6.5 Creedmoor + 143 ELD-X

[lazyMlazyK]

My chronograph is out of commission for now, so I decided to hit the range last night to see if I could determine it through a ballistics app. I'm using a T/C Compass with a 1:8 22" barrel, CCI 200 primers, Hornady brass, 143 ELD-X bullets, and 40.5 grains of H4350. Zeroed at 100 yards, I came up 3.25 MOA to be on at 300. Setting the velocity in the Hornady 4DOF app to 3,000 fps gives me a come-up of 3.28 MOA, which is pretty close to what I found. This seems pretty dang hot, doesn't it? I'd be expecting more along the lines of 2,700-ish fps. I've not seen any pressure signs, and this is a fairly mild load, not real close to max in the Hornady reloading book. Maybe I've got my "Sight Height" wrong? I'm not sure how to exactly determine that. Used the default of 1.5" on the 4DOF online app. Scope is a Viper PST Gen II 5-25x50.

Pretty happy with this load, however slow/fast it shoots. Was grouping 1.58" at 300 yards last night. Not bad for a <$300 rifle! Fun to plink off clay pigeons at 330 yards.

 

[FeMan]

Your approach is sound. However, it is subject to the input of a lot of variables. If you are going to do this and get trustworthy results, you need to be sure that all the "known" inputs (zero distance, sight height, bullet BC, etc.) are dead nuts correct. The farther you are shooting the more reliable your results will be. 300 yards is just not far enough. 600 yards is probably the minimum I would trust for what you are doing. I do the same thing you are trying to true my BCs, but I use a min of 1,000 yards and shoot over a chrono after I get the zero and bore height nailed down.

BTW, I ran that in Quickload and got 2600 fps for my lot of powder and your setup. I am not saying QL is exactly correct but I am very sure your MV isn't anywhere near 3,000 fps. In my 30-inch 6.5 CM with Lapua brass, I would only get 2,775.

I hope that helps.

 

[lazyMlazyK]

That is helpful, thank you. I thought my estimated velocity sounded crazy, but couldn't verify it myself yet. I'll have to look at my bore height one of these nights. Right now, the longest distance I can shoot is 330 yards/300 meters. Need to find a landowner that would let me set up something longer range. This is just a hunting rifle, so for now 300 yards is about all I'm probably going to worry about. Might step it out to 500 yards one day just to see what it can do.

Using the 4DOF calculator, I changed the velocity to 2600 fps and the sight height to 3.9". This made my real-world come-up make sense. I'll have to take some measurements of the actual sight height to verify.

 

[darkangel_r2]

My chronograph is out of commission for now, so I decided to hit the range last night to see if I could determine it through a ballistics app. I'm using a T/C Compass with a 1:8 22" barrel, CCI 200 primers, Hornady brass, 143 ELD-X bullets, and 40.5 grains of H4350. Zeroed at 100 yards, I came up 3.25 MOA to be on at 300. Setting the velocity in the Hornady 4DOF app to 3,000 fps gives me a come-up of 3.28 MOA, which is pretty close to what I found. This seems pretty dang hot, doesn't it? I'd be expecting more along the lines of 2,700-ish fps. I've not seen any pressure signs, and this is a fairly mild load, not real close to max in the Hornady reloading book. Maybe I've got my "Sight Height" wrong? I'm not sure how to exactly determine that. Used the default of 1.5" on the 4DOF online app. Scope is a Viper PST Gen II 5-25x50.

Pretty happy with this load, however slow/fast it shoots. Was grouping 1.58" at 300 yards last night. Not bad for a <$300 rifle! Fun to plink off clay pigeons at 330 yards.

40.5 of h4350 was giving me 2660 fps in a 24" bolt with the 140 eld. You should be a little slower because of the 2" shorter.

 

[FeMan]

Your sight height should be somewhere around 2". Mine measure from a low if 1.8" to a high of 2.5: depending on the setup. Make sure you have the environmental conditions input accurately too. Altitude can make a huge difference if not adjusted (i.e. like left at sea level).

If it helps, as long as you have the dope figured out at 300 with reasonably accurate inputs, you should be good out to 500 easily for big game hunting. Based on what my QL run gave me and the input from darkangel_r2, I would say you are somewhere around 2600 fps. 0.5 moa is definitely great for a cheap factory setup!

My bet is you are somehow really an inch high at 100. If you switch between bench and prone that can easily make that much difference or more.

 

[jmkasza]

FWIW, I'm using the 143gr ELD-X, Hornady brass, and WLR primers. I also use the Hornady app. My similar, but slightly higher charge of H4350 is giving me 2708 fps out of a 26" barrel. At 300 yards the come-up is 4.25 MOA. My range limits paper targets to 200 yards, so all I can say is it looks good and centered at 300 and I hit the steel plate very consistently. I have my scope height set at 2.05"

 

[lazyMlazyK]

FWIW, I'm using the 143gr ELD-X, Hornady brass, and WLR primers. I also use the Hornady app. My similar, but slightly higher charge of H4350 is giving me 2708 fps out of a 26" barrel. At 300 yards the come-up is 4.25 MOA. My range limits paper targets to 200 yards, so all I can say is it looks good and centered at 300 and I hit the steel plate very consistently. I have my scope height set at 2.05"

Well, I'm stumped. Why the heck would my come-up be less than yours, if you're running a higher velocity load with the same bullet? I was shooting off a front rest and rear bags.

