wc 872

[Turk]

Gentlemen, I have a perplexing delema. After loading hundreds of 45/70 loads with 405 .458 ww bullets and 3gr. 4198 - 46 to 50 grs. WC 872, no crimp,no wad,fed 215 primers, .456 expander,oal just touching lands. Velocity in the 1200 to 1300 range,good accuracy,no problems. Wednesday I was going to test two different bullets,two different lubes and .458 and .460 bullets. Fresh loads were made and headed for the range,set up the chrono and started shooting. To my suprise these loads were going 1550 to 1600 fps!! Loads were pulled and the powder amount was ok. I,m at a loss to the reason for this increase in velocity, Any help would be appreciated---Turk

[Buckshot]

..............Turk, I see this is your 2nd post so allow me to welcome you to the board. If you're duplexing you must have been around the game awile. Don't tell anyone your'e doing that. They'll think you're nuts :-).

So did these loads FEEL like they were doing 1600 fps?

There are all the other things to ask, like powder lot, primer change, are you SURE the charges were the same, and then a tempurature difference issue. There is NO reason for powder out of the same cans as loaded before to jump 300 fps.

.................Buckshot

[44man]

Sounds like the larger boolits are allowing the powder to burn better with the little more bore resistance.

[Turk]

Buckshot, Have been around awhile,I,m 70 been reloading since about 1958. I got the duplexing surplus powders idea from you,and the old shooters forum. Yes the loads felt like they were hot. Other loads that day chrono'd ok so its not the chrono. Both the .458 &.460 loads were hot. I pour the powder out of the big jugs into 1 lb. jugs to work with,the last loads out of that smaller jug were ok,then I loaded these loads that were hot,same jug, same loads,but hot. When the powder got low in the small jug I refilled it from the large one and loaded some with 3- 4198/ 50 wc872 same bullets,primer etc. Those loads were 1250 fps like normal WC 872 lot #47845 storage temp between 55-75 degrees powder from bartlett. How could this powder have changed? I went though 32lb.s of it no problems till now. Your right people think your nuts to duplex smokeless.-----Turk

[45 2.1]

Since your using a slow powder and duplexing it to get it to burn mostly right, anything you do, like increase engraving resistance with a bigger boolit, or when a change in temperature occurs will change the burn rate of the powder. It looks like you need to increase the duplex charge slowly until this sort of thing stops, at least what your firearm is rated for since you haven't said what your shooting it in. There are more variables there than you realize.

[StarMetal]

Turk,

Welcome to the board. Hey...maybe when the powder got low in that jug it was exposed to more airspace and it became drier or more moist. You know how an internal combustion engine, like a gasoline one, burns the fuel mixture better when there's more moisture in the air intake. Don't know if powder burnts more efficient when it's drier or more moist. Felix might be able to jump and answer this one. At any rate think about it, you've been working out of that one jug and it's been opened and closed more often then the fresh just your topped it off with. That exposure has to do something over time. Have you noticed over time that you have to adjust your powder measure? Do you weigh your charges? Have you seen a change in the weight of the powder? This would be from the drying out or gaining moisture I'm talking about.

Joe

[Turk]

Star metal, I use a Harrel measure I did notice when I weighed the powder my setting for 50 grs was 82, had to go to 83.5 to get 50 grs, but the refill powder was the same needed 83.5 to get 50

[Bass Ackward]

Yep. Strange.

I go along with the group to increase the 4198 to about 5 grains and then I would change to a standard primer. No need for a blow torch to ignite 4198 and let it do the work for you instead of the primer.

[felix]

Joe, in general and depending on deterrents used, water vapor will not affect powders with nitroglycerin above a certain amount, say 5 percent anyway. But, like in engines, water vapor tends to cool the "spark" strike/spike. This implies ignition will be smoothed out, and will allow for more "compression", either statically or dynamically. In other words, cooler the operation, the heavier the load can be without ping or flattened primers. Single base powders by their nature have less protection against any kind of moisture, meaning more ignition problems can be expected. ... felix

[Turk]

I have in the past ran though all the primers and went from 3grs 4198 to 5.5 4198 in 1/2 grain steps varying the powder charge from 45 to 55 grains. The differences in velocity were only about 100 fps. This load has been well worked out,tests were made on expander size,crimp or no crimp,wad or no wad,different wads,bullet alloy 20/1 ,ww, 6-2, 6-4, lube,seating depth,bullet touching or jumping to the lead, .457,.458,459 .460 diameter thousand of rounds tested without any unexpected results. The load I was using was the best of the lot,very stable around 30-40 fps deviation. These were fresh loaded so there should not have been any bullet to case bonding,cases are allways neck brushed to have consistent bullet pull. Somehow it seems the powder in the small jug I pour the powder into out of the larger one to use at the bench changed it's burning rate to more like wc852. Loads out of that same jug two months before were ok. Then this last bunch of 120 were hot by 300-400 fps,then I refilled the bench jug with the same lot loaded 50 more and they were ok,1250 fps. beats me whats going on--Turk

[StarMetal]

Ok....you fellows are saying "jug". Now that makes me think plastic like Hodgdon packages in. Am I correct? I wonder if there is a reaction of the powder that is next to the surface of the plastic walls? Remember that thing someone said about you should rotate you cans or jugs of powder every once in awhile to mix up the powder inside so the same powder doesn't stay alongside the walls of the container too long? I believe the best containers for keeping powder in are the metal cans like IMR comes in. I never liked the cardboard ones like Alliant use to package in and plastic, which is the rage today, gives me visions of moisture. Maybe the powder manufactures think we are going to use this stuff so fast that it's not going to be in the container for long.

Joe

[Dale53]

I am going to risk being an alarmist here. I believe what really happened, given the evidence here is that somehow powder was returned to the wrong "jug". It is VERY easy to unconsiously do this. Do not be so sure that it has not happened. That is just about the only thing I could think of that would so seriously raise the pressure and velocity.

Maybe you ought to think about discarding the questionable powder. Sure it will cost you a couple of bucks. What is your rifle and eyesight worth??

Dale53

[Char-Gar]

Turk...Looking back at your original post, you were using a 405 grains bullets for you base line load. Then you said you wanted to use "two different bullets", but I don't see what the weight of these were. There may be a clue to the increase in velocity here..

You have had the opinions of the cognesenti and my best guess is either:

1) Got some powder mix up in the jug to jug stuff.
2) Some kind of change (bullet weight, alloy, size etc) that increased the resistance and gave the powder a better burn.

[Turk]

Bullets were all 405-410 straight ww. This is the only flatend ball powder I have at this time,it was 60 degrees out when fired. The original powder was from bartlett lot #47845 there were no problems with this powder for 32 lb.s worth of loads,the 120 were loaded with the last of it,these were the high preasure loads,the next 50 were loaded with Hi Tech lot # 47845 same lot number different vender,these 50 were loaded the same and were ok..

[swheeler]

Turk; You never know, but just maybe the vender got some denser, faster powder mixed in with that jug by accident. Then after the constant pouring, and moving the denser powder all collected in the bottom of the jug? Now I'm not making any accusations, just thinking of what could be amiss- seems like JR posted something about buying surplus 4895 and finding a small percentage of a ball powder mixed in with it. If this happened with two ball powders it would it could explain your delema- just so you know I have different lots of WC872 that produce 200 fps difference in velocity in the 30/06 sized case.
Scooter