I drank the cool-aid, and it was good!

[rasp65]

Ranger Here is a video from Berger bullets that traces the epicyclic motion of a bullet fired. http://www.youtube.com/watch?v=4pF8W...e=channel_page I remember reading an article somewhere but I can't find it about this subject. But basically a flat base bullet will stabilize quicker(that is why short range benchrest shooters use them) than boattail designs.

[RStewart]

LRS-
Finally made it out to the range today.
Arrived around 8 AM. Temperature was 80 degrees when I started, 94 degrees when I left. Humidity was 75%. Winds were 1-3 mph from 90 degrees but later moved up to 3-5 mph with higher gusts. Target range was 100 yards. Shooting under a covered firing line.
Equipment-
AA 20 Hunter w/Gisselle SSA trigger and PRS stock. WCI muzzlebreak. Harris bipod. Leupold VX-III 8.5-25x50 scope.
Ammo-
120 grain SMK's over 30.2 grains AA2520 loaded to an OAL of 2.220".
Shooting position-
Prone and Sitting

My first 2- 5 round groups were a bit disappointing as they wavered in the a little over 1 moa area. I attributed this to the inherent movement you have shooting prone from your shoulder. I added a back bag and the next 2- 5 round groups tightened up to .75" and .71" respectively. I was helping another shooter get zeroed in, so I took a break between each 5 round group to help him and let the barrel cool.
By now it was getting hot and the sweat was coming pretty freely. So, I decided to put my sling on and see how it shot from the sitting position. The 1st 5 round group opened up to .88". I tightened my sling and made it as was well positioned in my shoulder. The next 5 round group was a bit better at .81."
Now keep in mind these would all be in the 10 ring at 600 yards, so for me this is quite accurate enough for a semi-auto. Now I just have to concentrate on the other BIG thing that will knock you out of the 10 ring at that range, the wind....
My loaded rounds were never exposed to direct sunlight. They were loaded in a 73 degree room and shot in ambient temperatures of 80- 94 degrees. I did not see any pressure issues on the primers, but did see a few extractor swipes.
I will continue to work with the 2520 with 120's, 123 SMK's and 123 AMAX's.
For kicks, I had also loaded up 10 rounds each of Varget and H335. Varget was a complete bust. But H335 shot a pretty decent group. May be worth playing with some more.
This is my FPR rifle, but since the NRA has the any optics class that can be shot as part of the Across The Course matches, I wanted to see how it did out of the sling. When it cools off I may give that a try as well.
That's my report. Not overly scientific, but my experience. I'll keep you informed.

[LRS_Ranger]

Thanks for the range report! I had really good luck with the 120SMK and 2520, but I have a ton of 123 scenars so that's what I am going with for now. Maybe I'll get a box of the 120's this week so I can play with them and 8208...

[infidel470]

Interesting reading for understanding the multitude of forces pertinent to bullet movement.

http://www.nennstiel-ruprecht.de/bullfly/fomo.htm#twoarmsmodel

http://yarchive.net/gun/ammo/bullet_spin_rates.html

[LRS_Ranger]

To whoever is following this thread, I took the same loads I shot the other day at the 600 and took them out to 950 yards yesterday. Altitude was 2100 feet, with a 3-5 MPH breeze from about 11 o-clock to dead in front. The Amax's showed their velocity variances by going low every few shots. Other than that though they were performing well. The 120's went subsonic around 900 yards, and took 45 MOA to get there. (I even pulled one out of the target stand that failed to go through 2 2x4's; at least it hit nose first...) The Scenars were where it was at, and it was not at all hard to hit the 12 inch steel I had hung out there. I even managed to hit the 8 inch steel too.

I need to get a bubble level, as at that distance, any cant in the rifle will throw the bullet wide. 6 inches in either direction will cause a miss, so I had to be really extra careful of that. However, the Grendel did admirably out that far, and is very predictable. I guessed my elevation, shot once, made an adjustment and then hit the steel on the 2nd shot. Everyone that shot my rifle hit with it, even those that had never shot long range at all.

Anyway, thought I would give you all an update.

-LRS

[RStewart]

I am definitely following this thread.

It sounds like you found the "wall" for the 120's. You still shooting everything with the 8208? I think it's time to load up some 123's and see what happens.

Rick

[LRS_Ranger]

I have gone to 8208 exclusively for a few reasons. First of all, I have 8 lbs of it. But more than that, it gives me higher velocity, is more temperature consistent, and burns exceptionally clean. I'm getting a solid 2630 or so at under a max charge, with a 20 inch barrel. For those with a longer barrel, I would be interested to see what kind of velocity could be obtained. JBM says I'm not going to go subsonic till around 1200 or so, and next time out, I'm going to test this theory. At any rate, my experiences on Sunday lead me to believe that the Grendel is indeed a capable 1K round, despite what others have said. Regularly hitting a 12 inch target at 950 yards is exceptional. Benchrest accuracy? No, but definitely good for an AR-15 and a cartridge starting in the 2600 FPS range. I'm happy with it...

As a side note, I'm thinking about looking around for another LR bullet, does anybody have any suggestions, or is the Scenar pretty much the top predator?

-LRS

[steel89]

LRS
You hit on one of the things that has sold me on the 8208. It does burn exceptionally clean. After 100 rounds last range day I pulled the bolt/carrier for a good cleaning and was amazed that a wipe down seemed excessive. When you add in the good velocity and temperature stability, I'm sold on this as my go to powder.

[RStewart]

At any rate, my experiences on Sunday lead me to believe that the Grendel is indeed a capable 1K round, despite what others have said. Regularly hitting a 12 inch target at 950 yards is exceptional. Benchrest accuracy? No, but definitely good for an AR-15 and a cartridge starting in the 2600 FPS range. I'm happy with it...


-LRS

When you consider that at 1000 yards the x ring is 10" and the 10 ring is 20", with that accuracy, you'd definitely be competitive.

Rick

[steel89]

Amazingly the rain in So. Fla. stopped for the hour that I was at the range this morning. I shot five groups of 120NBT using 28.5 gr of 8208. My load development last range day using a COAL of 2.235 with this load showed good promise at 2538fps. Out of the five groups of five I shot today at 100yds, I had three groups of .5 MOA. There are no ranges where I can see how they hold at 300yds on a 16" AA bbl., but I think I have a solid hunting round for this year.