Velocity issue...

[trentcwwilson]

I don't know what wildcat you're shooting but a lot of wildcats have an improved shoulder and minimum case taper. These cases usually don't show pressure like a normal tapered case they are usually made from. A chronograph can show when things are about to go wonky, when an improved case wont. It's your choice to budget a chronograph in or not, I just think they are useful tools and I'll have at least one in my toolbox.
260 Dingo. 6.5-06 with enough case taper for extraction, 42° shoulder, throws the 95 grain V-max at 3975, the 140 grain ELD at 3550. I know about how wildcats show pressure. This isn't my first rodeo with them.

I know about Lapua's brass. It's second to none. Now if they'd start making 30-06 brass, it buy it in bulk. We've got a lot of people buying the 260 in MASSIVE quantities.

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[trentcwwilson]

I know I'm coming in late and repeating what has already been said and discussed, but unless you are using a chronograph, you can only speculate that your POI has shifted due to velocity. You mentioned purchasing a Magnetospeed. Again, as discussed, clamping something to your barrel will affect harmonics, and if you are looking for load development for groups, that may not be the best tool IMO. I have gotten by with a cheap Competition Electronics Prochrono model, which has worked well, with one caveat. I had to buy the indoor light kit for reliability, and RARELY due I have an error reading when using the light kit. I do agree with buying quality equipment though, but I can't complain about my chronograph. I'd be very lost without it. As said, even an error now and again still beats guessing.
So far, the Prochrono hasn't been able to read the 260 Dingo. The MagnetoSpeed has. Then again, we know how the rounds shoot and could give a **** how adding weight to check velocity affects accuracy. What I'm wanting to know is what kind of gain in velocity could give me that reading. I don't care about barrel harmonics or anything else. Now let's try to reel this thing back in to the original question.

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[Deadshot2]

Because I know how to read pressure and have a very experienced(over 50 years) reloader helping me. The only time we've used tech was to measure the velocities of our most accurate loads. 3975 for the hunting round and 3550 for the target round.

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What caliber? Hopefully not the one in your opening post as speeds close to 4k fps are not known in .308's with 175 gr bullets. If it is, then you certainly are sitting on a time bomb as someone else mentioned.

[trentcwwilson]

What caliber? Hopefully not the one in your opening post as speeds close to 4k fps are not known in .308's with 175 gr bullets. If it is, then you certainly are sitting on a time bomb as someone else mentioned.
Read comments above yours.

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[Deadshot2]

Read comments above yours.

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Thank you. Our posts kind of overlapped with network delay. You had the answer before my question made it out. :o

The 06 case sure does allow for a large load of fuel.:thumb:

[trentcwwilson]

Thank you. Our posts kind of overlapped with network delay. You had the answer before my question made it out. :o

The 06 case sure does allow for a large load of fuel.:thumb:
To the tune of 59 grains of reloder 22...

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[taylorce1]

260 Dingo. 6.5-06 with enough case taper for extraction, 42° shoulder, throws the 95 grain V-max at 3975, the 140 grain ELD at 3550. I know about how wildcats show pressure. This isn't my first rodeo with them.


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.

[trentcwwilson]

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.
Again, first time I've ever had this happen. I'm not arguing with you, yet you wish to be an *******. That's fine.

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[squirrel_slayer]

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.

[trentcwwilson]

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.
I haven't measured anything. Those drops were for these loads BEFORE the brake was installed.

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[taylorce1]

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.

[squirrel_slayer]

:pop2:

[Deadshot2]

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.

[J.Baker]

Again, first time I've ever had this happen. I'm not arguing with you, yet you wish to be an *******. That's fine.

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And that just earned you a 3-day vacation.

[RC20]

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)

[Arky 223]

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.

[RC20]

deleted, dual post

[RC20]

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/forums/f19/muzzle-break-velocity-64213/

And one comparing with and without and actual velocity.

https://www.thehighroad.org/index.php?threads/muzzle-brakes-and-velocity.382219/

[taylorce1]

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.

[schnyd112]

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.