Different Load Data

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CourtenayBoy

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Every time I think I have some proper numbers for the few cartridges I reload for, I see different ones. Different min/max charge weights and COL. Different velocities for identical charge weights from the same manufacturer year over year in their different editions of their manuals. Never mind looking up powder manufacturers numbers to verify against manuals...........It seems I am to extrapolate some common ground between all sources and slowly work it up myself.

At times, being wet behind the ears still when it comes to reloading I just shake my head.
 
Of course the min/max powder charges ,COL, and velocities vary from manual to manual, the barrel and chamber dimensions vary from firearm to firearm, and lots of powder, brass and bullet also vary.
 
Below are two pressure and velocity charts from Quickload, the powder charge are the same for both cases. "BUT" there is approximately 6,000 psi difference in chamber pressure due to the case capacities, the top chart shows a case with the most case capacity the bottom has the least case capacity.


308_zpsf81bb4cc.jpg


288_zps26698a67.jpg


If you do not have the same exact firearm used in the manual, the same powder, same cases and primers the load data will vary. This is why you are told to start low and work up with your load.

The .223 and 5.56 are both loaded to the same exact chamber pressures, 52,000 cup or 55,000 psi. "BUT" the .223 and 5.56 cartridges have different throat lengths, now look at the chart below. The first green bar on the left is a factory loaded .223 cartridge fired in a .223 chamber, it shows the factory doesn't load the cartridges to the max rated pressure of 55,000 psi. The blue bar on the far right is a 5.56 cartridge fired in a military chamber and very close to 55,000 psi. If you fire the same 5.56 military cartridge in a .223 rifle with a shorter throat the pressure jumps approximately 5,000 psi.

Now to add more confusion, I have two AR15 rifles and a Savage .223 bolt action and the throat is longer in the Savage rifle than both my AR15 rifles. NO reloading data is written in stone and every firearm and its ammunition will be different.

barnes-pressure_zps9347fe41.jpg
 
I rekon I experienced something like this today, aswell as shooter error but I had 2 neat shots touching using once fired rp brass from my rifle, then I fired a 3rd shot an I did pull the shot, but I wouldn't of thought so bad... I blame the slightly heavy LC6 trigger, Anyway it printed 2 inch lower to the right.... wonder if the elevation was me or the round? I didn't have any more rounds to shoot afterward to eliminate the shooter error (flier) D'oh!

that's 55gr of "varget" with Fed LR primers, R P brass, 225gr Woodleighs 2 different lots of brass, as above both FLS, some new an some x3 times fired


The rifle is a Ruger hawkeye mkII .35 whelen
the barrel floats just, which makes me think the Hot barrel after 2 rapid shots and a slightly different hold/rest aswell as slight heavy trigger and the pushed right (left hander) last sight picture , so the barrel could of had different point of contact, thus throwin the shot also.


Im not 100% worried about it though, its a stalking rifle for -200m So it will be more than adequate.

One more thing while im thinkin about it, it seems to print 2 reasonably closer , shooter dependant, an then throw the 3rd a bit... What would be the issue here?

Thanks a lot for reading :)

WL
 
I have a bunch of manuals ... mostly since 1998/2000, but one I often refer to is an old Speer Manual
from the 60's. Loads were a "little hotter" back in the day when law suits weren't so prevalent.
Some of the "minimum" loads for the 25-06 with H4831 back then - are now shown as "maximum".
 
Personally I try and stay in the middle ground given the variability of loading recommendations. Having said that remember modern guns are typically proof tested to 30% overload compared to the maximum regular load, so there is a margin for error. A lot less confident with older guns.
 
WhelanLad said:
I rekon I experienced something like this today, aswell as shooter error but I had 2 neat shots touching using once fired rp brass from my rifle, then I fired a 3rd shot an I did pull the shot, but I wouldn't of thought so bad... I blame the slightly heavy LC6 trigger, Anyway it printed 2 inch lower to the right.... wonder if the elevation was me or the round? I didn't have any more rounds to shoot afterward to eliminate the shooter error (flier) D'oh!

that's 55gr of "varget" with Fed LR primers, R P brass, 225gr Woodleighs 2 different lots of brass, as above both FLS, some new an some x3 times fired


The rifle is a Ruger hawkeye mkII .35 whelen
the barrel floats just, which makes me think the Hot barrel after 2 rapid shots and a slightly different hold/rest aswell as slight heavy trigger and the pushed right (left hander) last sight picture , so the barrel could of had different point of contact, thus throwin the shot also.


Im not 100% worried about it though, its a stalking rifle for -200m So it will be more than adequate.

One more thing while im thinkin about it, it seems to print 2 reasonably closer , shooter dependant, an then throw the 3rd a bit... What would be the issue here?

Thanks a lot for reading :)

WL
Click to expand...


