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

[LRS_Ranger]

Well, with all the hullabloo about 8208 I went in with a friend and got an 8 lb jug. Today I loaded from 27.8-29.2 grains in .2 grain increments. 123 AMAX, Lapua brass, CCI 450's, 2.270 COAL, and 1.5 thou of neck tension. I only got chrono info on the 29 and 29.2 charge weights, and they were 2605 and 2630 FPS average respectively. I hit a node on the head at 28 grains, and I and pretty close to another one at 29.0 grains. I'm glad it all worked out, because I have 8 lbs of the stuff. If it works as well as I have heard with 155's in the 308, I'll never use Varget again...

I am also going to use my AMAX load to find a 123 Scenar load as well; a 2600 FPS+ Scenar would be the cat's ass...

As a side note, the upper I'm using is a SAC build with a 20 inch Krieger bbl.

[Nimrod]

How do you feel about pressure at 29gr?

Hodgdons max charge for a 123gr serial is 28.5.

[LRS_Ranger]

I was watching closely the whole way up... No primers were flat, did not have cratering of the primers, and everything looked normal. I realize that it's a little bit hot, but everything seems alright... I should probably drop down again and work up when I switch to Scenars though, just to be safe.

[Nimrod]

Keep us in the loop.

You ever shoot anything with those scenario?

[LRS_Ranger]

Yea, I've burned through almost half a box of 1000 of them... they don't shoot for crap at 100, but out at 300 and beyond they are awesome. If the Amax's shoot well at all distances, I will most likely shoot those exclusively after I use the rest of the box of Scenars.

[RStewart]

I think there is definitely something to the group tightness at 100 yards versus 200 yards. I just got in 500 of the 123 AMAX and was planning to pick up a Pound of the 8208 to try. This is good info to compare the 8208 with the 2520 at longer ranges. Keep the info coming. I'll post up what I find, also.
Rick

[LRS_Ranger]

Next week I should be able to get out to the 600 yard... I am thinking that I am going to refine my load this weekend and bang some steel. After the 600 I'll post up how it worked.. For now I am going to stick with the AMAX, I'll mess with the Scenar's later.

[RStewart]

Next week I should be able to get out to the 600 yard... I am thinking that I am going to refine my load this weekend and bang some steel. After the 600 I'll post up how it worked.. For now I am going to stick with the AMAX, I'll mess with the Scenar's later.

Well? How did it go? I just got in 500 Sierra 123's, so now I can do a side-by-side of the 123 AMAX and the 123 Sierra. Just finishing up a month long shutdown so there has been no shooting for me in over a month. I'll post up info on the comparison soon.

[LRS_Ranger]

Update:
I have useful load with both AMAX's and Scenars. All loads are with CCI450's, Lapua brass, about 1.5 thou of neck tension.

123 Scenar, 28.4 of 2808, and 2.268 COAL 2630 FPS
123 AMAX, 28.5 of 2808, and 2.270 COAL 2625 FPS
I can get around .5-.6 inch average with the Amax at 100 yards, but the velocity is not always consistant. The batch of brass I was using for this load has been loaded about 4 or 5 times and I haven't annealed yet, so I am guessing that inconsistant neck tension could be the source of some of my problems there. When I took it to 600 yards, it seemed to shoot fairly consistant except for the low flyers. I am going to try this in newer brass, or anneal that batch and see if that clears up some of the problems. I really would like to like the Amax's as they are much cheaper than the scenars. With consistant velocity this would be fairly good load.

The scenars run EXTREMELY good extreme spread numbers (less than 10 FPS) but still shoot like crap at 100 yards. .7-.9 is fairly common. However, when you take them out to 600 they start to shine. Vertical at range is very good, with the bullets tracking in a line across the target due to wind. I had an occasional low shot, which I am owing to the fact that I threw the charges. Next time I am going to throw and trickle, and I bet that even the occasional 2 inch low shot will go away.

Just for kicks and giggles I threw together a few loads with 120 Nosler BT's and 28.5 of 8208. I only shot them at 100, but they went to the same point of impact as both the other loads. I only shot 3 rounds, but they were under an inch. Velocity was around 2590 average.

I really want to like the Amax's. They are so much cheaper that the Scenars, and have a similar BC. I am going to load them in fresh brass and see what I can make happen. If I can't clean up the extreme spread numbers though, I guess I will stay with the Scenars, unless I am trying to shoot something small close up. I would like to try some Nosler 120's with this powder as well. Maybe that will be my next experiment. The 120's shot extremely well with 2520 in my rifle.

-LRS

[RStewart]

I had an oppurtunity to take one of the Grendels out this past weekend to a BBQ and shoot. I loaded some 120 SMK's over 30.2 grains 2520 loaded to 2.220". I did not get to personally shoot these loads, because everyone else wanted to shoot it, but it was busting the crap out of 4" clay pigeons at 200 yards. No misses. Not exactly a technical report, but at least the loads did not appear to have any pressure issues. Temperature was 95 degrees. I plan to start refining my loads and have some 120's, 123 SMK's, and 123 AMAX to play with.

