Quickload Optimal barrel timing calculator download

[sharp.shooter.ser]

I have used it before with very good results (found at least 10 charges that are working good for different calibers). It might not give you the exact result, but it will put you close, shortening the search for proper combination of powder, oal etc. Its important to get all the variables as accurate as possible (case capacity, bore cross section area etc.) and adjust the burn rate (because it differs from lot to lol) and it should then match your bullet speed. Once there, table is pretty much accurate

 

[culpeper]

Yeah, I just tried it for a heavy varmint barrel 257 Roberts. Used QL to find the barrel time for 26". That is all I did. The MV was well behind max. First 50 was a little too slow. Next 50 the MV matched. But both sets were shooting .3-.4 moa at 200 meters. 100 gr SMK, AA4350, .015 off lands from jammed. I think there is some wiggle room on the timing depending on the rifle. This is a heavy varmint Remage I slapped together. It saved a lot of time and resources. I would prefer a little more MV but I'm going to stick with it. It is fine out to 500 meters no problem.

 

[Dave M.]

It doesn't make sense that it would since the bullet is no longer in contact with anything (other than the escaping gasses and the air in front of it).

Good point.

 

[340 Wby]

Hi, I have programmed a web version of my OBT Tool. It will generate data, and you can save the output as a txt file on your pc or phone.
Link: OBT Tool

 

[Murray Brook]

Great program @340 Wby . TKS

 

[MagnumW]

Wow... Just wow.
Can anybody give me the Cliff notes version?

That is the cliff notes version, see Charlies recent post for more…..

Barrel Harmonics Associated With The Target

The attached report is a bit lengthy! Using principles presented by Kolbe, Vaughn, and Long a method was developed to use the target to decifer the barrel harmonic frequency and amplitude based on conducting an Audette ladder to identify a node. While many vibrations occur, the initial results...

forum.accurateshooter.com

 

[Dave M.]

http://www.the-long-family.com/OBT Table.pdf

For OBT, and barrel length, can anyone tell me exactly how barrel length is measured? I’m assuming that it is from start of the rifling to the muzzle, but not sure. Just curious really.
Dave

 

[jackieschmidt]

Just curious. What happens when you stick a tuner on the end of the barrel?

 

[rwj]

Just curious. What happens when you stick a tuner on the end of the barrel?

By adding mass, you are changing the natural frequency of the barrel.

 

[jackieschmidt]

By adding mass, you are changing the natural frequency of the barrel.

So, if rules allow, or you can tolerate it, rather than going through all of the steps required in the procedures being discussed, just put a tuner on.

Works for me.

 

[Dgd6mm]

Does a tuner tune any reasonable load?

 

[dcali]

Since nobody else is going to say it, I will. OBT is wrong, and you're wasting your time using it. Do load development the proven old fashioned way - by varying charge weight and seating depth with a appropriate powder for the cartridge, bullet weight, and barrel length.

 

[rwj]

So, if rules allow, or you can tolerate it, rather than going through all of the steps required in the procedures being discussed, just put a tuner on.

Works for me.

I have no direct experience with tuners from which to comment. But your notion has merit in that by turning the tuner weight, one is moving the mass axially which also changes/tunes the natural frequency.

 

[jackieschmidt]

I have no direct experience with tuners from which to comment. But your notion has merit in that by turning the tuner weight, one is moving the mass axially which also changes/tunes the natural frequency.

That is exactly what it does.

And contrary to what some rather knowledgeable shooters have said as of late, they do work.

 

[mikecr]

Since nobody else is going to say it, I will. OBT is wrong, and you're wasting your time using it.

I agree that it's total nonsense as merchandised.
There are of course vibrations traveling back & forth & all directions in barrels, as Harold Vaughn showed. He also showed that there are travel patterns in this from any attachments to a barrel (action/tuner).
These vibrations sum into all kinds of unpredictable abstracts.

People want a simple OBT realm to work so bad that they'll believe it,, and talk themselves into validations.
It's also a simple & silly routine to fluff up QL sales.
The only reason OBT is still around..

Tuners do work. That's different all together.

 

[Dgd6mm]

I have used it before with very good results (found at least 10 charges that are working good for different calibers). It might not give you the exact result, but it will put you close, shortening the search for proper combination of powder, oal etc. Its important to get all the variables as accurate as possible (case capacity, bore cross section area etc.) and adjust the burn rate (because it differs from lot to lol) and it should then match your bullet speed. Once there, table is pretty much accurate

 

[jackieschmidt]

Does a tuner tune any reasonable load?

I think it depends on the accuracy requirements of the combination.

I my pre mentioned post, I spoke about taking a BAR (not known for sub minute angle accuracy), and by adjusting the BOSS got it shooting well within the accuracy requirements for typical hunting scenarios.

In an extreme accuracy Discipline such as Short Range Benchrest, the load has to be pretty close in it’s optimum agging capability. The tuner is a asset, something you can change on the spot.

 

[rijndael]

Digging in to the details of OBT and the math involved is over my head. I developed my loads the old fashioned way, my way, but I ended up pretty darn close to both of the GRT predicted nodes. My 6.5 CM was .07 grains off and my 6GT was .19 grains off. That was once I adjusted the charge weights and measured velocity variables.

My 2 above loads are 33.6 of Varget with a 107 SMK and 40.3 of SWP and a 123 Scenar.

 

[340 Wby]

New web based version that will handle negative Nodes. Just use - in front of desired Node.

Looks like this:


Link to program: https://weatherby.dk/Calculators/obt20.html



Enjoy!

 

[Braam 316]

I have never used the app.
Cliff note version. But this is my way i use.
I carefully measure barrel and note length. place length in calculator and note the obt given. I quick load I make sure all inputs including barrel lengths is correct. Then i play with charge weight and seating depths to get the barrel time where i want
i pay very close attention not to exceed pressure.
please pm and i can try to assist further

Hi

Please can someone help me, Do you include your silencer in the barrel length?
or to rephrase, Does one add the silencer length to the barrel length?

24" plus the 4" = 28 inch for the OBT calculation.