Win 748

Ammunition, reloading, shooting, etc
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Griff557
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Joined: Sat Jun 22, 2019 3:34 am

Win 748

Post by Griff557 »

I’ve had good luck loading IMR 4895 and 168gr FMJBT’s but I would like to try Win 748 and conserve my 4895. I haven’t seen any load data for the Krag and 748. I’ve seen load data for the 30-30 and Win 748 and I think I’ve read you can use 30-30 data as a starting point for the Krag?

FredC
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Location: Dewees Texas

Re: Win 748

Post by FredC »

I would hold off on that till you get some feedback. Some powders get erratic at too low a charge. Erratic can be bullets not leaving the barrel or detonation (both are dangerous). I like Varget because it is tolerant of wide pressure levels. Powders like Lilgun show the starting load and max load to be very close. That might be a clue with your Win748 look at the starting load and max load for several calibers to see how tolerant it is of low pressures.

FredC
Posts: 1991
Joined: Fri May 31, 2013 4:38 pm
Location: Dewees Texas

Re: Win 748

Post by FredC »

I did a quick glance at a Lymans #48 manual and it had 748 powder for every weight jacketed bullet for 308 Winchester. Starting loads for 308 Winchester were in the safe pressure range for 30/40. 308 and 30/40 cases are very similar in case capacity. That said it is SOMETHING TO STUDY till you get an answer. Please note FREDC did not say they were safe for you. I am not even sure if the 748 powder Lyman listed is W748. Also note that Lyman has listed charges some here felt were dangerous.

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butlersrangers
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Re: Win 748

Post by butlersrangers »

I have about 5 lbs of Winchester 748 powder left in an 8 lb. canister, that I bought 25 years ago.

I searched for loads to use in the .30-40 Krag. The only data, I found, that was close, was for the .303 British round.

I fired a bunch of reloads in many different Krag rifles and carbines using 40 grains of WW-748 powder, 168 grain Sierra Match Kings, 165 grain & 180 grain soft-nose projectiles, Winchester brass and Winchester LR/magnum primers. These reloads all performed very well.

I made reloads with 147 grain FMJ projectiles, 42 grains of WW-748 powder, and Winchester LR/magnum primers, and these loads performed OK.

Last year, I loaded a few rounds with 150 grain M-2 projectiles, 40 grains of WW-748 powder (which smelled acrid), and RWS standard rifle primers (of unknown age). The first round fired normally, but, the ejected cartridge case was smokey and wet. The second round was a quiet "squib", that pushed the bullet a few inches up the barrel and failed to ignite the powder.

My first belief was that my WW-748 powder had deteriorated and chemically broke down.
A week later, I had a similar thing happen in a .30-06, with a cast-bullet load, using using #2400 powder, and the RWS primers.

Now my main suspect is the RWS primers, (which I have relegated to Gallery Practice loads, using a .310 Lead round-ball and a few grains of Bulls-Eye).

I have not gotten back to testing my WW-748 powder. There are far better and more versatile powders for the .30-40.
WW-748 appears to require Full Power Loads developing adequate pressure and Magnum Primers for proper ignition.
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Griff557
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Re: Win 748

Post by Griff557 »

Interesting replies-thanks. I bought the W748 with loading for my AR in mind. I noticed there were quite a few published loads for the 30-30 and it got me thinking about loading for the 30-40. I probably only shoot a hundred rounds or so a year out of the Krag so it’s not a huge deal. I was just thinking if it was safe and do-able why not but if it’s on the edge or not safe it’s not worth experimenting with

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butlersrangers
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Re: Win 748

Post by butlersrangers »

I bought the 8 lb. canister of W-748 because it was cheap and I was expecting to reload lots of .308 and .223 ammo. That did not come to pass.

Like yourself, I thought it would be useful for the Krag. Plus, it is easy to meter, and 'cool burning'.

I think it useful in the Krag, with 150 grain to 180 grain bullets, Magnum rated Primers, and charges worked up from 40 to 41 grains. (150 grain projectiles should be OK with a 42 grain charge).

Parashooter provided these useful estimates, years ago, when I asked a question, similar to yours. (Note it is based on 170 grain projectile).
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FredC
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Location: Dewees Texas

Re: Win 748

Post by FredC »

I remember that chart from Parashooter, forgot that 748 was being discussed. I went to the garage and brought back 2 loading manuals. The #48 Lymans and #12 Speer. Both have starting loads for 308. The Lymans uses 40 grains for the 168 grain hollow point boat tail. Pressure in the 308 was 32,800CUP Parashooter's Quickload will be PSI which is a completely different animal with no set formula for comparing one to the other. The Lyman velocity with a 24 inch barrel was 2371. So the starting load for the 308 and max load for the 30/40 look real close and agree with Parashhoter's Quickload.

