107 SMK's and N133

I've shot about 50 of these loads so far out of 19.5" AA Hunter and I can't get MOA at 100 yards. At 200 I'm usually close, and have one group that is under two inches. At 300 yards, I shot a group today that measured 1.6" (5 shots). Is this normal? Do the 108 Scenars have this characteristic, also? I understand why a group size would relatively shrink as distances increases, but I can't grasp why they would literally shrink as range increases. I mean, my 100 yard group today was almost 2 inches. It's barely over an inch and a half at 300.

Please understand that I'm new to benchrest type shooting, long range shooting, and reloading.

Thanks.

eta - I understand that some bullets don't stabilize until 150 or 200 yards out. But in that case, the groups would be something like 1 inch at 100, 1.8 inches at 200, and 2.2 inches at 300. But to have the groups actually smaller at 300 than 100 is weird.

I don't know if there is enough time in the Day to tell you why.

These easy way to say it, is this. Shoot five, five shot groups to get your agg for each range. This will tell you what the rifle is capable of with that load for that yardage.

The reason that's important is to eliminate several things. (One) you can not find a condition that will hold long enough to get that many targets shot.

(Two) your technique on the bench will show errors, this will help you make your shot calls.

The limitations of your equipment, scope magnification first. How well can you see the bullet holes at each yardage? Remember you have to aim at the same place each time to be able to tell if you can steer the rifle or if the rifle won't steer.

Wind flags? are you able to dope the conditions? You had better understand that without flags and being able to read the conditions, you are only burning up components, including the barrel.

Last thing we have on our hands is bench technique and bench gear. You might need to get with another shooter that shoots the same platform as you do and only if he has better success, analyze his gear and techniques.

The rifle and load is the last thing to concern yourself with until the above is taken care of. :)

I've shot about 50 of these loads so far out of 19.5" AA Hunter and I can't get MOA at 100 yards. At 200 I'm usually close, and have one group that is under two inches. At 300 yards, I shot a group today that measured 1.6" (5 shots). Is this normal? Do the 108 Scenars have this characteristic, also? I understand why a group size would relatively shrink as distances increases, but I can't grasp why they would literally shrink as range increases. I mean, my 100 yard group today was almost 2 inches. It's barely over an inch and a half at 300.

Please understand that I'm new to benchrest type shooting, long range shooting, and reloading.

Thanks.

eta - I understand that some bullets don't stabilize until 150 or 200 yards out. But in that case, the groups would be something like 1 inch at 100, 1.8 inches at 200, and 2.2 inches at 300. But to have the groups actually smaller at 300 than 100 is weird.You need to make sure that you are doing your end of this perfectly, your bench form. Spend some time shooting factory loads off the rest and focus every time on all your steps to the point where the bullet is in flight. Don't rush things, let the barrel cool down all the way before starting a new string. I do not know much of gas guns but, I shoot three shot strings in my bolt guns. I believe that any thing more than that is pointless most hunting barrels are far to light to maintain a grouping past three shots and I would have to say that the same goes for light barreled AR but like I said I don't know that much about them.

http://home.earthlink.net/~dannewberry/dannewberrysoptimalchargeweightloaddevelopment/
I don't know if the link above will get you there but check out what this guy says about load development. I only recently heard about this and it may help.
Just google optimal charge weight load development if the link doesn't work.
Wayne

I've shot about 50 of these loads so far out of 19.5" AA Hunter and I can't get MOA at 100 yards. At 200 I'm usually close, and have one group that is under two inches. At 300 yards, I shot a group today that measured 1.6" (5 shots). Is this normal? Do the 108 Scenars have this characteristic, also? I understand why a group size would relatively shrink as distances increases, but I can't grasp why they would literally shrink as range increases. I mean, my 100 yard group today was almost 2 inches. It's barely over an inch and a half at 300.

Please understand that I'm new to benchrest type shooting, long range shooting, and reloading.

Thanks.

eta - I understand that some bullets don't stabilize until 150 or 200 yards out. But in that case, the groups would be something like 1 inch at 100, 1.8 inches at 200, and 2.2 inches at 300. But to have the groups actually smaller at 300 than 100 is weird.

