Trust Your Nose!

[butlersrangers]

Well, today was a lovely afternoon for a Range Session .... and a day for continuing education.

I had some various loads I wanted to try in a new 'project' Krag. This morning, I also loaded up 10 'bonus' rounds using M-2 Ball projectiles, I got yesterday.

I wanted to devise an 'economy load', using 40 grains of W-W 748 propellant and inexpensive jacketed bullets.

(I have 5 pounds left, from an 8 pound canister of 748, bought cheap about 25 years ago.
I have tried to find applications for this not so versatile powder and have been using it as recently as a month ago).

When I opened the canister today, the 748 smelled a bit more pungent than I recalled. I figured it was my imagination, shrugged my shoulders and promptly loaded ten rounds.
(You can probably see where this is going).

At the Range, after setting-up, I started shooting with the M-2 reloads. The first shot seemed normal and the projectile hit the target 2 inches to the right of point of aim.
When I ejected the case and inspected the brass, it felt 'wet' and was 'sooty'.
The next round I attempted to fire was a 'Squib' and I didn't even hear the primer detonate. I waited 25-30 seconds before opening the bolt and even speculated the 'firing-pin' had broke.

When I opened the bolt, I was amazed to see a cartridge-case without a projectile! I glanced at the shooting bench to verify the case from my first round was on the bench-top and I had not loaded an empty.

I carefully examined the case of the 'Squib' round.
It had received a healthy primer strike.
At the case-mouth, there was a column of damp congealed propellant.
My shooting session was over for the day; I had a bullet lodged in the bore and no adequate equipment with me for its removal.

When I got home, the bullet was quickly driven rearward from the barrel, using an iron rod and copper mallet. A quick clean removed the powder residue from action and barrel.

I now have five pounds of fertilizer or bonfire starter, that kind of smells like vinegar. (I don't know how old that W-W 748 was, when I bought it, long ago). I don't have to worry myself anymore trying to find data using W-W 748.

Fortunately, I only have eight rounds to 'break-down' and salvage. I learned, today, not to doubt my nose and never to use powder that smells like Sauerkraut!

p.s. - I'm adding a pound of IMR-3031 and a pound of IMR-4895 to my Christmas List.

[Kerz]

Thanks BR for the report. Interesting for sure. It's a new one to me. So the powder was dry (obviously) when you loaded the cartridges and changed after a primer ignition. What did the powder from the other disassembled rounds look like?
Vic

[butlersrangers]

The canister of W-W 748 has been stored in a cool, dry, dark basement, since purchased. The powder is dry and appears normal, except for a more pronounced vinegar like odor.

The first round fired normally with no residue left in the case. The 'fired' case 'felt damp' to my fingers and was sooty & stained on outside of neck.

The second round appeared to misfire. (I did not hear the primer detonate, just mechanical noise of mechanism). The bullet was moved up the barrel, almost to the rear-sight.
The powder granules appeared unburned; some of the powder stuck together in 'damp' clumps. The powder remained in the case, a column of sticky grains projecting from the case-mouth.
The powder smelled very acrid.

The brass cartridge-case was new. I don't believe there was any moisture or oil contamination. The RWS primers have been problem-free in reloads over the past couple of years. None of the components appeared suspect, except the powder smell, that I brushed aside. Everything was freshly assembled.

I have never had this happen before.

I believe the primer must have fired, initiated a bit of a chemical reaction in the (deteriorating) powder, and enough pressure was present to move the bullet a few inches into the barrel.

[Parashooter]

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 !

[butlersrangers]

Thanks 'Parashooter' for your input and experience.

I guess, I will load-up a few test rounds of .30-06 or .308, using standard data for W-W 748, before tossing 4 to 5 pounds of powder.

I have never experienced this problem of powder failing to ignite, before.

The pronounced acrid smell of the powder got my attention and suspicions!

[butlersrangers]

Maybe the problem was a bad primer?

I went to the Range on Monday and had a 'squib' round with a 155 grain cast bullet load with Hogdon #2400 powder.
(19 other cast loads with the same components fired normally with decent accuracy).

Like the squib with WW-748, I noticed the mechanical noise of the 'striker' more than any primer detonation.
Both of my squib rounds involved an RWS primer (different boxes from same lot).
Two entirely different powders were involved.

The fast #2400 powder appeared consumed, but, left a heavy soot inside the case.
No significant pressure was produced and the lead alloy projectile lodged in the bore. It was easily cleared, to the rear, with a cleaning rod.

The RWS primers are 47 years old. They were given to me about 12 years ago. I don't know their storage history?

I'm going to relegate the old RWS primers to cast bullet practice loads and 'trash' them, if there are continued failures.

[FredC]

Two things before you discard the primers. Were they pushed all the way "home" with the proper shaped punch. I think some of the older primers had a rounded dome shape and should have been pushed with a matching shaped punch. Seems like all the ones i have used lately have a large flat area to push from. When using the reduced loads with Unique and 2400 I never used any filler to keep the powder near the primer. But when target shooting I would point the rifle up before aiming to make sure the powder was near the primer. Hard to remember when in hunting situations where a follow up shot is needed, but I never had a misfire in those situations, so it may not have been important. I never tried pointing the rifle down before aiming to see if that was even a thing to be concerned with. Maybe someone that has can enlighten me.

[butlersrangers]

The suspect primers were fully seated with a Lee 'hand primer-seating tool'.
(As a check, I automatically run my index finger across the base of the case, as the case is removed from the tool).

I have only ever had two 'squibs', from rounds, that I reloaded.
They have occurred in the past few weeks and involved RWS primers from the same 1973 lot.
(Until the failures, these primers had performed normally in scores of reloaded rounds).

The only other common factors in the misfires are the same Winchester brass and the same Krag rifle.
(The brass and rifle give no suspicions of being the problem).

The two 'failures to fire properly' did not make a discharge noise or normal primer noise.

There was atypical ignition of the #2400 powder and little ignition of the #748 powder.
Lots of soot was produced.

With both 'failures', the projectile exited the case and moved a few inches into the barrel.

[donki1967]

Sir,
Keep the old RWS primers as part of your collection!
Don't use them

[butlersrangers]

"Donki1967" - I'm going to take your advice.

It is False Economy to risk making unreliable ammo and push my Luck!

I fortunately have plenty of good primers.