Parashhooter's note that magnum primers might give better consistency was applied in the Speer manual, they used a magnum primer with every load using 748 powder. They used a starting load of 42 grains for the 308 (168 BTHP) but pressures are not mentioned in this manual, so 42 grains with a magnum primer could be too hot for a 30/40. Interestingly their velocity was 2448FPS. barrels are like that one will be different than another on velocity and pressure. Looked up the rifle used by Speer and it was a Remington bolt action with 22 inch barrel so no pressure readings.

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Parashooter
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Re: Win 748

Post by Parashooter »

Looks like we discussed this again fairly recently. Remember this one? viewtopic.php?f=5&t=5618&p=36640&hilit=748#top
I have experienced similar failures to fully ignite when working up loads with dense spherical powders in medium military rifle cartridges. In every instance this was a result of charges insufficient to develop enough pressure/heat to light up the entire charge. The cure was simple: shovel in enough powder to get up to normal working pressure.

Powders like WW748 achieve progressive burning by virtue of fairly heavy deterrent coatings on the outside of the granules. Without sufficient heat, the deterrent doesn't burn off effectively and allow the underlying nitrocellulose propellant to ignite.

Running your load through QuickLOAD simulation, it looks like the 40-grain charge is generating only about 70% of normal pressure - 32723 psi vs the 47137 psi maximum (PMax) for the .30/40 by CIP piezo standards. Increase the charge by several grains and you may find better results (and avoid discarding potentially usable powder). Here's the estimate (NOT tested load data!).

Cartridge : .30-40 Krag
Bullet : .308, 150, Sierra SP 2130
Cartridge O.A.L. L6: 3.089 inch or 78.46 mm
Barrel Length : 30.0 inch or 762.0 mm
Powder : Winchester 748

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.163% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill Charge Vel. Energy Pmax Pmuz Burnt Barrel-time
%-- %-- Grains fps - ft.lbs -- psi -- psi -- % -- ms
-11.6 73 38.00 2472 2035 28692 5162 95.2 1.681
-10.5 74 38.50 2501 2083 29653 5232 95.6 1.659
-09.3 75 39.00 2530 2132 30645 5299 96.1 1.636
-08.1 76 39.50 2560 2182 31671 5365 96.5 1.614
-07.0 77 40.00 2589 2232 32732 5429 96.9 1.593 [Your charge]
-05.8 78 40.50 2618 2282 33827 5490 97.3 1.571
-04.7 79 41.00 2647 2333 34960 5549 97.7 1.550
-03.5 80 41.50 2676 2384 36131 5606 98.0 1.530
-02.3 81 42.00 2704 2436 37341 5661 98.3 1.508
-01.2 82 42.50 2733 2488 38592 5713 98.6 1.486
+00.0 83 43.00 2762 2540 39887 5763 98.8 1.465
+01.2 83 43.50 2790 2593 41225 5811 99.0 1.444 ! Near Maximum !
+02.3 84 44.00 2818 2645 42611 5855 99.3 1.424 ! Near Maximum !
+03.5 85 44.50 2846 2698 44038 5898 99.4 1.404 ! Near Maximum !
+04.7 86 45.00 2874 2752 45526 5937 99.6 1.384 ! Near Maximum !
+05.8 87 45.50 2902 2805 47060 5974 99.7 1.365 ! Maximum !

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butlersrangers
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Re: Win 748

Post by butlersrangers »

Parashooter - Thanks for the projected data with a 150 grain projectile. It looks like 42 1/2 grains could be a safe point to start with W-748 and a 150 grain projectile.

I did not forget your past input. 'Griff557' asked the same question I did, years ago.

I thought it useful, given the current powder situation, to bring up past discussions of W-748.

(I believe old compromised RWS primers were the main factor in my ignition mishap, last year).

IMHO - W-748 has potential application in the .30-40 cartridge: with near full charges (that keep things in the Krag's pressure range), Magnum Primers, and bullets ranging from 147 grains to 180 grains.

All things being equal, I would prefer IMR-3031 and IMR-4895 for loads using bullets in the 147 to 180 grain weight range.

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