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Home built Cerekote curing oven

6/7/2015

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I decided to make my own curing oven for Cerekote. I wanted something large enough to cure up to 30 inch barrel and have room to cure all parts going on an AR-15.  

I was going to build the cabinet myself but after some research and looking for steel I decided I would be money and time ahead to just find a cabinet that would work. Here is a parts list of what I used to build my oven.

PID controller with thermocouple and ssr   

Electric oven element    

Contactor 

Stack-On® 21" Buck Commander Bow and Gear Storage Cabinet   

1- 4x8 sheet of 5/8 drywall  I needed more to do door but at this point it is working fine without it on the door.

Duct insulation 

Electrical junction box  

15 amp standard light switch

220 oven/drier cord 

Shelf hangers   

Misc bolts and hardware.

I started out taking all the stuff out of the cabinet. I located where I was going to put the element. I cut the hole in the cabinet for the element to protrude. 



Once that was done I installed the drywall. I used 1/4" carriage bolts and fender washers to hold it in. I then lined it with the duct insulation by stapling it to the drywall.I taped the seems with aluminum tape also taping the inside of the door.  
I then mounted the element and box and installed the shelf bracket rails. Now it is all done on the inside and ready to wire
The wiring is the tricky part. For me I got mine done and wired and it didn't work. I needed 110v to power the pid and contactor and made an assumption that was wrong. so with my design I had to run a 110v power and 220 to my box to get it to work.
After the first run I rechecked why my first wire diagram didn't work and found out when I wired my breaker box in the garage I forgot to tie both ground rails together so when I used the center wire for my common wire it wasn't connected to the common rail. I rewired my breaker box correctly by installing the jumper wire from rail to rail and then wired it as I had the first time and now it works fine and I don't need the extra 110 cord to power the box
here is my box and here is a couple of different wire diagrams to give an idea how to wire. 
Over all it turned out well and it works that is the important thing. couple of things to watch for: when buying your pid make sure it is a F deg. and not Celsius if you don't want to make a conversion chart like I had to do.Make sure to get aluminum foil tape not just reflective duct tape,
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Accuracy testing the 7mm Valkyrie

5/11/2015

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Sunday I got out to test 5 loads to try and find the accuracy nodes In the 24" 7mm Valkyrie AR barrel. The day was cool and over cast. Temp was 60 but it felt like it was in the low 50's with the 15-25 mph winds from my 7-8 o'clock.

Todays tests were also going to include cycling tests with the faster powders like h335 and imr 8208. I have been slowly opening up the port. It is at .093 now which is larger than I figured we would need but i wasn't getting bolt lock back and not all rounds were being picked up with aa2230,h335 and 8208 at the .089 port size. Well those problems are fixed now. The gun cycles perfect with 3-4 o'clock ejection with both h335 and 8208 didn't run 2230 today.

Good news is all loads tested had an accuracy node at .8 moa or better with the nosler 140 BT coming in at best with a .398 moa group at 100 yards a second was .409 moa. The 160 federal fusions i did 5 shot groups the rest were 3 shot groups. The 160's came in with a best of 

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7mm Valkyrie AR for big game

5/8/2015

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By Craig Black


The preliminary results are in on the performance of the 7mm Valkyrie AR as far as velocity over a large range of bullet weights. Thanks to new powders like leverevolution the 7mmVAR gets velocities normally associated with 7mm08 factory loads. A 140gr Nos BT at 2800 to 2830fps, 154gr SST at 2700fps and 160gr Fusion at 2600fps to 2660fps and lastly a 168gr Berger at 2600fps. These are well documented 7mm08 velocities and the hunting capabilities of the 7mm08 are well documented. In other words if guys are having success with factory 7mm08 ammo on particular game we can safely assume the same results or very very similar with the 7mm Valkyrie AR since the performance is the same as factory 7mm08. 7mm bullets have excellent sectional densities that are appropriate for medium to large game. For example a  7mm 160 grain, has a sectional density of .283 which is considered CXP3 which is the category assigned for large game such as red stag, kudu, elk and moose.

