It's pretty durn hot here, so this afternoon instead of a siesta I loaded up a batch of various loads in 308 Win using IMR 3031.

Sierra 110 grain hollow point 43 to 45.5 grains
Remington 150 SP (thurty-thurty) flat based 40 to 44 grains
Remington 165 PSP core-loks flat based 39 to 41.5 grains (my favorite bullet weight for the 308 Win)
Hornady 180 SPBT interlocks 37 to 41 grains, and

190 grain Carroll hard-cast .309 , yet to be determined load.

With a barrel of 600 mm I'm hoping to see some good results for the 110 Speer @  about 45 grains, the Rem 150 @ 43 grains, the Rem 165 @ 41 grains, and the Hornady 180 @ 40.5 grains.  One barrel is a new Israeli replacement on a 1940 k98 action w/ 1 in 12 twist; best guesstimate w/ rod and patch.  


The other  has a slightly shorter barrel and more wear, and I'll probably keep in it reserve for the hard-cast work up.  Took off about a 1-1/2 inches of the barrel to remove a bulge in the muzzle, but the stock is classic; arsernal repair at the cross bolt and three brass pins through it; I wish it could tell stories.



Speaking of hot, I plan to shoot the 3031 loads in the most moderate temperatures I can, which may challenging right now.  I'm no expert on IMR powders, but I don't recall them being particularly resistive to excessive temperatures.

Nels

Nels,
 
I'm looking forward to hearing how those charges shoot.
 
I've been hearing a lot about "temperature sensitivity" for the past few years. While it 'makes sense' (we are after all, talkng about a chemical reaction), I have not seen the "sensitivity" of the old powders, that the gunwriters (ptooey) and powder manufacturers report. In my opinion, until the temperature changes are extreme - say greater than 50 degrees F - the differences between the new "temperature insensitive" powders, and the old "temperature sensitive" powders, is more a matter of marketing/sales hype than practical reality.
 
I will acknowledge however that I have seen pressure/velocity differences when shooting at zero degrees F as opposed to 60 degrees F. I will also add though, that I saw essentially the same differences with "new" powders as I did with "old" powders.
 
Please let us know how those I3031 loads shoot.
 
Paul

Result summary of some 308 Win 3031 loads.
Temps: low 80's
Elevation: 5930 ft.
Winds: calm
Range: 100yds
Rifle: k98 in 7.62, 600mm barrel length, iron sights, shooting on sandbag rest

110g Speer hollow points: best accuracy 45.5g out of 43/44/44.5/45.0/45.5
150g Rem SPFB: best accuracy 43.5-44.0g out of 40/41/42/43/43.5/44.0
165g Rem SPFB: best accuracy 41.5g out of 39/40/40.5/41.0/41.5
180g Hornady SPBT best accuracy 40.5g out of 37/38/39/40.0/40.5/41.0

The toughest part of testing these rounds was the shooter.  Those original mauser sights are starting to give me bigtime eyestrain.  Although I struggled with them all morning, I took my time and don't believe it factored very much into the results.

None of the rounds exhibited over-pressure by examination of the cartridges and primers, although the 41.0 g load with the 180 bullets gave noticeably greater felt recoil.  As I shot starting with the 110's and finished with the 180's, the POI rose a few inches vertically from the POA.  Maybe this is partly from barrel heat up but I believe bullet weight and recoil is the major factor for that observation.  All bullets cut the paper crisply, no flyers or instability evident.

The big surprise for me was the results for the 180 hornady.  40.5g of 3031 was clover leaf accurate.  I've never really found a super-accurate load for the 180 bullet in this cartridge yet, but man this is it!

The 110 Speers at 45.5 grains flew impressively fast, flat and accurate for a blunt bullet that one has to seat rather short in the cartridge neck and jump to the lands.  Mild recoil.  2nd best accuracy for the day's results next to the Hornady 180s.

