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Posted: 7/30/2015 5:35:49 PM EDT
Thought I would share my wildcat project the 7mm Valkyrie AR
 
The 7VAR as i call it for short came about from my love for the 270AR that was designed and sold by Harrison at ar15performance. With my experience with the 270 I had the idea of putting a 7mm in the case to make a long range hunter in the ar15. i had to shorten the case to make it a bit more versatile with bullet selection. The Valkyrie will shoot from 100 grain bullets up to the 168 berger classic hunter. With the 168 berger running 2575 which is my accuracy load in the 24" barrel the H.I.T.S. score puts it in the large game catagory to 600 yards 400 yards, 500 and the final is 600 yards   
The Valkyrie was also designed to run at 2.295 oal with some bullets liking to be loaded to 2.345 oal which I use a windowed magazine to accommodate those.Most sierra and speer bullets actually need to be loaded 2.27-2.29 to stay of the lands. Nosler bullets like to run longer but they run ok at 2.295 but you can get a little more accuracy if stretched out the same goes for the Hornady sst bullets. the nosler 150 long range accubond also works but has to be loaded at 2.35. It is based on the 6.5x47 Lapua case with the shoulder pushed back to allow it to run in the ar15 at 2.295 oal and necked up to 7mm. Case trim length will be 1.596-1.60 and case capacity is 42.6 grains of water. it requires neck turning and reaming because i wanted the most accuracy out of the round and i don't like necks that are .022 or more thick. I use Pri 6.8 mags they work best just like in the 270AR because the magazines are stiffer and don't bulge when loading. they are good for 7-8 round no matter the size of the mag 10,15,25 after 8 rounds they start binding. One of the end users is trying to design a billet windowed mag that will hold 10 rounds. The Valkyrie has been tested in 16.5,20,21,22,24 and 26 inch barrels and across the board there is right at 25-28 fps lost per inch so any data i post for 24 and 26 inch barrels just subtract 28fps per inch for the length barrel you want to know about and it will be very close to that. Specifications: Cartridge overall length 2.295 inches Case trim to length 1.596-1.6 inches Shoulder measurement with hornady 375 adapter 1.305 on fresh cases. Velocity's 26” actual data 120 class 3000 130 class 3080 max 140 class 2875 150 class 2670 not max 160 class 2660 168 Berger 2675 24” actual data 110 class 3075 not max 120 class 3000 130 class 3000 140 class 2850 150 long range ab 2700 160 class 2660 168 Berger 2625 20" Actual Data 120 sierra 2860 not max 130 speer 2800 139 sst 2690 145 speer 2630 not max 160 fusion 2437 168 nosler 2416 16” Actual Data 110 TNT 2843 120 sierra 2804 130 Speer 2800 139 sst 2700 140 nosler bt 2600 The 7VAR used the 800 series bolt/extension from AR15 Performance so it can run up to 60,000 psi. The Valkyrie is a reloader only caliber. It is a full power hunting round that fits in the AR15. It matches some 7mm-08 factory ammo ballistics. The case forming requires neck turning and reaming, neck thickness needs to be .014 - .012. As stated 6.5x47 lapua brass is the best brass to make the cases from. It forms the easiest, lasts the longest, is small primer and handles the pressures the best. Also there is zero loss rate when forming. 6.5 Creedmoor cases also work but the brass is softer and only lasts 2-4 firings on average. It also has a loss rate of 10% when forming from creases/folds in the neck/shoulder area. it does have the highest case capacity. Winchester 308 brass also works but you still have a 10% loss rate when forming. There will be 2-3 guys offering brass conversion for the 7 VAR, 270AR and the 257 Bobcat. Already processed brass will also be available in a limited capacity to start. Dies will be from Whidden gunworks with their competition micrometer seater die which is one of the best in the industry. Barrels will be made by X-Caliber Some of the powders that work well with the Valkyrie are: Leverevolution,CFE 223, xbr 8208, H335,Benchmark, AA2520, TAC, AA2230 and Xterminator. Also r15 and arcomp might also work well also n530, n540 should be workable powders. imr 4166, h4895, imr 4895 will also work but velocities are down from lever and cfe but they have very good accuracy. here are some ballistic charts   
      
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Interesting, bears more than a passing resemblance to the 280 British cartridge. I have toyed around with the idea of building a rifle in that caliber for years. Reamers exist and so do reloading dies but I do not reload so that idea has gone nowhere.
The concept is also somewhat reminiscent of that 30 AR caliber Remington was hyping awhile ago. I don't think that went anywhere though. I haven't seen a rifle in that caliber in years and I don't think I ever saw a box of ammo for it. |
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Quoted:
Just wanna say that, as a NON-Wildcatter, I am VERY impressed at how much labor you put into this project. In fact, all of you Wildcat guys impress the living hell out of me. This is just some darn neat stuff!!!! Thank you, yes it is a lot of work but man is it a lot of fun also. when you see the results of your work on paper it makes all the work worth it. |
| Just curious as I've never experimented with any loads that have a profile like this...WSM and such. I know these types of rounds have great potential in bolt rifles, but is there any feeding issue in semi-autos due to the profile of these cartridges under rapid fire? Asking not challenging. |
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Brit wanting to stuff .280" British into an AR:
http://www.ar15.com/forums/t_1_5/1781123_.html |
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Quoted:
“Iowa? I could have sworn this was heaven.” http://i4.photobucket.com/albums/y124/BIGGDAWG800/7mm%20Valkyrie%20AR/20150815_141347_zpsjhvbixpy.jpg I'm more than very interested in this round. sometimes i think it is close lol let me know if you have any questions. |
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