30 VAR

[HMC710]

Greetings All!

Its been a while. Another year, swamped with work and trying to get some things done at the shop for all yall.

Latest project was based on one of Bro's old 30 BR barrels with 1:17 twist. We cut it down to 18" and reprofiled it with a bull barrel AR profile and then deep chambered using a 300 BO reamer to accept a 1.750" case. With basic brass we could go all the way to 1.800" but kept it at 556 brass lengths for ease of conversion. This is an exercise in maxing out velocity from the 300 BO or 762x40 with the slow twist varmint barrel, hens the working name 30 VAR for varmint AR.

Brass was made by taking 556 brass, running through a 7 TCU sizer to open the neck, then through a 300 BO sizer to get to 30 cal. Test were done with the lightest 30cal varmint bullets I had + some of Bro's bench rest bullets.



Low on powder selections so I went with 22gr of 4198 for the longer BR bullets and 25gr (almost full case) for the 110 HP. Test fires show no sign of pressure so I'll see what these do and go from there. QL says we can push 2800 + so we'll see what happens. Test firing the 110s with the bull barrel was a very low recoil event! The case on the far left has been fire formed and you can see the crisp shoulder.
H

[paulsblackrifles]

Happy Holidays,
The 30VAR looks interesting. Would you have better luck using a 350 Legend for the parent case?
I am not sold on the 300BO/300 Whisper. They seem to lack the power I am looking for, the 300 HMR doesn't seem to be much better. Granted the BO and Whisper are designed for heavy subsonics. I am taking another look at the 300 Whisper as I have another Contender barrel and I threaded it. With the Varminter 2 can it bears another look.

I have formed 350 Legend brass from .223 brass but it was a long slow process including annealing.

[HMC710]

Hey Paul, Happy New year my friend!!!!

Hence lies the problem with the AR platform.... limited capacity... people need to remember what the design criteria was on this....

from our R&D the 30 HRT is the most power you will get from a 30 cal AR15 round. you can bump up the 762x39, but true case pressures with the 6.8 case lets you "reach out and touch someone...."

The VAR was / is a simple exercise in maxing the 556 case. Yes, Legend cases will work, but they are limited to pressure where the 556 cases can top out at 60ksi. But, I'm guessing some soul will get 3,000 fps out of the 30 VAR

[paulsblackrifles]

I thought the 350 legend case was rated as high a PSI as the 223/5.56 case.
The main problem with the 6.8SPC is the specs called for a special .277 military projectile. There are a limited number of projectiles for that slow a velocity in .277. I talked to my LGS and there are 6mm/6.8 wildcats out there, I should be using.

A 30 cal 125 or 110 grain projectile at 3,000 should do what I want to a whitetail deer.

Paul

[HMC710]

Hey Paul,

Yes, you are correct on Legend pressures, good to 55ksi, I had 450BM on the brain. Yes, the Legend case could be trimed and used for the VAR. I was using Starline basic brass for the 30 VAR.

But again, with limited case capacity... what's the real point?

The 30 HRT rimless 6.8 case maxed out in length to handle the 125gr is going to be a better round I believe. Been testing out of a contender barrel and waiting on my reamer to do an AR version.

[paulsblackrifles]

I'm cheap! I like to shoot less expensive projectiles. That's why I like the smaller projectiles, .224, 6mm, 6.8 and the like. .308 bullets and .355 bullets are not as cheap as the smaller bullets. The saving grace is I have enough to keep shooting them if I don't get too crazy.

But hunting, that isn't really an issue. It should only take one shot per deer.

[HMC710]

Have a 3 day tour to do the end of this week and its in driving distance with a range close by. Going to warm up the 30 VAR rain permitting...

[paulsblackrifles]

Have fun, run the 30 VAR thru its paces.

[HMC710]

I wish... rain turned to snow. Just cant' catch a break...

[HMC710]

Chrono went down a few years back and haven't replaced it yet so no numbers on the 30 VAR. Got some 87gr bench rest bullets to try with this and some more 110 grains coming. I guess I'll have to invest in another chronograph at some point. That will be like #5...... geesh.

[HMC710]

Now that we've got a new chrono its time to put the 30 VAR through its paces and compare it with the 30 HRT.

[HMC710]

Well, I am sad to say that the 30 VAR barely cracked 2000 fps with the 4198 load. I knew it was a bit slow of a powder, but got some 4227 to try and will give it another go.

[HMC710]

I also measured my 30 VAR cases and they were a bit short of 1.75" so I'll have to take a look and see whats going on there and what the max OAL I can get with the 110g bullets.

[HMC710]

Chrono'd the test loads with 4227 vs the slower 4198 and woke the Var right up. 2550 fps baby, right where the 30 SPC is.