The Rem 150's and 165's seem to shoot fairly well irregardless of load.  I shoot two or three rounds of light loads before shooting groups of three in the load areas of interest.  Interesting observation for the 165 Rem was the 39g and 40g load went almost through the same hole.  (Maybe another barrel node at that lower speed?)  Anyway the 150's Rem in my rifle have a big sweet spot between 43.5 to 44.0 grains that I'd have to go back and optimize further. This load for the 150 is the only one I had that approaches being considered "compressed".   The 165 Rem results were ho-hum but showed a general preference for a tighter grouping at 41.5 g.  

I don't have a good way of judging "efficiency" or how well the 3031 burns within the barrel, but after I finished with the 3031 rounds I shot a number of cast bullet rounds from another rifle with Accurate 5744.  Now I'm usually pretty good about not blinking on squeezing the trigger so I usually see the shock wave/vapor flash at the muzzle. (also part of my problem of being far-sighted)  When I switched from 3031 to 5744 the difference at the muzzle was like I had gone to shooting black powder.  The 5744 definitely had a lot more smoke and stink, but of course the cast bullet w/ partially filled cases is a whole different game.  What I'm saying here is I think the 3031 burns pretty clean without a whole lot of flash outside the barrel based on what I can observe.

Out of this, I think I found a pretty good load for the 180 Hornady and 110 Speers.  For the 150's and 165's I'll probably stick with the 'ol standby 4064 and Varget.

Now if I could just get a chrony........

Nels

Y'know Nels, if you keep producing work like this, I'm may just break down and buy you a chrongraph myself. :)
 
I'm crunching your numbers, and we'll see what I can get QL to spit out.
 
Really good data.
 
Paul

Quote from: gitanoY'know Nels, if you keep producing work like this, I'm may just break down and buy you a chrongraph myself. :)
 
I'm crunching your numbers, and we'll see what I can get QL to spit out.
 
Really good data.
 
Paul

Hello Nels.....Paul is right on....without a chroney, in my view, your numbers just don't mean much. Speed/mass kills. Spend the 100 bucks and then have some fun.:D  Regards, Rick.

For me, it is accuracy uber alles!
 
Speed and mass have no value if I can't put it where I want it.
 
Let me explain a bit more on the 3031 "test rounds".
 
I put to the test four bullets and a variety of loads using less than 50 rounds in about 2 1/2 hours at a public range.  Came away with two excellent loads and a couple of more that need further investigating, if I so choose.  I'm pretty happy with that despite no chrony.  The key for me is in calculating and planning the loads prior to trigger time.
 
I studied Paul's QL charts on the 308 Win and the optimum barrel times. (my 600mm barrel falls between 23 & 24 inches).  I cross-examined the 308 Win load tables w/3031 in two published load manuals, plus Ken Water's pet loads, plus IMR's web page load chart for 3031.  I selected my loads of interest where I estimated the velocities would best match the optimum barrel residence time in the higher, but acceptable pressure range.  For each of the "main" loads of interest  I loaded 3 rounds.
 
Now for the two "good" loads I discovered in 110 Speer @ 45.5g and the 180 Hornady@ 40.5g; they are both in the upper end of the pressure spectrum and they are plenty "fast" for me.  I'd be tempted to go again with these two and load up and down each side of the loads respectively plus or minus a tenth or two tenths grains for optimum grouping at 100 and 200 yds, but again, it would be for accuracy, not speed.  And maybe 5 rounds each for a wee better confidence.  And remember to take my camera too.
 
Now I could see the argument for speed (and a chrony) if a barrel had more than one "sweet spot" or nodes and I want to make sure I'm on the faster one.  Or I want to confirm my load predicted velocity correlates to actual velocity, which is alway reassurring.  For safety's sake I've had pretty good luck using case head expansion for monitoring pressure and following safe load practices.
 
I did wonder a bit about pushing those 110 Speers over 3,000 fps with those open lead hollow point blunt tips, but they cut the paper square and clean as any other bullet.  Impressive little bullet.
 
Yep, I'll eventually get a chrony; but I don't feel handicapped without it.  It's the terminal end that counts.
 
Nels

You won't find any argument from me with respect to your logic Nels. Accuracy (precision, more often than not) is what I, and most hunters I know, are focused on. But there are a couple of assumptions required if you don't have a chronograph, and I have found those assumptions to be false, or at least very weak, more often than not.
 
