OCW vs. QuickLoad.

[jlow]

I used and have benefited from the OCW method of reloading in terms of finding accuracy nodes. In the last year, I have also been using QuickLoad to do the same. My questions to the experts is it seems that in every occasion I have used both, QuickLoad’s prediction always seems to co-inside with those from OCW. There are sometimes slight differences but it has been 0.1-0.2 grain difference.

So apart from the caveat of working up from a low charge to avoid pressure problems, is there a reason not to go straight to the QL predicted accuracy node area and bracket it as per normal OCW but with a much narrower charge range. Seems like this would save components and then from there go on to tightening the groups using seating depth adjustment.

 

[Joe R]

At one time I thought that OCW was the cat's miao, but after I processed Chris Long's OBT I forgot about OCW. Now I just use QL, the OBT table and a chrono. It gets me there a lot faster.

IMO that OCW is really a subset of OBT.

Joe

 

[jlow]

Exactly! I do run a narrow OCW to confirm and to see how wide the nodes are but other than that yes QL/OBT table…

 

[Link]

What does the intelligence level have to be to use QL.? And what's the price ?
It seems to good to be true , ask the machine and it spits out load info.


:

 

[Joe R]

Link said:

What does the intelligence level have to be to use QL.? And what's the price ?
It seems to good to be true , ask the machine and it spits out load info.

:

It costs $153 plus shipping. See http://www.neconos.com/category/Software-2

I don't know how others feel about QL, IMO it is a bit complicated to get started because there isn't a tutorial or a really good manual. I did find a YouTube video that was helpful. There are some good tips on how to use on this site as well as Chris Long's site.

The trick with QL is the more info you give it the better its results. It's interface seems very Windows 3.1, but it works. I would love to have options but it's the only game in town. I hope Hartmut Broemel is in good health because if anything happens to him we're all going to be SOL.

Joe

 

[jlow]

It’s a great program but it is very definitely not for everyone.

I am pretty computer literate having stated with a PC in 1982 and very DIY type. Through the years working in the lab I have recognized that there are definite segment of our population that do not relate well to this stuff – I mean there are people who do not know how to use a screw driver let alone these highly technical programs and how to accurately measure a case volume…. Something that quite a few folks on this board cannot do....

Not a real surprise as I too relate poorly in terms of skills to other areas myself – I guess it’s what makes the world go around i.e. the fact that we are different. However, if you have the knack in this area, something not to miss.

 

[Mike402]

Now I just use QL, the OBT table and a chrono. It gets me there a lot faster.

I do the same thing, and it really has gotten me to the end result much quicker. I have found that different bullets still like the same Pmax to muzzle number in the same gun.

However its not gospel. Case in point - I have a FN SPR w/ 24" barrel. The OBT was scary close to the 24" number in the OBT chart. However, I sent it off to have a muzzle brake installed, and I had to work up a new load when I got it back. Theoretically you would assume the barrel length is the same, but the brake changed everything.

 

[jlow]

I think the brake acted like a tuner.. The question is when you recalibrated your rifle information after adding the brake, did QL properly predict you accuracy node even if it was different than before the brake?

 

[Mike402]

I think the brake acted like a tuner.. The question is when you recalibrated your rifle information after adding the brake, did QL properly predict you accuracy node even if it was different than before the brake?

Ok bear with me, not sure I understand your question 100% I definitely agree with you re the tuner analogy with regards to the brake.

I had a great Varget load, lets call it consistent .5 moa average from bipod/prone. Fast forward to brake install, and groups opened up to .75 with ES/SD going to double digits. Velocity remained practically the same. In the end, I had to add .4 grains to get back in the accuracy node. Velocity obviously went up after that.

Here are the numbers: According to the the OBT node chart, node #5 for a 24" barrel is 1.2282. My BT 10% Pmax to muzzle in QL was 1.222 with the old load. When I plugged in the new charge weight, the velocity increased in QL to what I confirmed via my magnetospeed (within a few fps amazingly enough). Good sign, but the BT in QL decreased to 1.208.

So my confusion comes from this part of your question: "did QL properly predict you accuracy node even if it was different than before the brake"

My understanding is that you aim to get close to the published OBT nodes in the barrel length node chart. Theoretically that should get you close to your Optimal charge weight, which lined up almost perfectly pre brake. Post brake, the revised QL OBT is still close but not an exact match for the OBT node in the chart.