Sometimes you have to do a lot of shooting to determine what the pattern is. You can even find out that there is no pattern.

If the first two are always close together and the third is always well out of the group it could be a barrel that walks as it heats. You could also have a rifle that wants to double group, or it could be that its a two inch rifle and those two close ones don't mean anything beyond random chance.

Anything you do is going to require more shooting. Five or six three shot groups starting from dead cold might enough to show you if its always going to print the first two together. A good reality check is to take all 5 or six of those targets, stack them and hold them up toward a light. You'll be able to see through the stack and have a real good idea of what a 15-18 shot group would have looked like. If that's a basically round 2" "composite group"(for instance) that's what you have. You can also find your "two and one group", several 2" equilateral triangles and more than a few in the cluster that touch or went in the same hole. They don't mean anything, but you can go crazy thinking that they are indicative of anything other than random chance. Another trap is that the center of this hypothetical group will almost certainly hold most of the bullet holes. Human nature being what it is, its tempting to want the dense center to be the "real group" and the widest spread shots to be fliers. That's not really how it works either. If you shot a whole box of shells at the same target the 2 widest shots define the group, and every other possible combination is going to look better. Plotted on a graph it would just be a bell curve.
 
The data in manuals reflects conditions on the day of the tests with the rifle/universal receiver only. Some of the manuals, Lee's for example, use data the publisher didn't collect. Lee doesn't do any testing of the loads in their manuals. It's all Hodgdon's data. Plus bullet and powder makers books only have data for their products. Then you get into powder lots being different, using a primer that isn't the same as the test primer, etc, etc.
Buy a Lyman manual. Lyman doesn't make bullets or powder, but they do do their own testing. Plus it has more loads using more powders and bullet weights than any bullet/powder makers book.
 
If you start low and work up and read your fired primers they will tell you a story about pressure.

pressuresigns_zps50637610.jpg


Below is a exaggerated example of case base expansion due to over pressure, measuring the base of the case is another method of checking for over pressure.

flow_zps2b838d87.gif


Another pressure sign you will see is the brass starting to flow into the ejector in the bolt face, which is pictured in the links below. Just remember each brand of primer and cartridge case will will have different pressure limits and are only visual signs and not direct pressure readings of actual pressure.

Primers and Pressure Analysis by James Calhoon
http://bulletin.accurateshooter.com/2012/03/primers-and-pressure-analysis-by-james-calhoon/

And primers can have an effect on chamber pressure.

3CCIBR4_zpsa43a3c3a.jpg


5Remington75_zps2b532d7c.jpg


Evaluating Pressure Signs in Reloaded Cartridge Brass
http://bulletin.accurateshooter.com/2011/04/evaluating-pressure-signs-in-reloaded-cartridge-brass/

TECH TIP: Check Your Cases for Signs of Over-Pressure
http://bulletin.accurateshooter.com/2008/08/tech-tip-check-your-cases-for-signs-of-over-pressure/
 
sunray said:
The data in manuals reflects conditions on the day of the tests with the rifle/universal receiver only. Some of the manuals, Lee's for example, use data the publisher didn't collect. Lee doesn't do any testing of the loads in their manuals. It's all Hodgdon's data. Plus bullet and powder makers books only have data for their products. Then you get into powder lots being different, using a primer that isn't the same as the test primer, etc, etc.
Buy a Lyman manual. Lyman doesn't make bullets or powder, but they do do their own testing. Plus it has more loads using more powders and bullet weights than any bullet/powder makers book.
Click to expand...


sunray, open mouth and insert foot, what is written across the top of the Hogdon's manual below?

For someone with 19,363 posting in this forum your postings are questionable and your information sadly inadequate. You need to read and learn more and post much less. I feel sorry for newcomers in this forum reading so much of your misinformation and looking for the correct answers. I have the Lyman manuals and it is just "ONE" manual I look at when comparing the load data to get an average. The firearm I'm shooting and working up loads in gives me the rest of the pressure information that actually needed.

One of the biggest reasons pressure data varies is because some of the data is taken from pressure test barrels using copper crushers or transducers. If a specific firearm is listed for the data a strain gauge was glued to the barrel and calibrated with a known pressure cartridge. The data varies because different test methods are used along with a variety of different firearms.

2014Annualmanual-LG_zps37c355d5.jpg


Hodgdon 2014 Annual Manual Now Available
http://bulletin.accurateshooter.com/2014/01/hodgdon-2014-annual-manual-now-available/
 
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Dogleg said:
Sometimes you have to do a lot of shooting to determine what the pattern is. You can even find out that there is no pattern.

If the first two are always close together and the third is always well out of the group it could be a barrel that walks as it heats. You could also have a rifle that wants to double group, or it could be that its a two inch rifle and those two close ones don't mean anything beyond random chance.

