To the tune of 59 grains of reloder 22...
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Well with all this experience you claim to have, I don't know why you don't have the answers already? Why bother to come to an internet forum and ask someone else to do the math for you? So why don't you get back to us with the answers, since you have all the information and haven't given us any.
What i'm not understanding is if you have already shot this load at 200 and 300 yards with a corrected zero and you already know the drops how don't you know what estimated velocity you have?
so you said you dialed 4.28moa at 300 yards and it is "still not correct" did you measure where your POA was and measure where your POI is then calculate the difference? did you dial the correction and confirm? then once you confirm your elevation. you put your info into your ballistic solver or do the math from formulas that are easy to find and get your answer.
Simple answer is, nothing was recorded or POA POI difference measured. If he had then he could have figured out the velocity change if any and how much. Right now all anyone really knows is that he had a 4" different POI from POA at 100 yards after installing a brake and there is no way to calculate velocity from that information. However, he states he shot out to 300 yards but no other info is given.
He's simply searching for a problem that isn't there, or hoping he gained more than the expected amount of velocity just by adding a brake. He refuses explanations that don't involve increased velocity, because they aren't the answers he's wanting. Then goes on to tell everyone how experienced he is as a wildcatter and that he has the help of a 50 year reloader, yet doesn't have the tools, access to tools, or the ability to think through figuring it out on his own.
:pop2:
First of all, are you going to shoot this rifle with the brake installed? Or not?
If yes, just set some targets up at increasing distances, re-zero at 100 yards, then record elevation required to hit center target at 200, 300, 400, out to however far you expect to shoot.
Record these elevation values on a piece of card stock then tape it to your stock with some clear Shipping tape. From there who cares what speed you are achieving. The simple answer should be "Enough" if you are hitting distant targets without having to "go around twice on your elevation turret".
The nice thing about "Cheat Sheets" is that the battery never goes dead. If you are accurate on your ranging, you'll have a solution right there under your cheek. Just dope the wind and pull the trigger.
Well if nothing else he is making me look pretty good. Ok, note to self, do not use that word.
It does seem to me this is the second post that had the answer or was not willing to look at suggestions. The term Rodeo came up as well.
It does have me scratching my head, but then as I was reminded a while back, we are dealing with people (and of course I include myself in that even if I am on the margins somewhat)
When a bullet leaves the end of the barrel it becomes a free falling object. As such nothing is going to increase the velocity. Something added to the end of the barrel slightly larger in dia. the bullet, such as a brake, may actually decrease the velocity. Physics 101.
deleted, dual post
It sounds like there may be a bit of boost, but if there is its miner, new to me, I don't deal with brakes but interested in the subject.
I don't know if the guy is correct but worth a read I think.
http://www.longrangehunting.com/foru...elocity-64213/
And one comparing with and without and actual velocity.
https://www.thehighroad.org/index.ph...locity.382219/
Maybe I was being a little bit of a "Richard", but I dislike when someone is unwilling to accept an answer that isn't one of their own choosing. In my experience a 4" shift in POI can't be accomplished by velocity alone. It would require pushing the bullet far beyond the limits of the cartridge and the rifle.
I've tried my best, but using JBM's ballistics software program you can't explain a 4" POI change based on velocity alone. Even if the OP's brake magically made his bullets go 3000 fps from a 2680 fps baseline it would only change his impact by .3" at 100 yards best I can figure. To get an almost 2" change of POI based on velocity alone, you have to push the bullet in question to 4800 fps which is the max speed that JBM ballistics allow and we know the OP's rifle and cartridge which I'm assuming is .308 isn't capable of.
you are dead on there. I don't care who you are, you could be shooting a mile per second (5280fps) and it's still not going to change your 100 zero by 4". As to the barrel harmonics, anyone who has shot with a mangetospeed sees what happens when you add weight to the end of the barrel. It throws me high 2-2.5" and right 1-1.5. It is inconsistent because it is attached a little different each time. The brake is not constantly removed so the poi shift remains consistent.
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.
I know I'm still being a "Richard", but your off by 10 fps. :eyebrows:
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.
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.
A bit off Topic but my take on Nightforce is they are a good product, would like illumination if not.
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.
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.
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.
There is a rate this thread option at the top.
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!