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The 7mm also have ballistic coefficents (BC) in the high 400's to even low 600's for some bullets. The Federal 160gr Fusion bonded bullet has a BC of .528 for example. The Hornady 154gr SST has a BC of .525 better than a 140gr 6.5gr SST of .520. These high BC's mean that to get long effective hunting ranges and they don't require magnum velocities to get those ranges. Basically if your hunting in normal hunting ranges below 500 yards you don't need a canon to hunt with a 7mm. The 7mm08 has a well known record of taking everything from deer to moose. A google search of 7mm08 and moose brings up all kinds of examples of moose and some very large trophy moose taken with 7mm08.

Hornady came up with the H.I.T.S system for hunters to get general ideas for effective hunting ranges and to aid weeding through internet hype and forum spin that are ever so common. Its general it helps a hunter validate what they read online. Usually when someone says they don't trust Hornadys H.I.T.S system I find they are hyping an under powered caliber recommending it for game its not ethically capable of taking or simply don't like the results for there favorite caliber. You can get Hormady H.I.T.S numbers for a particular cartridge by running a bullets caliber, bc and muzzle velocity through a ballistic calculator to get velocities for various yardages. You then take those velocities and run them through Hornady H.I.T.S. For example get if want to see what H.I.T.S predicts for the 7mmVAR for a 160gr Federal Fusion with a MV of 2600fps with a BC of .528 to get the velocity at 400 yards. Then take that velocity at 400 yards and then run it in the H.I.T.S calculator on the hornady website. The results validate that the 7mm08 and 7mm Valkyrie AR are big game capable cartridges. A score of over 900 is considered big game capable for Elk and Moose. Hornadys H.I.T.S system indicates that a both the 7mm08 and 7mm Valkyrie AR are large game capable to past 350 yards. The H.I.T.S score drops below 900 at 390 yards which is a velocity of 1990fps at sea level as the elevation goes up so does the range its in the large game category. 
  
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The 7mmVAR cartridge has a shorted over all length (OAL) of 2.295in to fit in a AR-15 . This smaller OAL means that not all 7mm bullets are appropriate for the 7mmVAR. The spreadsheet list is a good resource to check if a bullet will work. If the ogive is to far back the bullet may not work. We've documented about 50 bullets from 100gr to 168gr that will work in the 7mmVAR giving the hunter selections from varmints to Moose. Solids copper bullets for 7mm are generally 140gr pills but lower grain do exist like the 130gr Cutting Edge MTH and Barnes 120gr TTSX. Moose have been taken with the 7mm08 and the 120gr TTSX. The Cutting Edge MTH bullet has a decent BC of .460 so I would probably go that route as a full copper bullet. I mention that because California goes lead free in 2019 making the 7mmVAR and like calibers the 270AR being another example as good choices for that state. While the sectional density is lower the actual “terminal sectional density” has the same results as larger weight lead bullets. Tests of copper solids show that lower weight copper bullets penetrate flesh and punch through bone like much larger lead based bullets.

The velocities I mentioned are from a 24in barrel and compared to a 7mm08 24in barrel. Its likely as a hunter that you will not want to use a AR with a 24in barrel. Maybe a 20in or 22in fluted barrel make more sense which means effective hunting ranges will need to be adjusted down. Early testing indicates that velocity drop is about 28fps per inch with the same charge of leverevoultion. Some of that velocity could be gotten back most likely with faster powders in the shorter barrels. The most common barrel length for 7mm08 are also 20 and 22in barrels. 

Taking the real world experience with large game and the 7mm08 and hunting effective range calculators like the Hornady H.I.T.S system shows that the 7mmVAR is a large game capable cartridge with in reason. If your an ethical hunter and don't take what I would call unreasonable shots at game the think the 7mmVAR makes a good choice for medium to large game in the AR-15 platform. In fact the 7mmVAR actually delivers more energy down range and gets higher H.I.T.S scores than some calibers only available AR10 like the 308, 6.5 Creedmore and 260 Remington. You read that correctly because of the velocity and big BC's and high sectional densities the 7mmVar actually has competitive or in some cases better stats than main stream cartridges in the larger heavier AR10. If your like me your going to run those numbers to challenge that statement please do you'll see what i'm talking about.  For example a 308 with a 165gr SST at 2840fps (factory hornady) is in the large game category to 330 yards according to H.I.T.S compared to a 160gr 7mm at 2600fps with a big game capable range of 390 yards to give you some perspective. 

