Range Report .243 range question couldn't hit steel at 900 yards =(

[MadCountyDep]

Went shooting with a co-worker on Saturday. My rifle is a rem 700, 20" barrel, Rock Solid stock, 12x SWFA scope...
I confirmed my zero at 100 yards using remington 100 grain softpoints (cheap ammo till i start reloading)
Gun was pulling solid 3/4" moa groups at 100 yards...
From there we tried to stretch it out to 930 yards. It was a little hard to spot the hits on the hillside because there was tall wet grass however it seemed like the hits were all over. The target was a 20"x20" steel plate, but the shots were varying from 6' off to the 2 o'clock to 6' off to the 9 o'clock.the rounds were chronoing at 2714 fps and i think they were going trans sonic between 900 and 930 yards. Wind was alternating between 2-4 mph and changing from 90° to 220°

So, would the rounds going trans sonic cause the huge variation of impact points?
I would think if i could hold sub moa at 100 yards, i could at least get on target at 900
Fwiw, i was hitting a 900 yard plate the weekend before at a different range

 

[MadCountyDep]

Here's my 100 yard target fwiw

 

[damoncali]

Entirely possible with that bullet. Not sure which bullet you used, but 100 grain soft points in a 6mm are not likely to produce good results that far out. Run a ballistics calculator with the exact bullet and see how much velocity is left - I bet it's substantially transonic if not subsonic by 900 yards.

You need to try some long range bullets. I dont know what will shoot out of a stock barrel, but something like a Sierra 107 MatchKing should do it if it will work. For a 243 winchester, 2700 fps sounds a tad on the slow side as well, but not terribly so. (I bet the 20" barrel is part of the problem here - by comparison, my 6mmXC will do about 2900-3000 with 107's, but out of a 30" tube.).

Wind also probably played a role, especially if your bullet was not the right type for the job. 6 feet of wind deflection doesn't sound out of the question at all.

 

[bodywerks]

Not surprised at all that you were having trouble. You are stretching the capabilities of that bullet to (if not beyond) its limits. Assuming all other factors accounted for, a constant 2mph wind across the entire range will drift you off that 20" target. Then start thinking about the BC of that bullet, its overall design and intended use, and if its not considered 'match'ammo the velocities could be varying 50-75fps.. That velocity variance is also enough to cause a miss.
The 243 is a fine cartridge. But with your short barrel you are limiting its range potential regardless of what bullets you feed it. If you want to hit 900 with any sort of reliability you're going to have to have a better bullet (Berger 105, hornady 105amax, sierra 107 smk, etc), and the highest cup pressure accuracy node.

Sent from my DROID BIONIC using Tapatalk 2

 

[MadCountyDep]

Thanks guys, that makes complete sense. I've been slowly amassing reloading equipment, and after shooting at 500-600 I should have known I was severely pushing the limits of ultra cheap factory ammo.

My buddy was shooting 150 grain (approx) .260's from his gun with a 21" tube but his loads are his own custom with bergers and his wind hold was spot on every time.

 

[demolitionman]

How many MOA did he have to dial for with his .260?

 

[MadCountyDep]

I'd have to check to be sure but I believe his dope has him at about 6.8 mils at 930yds. With the wind being erratic but mild, we just held over for wind as opposed to dialing it in.

 

[Jnikoley]

I'd have to check to be sure but I believe his dope has him at about 6.8 mils at 930yds. With the wind being erratic but mild, we just held over for wind as opposed to dialing it in.

If thats your dope from a 100y zero, youd be hitting short. You'de need about 12 mils for 930. I think you might have been hitting short. You may have been seeing your riccocet impacting target area. This would explain the erratic hits left and right.

 

[bodywerks]

The 6.8 mils was for his buddys 260 and 140ish grain bullets. Going off sluggish memory at 6 in the morning that doesn't sound too far off.

Sent from my DROID BIONIC using Tapatalk 2

 

[Jnikoley]

The 6.8 mils was for his buddys 260 and 140ish grain bullets. Going off sluggish memory at 6 in the morning that doesn't sound too far off.

Sent from my DROID BIONIC using Tapatalk 2

From "Ballistc" for the .243:

 

[Jnikoley]

The 6.8 mils was for his buddys 260 and 140ish grain bullets. Going off sluggish memory at 6 in the morning that doesn't sound too far off.

Sent from my DROID BIONIC using Tapatalk 2

From "Ballistic" for the 260:

 

[bodywerks]

From "Ballistc" for the .243:
View attachment 3859

Great. That's for the 100gr 6mm bullet. What is it for a 140gr 6.5mm bullet with a .584 g1 BC? That's what we are talking about in reference to the 6.8 mil dial up that the OP mentioned, not his 100gr 6mm snub nosed hunting bullet.