One other thing to check also. I am sure you know, but people forget.... Check your scopes parralax setting, and verify it with your head from the bench when you shoot. It is one simple thing that could perfectly explain your backwards seeming accuracy results. It may not be the reason, but it's easy enough to check and should be eliminated first.
HTH

One other thing to check also. I am sure you know, but people forget.... Check your scopes parralax setting, and verify it with your head from the bench when you shoot. It is one simple thing that could perfectly explain your backwards seeming accuracy results. It may not be the reason, but it's easy enough to check and should be eliminated first.
HTH


This is what I've been suspecting. The only way to get rid of it is to set the parallax adjustment to 1000 yards. The target becomes fuzzy but if you don't look straight through the scope, then you can't see the crosshairs. Any movement left or right and it blackens. Problem is, everything is a little blurry at this setting. So, I turned it back "down." Maybe it's time to crank it back to 1000 and learn to live with it.

http://home.earthlink.net/~dannewberry/dannewberrysoptimalchargeweightloaddevelopment/
I don't know if the link above will get you there but check out what this guy says about load development. I only recently heard about this and it may help.
Just google optimal charge weight load development if the link doesn't work.
Wayne
That's a cool link. Thanks.

This is what I've been suspecting. The only way to get rid of it is to set the parallax adjustment to 1000 yards. The target becomes fuzzy but if you don't look straight through the scope, then you can't see the crosshairs. Any movement left or right and it blackens. Problem is, everything is a little blurry at this setting. So, I turned it back "down." Maybe it's time to crank it back to 1000 and learn to live with it.

Jerk:

What you describe shouldn't be happening with a decent optic.

Also, it sounds to me like you are using a pretty high magnification setting due to the shading and blacking out of the reticle if you move your head slightly behind the optic. I don't shoot for group at 100 yards but from 200 to 1000 I use about 16 - 20X depending on the environmental conditions.

If I were having this seeing issue, I would ensure the ocular lens is adjusted so the cross hairs are very clear to my eye. I would use a magnification of about 10X or less at 100 and from 16 - 20X from 200 to 1000. Then I would take out the parallax for the range and check the parallax a couple of times to ensure it has been removed to the greatest extent possible.

The higher your magnification, the greater the need to adjust the parallax and the higher the magnification, the greater the adverse effects of environmental conditions on your sight picture. So I don't use anything over about 20X. Just isn't needed unless you are heavy into long range bench rest stuff.

If you have done all of these adjustments with checks and the optic still isn't giving you a clear picture -- it is the optic and not you.

LR1955

i thought N133 was too fast for the 107-108 gr bullets and exceeded max pressures?

Jerk:

What you describe shouldn't be happening with a decent optic.

Also, it sounds to me like you are using a pretty high magnification setting due to the shading and blacking out of the reticle if you move your head slightly behind the optic. I don't shoot for group at 100 yards but from 200 to 1000 I use about 16 - 20X depending on the environmental conditions.

If I were having this seeing issue, I would ensure the ocular lens is adjusted so the cross hairs are very clear to my eye. I would use a magnification of about 10X or less at 100 and from 16 - 20X from 200 to 1000. Then I would take out the parallax for the range and check the parallax a couple of times to ensure it has been removed to the greatest extent possible.

The higher your magnification, the greater the need to adjust the parallax and the higher the magnification, the greater the adverse effects of environmental conditions on your sight picture. So I don't use anything over about 20X. Just isn't needed unless you are heavy into long range bench rest stuff.

If you have done all of these adjustments with checks and the optic still isn't giving you a clear picture -- it is the optic and not you.

LR1955

Thanks. My friend and fellow board member/Grendel owner "firefuzz" has been trying to tell me this, also. I really appreciate your response.

Boomer- Lapua doesn't list pressures but 27.5 grs. is .3 grs under their max load for the 108 Scenar. The 108 Scenar and 27.5 grs of N133 is Arne's accuracy load, and has been used by numerous members here.

i thought N133 was too fast for the 107-108 gr bullets and exceeded max pressures?


:eek: I think you're right. I did a little research and found a post from Bill Alexander which he claims this load is 20% over pressure (exactly what you said; nice memory)

Post#12 (http://www.65grendel.com/forum/showthread.php?t=2761&highlight=n133+scenar)

I'm really impressed with this powder, though. This is the first time I've used Vv. It is amazing how easy the barrel is to clean after using it.

:eek: I think you're right. I did a little research and found a post from Bill Alexander which he claims this load is 20% over pressure (exactly what you said; nice memory)

Post#12 (http://www.65grendel.com/forum/showthread.php?t=2761&highlight=n133+scenar)

I'm really impressed with this powder, though. This is the first time I've used Vv. It is amazing how easy the barrel is to clean after using it.

that's had what i'd thought he said, i just couldn't find the post anywhere to quote it. which is really too bad since it's such an accurate load for almost everyone :(

that's had what i'd thought he said, i just couldn't find the post anywhere to quote it. which is really too bad since it's such an accurate load for almost everyone :(

Yeah, It really looked promising. I shot my first ever sub-moa 5 shot group at 300 yards with it. Hell, it was almost 1/2 moa...all shots within 1.6" inches center to center.