7mm08 Moose Kill

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7mm Valkyrie 24" barrel test day

4/27/2015

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Had a great day at the range yesterday. I took the first AR chambered in 7mm Valkyrie AR (7VAR) out for the second week of testing. Rick also took out his 16.5 inch VAR for it's first shots.

 I learned a lot and you can see by the pressure readings i was finally getting close to the top end. we can run this at 60k with the 800 series bolt. I can't believe the performance we are getting with the 160-168 class bullets from the 24" barrel 2600 fps wow that makes it a elk round to about 500 yards with an AR15

I have Rick's 20" barrel at the smith getting chambered then we will get some 20" data. A lot of guys are interested in that data because 20" will probably be the most popular hunting length. 

Accuracy also looks good, I really didn't do too much yesterday with it and when I did I had the magnetospeed chrono on the barrel. Next weekend i will run some accuracy tests with a few bullets and run a few with some other powders. The lever loads ran the gun fine today but the faster powders like h335 and 8208 did not so i opened up the port to .089 for the next trip.

That is all for now enjoy the pictures and data


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7mm Valkyrie AR

4/7/2015

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Initial testing observations
I have begun testing on my new wildcat for the AR-15 the 7mm Valkyrie AR or 7 VAR for short.
The first gun chambered is a savage Axis just because it is faster and easier to chamber and make a bolt action barrel. I have 3 ar test barrels in route they will be 24” heavy barrel for me and a 20” and 16.5 Inch for Rick. They are due in next week.
Sunday was the first test day for the Valkyrie. I just did velocity ladders checking for pressure signs on the cases and breaking in the barrel. I sighted in with 130 speer bt with CFE223 starting with 36 grains and I worked up to 38.3 didn’t hit max and velocity numbers were coming around. Started out at 2600 and ended at 2747 fps.

Next up was the 139 hornady sp bt with cfe223 you can look at the pic and that is 10 rounds ranging from 34.1 to 36.8 grains no where near max. Velocity started at 2434 fps and ended at 2593 fps with no pressure signs. I will estimate max at around 38.5-39 grains.
Next up was the 168 berger Classic with Leverevolution.  I must say here that I really think lever is going to be “the” powder for 130 and up bullets as far as velocity goes. I also think accuracy is going to be good with it. The bergers started at 31.5 grains at 2326 fps and I loaded to 34.2 grains at 2506 fps and again I am a ways from max I will guess max will be around 35.5 grains and we should get close to 2600 with them in a 24” barrel.
I should note here that the savage test barrel is 26” bull. It is going to be a bench gun for me so I wanted the length it also gives us another dimension in testing. We will have 16.5,20,22,24 and 26” test barrels so it will give us a good idea what each length will give us for accuracy and velocity.
Now I moved to the 120 Vmax with H335. With this combo I started at 33.3 with a velocity of 2691 fps to 36 grains at 2834 fps not at max with this one either. 37-37.5 will probably be max with this combo needs more testing as with the rest. 
139 sst was next up on the plate with lever here you can compare the sst to the 139 btsp with cfe and see the big difference in velocity but pressure signs are not much more with lever. I ran the same charges here as I did with the cfe and btsp  34.1 of lever got us 2579 fps and the 36.8 grain top charge hit 2760fps not max charge yet 38-38.5 will probably be max charge with this combo also and 2850 fps I am hoping. Accuracy is also looking good. 
The last and final test of the day was the 140 nosler ballistic tip with imr 8208,30 was the start charge at 2396 fps last charge was 32.7 at 2623 fps.  velocity is lower than expected but I was not near max, I retested last night with an accuracy ladder up to 34.2 and I was approaching max I didn’t take velocity readings will do that when I narrow the final load down. In the pics you can see the accuracy test. I wasn’t shooting the best and had to dial the scope a couple times but when I was doing my job it is showing great promise.
I also ran the 140 nosler ballistic tip with lever last night for velocity and I was impressed. The picture shows 8 shots that range from 35.7 to 38 grains at 100 yards and you can just about cover with a quarter. I also hit 2832 fps at 38 with a little room left at this temp  it was 37 deg.  It might be max in the summer heat.
Overall I am very happy with what I am seeing. It is hitting some of the goals already with a lot of testing to go. All the parts are here for the ar build. Just waiting on the barrel.

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    Author

    I am Bruce Finnegan a gun nut that saw a need for a large capacity wet tumbler so I built my own. 

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