Anything you do is going to require more shooting. Five or six three shot groups starting from dead cold might enough to show you if its always going to print the first two together. A good reality check is to take all 5 or six of those targets, stack them and hold them up toward a light. You'll be able to see through the stack and have a real good idea of what a 15-18 shot group would have looked like. If that's a basically round 2" "composite group"(for instance) that's what you have. You can also find your "two and one group", several 2" equilateral triangles and more than a few in the cluster that touch or went in the same hole. They don't mean anything, but you can go crazy thinking that they are indicative of anything other than random chance. Another trap is that the center of this hypothetical group will almost certainly hold most of the bullet holes. Human nature being what it is, its tempting to want the dense center to be the "real group" and the widest spread shots to be fliers. That's not really how it works either. If you shot a whole box of shells at the same target the 2 widest shots define the group, and every other possible combination is going to look better. Plotted on a graph it would just be a bell curve.
Click to expand...

Yeah I see what you're saying Dogleg.
interesting, but too expensive for me to be shooting many more rounds, price of Woodleighs just isn't worth shooting at targets when they will do a great job on the game at intended ranges!


I can also see about wanting things to be what You want them to be, an going crazy etc.... when it could just be Chance that put em there.


I honestly need to smarten up my Act an invest in a decent shooting rest if im wanting to be 'precise' and eliminate these off shots.

Anyway thanks.

an cheers!

WL
 
grinder08 said:
Personally I try and stay in the middle ground given the variability of loading recommendations. Having said that remember modern guns are typically proof tested to 30% overload compared to the maximum regular load, so there is a margin for error. A lot less confident with older guns.
Click to expand...

They are proof tested to 300% pressures not 30% over load............I consistently run in the +30% margin and have never "cracked" an action, lost a lot of brass but never hurt a rifle.

Sunray..............go back to where ever you came from, your posts are a complete waste of time and effort.....JEEEEZZEEEE
 
CourtenayBoy said:
Every time I think I have some proper numbers for the few cartridges I reload for, I see different ones. Different min/max charge weights and COL. Different velocities for identical charge weights from the same manufacturer year over year in their different editions of their manuals. Never mind looking up powder manufacturers numbers to verify against manuals...........It seems I am to extrapolate some common ground between all sources and slowly work it up myself.

At times, being wet behind the ears still when it comes to reloading I just shake my head.
Click to expand...

Pick the bullet and the powder you want to use, then find a starting load that uses both and work up from there watching the primers and case head expansion for signs of pressure. If you can't find a starting load for your exact bullet, search the books for one of similar style and of the same weight and once again use the starting loads and work up. If you switch primers go back to the start load and work up. Switch cases...go back to the start load and work up. Don't worry about manual "X" not having the same start or max loads as manual "Y" they are both right for the particular gun or test barrel used to collect the published data, just find a suitable start load in any manual and work your way up slowly. Sometimes your max will be shy of the published data and sometimes it will be above it, simply because your chamber specs are not identical to the one used in testing. A good example is the info found in Hornady's publications for the .308 Win with their 180gr BTSP Interlock bullet and RL-15 powder...I'm almost 3 grains over their published max load and I still don't have sign of being over pressure. With Hodgdon's data for the 7mm-08 with Hornady 154gr SP Interlock and H414 powder I'm getting pressure signs at 0.4grs under the published max load. Each rifle load combo is a mystery of its own...the only set rule is to ALWAYS use a starting load and slowly work your way up till you get signs of pressure...then back off a little!
 
Dogleg said:
If money is tight, I'd use home-made sand-bags and spend the money on components instead. Time spent on position shooting will get you farther than all the sand in the Sahara.
Click to expand...

This evenings doings, with the son on hes 2nd hunt in the backpack. will do a story in the coming days.

IMG_0435sambarrrr.jpg~original

IMG_0444woodleighskin.jpg~original

IMG_0454woodleighOUT.jpg~original


Using the 55gr Varget and that is a 225gr RN Woodleigh. will try weigh it on the beam scale one day if it goes to atleast 220gr.

120m shot angling towardish, bullet would of went 30inch through her. She didn't appear hit an took off uphill for 50 meters before it all became too much, enough blood trail but nothing OT.


good times
WL
"faith in the Whelen"
 
WhelanLad

After looking at your "warm" Australian photos I would like to say we have over a foot of snow here and eight more inches are expected. :mad:

So I have one question..................

Do you dip your bullets in Vegemite to kill game quicker? :evil:

Here in the U.S. if you put the grain piles five feet apart the game is easier to hit and the range doesn't matter. Plus the blood trails are easy to track in the snow.

deer_zps7c735c90.jpg


On snowbound days like today I do a lot of dry firing and practice night shots with my Paul Hogan Magnum Roo light.

roo-2_zpsc8d78fee.jpg


roo-1_zpsf2fb0d0e.jpg


:cheers:
 
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