heavy walled upper receiver.
     

    Blackhawk95

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    Re: 6mm Turbo 40 Improved

    I would say the best bet would be to have Whitley build you an upper. so all your tolerances will be correct and have the most accuracy.

    also from what i understand is the .22Ar reamer he uses is a custom design to aid in feeding. Ive not had a single feeding problem with mine.
     

    toygunner

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    Re: 6mm Turbo 40 Improved

    I have a 6 RAT that I traded for here on the Hide. It is very similar to the 6 turbo. It has a 27" barrel. It shoots either 107 SMK or Hornady 105 BTHP with 29.2 and 29.3 gr. of RL-15 right around 2850 fps. Accuracy is excellent. I've shot it far as 1000 yds on a gusty windy day and hit twice. We could not tell through the scope. After shooting the fresh painted steel we could see the hits after the drive down. It's definitely the stuff to the 850yd. mark. I would almost put it up against my 260 bolt gun. It shows a distinct edge over the Grendal.
     

    Xcount

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    Re: 6mm Turbo 40 Improved

    The main reason there is a 6RAT is because Whitley won't sell just a barrel. Guys were mad that they had to buy a whole upper so someone designed a reamer that copied the 6T40imp and now it's all the rage?
    I have one of Robert's uppers and it is a great way to go, as simple as a phone call and you get the best, from the original designer. I've never heard of anybody complaining about a Whitley upper.

    The cartridge flat out works great but remember, it wasn't designed to shoot 1000 yards. It's built off of the 6PPC cartridge, which is a short range benchrest record setter. You will be limited past 600 and there are definitely better choices.
     

    sititunga

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    Re: 6mm Turbo 40 Improved

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Xcount</div><div class="ubbcode-body">The main reason there is a 6RAT is because Whitley won't sell just a barrel. Guys were mad that they had to buy a whole upper so someone designed a reamer that copied the 6T40imp and now it's all the rage?
    I have one of Robert's uppers and it is a great way to go, as simple as a phone call and you get the best, from the original designer. I've never heard of anybody complaining about a Whitley upper.

    The cartridge flat out works great but remember, it wasn't designed to shoot 1000 yards. It's built off of the 6PPC cartridge, which is a short range benchrest record setter. You will be limited past 600 and there are definitely better choices. </div></div>

    Thanks but it pushes 108 gr bullets to 2850 - 2900 fps, which isn't far off from a 243 and almost identical to the 6mm BR, which is shot to 1000 yds. If you run the ballistics using the 108 Berger this little round looks like it will perform quite well at 1000 yds. At these velocities it should remain supersonic out to about 1300 yds.