223 16" AR15 4000+fps 53gr TSX

[Adam in WI]

My loads were always faster before I got a chronograph ......

Ain't that the truth, though... I got my first chrono right around the time I was playing with 168 Bergers in the 7mm Rem Mag. Berger's data said I should've been in the ~3075 range (working from memory here). Not only was I way low (~2880), that rifle had a generous enough chamber and throat to allow me to comfortably exceed their expected velocities. Another later 270 WSM exceeded expected book max velocities with less powder. Had I jumped to book max charges I would've likely locked a bolt up. You simply don't know what you don't know. The OP could've easily bought a nice chronograph with the funds required to replace that "grenaded upper".

 

[Big_Daddy]

My loads were always faster before I got a chronograph ......

You win the award for the "Best Response To a Thread" comment....
Well done!!

 

[clowdis]

It's pretty easy to get these drops if you're using an angled scope rail, maybe 10* or 20* angle. That's what angled scope rails are for.

 

[Rock Knocker]

5spd that is a heck of a load for CCI400s what did they look like?

 

[5spd]

5spd that is a heck of a load for CCI400s what did they look like?

Pretty flat, primer flowed back, ejector scrapes. Not a load I'd use but figured I would test to see the speed OP posted....not close, not safe IMO

 

[Rock Knocker]

Adam in WI, the exploded upper had nothing to do with me testing max loads, in fact I was loading my plinking 26.0gr H335 50gr SP the mildest load I shoot. It's the only load i throw a charge for, if i was testing and hand measuring each load theres a good chance I would have seen flake powder mixed with my ball powder. Rifle and pistol powder got mixed together ether in the powder measure or someone poured the powder from the measure into the wrong container... multiple guys using the same reloading equipment.

 

[Flouncer]

An F1 Shooting Chrony is only $129......

 

[Rock Knocker]

Yes Flouncer and many things I purchased this year were much more than that.

But good thing I dont work for NASA. I was able to meet up with Hoot and he set up his radar, it showed my average form the 53 TSX at 3300. My range calculations were way off, I will set up and shoot consecutively at 100-200-300 and maybe 400 to see what was so far off.

 

[mac86951]

Yes Flouncer and many things I purchased this year were much more than that.

But good thing I dont work for NASA. I was able to meet up with Hoot and he set up his radar, it showed my average form the 53 TSX at 3300. My range calculations were way off, I will set up and shoot consecutively at 100-200-300 and maybe 400 to see what was so far off.

Well, great to hear, and glad you're safe. Also, no worries, NASA did have that one mars lander that I think WAS going around 4000ft/s when the parachutes tried to open. Something about a units problem, m/s vs ft/s.

Measuring Velocity and ballistic curves need lots of mathematical constants adjusted for conditions. Those of us in long-range typically measure our velocities and adjust with BC which in itself changes with conditions primarily velocity.

Going the other way, using BC as a constant you're at the whim of the bullet makers published specs and I'm sorry to say is often a marketing ploy. IE I publish a bigger number, more people buy it. Often this is accomplished by changing the velocity range that it's calculated from or distance it's measured across, IE what's BC from 4000-3000fps vs BC from 4000-1600fps.

Ironically, if not radar measured; BC is calculated from known velocity and known distances, so you're right in that working backward can net you velocity results, but it seems industry has made more fudge factors in this method since Chronographs are widely available.

My advise, run the calcs both ways a few iterations. Make the most accurate measurements of bore axis to sight axis that you can; and tweak the BC value at the end to account for your local air density factors and final correction. Calculators are good, but I've seen a good dope chart set at local conditions beat calculators very often.

-Mac

 

[457ciSBC]

Yes Flouncer and many things I purchased this year were much more than that.

But good thing I dont work for NASA. I was able to meet up with Hoot and he set up his radar, it showed my average form the 53 TSX at 3300. My range calculations were way off, I will set up and shoot consecutively at 100-200-300 and maybe 400 to see what was so far off.

Cool and you got to meet a fellow member, all is well.

 

[jelenko]

Something about a units problem, m/s vs ft/s.

Yeah. I read/heard that also.
Thing is, as an engineering student in the US, we used meters/sec not ft/sec. My reaction was 'BS'. Somebody screwed up and that was their cover story.

 

[Mad_Charlie]

My loads were always faster before I got a chronograph ......

And our barrels were always clean, until we bought bore scopes.

 

[Flouncer]

Well, it was all fun and games until the Flying Monkees attacked !!!

 

[Big_Daddy]

Yes Flouncer and many things I purchased this year were much more than that.

But good thing I dont work for NASA. I was able to meet up with Hoot and he set up his radar, it showed my average form the 53 TSX at 3300. My range calculations were way off, I will set up and shoot consecutively at 100-200-300 and maybe 400 to see what was so far off.

Good on you for hooking up with another member and getting some "hard" data.
Thank you for the follow up post.
IMO.....it adds a lot to your "board credibility"

 

[Ackman]

Instead of jumping all over the poster, criticizing, look at his gun. See how high the OP's scope is above the bore line. My AR has an HK polygonal barrel. It's also an early one with a carrying handle. Mounted on the carrying handle, scope centerline is 4" above the bore centerline. Years ago when we first put it on paper with 55's, the 100yd and 200yd poi was about the same, there was seemingly no drop. Not because the bullets were going real fast, but because of how the perceived trajectory changes when the scope is mounted higher....in the case of my gun, much higher. The OP's scope is also up there. ***** Can't say for sure how much faster, if any, a polygonal barrel is, but they work good.

 

[Rock Knocker]

I know my measurements were off, my 100 yard zero was higher than expected when measured and I put 2.5 inches of scope height in the ballistic calculator.

What got me all fired up was how much flatter it was shooting at 300, 100 and 300 yards have always been my benchmarks for this gun and scope and 9 to 14 inches of drop is what I usually see. I have been much more reserved with this Barnes ammo during this shortage, I've only shot two groups past 100 yards when I would usually be shooting a few groups a week.