So my theory now is that a tuner and/or brake may throw off barrel vibration/oscillation enough that it no longer may line up with published OBT nodes by barrel length.

 

[1shot]

I hope someone doesn't accuse me of hi-jack this thread as I have learned or confirmed some things I read already. My question is have any of you found through practical application (shooting through a chrono or pressure" that V-V powders both in their manual and in the data supplied to QL to be very conservative? I ask this because in the same barrel with identical loads, I'm always higher than QL says is safe.
Thanks for any input,
Lloyd

 

[Joe R]

1shot said:

My question is have any of you found through practical application (shooting through a chrono or pressure" that V-V powders both in their manual and in the data supplied to QL to be very conservative?

Yes, the QL data regarding "safe pressures" is conservative. It is biased towards safety and limiting liability, as it should be, for the average shooter, not competitive shooters.

It is my opinion that many, if not most competitive, shooters are playing in areas well behind what powder manufacturers and QL deem "safe". Pushing the envelope is the nature of competition. For example the Max load for Varget pushing a 200 grain Berger is 42.0 grains. I don't know a single competitive shooter that has a load that mild. Most/all are at 44.0+ grains. One guy at my range is using 45.9 to push 215 bergers and getting a single use from his brass, and his rifle hasn't exploded yet. Remember that most competitors have custom rifles not factory rifles. YMMV.

Kindest regards,
Joe

 

[jlow]

I think the brake acted like a tuner.. The question is when you recalibrated your rifle information after adding the brake, did QL properly predict you accuracy node even if it was different than before the brake?

Ok bear with me, not sure I understand your question 100% I definitely agree with you re the tuner analogy with regards to the brake.

I had a great Varget load, lets call it consistent .5 moa average from bipod/prone. Fast forward to brake install, and groups opened up to .75 with ES/SD going to double digits. Velocity remained practically the same. In the end, I had to add .4 grains to get back in the accuracy node. Velocity obviously went up after that.

Here are the numbers: According to the the OBT node chart, node #5 for a 24" barrel is 1.2282. My BT 10% Pmax to muzzle in QL was 1.222 with the old load. When I plugged in the new charge weight, the velocity increased in QL to what I confirmed via my magnetospeed (within a few fps amazingly enough). Good sign, but the BT in QL decreased to 1.208.

So my confusion comes from this part of your question: "did QL properly predict you accuracy node even if it was different than before the brake"

My understanding is that you aim to get close to the published OBT nodes in the barrel length node chart. Theoretically that should get you close to your Optimal charge weight, which lined up almost perfectly pre brake. Post brake, the revised QL OBT is still close but not an exact match for the OBT node in the chart.

So my theory now is that a tuner and/or brake may throw off barrel vibration/oscillation enough that it no longer may line up with published OBT nodes by barrel length.

What I mean is when you developed your first load (without the brake), you used your actual charge weight/MV to calibrate your QL so that the MV in QL line up with your actual MV. When you add the brake on, things changed and so unless you charge weight/MV relationship did not change, you might need to get new re-calibrate your QL.

In the end, you appear to be only 0.4 grains off which means if you do what I do, which is to get an estimate of where my accuracy node is and do an abbreviated OCW, you would still bracket and hit the new accuracy node since it is not that far away.

 

[Marksman63]

I used and have benefited from the OCW method of reloading in terms of finding accuracy nodes. In the last year, I have also been using QuickLoad to do the same. My questions to the experts is it seems that in every occasion I have used both, QuickLoad’s prediction always seems to co-inside with those from OCW. There are sometimes slight differences but it has been 0.1-0.2 grain difference.

So apart from the caveat of working up from a low charge to avoid pressure problems, is there a reason not to go straight to the QL predicted accuracy node area and bracket it as per normal OCW but with a much narrower charge range. Seems like this would save components and then from there go on to tightening the groups using seating depth adjustment.

That's what I do, as well! It seems working for me

 

[Mike402]

I think the brake acted like a tuner.. The question is when you recalibrated your rifle information after adding the brake, did QL properly predict you accuracy node even if it was different than before the brake?

Ok bear with me, not sure I understand your question 100% I definitely agree with you re the tuner analogy with regards to the brake.