Sent from my DROID BIONIC using Tapatalk 2

 

[bodywerks]

From "Ballistic" for the 260:
View attachment 3864

That shows trajectory only from what I'm seeing. You need to look at what the dial up needs to be for the rifle scope.
I added a 140 Amax and assumed 2750 to a rifle i already had and got this. Much closer:


Sent from my DROID BIONIC using Tapatalk 2

 

[bodywerks]

If i assume 2850 the dial up is 6.5 mil

Sent from my DROID BIONIC using Tapatalk 2

 

[Jnikoley]

If i assume 2850 the dial up is 6.5 mil

Sent from my DROID BIONIC using Tapatalk 2

Agreed, but if you used the same dope for the .243, you'de be way off. The chart I posted for the 260 gives ur dope from a 100y zero.

 

[MadCountyDep]

I was not going off his data for my dope.... I was dialed to about 10.2 mils for the range I was using Shooter which had me at about 9.8 mils, but Ive found the soft point bullets drop faster than match grade.

Hopefully once I get the rest of my reloading stuff it'll get better

 

[bodywerks]

Very true

Sent from my DROID BIONIC using Tapatalk 2

 

[dk-1]

Wow, there seems to be some confusion here......

6.8 mils was the needed dope for a 140 Berger VLD (.612 BC) launched from a 23" Kreiger 5R at 2875 fps with a 100 yard zero to 933 yards.....

The soft nose hunting bullets were subsonic at that distance at that elevation on that given day with a high pressure front moving in.....

105 AMAX's are out of the question for his .243 because of the factory Remington 9.125 RH twist, but 87 gr Berger VLD's have shot great out of two factory tubes I know of....

We'll get you there, Josh...

 

[demolitionman]

Kind of a thread hijack here, but, is there any advantage to using the Litz projected ballistics when selecting the bullet in shooters list? Specifically the 130VLD and 140vld?

 

[dk-1]

Kind of a thread hijack here, but, is there any advantage to using the Litz projected ballistics when selecting the bullet in shooters list? Specifically the 130VLD and 140vld?

I think there is because they offer a G7 BC which is a better model for most modern match bullets.... Plus you are using data collected/calculated by the guy who wrote the book on the subject!

 

[bodywerks]

Its always better to go with the g7 standard, as it is modeled after a more similarly shaped bullet.
I highly recommend the Litz variant as well, and i suggest you read his book as well. It explains why the g7 standard is pretty much always more accurate and explains his methods of verifying/evaluating a manufacturers claimed BC.

Sent from my DROID BIONIC using Tapatalk 2

 

[damoncali]

Kind of a thread hijack here, but, is there any advantage to using the Litz projected ballistics when selecting the bullet in shooters list? Specifically the 130VLD and 140vld?

There are two separate things going on here. One is that Bryan collected his own BC data. He seems to have done it carefully and is a smart guy, so I'd guess it's good. But there are also careful smart guys working at Sierra, etc. Their data also seems pretty good.

The other is that most (but not all) of the bullets we use (longish boat tails) are a better match to the G7 drag profile than the G1 drag profile. Most bullet manufacturers do not report G7 BC's, which are different and incompatible with G1 BC's. If you're cynical, it's because G1 values are numerically higher and easier to sell. If you're not, it's because bullets have changed over the years. Once upon a time, we shot lots of short, flat based bullets that *were* a better match to a G1. In any case, if you want to use a G7 drag function, you are stuck with Bryan's data (which has both G1 and G7 BC's). Berger also releases G7 BCs. I don't know if anyone else does.

The breakthrough of his book was to help educate consumers about the benefits of a G7 drag function, and perhaps push the manufacturers into publishing that data where appropriate.

 

[demolitionman]

Damon, I can take the "typical" Berger ballistics in shooter and simply select G7 (as I have done since I got the app), so I found it odd that not only is that an option but I too have the option of the "Litz VLD" which has the ore programmed G7. I know it simply comes down to shooting whatever matches my real world results but like all things, I was curious and wanted to apply the best trajectory bc value I could keeping in mind I have little experience long range and am just learning the ropes of it all.

 

[Captain Kirk]

That is very slow for the 90gr. My guess is it was going transonic, many lighter bullets don't make the transition well and you get massive POI shifts when it goes subsonic. For longer range higher BC bullets and velocity is everything, I have shot the 90+gr 6mm bullets past 1200 yds with great results but the velocity was more in the 3150-3200 fps range. My current 243 load is using the TUBB 115 DTACs at 3000 and the longest I have stretched them is to 1370 but with great results.

 

[damoncali]

I don't have shooter, so I can't really comment on what they have in the bullet library. But in theory, if two people measure the same bullet and compare it to the same drag function, you should get very similar numbers. And given that Litz did a lot of work for Berger, it seems even more likely. Do the two options give you pretty much the same answer? It's like having two different translations of the same book. They should both tell just about the same story.

Of even more interest (to me at least) is Bryan's announcement elsewhere on this forum that he has integrated custom drag functions into his latest software. This, assuming accurate data, is the ideal - just do away with all those standard bullets and their compromises and use the actual drag for each bullet. It's a great development that will shed a lot of light on the behavior in the transonic range. And just how far off various bullets are when using the standard drag functions. I don't know how he came up with the custom drag functions, but I'm eager to see.