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What make is the 20x..if it is a SWFA, it's not. the only way to do it is to make 2" dots on a target, 10 of them, connect them with a line vertically on a 100 yard target and see if they fit in. The Sniper's Hide sells targets that has this feature. My SWFA was doubled....
I'm fairly certain it is a true mil. I have the MilRad version, and when I set up a mildot confidence target, the diamonds were dead-on 3.6". There are hash marks at .5 mils.
According to their site, even the standard 20x mil-dots are true mils:
http://www.opticstalk.com/uploads/61...X42Subsbig.jpg
And the Mil-Rad version:
http://www.opticstalk.com/uploads/298/20XReticle.jpg
I could be wrong though... in fact it happens more than I'd like to admit.
Also, what program did you use to get the drop on that mil-dot? It's pretty clean-looking.
Actually no program...it is a page out of John Plaster's book "The Ultimate Sniper". You can do the same thing on JB, and when you get the solutions in MILs or MOA, make it out on a Word format by inserting a MILDOT reticle and adding the drops.
I have to say, I was inspired. I created a come-up chart using MSPaint. I made a mil-dot reticle (with exactly .36" between dots) and started crunching numbers. Mine lines up almost exactly with yours, except my 75y is a bit lower. I used a .132BC / 1066 MV for Lapua Midas+...I don't have a chrony so I used the published data. I then repeated the process for 2 more zeroes @ 100 and 150 yards. Then I made a sidebar with the drift for full-value wind. On the backside of the card is a drift chart with clicks to zero it out.
The math is fairly complicated but it works out easily enough and seems to be accurate based on comparisons to other peoples' published dopes.
I'm going to the range again on Friday to work on my Mk. II FV some more (I need to spend some time tuning it now that I have a good torque wrench) and I'll see how close this dope is then.
If anyone would like a blank copy and some instructions, message me and I'll do my best to explain.
The Mil-Dot reticle:
http://i33.photobucket.com/albums/d7...ps88ce5adc.png
The drift chart:
http://i33.photobucket.com/albums/d7...ps59496263.png
NOTE: This chart is for Lapua Midas+. It should be reasonably close for Eley, Wolf, SK, etc....basically any 40gr pill with a similar BC and MV. It's also using data from an 80 degree day with moderate-high humidity, which is the most common condition where I live.
Be very careful how much you torque the action. Many a blog warns about too much torque. Pay out the money and get this ingenious torque wrench:
http://www.brownells.com/gunsmith-to...prod32490.aspx
I keep it in my drag bag for full bore comps. along with assorted torque heads. Posts on places like Rimfire.com say may 27 inch pounds at the most. Some say, (if you have a wood stock) torque till you hear the wood crackle. I think that is too much. There is no easy way to pillar bed this thing, and humidity does play a role...
Your chart is great! My BC was .135 and my MV was 1050. Like you, not chony'd. Let me know how you make out.
Actually I bought a Seekonk torque wrench with a 100 in/lb dial and a memory needle...from what I understand, they're fairly near the top of the heap for torque measuring tools.
I was worried about the torque too, but I've taken the action out and put it back in with no problems, and with the washers and bottom metal distributing the load I'm not as worried as before. Worst-case scenario, I get a Boyds varmint stock and send it to Dan Killough to be bedded.
I will report (with pictures this time, I promise!) on the success / abject failure of my scope chart this Friday. I also get to try out my new metal targets...the Champion self-resetting diamond pop-ups. Only $10 at wally world!
This was off JBM Calculations, simple trajectory....
I guessed your altitude and temp...