I had a great Varget load, lets call it consistent .5 moa average from bipod/prone. Fast forward to brake install, and groups opened up to .75 with ES/SD going to double digits. Velocity remained practically the same. In the end, I had to add .4 grains to get back in the accuracy node. Velocity obviously went up after that.

Here are the numbers: According to the the OBT node chart, node #5 for a 24" barrel is 1.2282. My BT 10% Pmax to muzzle in QL was 1.222 with the old load. When I plugged in the new charge weight, the velocity increased in QL to what I confirmed via my magnetospeed (within a few fps amazingly enough). Good sign, but the BT in QL decreased to 1.208.

So my confusion comes from this part of your question: "did QL properly predict you accuracy node even if it was different than before the brake"

My understanding is that you aim to get close to the published OBT nodes in the barrel length node chart. Theoretically that should get you close to your Optimal charge weight, which lined up almost perfectly pre brake. Post brake, the revised QL OBT is still close but not an exact match for the OBT node in the chart.

So my theory now is that a tuner and/or brake may throw off barrel vibration/oscillation enough that it no longer may line up with published OBT nodes by barrel length.

What I mean is when you developed your first load (without the brake), you used your actual charge weight/MV to calibrate your QL so that the MV in QL line up with your actual MV. When you add the brake on, things changed and so unless you charge weight/MV relationship did not change, you might need to get new re-calibrate your QL.

In the end, you appear to be only 0.4 grains off which means if you do what I do, which is to get an estimate of where my accuracy node is and do an abbreviated OCW, you would still bracket and hit the new accuracy node since it is not that far away.

Yes I did initially calibrate my actual MV to QL via adjusting the burn rate. When I changed the charge weight in QL, it predicted the new correct MV. So I'm pretty confident that I don't need to recalibrate QL. It just didn't match up exactly to the OBT node chart. But like you said, it was still close enough that a targeted OCW around the predicted OBT works. I'm still a firm believer in the product and methodology behind it.

 

[Keith Glasscock]

Tuners do affect the OBT times. Unfortunately, the result is not totally predictable. In the case of the muzzle brake, you get the harmonic wave going past the end of the muzzle, then bouncing back along with the part to the wave that reflects off of the crown. I've found that I have to change barrel lengths on the OBT chart to match up when I use a tuner.

 

[jlow]

There are quite a few things that QL cannot account for. For example some obvious ones would be, the primer, brakes, even something as simple as neck tension (which can significantly affect MV). This is where adjusting the burn rate factor Ba comes in. When you calibrate using MV vs. power weight, you take account of these.

Yes, it is not necessary to be absolutely perfect as no one should take a powder weight that is predicted to be an accuracy node and just use it. That would be totally unsafe and you also have no margin of error in terms of hitting the accuracy node. This is why I still do an ascending powder weight/pressure sign first before doing an abbreviated OCW.

 

[mikecr]

I was an early adopter of QL, and I don't know of any OCW correlations provided by QL.
And while QL provides barrel time, which some loosely apply to OBT, neither sway meaning to OCW.

In other words, I know of no tune inference out of QL.

 

[RDavies]

Just how rigidly does a muzzle brake or tuner have to be fitted to the barrel for it to be included in barrel length for OBT measurements? I would have thought if a tuner was threaded onto a barrel, the sliding mass would not be part of the measurement? How about tuners with an aluminium tuner body, I would not have thought it would be included in the measurement?

 

[jlow]

Mikecr – Did not mean in any way that they are correlated… I only use OCW to figure out the width of the accuracy node ID by QL. AFAIK, QL cannot take into account a tuner, just like it cannot take into account a hotter primer, you adapt it via the calibration procedure.

RDavies – you do not measure a muzzle brake/tuner, you just measure the barrel from crown to bolt face. See above.

 

[CPorter]

Barrel length is always from the chamber end to the muzzle, anything past that doesn't really affect powder burn or the swell that runs from the chamber to the muzzle and gets reflected several times before the bullet exits. With OBT the idea is to have the bullet exit when the pulse is at the chamber so the muzzle will be its tightest around the bullet. A muzzle brake or tuner affects the up and down/side to side vibrations . According to Varmint Al's engineering page it changes the frequency as well as the amplitude.

If instead of a gradual reduce is barrel diameter on a HV taper barrel you placed a step reduction then you would have ringing reflecting off the step reduction as well as the muzzle and chamber ends.