What to do when you only have 100 yards for 600 yard load development?

[cavman]

I have a White Oak upper 1:7 twist in .223 (Wylde actually). RRA lower.

I expect to get out a half a dozen times only to a full 600 yard range for High Power Service rifle shooting.

That said, I will have access to my 100 yard range to develop rifle loads as well as shooting their reduced yardage matches.

My question is what to do about the 300 and 600 yards when I get out there?

What does one do to prepare loads that will be tested on the 100 yard range that can be reliable to hit well at 600?

55gr at 100 might be great, but heavier bullets probably be better. Does one pick a heavy bullet (knowing it will be shot at 600) and choose its best group at 100 yards?

 

[James2]

Does one pick a heavy bullet (knowing it will be shot at 600) and choose its best group at 100 yards?

That is what I would do. Then if you know the bullets ballistic coefficient and velocity, there are some programs online that can calculate its trajectory at the different ranges. One such is on Hornady's site. Then you will need a way to adjust your sights for the range. Some scopes have dots in them for that purpose.

 

[JimKirk]

Here's a link to a very good ballistic calculator that has all kinds of calculators that could help you find what works. Just because a load will shoot a 1/2" group at 100 yds. doesn't mean it will at 600, but it does give you some indication that the rifle is capable of shooting good.

In the program below change(set) your sight in distance to 600 yds. and it will tell you how high you have to be at 100 yds.

http://www.jbmballistics.com/calculations/calculations.shtml



Jimmy K

 

[JimKirk]

Here is a sample using a Hornady AMax 75 grs @ 2700 fps
The columns don't line up but you can figure it out.
Looks like you would need to be 16.6" high @ 100yds to be on at 600 yds.
Jimmy K



Trajectory
Input Data
Manufacturer: Hornady Description: A-Max
Caliber: 0.224 in Weight: 75.0 gr
Ballistic Coefficient: 0.435 G1

Muzzle Velocity: 2700.0 ft/s Distance to Chronograph: 10.0 ft

Sight Height: 1.50 in Sight Offset: 0.00 in
Zero Height: 0.00 in Zero Offset: 0.00 in
Windage: 0.000 MOA Elevation: 0.000 MOA
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg

Wind Speed: 10.0 mph Wind Angle: 90.0 deg
Target Speed: 10.0 mph Target Angle: 90.0 deg

Temperature: 59.0 °F Pressure: 29.92 in Hg
Humidity: 0.0 % Altitude: 300.0 ft

Vital Zone Radius: 5.0 in

Std. Atmosphere at Altitude: Yes Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Mark Sound Barrier Crossing: No Include Extra Rows: No
Column 1 Units: 1.00 in Column 2 Units: 1.00 MOA
Round Output to Whole Numbers: No
Output Data
Elevation: 19.673 MOA Windage: 0.000 MOA

Atmospheric Density: 0.07580 lb/ft³ Speed of Sound: 1115.3 ft/s

Maximum PBR: 325 yd Maximum PBR Zero: 276 yd
Range of Maximum Height: 153 yd Energy at Maximum PBR: 714.4 ft•lbs

Sectional Density: 0.214 lb/in²
Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -1.5 *** 0.0 *** 2707.0 2.427 1220.1 0.000 0.0 ***
100 16.6 15.9 0.8 0.8 2501.2 2.243 1041.7 0.115 20.3 19.4
200 29.1 13.9 3.3 1.6 2304.7 2.066 884.4 0.240 42.3 20.2
300 35.1 11.2 7.7 2.4 2116.9 1.898 746.2 0.376 66.2 21.1
400 33.3 8.0 14.2 3.4 1938.2 1.738 625.5 0.524 92.3 22.0
500 22.2 4.2 23.2 4.4 1769.3 1.586 521.2 0.686 120.8 23.1
600 -0.0 -0.0 35.0 5.6 1611.4 1.445 432.4 0.864 152.1 24.2
700 -35.6 -4.9 49.9 6.8 1466.4 1.315 358.1 1.059 186.4 25.4

 

[Jim Watson]

You can compare loads, get a basic zero at 100 yards, and compute the "come-ups" for the longer ranges of a full scale highpower match. I am not an XTC shooter, but around here the usual thing seems to be the 80 shot match.

On a full size range it runs:
20 rounds slowfire standing at 200 yards
20 rounds rapidfire sitting or kneeling at 200
20 rounds rapidfire prone at 300 yards
20 rounds slowfire prone at 600 yards.

A friend said he used to just shoot WWB for standing and saved the brass to reload for the longer stages.

Otherwise, the rapid fire stages require magazine length ammunition for which the 77 gr SMK was developed.
Slowfire at 600 yards is usually done with something like an 80 gr SMK loaded as long as the chamber will accept, longer than the magazine, fired single shot with plenty of time. You can get adapters to make it easy to load singles.

 

[cavman]

wow. What have I gotten myself into?

That looks great, though and should give me some good reading this weekend.
Thanks.

As an extension, what can one expect a 55 grainer to do at the longer distances? If we assume that the 75-80gr can hold the 10-ring at 600. And if we assume that the 55gr can hold an inch at 100, in a perfect world it would be 6" or so at 600 yards. But what would it most likely be, 12"? 18"?

I guess I am asking: if I can't hit the broad side of a barn at 600 with a 55gr, should I even expect to hit anything? Should I get my 75 grain loads up and running? (I will go, of course but trying to get expectations in order)

 

[kelbro]

600 yds, 55gr bullets, and any wind at all make for interesting 'patterns'.

There is no substitute for actually shooting your loads at those ranges to learn how they perform.