Trajectory (Simplified) Input Data Ballistic Coefficient: 0.132 G1 Caliber: 0.220 in Bullet Weight: 40.0 gr Muzzle Velocity: 1066.0 ft/s Sight Height: 1.80 in Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg Wind Speed: 5.0 mph Target Speed: 3.0 mph Temperature: 50.0 °F Pressure: 29.53 in Hg Humidity: 50 % Altitude: 700.0 ft Std. Atmosphere at Altitude: No Pressure is Corrected: Yes Zero at Max. Point Blank Range: No Target Relative Drops: Yes Column 1 Units: 1.00 MOA Column 2 Units: 1.00 mil Round Output to Whole Numbers: No Output Data Elevation: 10.644 MOA Windage: 0.000 MOA Atmospheric Density: 0.07471 lb/ft³ Speed of Sound: 1106.7 ft/s Maximum PBR: 132 yd Maximum PBR Zero: 112 yd Range of Maximum Height: 62 yd Energy at Maximum PBR: 68.7 ft•lbs Sectional Density: 0.118 lb/in²
Calculated Table Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead (yd) (MOA) (mil) (MOA) (mil) (ft/s) (none) (ft•lbs) (s) (MOA) (mil) 30 0.4 0.1 0.7 0.2 1009.7 0.912 90.5 0.087 14.6 4.2 40 0.2 0.1 0.9 0.3 993.6 0.898 87.7 0.117 14.7 4.3 50 -0.6 -0.2 1.1 0.3 978.5 0.884 85.0 0.147 14.8 4.3 60 -1.7 -0.5 1.3 0.4 964.2 0.871 82.6 0.178 15.0 4.4 70 -2.9 -0.9 1.5 0.4 950.8 0.859 80.3 0.209 15.1 4.4 80 -4.4 -1.3 1.7 0.5 937.9 0.847 78.1 0.241 15.2 4.4 90 -5.9 -1.7 1.9 0.5 925.7 0.836 76.1 0.273 15.3 4.5 100 -7.5 -2.2 2.1 0.6 914.0 0.826 74.2 0.306 15.4 4.5 110 -9.2 -2.7 2.3 0.7 902.7 0.816 72.4 0.339 15.5 4.5 120 -10.9 -3.2 2.4 0.7 891.9 0.806 70.6 0.372 15.7 4.6 130 -12.7 -3.7 2.6 0.8 881.4 0.796 69.0 0.406 15.8 4.6 140 -14.5 -4.2 2.8 0.8 871.2 0.787 67.4 0.441 15.9 4.6 150 -16.4 -4.8 3.0 0.9 861.4 0.778 65.9 0.475 16.0 4.6 160 -18.4 -5.3 3.1 0.9 851.8 0.770 64.4 0.510 16.1 4.7 170 -20.3 -5.9 3.3 1.0 842.5 0.761 63.0 0.546 16.2 4.7 180 -22.3 -6.5 3.5 1.0 833.5 0.753 61.7 0.581 16.3 4.7 190 -24.4 -7.1 3.7 1.1 824.6 0.745 60.4 0.618 16.4 4.8 200 -26.5 -7.7 3.8 1.1 816.0 0.737 59.1 0.654 16.5 4.8
30/10/13 10:32, JBM/jbmtraj_simp-5.1.cgi
Great torque wrench. I bought mine for bare bones reasons! Looking forward to your results. I too would love to find a good smith, but I just paid out big bucks to have my Rem 700 re-barreled in 6.5 Creedmoor!
Without crunching the numbers, it looks like the JBM chart falls close to the reticle chart. Now I'm really getting stoked to try it out...I got two of the diamond targets, I may get 2 more and set them at 25 yard intervals starting at 75. They're 7.5" tall by 2.75" wide, so it should be a test of both the rifle and the accuracy of the chart.
Also, Friday is looking better and better. Forecast says no clouds and negligible wind. The range is deep in a woodline so it's pretty well wind-free unless it's gusting over 5mph.
Getting busy with the come-up charts! Here's one for an SWFA MILRAD scope. The click values at the bottom changed because these use 1/10 mil clicks (.36" @ 100y) instead of the usual 1/4 MOA clicks (.25" @ 100y).
The MILRAD chart:
http://i33.photobucket.com/albums/d7...pse2a3cecc.png
Another noteworthy discovery: the SWFA SS scope has more than enough vertical travel to get the 150y zero. I'm not using any angled base either. I'm sure if I did, it would be even easier, but it works with a flat base. These are *fantastic* scopes!
I also mentioned a "full-value" wind for these charts....for me, that means 10mph. It makes the calculations ridiculously easy that way. So the charts are showing a constant 10mph wind from 3 o'clock. If it's 8 mph, just go 80% of the way to the mark for the range to your target....5mph go halfway. Ad infinitum. From the left? Just flip the chart the other way. From any other angle? Use the "clock rule" to determine how much to divide it by.
Clock rule: http://www.cybersniper.com/windus.htm
Last post for the night!
I decided to create a "Zero Checker" target to use on Friday to verify my zeros before I actually engage the longer-range targets. The idea is simple: Each box represents the POI at 50y for a zero at the given ranges. When aiming at the 50y box, the rounds should hit dead center in each box for the ranges given; up or down means I need to revise my charts, and left or right means the scope is canted the opposite direction.
The target:
http://i33.photobucket.com/albums/d7...psd2fdbc30.png
Shane. Are going to shoot that using hold overs with the mil dots?
No. The plan is to zero it at 50, then shoot 5 shots at the 50y zero. Then I'll re-zero the scope to 100 yards and shoot 5 more shots. If the match is correct, it'll land in the 100 yard box while I'm still aiming at the 50.
Basically, it's the reverse of using hold-overs; instead of moving the scope so the groups land in the same place at 50, I'm holding the rifle on the 50y target at all 3 zero settings and letting the POI change. The target is more to verify that my click values are correct for my zero ranges than it is to verify my holdovers.
However, the POI should still line up with the holdovers marked on my chart. In other words, if I'm aiming at the 50y box on my 100y zero setting, the POI should be ~2.2 mils high.
