Help with Quickload

[ballison]

I just got Quickload and could use some advise from someone with experience "tuning" the results to match real world data. I have some new Berger 130 hybrids to shoot in my 260, loaded a bunch in .2gr increments (H4350), and chrono'd them with a MS V3. When I plug my specific data (OAL, case H2O, ...) into QL, the velocities are consistently 50-60 fps lower in QL than in real life. So, an internet search says the best way to tune QL is to vary the powder burn rate factor and/or the bullet weight. My question is this, since this bullet has a VERY short bearing surface (.342" vs .500" of the 130 VLD), would you start by LOWERING the bullet weight (say to 128gr), thereby lowering the pressure and raising the velocity? Or would you start with lowering the burn rate, thereby raising the pressure and raising the velocity. I am thinking the first, as a bullet with a shorter bearing surface should produce less pressure and higher velocity, all else being equal. Correct?

I realize QL is not the "end all, be all", but so far it looks like a useful tool to help find starting ranges for load development and to estimate internal pressures.

 

[ballison]

gstaylorg,
That does help. Since bearing surface isn't used in QL, I was looking for a way to account for it. Maybe it is too insignificant (or too hard to model) to worry about. I'll play with the Ba until the data sets match.

Thanks.

 

[mikecr]

Do not knowingly put in wrong information(like wrong bullet weight). Instead look for the reason MV is wrong. Things like starting pressure, weighting factor, bore area, measured(not listed) H20 capacity, seated bullet base/bearing, powder temp, and last would be tweaking of powder for the lot.

IMO, bearing is meaningless. I've yet to see actual basis for bearing concerns.

 

[Dos XX]

Does QL take into account bore diameter or bullet diameter or pressure ring? Are these considered significant to developing pressure?

I measured the 130 hybrids I got in, and I can't find them to be over .2640 anywhere I measure them. Some Lapua Scenars I have will measure .2642. Neither seem "fat". I have seen some people talk about bullets that were .0006 over caliber diameter. Just curious.

 

[Marksman63]

IMHO, tuning the burn rate factor makes more sense in order to consider normal minor burn rate changes amid different lots of same powder

 

[ballison]

Does QL take into account bore diameter or bullet diameter or pressure ring? Are these considered significant to developing pressure?

I measured the 130 hybrids I got in, and I can't find them to be over .26400 anywhere I measure them. Some Lapua Scenars I have will measure .26420. Neither seem "fat". I have seen some people talk about bullets that were .0006 over caliber diameter. Just curious.

I went into QL and changed the bullet diam by a few 10,000ths, and it didn't change the output. I guess it is either not used or has an insignificant effect.

 

[savagedasher]

IMHO, tuning the burn rate factor makes more sense in order to consider normal minor burn rate changes amid different lots of same powder
[/quote What is burn rate? One of my cans was old $16.50 it lasted years. Now I'm shooting more it don't long. ;D The $16.50 stuff was old and ben open left in the hopper several times and was 50' faster then one of the new. The older shot faster :-\ :-\.
All that fancy stuff that QL does .I use only few the bullets number and shape friction or non case length barrel length bullet weight H2O capacity a must Shot start ( initiation) pressure. % of fill. and grains amount of burn in barrel , Chamber pressure Projectile travel in ( in ) PM Z1 I want the two of them as close together as I can get on or a little before peak pressure. I have never found a powder that the PM and Z1 close together on the peak of pressure curve that didn't shoot.
But how fast you burn your powder Tells me the faster it is burned the more fun your having ;D
Larry

 

[amamnn]

You might want to keep in mind the fact that QL does not allow you to input certain variables that will affect the load and downrange performance a bit. There are no adjustments for primer types nor for neck tension.

 

[savagedasher]

Neck tension, different primers,.0006 change in diameter add them all together and you won't get 50 to 60Fps. Case capacity 10 to 15. Wrong bullet weigh yes. Difference of lot's of powder Yes . Croney yes.
Burn rater of the powder is very common to give 50 to 60 fps difference. Some may be fast and the other slow.
All smart re loaders start low and work up. Larry

 

[Marksman63]

Neck tension, primers' brand, etc. everything converges in barrel time/muzzle speed. Therefore you could tune up QL according neck tension and other variables using a chronograph

 

[ballison]

Thanks for everyone's input. It looks like many of you are modifying the "Ba" until the QL output matches your chrony data over a reange of charges, then QL should give you more accurate predictions for other scenarios.

Thanks all!

 

[Dos XX]

FTRinPA,

Did you find that you can run those 130's at higher velocity than you thought you would be able to? I'm asking because I got them up to 2800fps in a 20" barrel, .260 Rem chambering. I am out of powder room using IMR4451. I have seen no pressure signs. I wish my F/TR brass and primers looked like these do.

Obligatory cautionary warning:
I worked up from a very low load in 1% increments. This is in my rifle, barrel, and chamber and might not represent other barrels and chambers which might see pressure at a much lower velocity.

 

[ballison]

FTRinPA,

Did you find that you can run those 130's at higher velocity than you thought you would be able to? I'm asking because I got them up to 2800fps in a 20" barrel, .260 Rem chambering. I am out of powder room using IMR4451. I have seen no pressure signs. I wish my F/TR brass and primers looked like these do.

Obligatory cautionary warning:
I worked up from a very low load in 1% increments. This is in my rifle, barrel, and chamber and might not represent other barrels and chambers which might see pressure at a much lower velocity.

That is half the reason I bought QL. Using H4350 in a 26" barreled 260, and going up in .2gr increments, I got up to over 3000 fps with NO pressure signs. I got a little nervous, and put everything on hold until I could get an idea of where I was at with pressure. According to QL, at 3000 fps, I am above the 60K psi max, but not as much as I thought. I'm going to back off a bit and chrono some more rounds, then try and "true" QL a little better. I believe getting 2950-2975 is quite doable, and safe, IN MY RIFLE!

DITTO ON THE DISCLAIMER!!!

 

[Dos XX]

FTRinPA,

Did you find that you can run those 130's at higher velocity than you thought you would be able to? I'm asking because I got them up to 2800fps in a 20" barrel, .260 Rem chambering. I am out of powder room using IMR4451. I have seen no pressure signs. I wish my F/TR brass and primers looked like these do.

Obligatory cautionary warning:
I worked up from a very low load in 1% increments. This is in my rifle, barrel, and chamber and might not represent other barrels and chambers which might see pressure at a much lower velocity.

That is half the reason I bought QL. Using H4350 in a 26" barreled 260, and going up in .2gr increments, I got up to over 3000 fps with NO pressure signs. I got a little nervous, and put everything on hold until I could get an idea of where I was at with pressure. According to QL, at 3000 fps, I am above the 60K psi max, but not as much as I thought. I'm going to back off a bit and chrono some more rounds, then try and "true" QL a little better. I believe getting 2950-2975 is quite doable, and safe, IN MY RIFLE!

DITTO ON THE DISCLAIMER!!!

Good luck. I would be very interested in your results if you don't mind sharing.

 

[mikecr]

Similar to a reloading manual!
Just what can you calibrate with a reloading manual?
Because we can't predict primer/striking or powder lot changes, we should all go back to throwing darts at reloading manuals? :