Velocity issue...

[stomp442]

One thing I haven't seen mentioned yet either is a possible scope problem. We don't know what brand or optic he's using. It could be a Nightforce or some BSA / Barska gem that tracks about as good as a North Korean ballistic missle.

[taylorce1]

you are dead on there. I don't care who you are, you could be shooting a mile per second (5270fps) and it's still not going to change your 100 zero by 4'.

I know I'm still being a "Richard", but your off by 10 fps. :eyebrows:


One thing I haven't seen mentioned yet either is a possible scope problem. We don't know what brand or optic he's using. It could be a Nightforce or some BSA / Barska gem that tracks about as good as a North Korean ballistic missle.

Your right we don't know if his optics went south, but with the info give the only thing we know has changed is the brake. OP did say he rezeroed leading us to believe the scope is function correctly, but didn't say if he was using a BDC reticle or twisting turrets to get on at 200 and 300 yards. If he shoots at 200 and 300 again and records the difference from his old data he can figure out his velocity change if any pretty easily.

[darkker]

Um....I'm NOWHERE near 60k. Hodgdon list 48,600 at a max of 45 grains. I'm shooting 44.7.

Sent from my SM-G950U using Tapatalk

I said 60,000+ PSI, Hodgdon doesn't list PSI data, they list CUP; those are not the same units and can't be interchanged.

Remember that lots of powder can vary in burning rate, quite widely, so the specific grain charge isn't important alone; you need to know the velocity per charge weight. That way you can compare to the pressure tested data, to get an idea of where you are pressure wise. Assuming that your lot and the lot Hodgy tested(which they don't list, btw) are the same is not a safe bet.
Hodgy posting CUP data has been one of my complaints for some time now. Quite some time ago now, SAAMI sent out some reference powder lots to the majors(Federal, Rem, etc) for pressure results. Once you exceed @ 45,000 PSI, Calibrated Copper Crushers report pressure swings on the order of 20,000psi. This is why the industry moved to PSI rather than CUP, because of the discrepancy in reported pressures.

[RC20]

A bit off Topic but my take on Nightforce is they are a good product, would like illumination if not.

[bearcatrp]

I didn't see this posted so will bring this up. Is the barrel your using the same twist rate as the test hodgdon used for there information? I know Hornady reload book uses 1:12 but my barrel is 1:10 thus do not get the same fps they list for a given powder measurement. Another note is I read someone bring up magneto chrono. Anything you attach to the barrel may and could adjust POI as am sure the extra weight will mess with the barrel harmonics. This is why I went with the lab radar. Am no guru like darkker and others are but any chronograph will help with load development. Especially if your pushing the limits. Don't have the smarts doing it on paper. Good luck finding your answer. I will watch this thread hoping to learn something new.

[psharon97]

With so little information, there's no way we would be able to answer the OP. Velocity must be known, both before the brake was installed and after the brake was installed. And as others have mentioned above, making ANY changes to the barrel, changing the torque settings on the scope or stock can and most of the time for me have changed the POI by several inches. The above advice, to chrono your data, is correct. Very few individuals, outside of companies like Hornady, Sierra, Nosler, ect, will be able to tell you, with any degree of precision, the exact amount of PSI your load, or even a factory load, is pushing in your particular rifle. If the bolt is tough to life on your rifle, you are probably pushing the PSI a little too high.

As has been stated several times, invest in a chronograph. LabRadar and Magnetospeed are about the best chronographs I've seen. I own the Magnetospeed and is very nice. The data the chronograph produces, along with a ballistic calculator, will get me within +/- 1 to 3 MOA at 1000 yards on a cold bore shot.

[pitsnipe]

We need a "like" icon. Would have worn it out with all of the great advice given here. Too bad, as it seemed as though it fell on deaf ears. Back to trolling.

[RC20]

There is a rate this thread option at the top.

[snowgetter1]

There is a rate this thread option at the top.

Thanks for the info! I rated it "Terrible".

[RC20]

I would rate it a head scratcher if I could, symbols would be better in that case!~

I keep learning things so it was remotely possible that a break did some odd things physics wise to allow more acceleration.