I usually don't chrono my loads until I find the nodes that group best. I used to frustrate the hell out of myself when I would get these great muzzle velocities, but the groups were poor.

I still plan to try some 8208, but since I got 8 lbs. of 2520, it may be a while. Lol.

[LRRPF52]

LRS_Ranger,

What magnification were you on when shooting at 100yds?

LRRPF52

[LRS_Ranger]

I usually shoot for groups at 100 around 14X or so. I have a 6.5-20 Leupold Mk4. I've experimented with different settings, and that is the one that shoots best for me. When I'm actually shooting at real targets I typically use less magnification (around 10X) unless I'm much further away.

[LRRPF52]

LRS_Ranger,

I was just wondering if your groups at 100 would shrink if you dialed down to 10x or even lower. It doesn't make sense that the bullets would be unstable at 100, then tighten-up further out. I've heard the argument about bullet RPM and balancing out, but shot dispersal between a group of projectiles can't be stabilized by bullet rotational balance to the axis of flight...only individual projectiles can. In other words, even if they were somehow individually not optimally balanced, they would still print the same or better group dispersal at 100 than 200. I bet if you dialed down and tuned your focus, you would probably see tighter 100yd groups.

I found it much more difficult to shoot on higher magnification at 100yds. With a rifle rest using Velcro straps and a solid mechanism to lock the gun down, I have been able to do it when doing accuracy-testing for a manufacturer, but it required a lot of mental focus, and extreme attention to the fundamentals, even with the rest. This was for rifles with .5 MOA guarantee, so test targets had to be sent with each rifle. It's not so fun when you have a stack of 20 .338 LM rifles that have never been shot before, with $66 boxes of Lapua/10rds .338 LM, day after day. I always had the S&B PMII on 25x for those tests, which I normally would never do at 100. It was more convenient to keep it on 25x so I could measure the groups, versus dialing back and forth, or looking through a spotter. That's the only reason I think it stayed on 25x...

I don't know if you're using a rest or not, but it helps me to settle the gun each time, no matter what position I'm using. That get's me closer to natural point of aim when I do it, so it takes less time and less shooter input to keep the reticle true through the center of my aiming point.

The biggest factor that comes into play is overcoming the mental game of seeing negative effects of shooter input magnified on such a close target, and feeding into the positive loop feedback cycle it does on your mind and body, which can easily spiral downward when apprehension kicks in, then fear of the shot, fear restricts bloodflow, muscles start shaking...along with the reticle, causing more apprehension...more fear of failed performance...O2 loss to muscles...spiraling down...down...down...BLAM!!! "Where did that one go...?"

Experienced shooters will have a tighter shot group under these conditions due to successful and habitual practice with consistent positioning, trigger control, sight alignment, etc., but still not exploit the accuracy potential of their firearm. I have seen several shooters report this same phenomenon, where their 100yd groups weren't what they would like, but the rifle/ammo/optic/mount/shooter system proves to be exceptionally sub-MOA at distance well past 200. Without exception, I think every instance involved shooting at 100 on higher magnification than necessary.

LRRPF52

[RStewart]

LRS-
Finally gonna get a chance to check my loads tomorrow. I'll post up my 2520 results with the 120 SMK's. We can compare notes against the 8208.
Rick

[LRS_Ranger]

I will try that. That's one thing that I have not tried to shrink my 100 yard scenar groups.

The way I've heard it explained as to why some bullets take longer to settle down, is to relate it to a child's top. Some do it more than others, and some hardly at all, but all tops, when initially spun, exhibit a bit of wobble till they gyroscopically stabilize and then continue to spin smoothly. Now picture the rifle bullet being spun out of the barrel by the rifling. That initial wobble is enough to deviate the bullet slightly from it's course. After the wobble stops though, the bullet stabilizes and flies as designed.

I'm always ready to try a new idea though, so I will give dialing down my magnification down a shot. (no pun intended... ) I do think that there is more than shooter mental stuff going on though, because the scenar is the only bullet that I can't get to group for crap. The 120 SMK's regularly shot into under half an inch for me when I was doing load development, and using the magnification I always have.

RStewart, I'll look forward to hearing your notes on the 120 2520 combo. It was a winner for me, but I had 1000 scenars so that's what I'm shooting. I'm interested in seeing how they work with 8208. I imagine similar to the 120NBT, which I got to almost 2600 over 28.5 gr of 8208.

-LRS

[rasp65]

Ranger Here is a video from Berger bullets that traces the epicyclic motion of a bullet fired. http://www.youtube.com/watch?v=4pF8W5liSRc&feature=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.