The first assumption is that the velocity values found in reloading manuals are correct.... or even close. I've been reloading for almost 40 years, and I can remember only very rare occassions - like two or three times out of hundreds - when the published velocity figures were even within 100 f/s of the measured values. And that goes directly to accuracy (in this case NOT precision). If you don't know your muzzle velocity, you can only determine trajectory through trial-and-error. Trial-and-error is not only "fine", it "works" for most folks. However, in the end, no matter what the MV is, the published ballistic coefficient(s) are equally suspect, and it is necessary and appropriate to actually field-test (trial-and-error) POI for any ranges one intends to use. With a chronograph, theat trial-and-error is significantly reduced.
 
The second assumption is that the charges, and their attendant MVs and chamber pressures are "safe"... in common parlance, "The loads aren't too hot." Since intil recently, pressure sensors were not available to The Common Man, "safe" pressures were inferred from velocities. Again, not what I have found to be true. Pressure is a very fickle mistress, and pressure is what "makes" velocity, and velocity is inextricably tied to accuracy. Not for 'hard hitting', but for estimating trajectory as closely as possible.
 
So... just as you used the QL numbers, Pet Loads, and reloading manuals to get at a place to start your trial and error, adding a chronograph to your 'tool box' will greatly illuminate your work-ups. More importantly though, reducing the amount of trial-and-error necessary to get in the vicinity of a "sweet spot" (of any kind), is where it will help most.
 
Terminal performance, other than accuracy, is essentially immutable. The bullet has a fixed mass, and the the accuracy-load one settles on will have an average velocity. The terminal characteristics determined by those two elements will fix the delivered energy. There's no "tweaking" that. In fact, trying to get the most energy (via max velocities) from a given bullet is likely what confounded my attempts to find accuracy-loads for a variety of powders, such as I3031. The potential problems of best accuracy near max loads is clearly explained in Optimal CHarge Weight theory.
 
All that said, especially with my obsession for accuracy and precision, I'd still feel significantly disadvantaged without the availability of a chronograph for accuracy-load work-up.
 
Please keep us posted on your excellent load work-up work. It substantially increases the database for fine tuning OBT and OCW.
 
Paul

"You won't find any argument from me with respect to your logic Nels. Accuracy (precision, more often than not) is what I, and most hunters I know, are focused on. But there are a couple of assumptions required if you don't have a chronograph, and I have found those assumptions to be false, or at least very weak, more often than not."
 
Paul is 100% correct and I have had the exact same experience. The chronograph is essential for getting the most out of a rifle.....accuracy and speed. Why would you settle for 2750 when you can get 2950 with the same size groups? Then of course, you have to pick the right bullet. I have been searching for the perfect bullet for 44 years and have not found it yet! I keep going back to the Noslers as all the others I've tried just don't measure up. This year I am going to experiment with the Swift Scirocco. Berger, Barnes and Hornady have left me frustrated. The good old Sierra Game Kings and Pro Hunters are my second choice. Regards, Rick.

Paul,
 
I've been playing with QL and Pressure Trace for several rifles and different bullets that I want to optimize. I'm working on my .375 H&H now but also will do the .300 Wby Mag, 30-06, .220 Howell, 7MM Rem Mag, 7mm-08 and .223. What I would like is an email copy of your Excel spreadsheet you used at the start of this thread to rate the different powders. I tried plugging in the formulations provided but there are a couple of items that don't show on the graphs here (G3 looks like bullet weight, G4 appears to be Saami max pressure). "OBT Tool" has me a little baffled (it may be referencing the OBT barrel length chart) as does O36 and J37. Any help is greatly appreciated. Thanks!

Az Speed,
 
Welcome to THL. I'm going to be very interested in seeing your field results using QL, Pressure Trace and Optimal Barrel Timing. I haven't been able to put together a successful range session this summer.
 
The spreadsheet data presented in this thread were my prelimnary efforts at working out an objective method for ranking powders. Improvements can be seen in general in this thread:
http://www.thehunterslife.com/forums/showthread.php?t=6504
 
I'll send you the most recent spreadsheets and then if there is any uncertainty, we can discuss the spreadsheets "offline" or by phone.
 
You have mail, :)
 
Paul