Now I have about 40 loaded rounds I have to pull.

I just hope that there is no hidden damage to the bolt lugs.

I suppose I can use this powder for 95gr Hornadys or 100gr Lapuas.

btw - Thanks, Boomer.

Now, back to the drawing board.

Just a thought, When the bullet is in the bore it is forced to rotate upon the center of the mass by the bore. After the bullet leaves the bore it will try to rotate upon the bullets own center of gravity. There is a transitional period where this takes place, depending on how far out of balance the bullet is and how fast the twist is it could happen very quickly or if the twist is very fast or the bullet is poorly balanced it could take a long distance to go to sleep.

:eek: I think you're right. I did a little research and found a post from Bill Alexander which he claims this load is 20% over pressure (exactly what you said; nice memory)

Post#12 (http://www.65grendel.com/forum/showthread.php?t=2761&highlight=n133+scenar)

I'm really impressed with this powder, though. This is the first time I've used Vv. It is amazing how easy the barrel is to clean after using it.

Viht's on-line manual lists this load as safe. I am not sure who is right on this. I know 27.7grs of N133 behind a 108gr Scenar causes my rifles to short stroke. The load is accurate.

Viht's on-line manual lists this load as safe. I am not sure who is right on this. I know 27.7grs of N133 behind a 108gr Scenar causes my rifles to short stroke. The load is accurate.
Hmmm...the guy who designed the cartridge, and has extensively tested it says it isn't safe, that it is somewhere around 60,000PSI.

Trust Viht or that guy? I think I'll go with the conservative estimate! I like my Grendel!!

Bill

Rule of thumb: Check with AA before doing any max pressure loads with non-listed loads by AA or Grendalizer.

Hmmm...the guy who designed the cartridge, and has extensively tested it says it isn't safe, that it is somewhere around 60,000PSI.

Trust Viht or that guy? I think I'll go with the conservative estimate! I like my Grendel!!

Bill

I totally agree. You would think though that Viht would revise their data based on this, but their listings still show this as a safe load.

I think it may be entirely safe for the brass, so used in a bolt gun it would probably be a great load. Everyone mentions how accurate it is.

But used in the AR, it's above the pressure limits, according to Bill Alexander, so I would be very careful if loading anywhere close to this load.

Bill

Update: I dropped the charge down to 26.1 grains and it is still an excellent load.

200 yards

http://img227.imageshack.us/my.php?image=200qk2.jpg

I don't know what the velocity is, but it was zeroed at 200 and it dropped 9 inches at 300.

The prairie dogs are fooked.

I was a good ambassador for the grendel today. An older gentlemen almost fell backwards when he saw the target. And they were wanting to know where I got that rifle.

Jerk, I ran Sierra III with the BC changing by .01 at...uhh...2000 fps IIRC, plugged in 1200 ft elevation, 40-whatever degrees and the low humidity my (smarter than he thinks!) kid looked up for your location, and 2575 fps gave the 9.0 drop 200-300 you reported.

Aw heck, I'm going to have to re-check. It might have been 2475. You can probably quick-check it on the Norma site using a custom bullet spec. I like how you can slide the variable "ticks" and play with the results.

The battery on the laptop with Sierra is still charging right now.

Jerk, I ran Sierra III with the BC changing by .01 at...uhh...2000 fps IIRC, plugged in 1200 ft elevation, 40-whatever degrees and the low humidity my (smarter than he thinks!) kid looked up for your location, and 2575 fps gave the 9.0 drop 200-300 you reported.

Aw heck, I'm going to have to re-check. It might have been 2475. You can probably quick-check it on the Norma site using a custom bullet spec. I like how you can slide the variable "ticks" and play with the results.

The battery on the laptop with Sierra is still charging right now.

I went back and measured it and with a zero of 200 it dropped 8.5 inches at 300. My scope is about 2.5" above the bore. When I played with the norma ballistics page it gave me a velocity of 2668 fps. But, I never did factor in elevation or temperature. I'm not sure that Norma's software even does that. IIRC, It was about 60 degrees that day and 1200 feet sounds correct.

My best 5 shot group at 100 was .645"
My best at 200 was .710"
300 was 2.67 (I don't know what happened here but it is at least still MOA. I do remember the wind really picked up at this stage)

ETA- I don't remember the temp. that day but I remember it was unusually warm for January.

