Thoughts on duplex load

[BBerguson]

450 Bushmaster hunting/maximum loads is my project. Was shooting 225gr jacketed with 40gr of lilgun (not min but not max either) on Friday. Plenty accurate but lilgun is very hard to ignite and gave my son a couple of hang fires and I got a haaaaang fire. His were clBang mine was a click..Bang. I know, I know, this is lilgun and it has pressure problems too which I haven’t seen but others have. I only have a partial pound left and may just use it up in 44magnum. Remember, 450bm is a small primer so the large primer in 44mag and less powder may be the best way to use up the lilgun.

But, back to duplex loads…. The only experience I have with duplex loads is in my muzzle loader using a capful of black powder and then finishing with pyrodex. It works fine for practice. It got me thinking about the 450bm and using IMR 4227 against the primer, say 10grs and then 30grs of lilgun. The powders are very similar in burn speeds and charge weights (max charges with .5 grs) but 4227 is much easier to ignite. This should of course be a compressed load or use a poly fill to keep the powders from mixing.

So, anyone have experience is a slow/slow duplex load?

BB

 

[CWLONGSHOT]

These scare the bjebus outta me.

I wont do it!

Wont use Lil gun either... I use AA#9 jacketed & 5844 for cast. Unique gor subs/plinkers.

Have you tried mag or #41 primers?

 

[BBerguson]

These scare the bjebus outta me.

I wont do it!

Wont use Lil gun either... I use AA#9 jacketed & 5844 for cast. Unique gor subs/plinkers.

Have you tried mag or #41 primers?

These loads were with mag primers, I don’t have anything “stronger”.

I won’t buy any more lilgun. Come to think of it, it’s kind of like pyrodex in a flintlock.

 

[Tomme boy]

Use a filler. Being a straight case it should would well. lilgun is like h110, it likes to be run near the top. It is a strange powder, as you go up it sometimes goes down in velocity. I have seen the pressures actually go down as you increase the charge. I have had round primers and the speeds match the box with a max charge. But 2gr less powder and it blew primers out. I got several lbs of it and I am not going to use it again in the 350.

 

[fiver]

4198 is too close in burn rate to duplex with.
what your trying to do with a duplex load is jump the initial pressure just enough to get the secondary powder closer to a zone it burns more efficiently in.
unfortunately if you can't stack the two powders and keep them there you end up with other problems.

i'd be a lot more inclined to do like Tomme says and hold the powder down against the primer.
this insures consistent ignition.

oh and a primer change might help too.
just cause a primer says magnum on it doesn't mean it is the best one for igniting the powder your using.
the different companies use different 'stuff' in their priming compound and quite often a different brand will ignite the powder you want to use better.

 

[Missionary]

I would contact the "manufacturer" and ask them.
Over the years I have called a couple and they were very helpful getting things sorted out.

 

[BBerguson]

I’m sorry, there is a thread on this site already about the same topic. I’ll read through that one and see what you all have to say!

 

[fiver]

i just read that one too... LOL
i said pretty much the same thing.
except for the part about talking to Dick, he died not too long afterward.

 

[CWLONGSHOT]

Use a filler. Being a straight case it should would well. lilgun is like h110, it likes to be run near the top. It is a strange powder, as you go up it sometimes goes down in velocity. I have seen the pressures actually go down as you increase the charge. I have had round primers and the speeds match the box with a max charge. But 2gr less powder and it blew primers out. I got several lbs of it and I am not going to use it again in the 350.

Not speaking to fillers. Just pressure here. One thing about this caliber. Its loaded to about 38k because of case head thrust to safe function safe in the AR.
So as most will use a mag/41 prime, your not gonna see a flat primer till you have far surpassed safe op pressures. (In AR) In the AR, bad things are likely before ya see a flat primer.
In a BOLT, its a different story and substantial increases can be acheived. Many threads about 460 S&W data used. (I dont advise nor will I do) BUT, OAL can be stretched in most. One is still
In "no mans land" but with in much safer pressure range.

CW

 

[JonB]

I only have one suggestion...
lil'gun is my goto powder for 22 hornet with jacketed bullets.
if you don't have a hornet (or similar), maybe just pass that last 1/2 lb along to someone else?

 

[BBerguson]

My 450BM is a bolt gun, CVA Cascade.

Jon, I’m thinking lilgun might work well in 30 carbine but yeah, that is a good idea to pass along if I can’t find a good use for it.

 

[Edward R Southgate]

That is one thing I have never had the first thought about . I ended up being the first one with cans of the batch of Little Gun that got sent out Pre Duplexed a few years back . That's as close to mixed powders as I ever want to get again in this lifetime . Like to ruined my .218 Bee model 43 . I loaded 12.5 g with a 35 gr Vmax and George at Hodgdon said it tested so high that they couldn't say what the actual pressure was. He took a couple of loads apart and cut the powder by half and the pressure was still enough that it should have wrecked my rifle twice over. He said I had mixed LG with Tight Group . I told him he was nuts as there was never two opened powders in my shop at one time . I also told him I had opened a brand new, just brought it home from Alabama Ammo store bottle of powder so it had had 0 chance to be mixed after it left the store. He said it could not have been mixed when they shipped it. I said thanks and hung up .

Two days later I received a call from Mr. Hodgdon himself . Seems they had discovered that George had been wrong about the chances of them having been the source of the mixed powder . He asked me to load 13 rounds like I the ones I had fired and send them to him. Then he put George on to explain the issue and to apologize for our previous conversation . I sent them the loads . Mr. Hodgdon called back a few days later asking about the condition of my rifle . I told him you could read Winchester on the bolt face in brass so I suspected there could be an issue with headspace as these rifles are prone to having issues with normally hot loads . He offered to pay for a gunsmith to check it out and said he would repair or replace the rifle if as needed. I had him send me a headspace gauge and checked it myself , it was fine .

When all was said and done he sent me a new batch 8 pounder of Little Gun , 200 new Winchester cases and a sleeve of 10 boxes of the 35 gr Vmax bullets .

Turned out that a disgruntled ex (now) employee had mixed it on purpose .

 

[Ian]

That would have grenaded a .410 or 28-gauge shotgun. Sheesh.

 

[waco]

I only have one suggestion...
lil'gun is my goto powder for 22 hornet with jacketed bullets.
if you don't have a hornet (or similar), maybe just pass that last 1/2 lb along to someone else?

Only thing I’ve ever used it in is my .221 Fireball. Works very well with 40gr V-Max bullets.

 

[Edward R Southgate]

That would have grenaded a .410 or 28-gauge shotgun. Sheesh.

Yup ! George said it would have Probably been alright in 12 gauge , I said I'd pass . Not being a powder for 12 gauge anyway it would never occur to me to use it that way to begin with . It made some interesting devices though ,they rattled the windows and were very noisy.

 

[fiver]

the 12ga. is about half the MAP of a 410.

WOW titegroup,,, that must have been a very motivated and gruntled employee.
one with some knowledge too.... just wow..

 

[CZ93X62]

"Disgruntled employee" mi nalgas--more like $%# &^%$ TERRORIST.

 

[Ben]

I'd switch powder before I'd duplex.

 

[JustJim]

I'm with Ben. The idea of duplexing two or more smokeless powders just makes me uncomfortable.

 

[dale2242]

The thought of duplexing scares the crap out of me.
I won`t be doing it.
Like Ben, I will be switching powders.