Is never been mentioned when used with tanks which I am an avid history buff of and particularly in regards to the AP rounds which would benefit from a boost.

I didn't think so but keep an open mind as many times what I thought was not right.

Actually I think we need several categories.

1. Overall.

2. Innovative use of language

3. Stubborness of the OP

4. Persistence in stubbornness of OP

add your own!

[pitsnipe]

There is a rate this thread option at the top.


Yea, just not the same. None the less, back to the popcorn................

[pitsnipe]

I would rate it a head scratcher if I could, symbols would be better in that case!~

I keep learning things so it was remotely possible that a break did some odd things physics wise to allow more acceleration.

Is never been mentioned when used with tanks which I am an avid history buff of and particularly in regards to the AP rounds which would benefit from a boost.

I didn't think so but keep an open mind as many times what I thought was not right.

Actually I think we need several categories.

1. Overall.

2. Innovative use of language

3. Stubborness of the OP

4. Persistence in stubbornness of OP

add your own!

I would suggest adding:

5. Good folks trying to help someone with preconceived answers

[Arky 223]

RC, instantly when the bullet leaves the end of the barrel two things happen, it starts falling toward the earth and it begins to lose velocity, nothing will increase the velocity unless it has a rocket boost.

[cchgn]

I would rate it a head scratcher if I could, symbols would be better in that case!~

I keep learning things so it was remotely possible that a break did some odd things physics wise to allow more acceleration.

Is never been mentioned when used with tanks which I am an avid history buff of and particularly in regards to the AP rounds which would benefit from a boost.

I didn't think so but keep an open mind as many times what I thought was not right.

Actually I think we need several categories.

1. Overall.

2. Innovative use of language

3. Stubborness of the OP

4. Persistence in stubbornness of OP

add your own!

5. I replace your reality with my own....lol

[taylorce1]

RC, instantly when the bullet leaves the end of the barrel two things happen, it starts falling toward the earth and it begins to lose velocity, nothing will increase the velocity unless it has a rocket boost.

A bullet doesn't technically start falling until it reaches the apex of its trajectory, not when it leaves the barrel. Now the other part of your statement is true. However, I'm sure redirecting the hot gasses escaping the barrel and other ejecta might cause a more correct velocity over a traditional chronograph so you could technically gain some velocity. I know I have less errors with my chrony at 20-25 feet than I do inside of 20 feet.

[Deadshot2]

A bullet doesn't technically start falling until it reaches the apex of its trajectory, not when it leaves the barrel. Now the other part of your statement is true. However, I'm sure redirecting the hot gasses escaping the barrel and other ejecta might cause a more correct velocity over a traditional chronograph so you could technically gain some velocity. I know I have less errors with my chrony at 20-25 feet than I do inside of 20 feet.


I have listened to several shooters who claim the bullet is actually still accelerating (somewhat) as it's still being pushed by the gases leaving the muzzle. According to them the bullet doesn't actually slow until it's beyond the influence of the muzzle blast. Probably why the condition of a rifle's crown is so critical ad the "bubble" needs to remain uniform so the path of the bullet isn't altered as it leaves this "zone".


I believe Arky 223 was referring to a bullet shot from a horizontal barrel. Yes, you can elevate the barrel to correct for this but his statement is correct for that level barrel.

[taylorce1]

I believe Arky 223 was referring to a bullet shot from a horizontal barrel. Yes, you can elevate the barrel to correct for this but his statement is correct for that level barrel.

I don't know anyone who shoots from a horizontal barrel, if you're using a rifle as designed (aiming with sights or optics) you won't ever have a horizontal barrel. Even if you do level the barrel to be horizontal depending on the flex of the barrel during firing you might have an upward trajectory, of course the opposite might happen as well.

I don't like to assume anything, but it's been five days. I doubt the OP will come back with the results from shooting the rifle again to tell us what he found out.

[Arky 223]

I was referring to any falling body, whether it is being shot in an arc or on the level. It still falls at the same rate. Depending on the highth of the arc which determines the distance it wil lhit the earth down range.