I fired a 5 shot group this last Sunday that was under 1.1 inches at 300 yards (26.1grs N133, SMK107, CCI#450, 2.26")

80°F
1200 Ft ASL

http://img237.imageshack.us/img237/8376/300yardsuh7.jpg

This is everything and more that I expected out of this rifle when I got it back in November of 2006.

I've shot about 50 of these loads so far out of 19.5" AA Hunter and I can't get MOA at 100 yards. At 200 I'm usually close, and have one group that is under two inches. At 300 yards, I shot a group today that measured 1.6" (5 shots). Is this normal? Do the 108 Scenars have this characteristic, also? I understand why a group size would relatively shrink as distances increases, but I can't grasp why they would literally shrink as range increases. I mean, my 100 yard group today was almost 2 inches. It's barely over an inch and a half at 300.

Please understand that I'm new to benchrest type shooting, long range shooting, and reloading.

Thanks.

eta - I understand that some bullets don't stabilize until 150 or 200 yards out. But in that case, the groups would be something like 1 inch at 100, 1.8 inches at 200, and 2.2 inches at 300. But to have the groups actually smaller at 300 than 100 is weird.

Jerk,
I too have a AA "Hunter" upper on a RRA lower w/ 2 stage trigger. Anyway, I was shooting at distance about a month ago and when I got home and I was comparing the targets from the Grendel it caught my eye that my groups at 100 and 200 yards were almost identical. Really weird to me, but not complaining too much.

My loads were either with TAC or W748 powder under 120 gr. SMKs doing around 2500 fps. I haven't tried any other bullet weights yet, wanted to standardize on the 120s for this and my other 6.5s I load for.

So have you figured out why your groups were having the reverse MOA thing going on?

Indy

I've shot about 50 of these loads so far out of 19.5" AA Hunter and I can't get MOA at 100 yards. At 200 I'm usually close, and have one group that is under two inches. At 300 yards, I shot a group today that measured 1.6" (5 shots). Is this normal? Do the 108 Scenars have this characteristic, also? I understand why a group size would relatively shrink as distances increases, but I can't grasp why they would literally shrink as range increases. I mean, my 100 yard group today was almost 2 inches. It's barely over an inch and a half at 300.

Please understand that I'm new to benchrest type shooting, long range shooting, and reloading.

Thanks.

eta - I understand that some bullets don't stabilize until 150 or 200 yards out. But in that case, the groups would be something like 1 inch at 100, 1.8 inches at 200, and 2.2 inches at 300. But to have the groups actually smaller at 300 than 100 is weird.

Shoot more. I don't really think that you can make any real conclusions based of of 5 shot groups, shoot 10. Usually, it seems, that a 10 shot group does a pretty good job of giving you an idea of consistency. It seems common that you can get the occasionally great 3 shot or 5 shot group, but it sure can't be counted on to happen all of the time.

Just load up more of this load and shoot it in greater volume and see how it does.

Don't make any judgements based off of one 5 shot group.

Just my opinion

I've shot about 50 of these loads so far out of 19.5" AA Hunter and I can't get MOA at 100 yards. At 200 I'm usually close, and have one group that is under two inches. At 300 yards, I shot a group today that measured 1.6" (5 shots). Is this normal? Do the 108 Scenars have this characteristic, also? I understand why a group size would relatively shrink as distances increases, but I can't grasp why they would literally shrink as range increases. I mean, my 100 yard group today was almost 2 inches. It's barely over an inch and a half at 300.

Please understand that I'm new to benchrest type shooting, long range shooting, and reloading.

Thanks.

eta - I understand that some bullets don't stabilize until 150 or 200 yards out. But in that case, the groups would be something like 1 inch at 100, 1.8 inches at 200, and 2.2 inches at 300. But to have the groups actually smaller at 300 than 100 is weird.

It's not that unusual. Think of it as the bullet doing a corkscrew around the line to the aim point. It may hit anywhere in the diameter of the corkscrew. As the bullet settles down in the 200-300 yard area, you get a smaller cone of error.

That may be caused by the blast of gas blowing by the bullet after it exits the muzzle

Not trying to poke anyone in the eye, but how was your concentration on the shot groups at 100 and 200 vs the 300. I've seen alot of my soldiers miss 50yrd targets while hitting 250 and 300. It's just to easy to fudge the standards of percesion when the target fills up the optics. also, was target the same at all distances. bullseye would get much smaller at distance and you would have to concentrate harder. I've been a Artilleryman for 22 years and accuracy doesn't get better at longer range. Just my 2 cents :)