That's what I was thinking. If you hold 1.9 mils over the 50 yard target the cross hair should be on the 100 yard target. This mil stuff is new to me, so I'm picking up a bunch of info here.Quote:
Originally Posted by shanejohnson2002
I edited the original statement...I was creating a new chart for a guy at my office and the 50y was at 1.9 mils on his...it should be ~2.2.Quote:
Originally Posted by justinp61
You're getting the idea though. It took me a while (and a really good instructor) to learn this stuff. Making these charts is helping me keep it sharp too...the math is all coming back pretty quickly.
Keep in mind too these charts are a best guess at the moment. They should be reasonably close, but they would be even closer if I could measure my MV with a chronograph. Keep in mind they are set up specifically for the Lapua Midas+ round; changing ammo will cause the chart to be off. Also a change in ambient temperature will cause the POI to shift...I calibrated the charts to my average local weather. Hotter days = higher MV and less air resistance, colder days = faster drop. Your best bet is to learn how to make these things and calibrate it to your setup / weather.
I went to the JBM site and printed a couple charts for the CCI SV, they'll give me a place to start.
Awesome! If you need any help, PM me and I'll do my best.
Found some errors in my calculations...going to fix some of these charts.
1) The Drop Test target was WAY off. I must have divided by the wrong number or something. It's been revised and is reposted. EDIT: Re-checked the numbers....I'm an idiot. It'll work just fine.
2) Probably related to the above, but my click values for the 100 and 150 yard zeros are way off as well. Reposting that too. EDIT: Rechecked this too...but it was still wrong. Corrected version posted.
Thanks.Quote:
Originally Posted by shanejohnson2002
UPDATE:
Range visit went well. I took my "slightly" modified FV, and the new G out. The G performed very well, consistently grouping right at or a hair over 1 MOA, which is pretty much what I expect from a pencil-barreled .22. Unfortunately, so did the FV, and it's normally a .3-.5 MOA shooter. I'll tear it down and work on it some more.
Can the G be improved upon? I think so. A bedding job, a lapping job, and dampening the barrel with either o-rings or heat shrink should bring the groups down into the .7ish range, I'd expect. As-is though, I think I have a winning formula with this rifle.
The scope isn't the clearest, but it was dead-on and repeatable. I clicked back and forth several times between my 3 zeros, and it was on the money every time. I shot everything at 12x, which is where the mils are calibrated.
...which is more than I can say for my SWFA scope. The elevation turret stopped working, so I'm going to take that apart to and try to figure out what the deal is.
The charts were on the money too. The only change is the 150y zero...it seemed to be closer when I used 67 clicks instead of 68. Using the chart, the 200 yard steel diamond was fairly boring...if I missed it, it was definitely me and not the rifle. Needless to say, I was pretty happy that I was consistently hitting a 2.75x7.5" target at 200 yards with a pencil barrel.
Speaking of, the new steel targets worked like a charm. Loud, and they flop backwards when you hit them, so there's definitely visual and audible feedback.
Now, here's the pics! First up, the G:
http://i33.photobucket.com/albums/d7...ps0bec8c60.jpg
http://i33.photobucket.com/albums/d7...ps4718a869.jpg
http://i33.photobucket.com/albums/d7...ps1e87df9d.jpg
Sigting-in target, to verify 50y zero:
http://i33.photobucket.com/albums/d7...psf017aa73.jpg
The drop test target....pretty dead-on, I'd say:
http://i33.photobucket.com/albums/d7...psa6dda0dc.jpg
And here's some pics of the FV:
http://i33.photobucket.com/albums/d7...ps160f8627.jpg
http://i33.photobucket.com/albums/d7...ps2e37211e.jpg
http://i33.photobucket.com/albums/d7...ps5c044a3e.jpg
http://i33.photobucket.com/albums/d7...ps5c044a3e.jpg
And the rather disappointing targets:
http://i33.photobucket.com/albums/d7...psccc5a0cf.jpg
Best 2 groups:
http://i33.photobucket.com/albums/d7...ps66514ec1.jpg
http://i33.photobucket.com/albums/d7...ps63179db9.jpg
And the new steel targets:
http://i33.photobucket.com/albums/d7...psd06ee72f.jpg
Shane
Don't take down the gun. Let it settle in a bit. I bet this is heat/humidity issues. The groups you are shooting seem fine. Also, you shot the groups after shooting the first rifle. Your eyes will start to play with you. ( am I correct? the shooting order?) Try it the other way. Also, what time did you shoot the G, and then the FV? I don't believe it is the gun. Lastly if you can, get of the bench and go prone. Use a rear rest.
Your bipod is on the high side...like I said, shorten the bipod, get prone.
You can't really see it in those pics, but I do use a rear rest....or a rear squeeze bag rather. I guess I can try to lower the bipod...I'll be back out again next Wednesday or Thursday and I'll take them both with me again.