 

[Canuck-IL]

I don't know of many 55gr match quality bullets and I wouldn't waste any load development time on plinkers. At reduced ranges (100 yds) most folks shoot one of the several 52 match grade bullets for matches.

Setting up for 600, 80s and 82s (Sierra, Berger, Nosler) dominate with some shooting the 75 or 80 Hornady AMAX. Note that the 80s are all designed to be single loaded - well beyond mag length. John Holliger, with his standard Service rifle reamer (as of May 2009 anyway), land contact for an 80 gr SMK should be at 2.475 as they reamed it. So John recommends 2.465 for single loading

Standard come-ups are
100 - 200 +2 MOA
200 - 300 +3 MOA
300 - 600 +11.5 MOA

These changes are cumulative. i.e. going from 200 to 300 is +5 MOA over the 100 yd setting. I used a program similar to that referenced above and got on paper with the first sighter.
/Bryan

 

[Drail]

Use saccharin tablets for targets.

 

[X-Men]

You have a nice upper there, most hight power service rifle shooters are using 77gn sierras for 200 and 300 yds, and 80gn sierras for 600 yds 24.0 gn Reloder 15, lake city brass, Rem 7 1/2 primers, 77's loaded mag length and 80's between 10 to 30 thousandths off the lands. This is the standard load for service rifle and should keep you in the X ring if you do your part. This is what I use in both my RRA upper and my Compass Lake Engineering upper, both have Wylde chambers.

from a 100 yard zero come up 2 minutes for 200 yards.

from a 200 yard zero come up 3 minutes for 300 yards.

from a 300 yard zero come up 11 minutes for 600 yards.

This should get you in the aiming black with these loads.

 

[JimKirk]

Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
....... in ... moa
100 16.6 15.9 0.8 0.8 2501.2 2.243 1041.7 0.115 20.3 19.4
200 29.1 13.9 3.3 1.6 2304.7 2.066 884.4 0.240 42.3 20.2
300 35.1 11.2 7.7 2.4 2116.9 1.898 746.2 0.376 66.2 21.1
400 33.3 8.0 14.2 3.4 1938.2 1.738 625.5 0.524 92.3 22.0
500 22.2 4.2 23.2 4.4 1769.3 1.586 521.2 0.686 120.8 23.1
600 -0.0 -0.0 35.0 5.6 1611.4 1.445 432.4 0.864 152.1 24.2
700 -35.6 -4.9 49.9 6.8 1466.4 1.315 358.1 1.059 186.4 25.4

Just what JBM said.

Jimmy K

 

[cavman]

Lake city brass,

i am only a 45 loader on my Dillon 650. The rifle is new to me.
I bought a box of 1000 5.56x45 M193 and the case head stamp says PPU 07. How much of a difference does the brass make in rifle?

I sort my brass in .45 ACP ( I have 10k or 15k in Federal and WCC) and I am only medium expert in Bulleye 45 at around 840/900) I just CANT seem to figure out good loads off a sandbag. ( i bought a Caldwell Hammer rest but to no avail in making it work for getting what I think is an actual group. They are all about shotgun pattern 8-9 ring at 50 yards. ( I can shoot the same pattern off hand so I can't tell what is actually best. So, I choose "standard" loads of ~4.0gr Bullseye powder and call it good, due to the fact that I haven't been able to actually figure out a "real" method to find my best group. (I can't tell the difference in groups from one case from another.)

Are rifle brass much of a different animal? Do they significantly make a difference from one brand to another when following someone's recipe?

 

[X-Men]

I use lake city brass because it is cheap(500 once fired for $60), and I sort it by year. Different brands of brass have different volumes and can affect pressure and accuracy. With any load you want to work it up just to be sure it is safe. Some brass such as federal is not good because the primer pockets get loose after 1 or 2 loads and the primers fall out into the trigger group(not fun during a match). M193 most likely has crimped primers, so you will need to ream or swage the crimp. I have never used this brass so I can't say how well it will work, work load up slowly and look for pressure signs.

 

[Bart B.]

Groups open up about 10 to 15% for each hundred yards past the first hundred. That should tell you how accurate they have to be if you want to shoot inside the 12-inch 10 ring at 600 yards.

 

[~z]

Bart, I have read much of your work and surely do respect your input, but I believe you are over simplifying the issue here. I don’t believe you can extrapolate that quite so linearly by distance. I would say that groups open up by some percentage per time of flight not per a yardage interval. The longer a bullet is in the air the greater the opportunity for external and internal effects to show up on paper.

What you said is basically valid and beneficial to many, but as the OP is pushing a 55gn bullet to 600yds, time of flight is the key.

~z

 

[Clark]

I am always happy to see a Bart Bobbit post on the internet.


I was using a 100 yard range, and then going hunting at 500 yards.
I used Quick target to make a chart to convert distances on my range finder to moa adjustment on the scope elevation turret.

Then I bought a roll of butcher paper and built a 12' high 4' wide target stand. That target stand was problematic to leave on public land.

Then I just started putting the giant targets up on the side of hills. I would back my car down the road 500 yards and shoot off the hood of my car. My ultra light 270 will do a 5" 3 shot group at 500 yards.

The trick is that at 100 yards the rifle must be sighted in very precisely to get the chart at 500 yards to work.

 

[Bart B.]

~Z says:

I would say that groups open up by some percentage per time of flight not per a yardage interval. The longer a bullet is in the air the greater the opportunity for external and internal effects to show up on paper.

That'll work. One could also measure how much groups open up per second of latitude. I used something most folks could relate to and also in units of measure they check for accuracy at. 'Twould not be a good for many folks to easily compare a .45-70's accuray degradation per 10th of a second of its bullet's flight to a .257 Weatherby's at the same interval. Think of the math required to put their numbers on equal planes of reference.