I did shoot one round at 100 yards to verify zero before shooting back at 300, and it looked good at 100 (POA and POI were the same at 100).

 

[darkangel_r2]

Well, I'm stumped. Why the heck would my come-up be less than yours, if you're running a higher velocity load with the same bullet? I was shooting off a front rest and rear bags.

I did shoot one round at 100 yards to verify zero before shooting back at 300, and it looked good at 100 (POA and POI were the same at 100).

Likely different scope height above bore. Did you account for temp and pressure when you did your first calculation? Those two things as Ironman said above combined with a different scope height can account for that variance.

 

[lazyMlazyK]

Likely different scope height above bore. Did you account for temp and pressure when you did your first calculation? Those two things as Ironman said above combined with a different scope height can account for that variance.

Oh yeah, that would do it.

I did account for temp. and elevation, but not atmospheric pressure.

 

[jmkasza]

Oh yeah, that would do it.

I did account for temp. and elevation, but not atmospheric pressure.

Well.. I double checked, the app had my default scope height at 1.5" too. When I switched it to 2.05" the come-up at 300 yards is now 3.9 MOA. For fun I ran it online (on Hornady's calculator) with all the same info and the come-up at 300 shows 3.66 MOA. I'd guess we are shooting similar velocities, maybe my load is a bit faster, but like others posted getting your scope height dialed in will close the gap.

 

[FeMan]

Oh yeah, that would do it.

I did account for temp. and elevation, but not atmospheric pressure.

I use a Kestrel and am not familiar with your app, but everything I have ever used was based on either 1) station pressure (usually measured using a barometer in the unit) , or 2) atmospheric pressure at sea level + actual elevation (both input by the user). Make sure of what your app is set for and that you are inputting (or measuring if it has an internal barometer) the correct information. If its anything like Streelok Pro, its easy to think you have compensated for elevation but actually haven't, or compensated for it twice.

 

[lazyMlazyK]

Changing atmospheric pressure in the 4DOF app doesn't make much of a difference at 300 yards. I just took the two extremes in pressure for the week in my area - 29.71 and 30.3 in-hg - and put them into the app. There was a come-up difference of 0.02" come-up at 300 yards between the two pressures. I measured my actual sight height last night to be approximately 2.15". The app still shows my come-up should be 4.33". I'll plug all this into Strelok later this morning but so far it's been about the same as the 4DOF app.

 

[FeMan]

Ok, if you are entering standard atmospheric pressure then the altitude is what you need to make sure is correct. That pressure is sea level and your station pressure is probably around 25 or so. The altitude entry will correct for that.

 

[lazyMlazyK]

Altitude for the range is right around 2000'. About the same as my work place, 5 miles away. At work, our grade is 1960'.

 

[wkdickinson]

Just as another reference - 6.5 CM, 140gr Hornaday ELD-M, 41.0gr H4350, 210M, Peterson brass and Bartlien 28" 5R barrel = 2,744 fps. Scope height is 2.56" with 56mm objective. With rifle zeroed at 100 yds., 300 yd. "come-up" is 3.46 moa % PM Ballistics program (%Litz).

 

[jaygorski]

My chronograph is out of commission for now, so I decided to hit the range last night to see if I could determine it through a ballistics app. I'm using a T/C Compass with a 1:8 22" barrel, CCI 200 primers, Hornady brass, 143 ELD-X bullets, and 40.5 grains of H4350. Zeroed at 100 yards, I came up 3.25 MOA to be on at 300. Setting the velocity in the Hornady 4DOF app to 3,000 fps gives me a come-up of 3.28 MOA, which is pretty close to what I found. This seems pretty dang hot, doesn't it? I'd be expecting more along the lines of 2,700-ish fps. I've not seen any pressure signs, and this is a fairly mild load, not real close to max in the Hornady reloading book. Maybe I've got my "Sight Height" wrong? I'm not sure how to exactly determine that. Used the default of 1.5" on the 4DOF online app. Scope is a Viper PST Gen II 5-25x50.

Pretty happy with this load, however slow/fast it shoots. Was grouping 1.58" at 300 yards last night. Not bad for a <$300 rifle! Fun to plink off clay pigeons at 330 yards.

I'd say you're looking at something in the 2640 range to my figuring

 

[Ultimag]

143 eldx
44.3 grns super performance
24 inch 1/8 twist browning xbolt hc speed
2789 vel
I can squeeze a bit more velocity but accuracy is great
with this load and so far has accounted for1 shot kills on 45 elk and 70+
deer from 20 yards out to 550