6mm-223

I was a little concerned initially since the barrel was a Midway badged AR Stoner and I am not sure who really makes the barrel. Here are the results from the first firing. This is at 50 yards with a 1/2 inch grid. I put the photo in a pdf.

I have to say this gun consistently shoots sub moa with everything I have tried from 58 grains to 80 grains. (I must admit I thought this was only possible with bolt guns. I was wrong.)

Once I jump to the 87 or 90 grain bullets, its all over the paper. I should mention this is a 20 inch pipe with a 1-8 twist so I didn't think it was a stabilization issue. But, perhaps I just wasn't slinging the heavier bullets fast enough to stabilize??

As an experiment I tried some 80 grain GMX (gilding) as they are longer than anything I have tried before. I was shocked to find a tight group with the slowest velocities I have measured out of this gun. The PoI also shifted low right...I am guessing due to the change in velocity.

My reason for wanting the heavier bullet/ non varmint is to use the gun on some fast goats. I guess I should just shoot what it likes and call it good!

87's and 90's H335 is your friend.
Varget is good but a man has to know his limitations.
I would try some.. I have had great luck with my 10 twist 6x45 and H335.

60's also love AA-2015BR max load.... like match winning potential.

Have you pushed a patch down your barrel to confirm that 8 twist?
Your 8 twist should have plenty of stabilization.
8-Twist RPM = 2700 x (12/8) x 60 = 243,000 RPM (2700ft/sec)

It is generally accepted that 160,000 RPM will stabilize a bullet.

I have tried H335, 2015, TAC, 4895, x-terminator and Varget with marginal inconsistent results. The 87 grain I have been using are the Hornady SP. I should probably weigh them to check the variance. Maybe its a bad lot. What bullet are you using? What barrel length? I should see if Sierra makes a non-varmit in the 87-90 range.

By the way mine also likes 2015 (25g) behind the 58 grain Zmax.

I have also been playing with the notion of ordering a 24 inch blackhole (another upper) to see if it would handle the heavier bullets better.

Quote:

---

Originally Posted by IceAxe

What bullet are you using? What barrel length? I should see if Sierra makes a non-varmit in the 87-90 range.

---

I have a Dtech built 1:10 20" full bull barrel 6x45 with an Olympic SUM (stainless Ultra-match broad cut barrel)
Bullets wise I have been shooting Sierra 90 grain GameKing #1535 BTHP as well as the Remington Bulk pack 80 grain SP. I don't shoot bigger than this in my 6x45 due to the 1:10 twist. With your 8 twist the Hornady 87 grain SP should work well too. (I like Hornady bullets for hunting and targets, I use the 100 grain interlock exclusively for hunting in my 243 Win)

I mainly use my 6x45 for yotes but I have been toying with the idea of antelope as I guide hunters and want to use something different. I would use the Remington 80 grain bullets for speed goats without hesitation as they have a proven track record as a game taker and my rifle shoots very well with them. Not up to the 60 grain for accuracy, but well enough for hunting.

Well, as luck would have it the Warehouse didn't stock the 90 grain Gamekings. They did have an 85 grain Gameking so I got a box of those. I also picked up a box of Nosler partitions also in 85 grain. My plan will be to work up some loads with H 335 and see if I can get them to group.

Ok, well I 've had the loads ready in H335 to go to the range...so maybe I should work some up with Varget and some other powders, since it will probably be June before this wind dies down.

Wind?
What Wind?
I don't know what you are talking about.
http://www.windpowerninja.com/wp-con...ine-damage.jpg

I went out this morning in an attempt to beat the wind.

7 rounds each
Sierra GK 85g - 25g H335 - group 2"
Nosler Part 85g - 25g H335 - group 3"
Hornady SP 87g - 25g H335 - group 2"

All three groups where averaging about 2650 f/s

I am at a loss on this one. It will shoot clover leafs with 58 through 80 grain bullets. I absolutely love this cartridge.

I have checked the twist with the cleaning rod and get between 8 and 8.5 inches for a rotation.The only thing I haven't played with is the seating depth. All have been loaded to a COL of 2.26 to fit the magazine.

I think I will order some of the 80 grain Remington and give them a try. But other than that I can stick with what works.

That sucks.
Interesting that Hodgdon Data lists 85 grain bullets with H335 @ 25.5 grains out to be around 2800ft/sec. Sierra's data 85-90 grain bullets says 25 grains @ +/- 2700ft/sec . My rifle is usually really close in the chrono from published velocity.
Is there any pressure signs? If not, I wonder if you try and drive up the velocity a little if the group will tighten?