How much energy left at 218yds?

[Bob_O]

Okay guys, someone please back me up by commenting on my video. 

I doubt this Andrew Claxton will start a discussion here like I suggested.

He instead keeps insisting that a 40gr slug with a muzzle energy of 67fpe only has 5fpe left at 218yds.

https://youtu.be/drpzYPOKYh4

 

[stoti]

Chairgun has it at 32lbs at 218yds with the parameters you gave and I just guessed at the BC. I plugged in .079. Don't let people like that bother you Bob. There's always gonna be haters. I love ya man!!!

Stoti

 

[T3PRanch]

40 grain slug with 5 ft/lb energy is traveling at 237.3 fps.

 

[Bob_O]

I don't think he's a hater.....he's just wrong and can't see it.

 

[DeutschKSK]

My .30 setup 47 gr pellet retains 22 ft lbs at that range..

Matt

 

[cahil_2]

I was with Bob yesterday when he dropped a pigeon at 195 yards and you could hear a loud smack when the slug contacted the bird. By the sound had to be at least 30 fpe. 

 

[Airmanator]

At 200+ yards. The energy left is not 40 or 5. More like 20 ft lb left. Want to really know. Go put a ballistic gel at 200 yards and shot it. Then compare it to a gun shooting 40 ft lb and see if it goes same distance. 

 

[Bob_O]

Well, I don't claim to be the authority on any of this. I just know what Strelok tells me.

If after I entered all the data for my gun, slug, scope etc. into Strelok, validate the BC using Strelok and have it give me a firing solution. Then I dial what it tells me to for elevation on a pigeon at 218yds, and it works out perfectly, I'm going to assume what it tells me for remaining energy is also correct.

That's what I'm relying on. I make turret tape based upon the table I posted. I range targets anywhere from 50 to 180yds and just dial to that range and hit time and time again.

I don't know what else to say.

 

[Guest]

There we go  

Doubt is incorrect Bob! 

This is what ChairGun tells me. 

 

[D-RIG]

I for one have never gotten the Chairgun BC calculator to work 

for a slug and I done a lot of testing over the years , ok 9below0

the profile your using is for a pellet a round nose pellet . Here is 

a wright up that was done for AirgunDepot . Enjoy the read .



One thing that complicates BC calculations is that they are done in relation to a standard model. For bullets the two most common standards are the G1 and G7 models, but pellets are so different that they have their own standard, the GA. A ballistic standard such as the G1 or GA is a model of a projectile shape from which the drag and BC can be calculated. The G1 is a model of a short, flat-bottomed bullet, while the G7 is for longer boat-tailed bullets. The GA is a standard domed pellet.



I did the BC calculation on the 40 grain 2-S nose and came up 

with a BC of 0.114 this was 2 years ago so Bob's BC number is

probably spot on in my opinion . 

 

[T3PRanch]

So really the argument is between Strelock and Chair Gun and the associated math used by each program OR there is an input error in data in one case or the other!

 

[guod123]

BC .0210? think that's the problem 

 

[tsakula]

bob shoot through chrony. thats going to be the most accurate

 

[D-RIG]

So really the argument is between Strelock and Chair Gun and the associated math used by each program OR there is an input error in data in one case or the other!

There is no argument in regards to each of the BC calculators 

but the Chairguns profile that was used above has the 

GA profile being used and that is for pellets and it will give a 

improper BC number when used for a slug . 

 

[Guest]

I can't see how a 40g slug or any pellet shape for that matter travelling @ 863 fps would retain a energy level of 40 ftlb POI @ 218 yards. 

 

[lbc_PSI]

Not familiar with Strelock. The table with your red arrow has U98.7 next to the 40fpe number at 220yds.. Does that mean Up -99 Clicks from your zero? Trying to back into this with ChairGun. Interpolating between 215 and 220 you'd have clicked up 94 or 95 from a 100yd zero? If so, Chairgun validates your -40fpe @ 218yds.

In order to only have 5fpe at 218, there would have to be a bad assumption for BC or the drag model on Claxton's part.

 

[Glem.Chally]

BC .0210? think that's the problem

This.

 

[Glem.Chally]

I can't see how a 40g slug or any pellet shape for that matter travelling @ 863 fps would retain a energy level of 40 ftlb POI @ 218 yards.

I can't see how it only has 5fpe when it's "high" bc projectile. You're the doubter the onus is on you to prove it has 5fpe. Chairgun only spits out what you input.

So what BC and projectile length did you give chairgun?

For example here's from my strelok using a 24gr slug with a worse BC than the 40gr.

 

[paul67]

  very confusing. 

Something is not right yes I am getting 9 fpe more but with 1/2 the Bc and 6 grains less I am still producing more at the target somethings not adding up.

 

[Guest]

So what BC number is correct for a. 22 40g slug