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Duplex Loads

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07 August 2016, 02:37
drhall762
Duplex Loads
Yes, there have been many discussions on this topic and I tried to sort thru them all.

My question is: "Has anyone used a small charge of black powder to ignite one of those 165+ grain charges of slow burning smokeless powder in the big magnums? Kind of like the artillery pieces that use BP to set off the main charge.


Dave

In 100 years who of us will care?
An armed society is a polite society!
Just because they say you are paranoid doesn't mean they are not out to get you.
07 August 2016, 03:11
drewhenrytnt
How many ctgs are there that use 165+gr of smokeless??

In my 600 Ovekill 151gr H4350 is all I can stuff in the case with a 30" drop tube and a 900gr CEB Solid. A Federal 215Match has no problem getting them started.

However, I have seen(and fired)a 4-Bore load that used 115gr Bluedot with 2gr Bullseye atop the primer.

Andy B


We Band of Bubbas
N.R.A Life Member
TDR Cummins Power All The Way
Certified member of the Whompers Club
07 August 2016, 17:16
Grumulkin
quote:
Originally posted by drhall762:
My question is: "Has anyone used a small charge of black powder to ignite one of those 165+ grain charges of slow burning smokeless powder in the big magnums? Kind of like the artillery pieces that use BP to set off the main charge.


One problem I see with that is the corrosive effects of black powder. I wouldn't want that in one of my guns.

I did at one time try some fast pistol powder under slow rifle powder. Having seen no benefit on paper, I stopped the experiment.
07 August 2016, 17:56
drhall762
I was just wondering if anyone ever heard of it or used it. I saw a brief comment to it but was totally unfamiliar with it. I have used smokeless under BP for a duplex cartridge load and there is a lot of advantage there.


Dave

In 100 years who of us will care?
An armed society is a polite society!
Just because they say you are paranoid doesn't mean they are not out to get you.
07 August 2016, 19:29
Luckyducker
I have read that some reloaders of the big elephant guns use a small amount of Bullseye powder dropped next to the primer to facilitate consistent ignition. If I remember correctly, I think it was either 5 or 6 grains. I have never heard of anyone mixing BP and smokeless in the same case.


Dennis
Life member NRA
07 August 2016, 19:45
dpcd
Black powder is not very corrosive; I use it all the time in cartridge rifles. and they never rust. It is the old corrosive caps and primers that were far more of a problem. Of course, you clean the bore afterwards.
But for Dave, I, too, use smokeless under black, but have not done the reverse.
08 August 2016, 04:38
Rapidrob
I have used duplex charges for years now in my 20mm loads.
Black powder works well and really does not cause any of the fouling you'd expect due to the very high pressures and heat created by the smokeless charge. I always use a water based cleaner anyway.
I use 40 grains of FFFG as an igniter charge for the 20mm and 8 grains of Unique pistol powder if black powder is not available.
The same set up will work for calibers as large as 25mm,as this is where I got the idea.
I have used duplex charges in the .40-65 Sharps and .50-120 as well with very good results.


Gulf of Tonkin Yacht Club
NRA Endowment Member
President NM MILSURPS
12 August 2016, 08:06
Joe from So. Cal.
About 4-5 times I put a tiny amount, maybe 1 gr., of Bullseye in the bottom of a 115 gr. charge of IMR 4350 in my 460 Weatherby cases. No good reason.

Each time when I opened the action a tiny little ring of copper, about .010" thick, curved about the same diameter or so of the bullet, would come out with case. I may still have one around here somewhere.

No signs of excess pressure or anything else weird. I had no idea why this was happening and never fooled around with this again.
20 August 2016, 11:42
Reloader270
I had also considered a duplex load some years back but after proper investigation the answer was - if you are not a professional on this topic, stay away from it. It is not worth blowing up your gun!
21 August 2016, 08:00
Atkinson
I have never seen the need for duplex loads, I get all I need with just using the proper powder. I think Duplex are a thing of the past and fun and games for some..but Im just a hunter so that probably makes a big difference in my approach to the subject..


Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120

rayatkinsonhunting@gmail.com
21 August 2016, 14:18
Saeed
Below are details of our 700 NE loads.

We were getting misfires until we used 2 grains of Bullseye below the powder charge.

Solved the problem.


2 + 235 H 5010

1766

6930

1000 WOODLEIGH SP

2 + 220 VVN 165

2082

9630



2 + 225

2099

9790



2 + 230

2129

10070



2 + 235

2150

10270



2 + 240

2170

10460



2 + 245

2260

11340



2 + 250

2334

12100



2 + 255

2241

11150

1000 DKT SP

2 + 200 VVN 560

1975

8660

1000 WOODLEIGH

2 + 235

2086

9660



2 + 245

2286

11610



2 + 170 RL 15

2011

8980

1000 DKT SP

2 + 180

2052

9350



2 + 190

2227

11020



2 + 250 VVN 160

2442

13240



2 + 255

2547

14560

BLEW THE PRIMER


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22 August 2016, 00:29
The Dane
I did it with great results in a 12 gauge rifle.
I had problems with loads in excess of 120grains Vv N140. The primer would pop and drive load + bullet into the barrel but sometimes not ignite.
I put 3 grains Vv N310 fast pistol powder under a disc cut from cigarette paper (nitrated and combustable).
Now i have 100% ignition every time.