300WSM Quikload clarification needed

[sithlord6512]

Hi There,
Just planning to test loads for my new dream gun (Sako 85 .300WSM). I plan on using 180 TTSXs. I have Quickload numbers, but unfortunately, in "cutting" and "pasting" to a word document, I've obviously made errors - I have two loads for the same powder/bullet combo which has me worried that NEITHER ARE CORRECT. Here is what I have

H4350+180 TTSX
max load = 63.00, max velocitiy=2968 fps (the last "near maximum" load).
max load = 61.74, max velocity= 2942 Fps (the last "near maxium" load).

If someone could verify which, if any, of the above is correct, It would be much appreciated.

Thanks

 

[DrMike]

Cartridge : .300 WSM (CIP)
Bullet : .308, 180, Barnes 'TTSX'BT 30879
Useable Case Capaci: 68.013 grain H2O = 4.416 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H4350

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 82 50.00 2358 2222 33777 7957 91.6 1.517
-18.0 84 51.25 2412 2326 35935 8191 92.7 1.480
-16.0 86 52.50 2467 2433 38217 8419 93.7 1.444
-14.0 88 53.75 2522 2542 40619 8638 94.6 1.409
-12.0 90 55.00 2576 2653 43155 8849 95.5 1.374
-10.0 92 56.25 2631 2767 45849 9050 96.3 1.338
-08.0 94 57.50 2685 2882 48713 9241 97.0 1.300
-06.0 96 58.75 2740 3000 51759 9421 97.6 1.265
-04.0 98 60.00 2794 3119 54998 9589 98.2 1.230 ! Near Maximum !
-02.0 100 61.25 2847 3241 58446 9744 98.7 1.196 ! Near Maximum !
+00.0 102 62.50 2901 3364 62118 9887 99.1 1.164 ! Near Maximum !
+02.0 104 63.75 2955 3489 66032 10016 99.4 1.133 !DANGEROUS LOAD-DO NOT USE!
+04.0 106 65.00 3008 3616 70207 10130 99.7 1.103 !DANGEROUS LOAD-DO NOT USE!
+06.0 108 66.25 3060 3744 74665 10229 99.9 1.074 !DANGEROUS LOAD-DO NOT USE!
+08.0 110 67.50 3113 3873 79429 10313 100.0 1.046 !DANGEROUS LOAD-DO NOT USE!
+10.0 112 68.75 3165 4004 84528 10380 100.0 1.018 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 102 62.50 3013 3628 72724 9601 100.0 1.089 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 102 62.50 2746 3015 51696 9735 94.5 1.262

QuickLoad projects that 63.0 grains may generate excessive pressure due to lot-to-lot variation. In this event, the first safe projection is 61.74 grains. This is where you got the numbers. However, 62.5 grains, even allowing for lot-to-lot variations in burn rates, should give you a safe load. This presents the opportunity to remind everyone to work up from a safe minimum regardless of the accuracy of the data--we can't predict what a new lot of components will yield.

 

[Guest]

I can't speak directly to the TTSX, but for a 180gr X-Bullet (no grooves), the Barnes #3 on my shelf lists a max charge of 65gr of H4350 (2947fps) in 300WSM. Several other manuals (Hornady, Lee, Hodgdon, and others) show similar max charges (in the 64-65gr range) with 180gr bullets, as well. All are showing velocities in the middle 2900fps range. I'd be comfortable working up over a chronograph to the low- to mid-2900fps range with H4350 based on what I know. Start low, for sure, and be careful. If you don't have a chronograph, I'd talk to Barnes and get their recommendation. They've sent me data on several cartridges in the past when I've emailed or called them.

The info Dr. Mike has posted is also a great guide. I'm a little surprised that QL is below literally every manual on my shelf, though, by a grain or two. Hmmm...

 

[DrMike]

FWIW, I have phoned techs at Barnes on at least one occasion to ask them to verify that they pressure tested their loads; they appeared wildly excessive to me. The tech I spoke with registered genuine irritation that I would even question the data provided; however, the velocities on several rifles and with somewhat faster powders appeared hot to me. To be certain, in some specific instances, I've never been able to come close to their charges as the cartridge generates such high pressures. Again, it is why we work up from a safe minimum and the various manuals counsel precisely such caution.

 

[Guest]

Doc, I've seen that to some degree as well, but in this case I get agreement across so many manuals (at least 4 current on my shelf) on the 64-65gr charge I can't help but believe that it's safe in some rifles. You are correct with regard to working up from a safe minimum, for certain. Safety first!

 

[sithlord6512]

Thanks guys.

While I am interested in the max charge/load, I'm actually more interested in the max velocity projections. My own little rule when following Quickload data is to "stop" when my velocity matches the Quickload velocity projections (provided no other pressure indicators are encountered first). I've read somewhere -something from John Barsness, I believe - that chambers in factory rifles, and even in custom barrels, are generally "looser" than the test barrels used in generating load data . This means that max charges in factory rifles often do not reach the same velocity (and hence, pressures) of test barrels. Therefore, as long as my velocities don't exceed Quickload projections, I am assuming I am safe (that said, I never exceed charge recommendations either - my goal is safety, accuracy, velocity in that order).

 

[Guest]

You've got the right goals - in the right order. Keep us posted on your results!

 

[DrMike]

You've got the right goals - in the right order. Keep us posted on your results!

+1

dubyam,

Your observation concerning the manuals is accurate. Two points to bear in mind. The data generated by QL is for CIP standards, which are a couple of thousand psi less than those for SAAMI for this particular cartridge. I don't know the reason for this, as it appears to be an exception in the data field. Adjusting for this difference, you get a marginally increased velocity. The other aspect I would invoke is that when Harmut Broemel was generating his burn rates, the Hodgdon powder was a faster lot. Consequently, I look for accuracy, ensuring that my load is safe. The bottom line for me is that a 180 grain bullet (construction is not an issue) at velocities between 2850 and 2950 delivers a death blow whenever I do my part and put it where it belongs on an animal. I don't believe any of my 300WSM loads are at max, because I obtain the best accuracy a grain or so below maximum calculated charge.

 

[SJB358]

QL is a great tool to the reloader as it allows you to work with the powders/bullets to an extent, but so many variables change you still have to be diligent as a loader. Case capacity seems like the biggest offender. Especially after it is fired in your chamber. It usually changes data pretty decently.