No duplex loads just a magnum primer in place of duplex load ?Originally Posted by Castaway
|
   
   
|
|
No duplex loads just a magnum primer in place of duplex load ?
So just changing the primer to magnum makes the fouling go away?
It is my understanding the original mercury fulminate priming had different detonation characteristics from what is used today. So maybe a change in priming makes a different.
Magnum primers tend to make the fouling harder and drier. Mild primers tend to produce the easiest fouling to deal with. It's common for the serious competitors to use paper shims and pistol primers to reduce fouling and get better SD's.
The only thing I have ever found that significantly reduces fouling is a smokeless kicker charge.
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
makes sense to me - I have not handled 4759 for ages but guessing because of its extra bulk you would likely lose three or four grains total capacity - that brings us to 65 gr - reduce the compression some so we dont crush the smokeless grains - yep it makes sense
couple of points I am curious about with duplex loading
1) I assumed that substituting some smokeless for black would get us a velocity increase - I believe somewhere 50 - 80FPS in my 45/70 where we lose 7 grains of black in favour of 7 grains of 4227 ----however I have not done the side by side test to confirm this
following on from that I also assumed an increase in operating pressure
2) somebody hereabouts (think it might have been "savvy jack " aka Brian Austin) posted some pressure test numbers showing for 44/40 ( I think) a decrease in pressure with duplex along with an increase of velocity ---has anybody seen this????
with the potential pressure increase in mind I have only ran duplex in my '92 and '86 actions -- I have a brass ('66) gun I would not do it in and also a Uberti 76 that only ever gets straight black
STOP...... you dont replace 7grns of BP with 7grns of smokeless...... you replace your 7grns of BP ,being 1/10th of the total charge weight with 1/10th or less of a smokeless powder charge or you will be increasing the power of the load..well thats the way I understand it to work anyway. Ive done it and it appears to be a LOT cleaner afterwards.
where did we get lost here ????
1) we talkin about 45/70 charges ----yes?
2) 70grains of black is full charge------? tis at my place so yes?
3) put 7 grains of 4227 in first
4) add 63 grains of blackpowder
5) dont shake ---dont stir ---dont even knock a case over and retrieve it --- just quietly add your overpowder wad and compress to the required depth
6) add a boolit and finish the assembly
so we lose 7 grains of blackpowder from the load and replace it with 7 grains of 4227
this grain for grain works because the bulk density of 4227 is near as dang it to the density of blackpowder
would require some small adjustment for SR4759 as it is a hollow tube grain structure specifically to increase its volume (lower density)
everything I have read on this says use a medium burn rate smokeless (4227 -- SR4759) UP TO a maximum of 10% of the blackpowder charge weight and reduce the blackpowder charge accordingly ---never seen anything that says use ten percent of a normal smokeless charge then top up with black (that might work ok, but would be a lesser smokeless charge)
Stay away from fast burning pistol powders (red dot and co) for this excercise !!!!!!
I think we are kind of chasing each other around the berry bush here
ps yes if you use the full 10%smokeless - proly increases velocity some
Pressure too we would think but I did see some numbers posted that said the opposite ----dont know where that was and it dont matter enough for me to dig it out
One of the older Lyman loading manuals has pressure tested load data for duplex and if I remember right, it shows a very favorable example of this for the 45-70 Govt. I am curious now too and I will try to dig out the old Lyman loading book later today. Duplex may not mean higher pressure automatically. I haven't assembled any duplex loads an many years so I can't remember.
Chill Wills
Lee Shaver, the gunsmith did a test that was published, maybe 20years ago, where he made three groups of Duplex loads. 1-smokeless on the bottom of the powder column. 2-smokeless added on the top of the powder column. And 3- the two powders, smokeless and the BP were mixed together before being placed in the case. The outcome? He found no difference in velocity or performance. I think that was an old Singleshot Exchange write-up. Take it for what it is worth....
I don't use a duplex load to increase velocity or performance. I use the duplex load simply because it shoots "clean" by greatly reducing the amount of BP residue left in the bore. I have had 100+ rounds shot through my TDs in a day without needing any sort of wiping, cleaning or blowing to maintain accuracy throughout the shooting.
I have chronographed and pressure tested [Oehler M43] my TD duplex 45-70 load [405 HB, 7 gr 4759, 54 gr GOEX Cartridge] and a standard 45-70 load [405 HB over 70 gr GOEX cartridge] in a 24" barrel test rifle. Also tested some original REM-UMC cartridges [no year on the headstamp] which had a 405 swaged bullet over 70 gr of what appeared to be 3 fg sized BP.
The last test I ran was in 2019.
The duplex load ran 1285 fps at 20,400 psi.
The standard service 45-70 load ran 1244 fps at 19,100 psi.
The REM-UMC ran 1233 fps at 22,000 psi.
Larry Gibson
“Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
― Nikola Tesla
because 7grns of smokeless is **** ton more POWERFUL than 7gns of blackwhere did we get lost here ????
1) we talkin about 45/70 charges ----yes?
2) 70grains of black is full charge------? tis at my place so yes?
3) put 7 grains of 4227 in first
4) add 63 grains of blackpowder
5) dont shake ---dont stir ---dont even knock a case over and retrieve it --- just quietly add your overpowder wad and compress to the required depth
6) add a boolit and finish the assembly
so we lose 7 grains of blackpowder from the load and replace it with 7 grains of 4227
this grain for grain works because the bulk density of 4227 is near as dang it to the density of blackpowder
would require some small adjustment for SR4759 as it is a hollow tube grain structure specifically to increase its volume (lower density)
everything I have read on this says use a medium burn rate smokeless (4227 -- SR4759) UP TO a maximum of 10% of the blackpowder charge weight and reduce the blackpowder charge accordingly ---never seen anything that says use ten percent of a normal smokeless charge then top up with black (that might work ok, but would be a lesser smokeless charge)
Stay away from fast burning pistol powders (red dot and co) for this excercise !!!!!!
I think we are kind of chasing each other around the berry bush here
ps yes if you use the full 10%smokeless - proly increases velocity some
Pressure too we would think but I did see some numbers posted that said the opposite ----dont know where that was and it dont matter enough for me to dig it out
its like putting petrol in a diesel motor or vice versa.
I measure charges on a beam scale not by volume....
Smokeless & Black in one case, this sounds fun. Following.
These men and their hypnotized followers call this a new order. It is not new. It is not order.
Duplex loading has been around a very long time. It first started with different grades of BP followed by semi-smokeless under BP than later still true smokeless under BP. Ideal and others made duplex powder measures. Same for the big-name target gunsmiths back in the day. When done properly duplexing has very long and distinguished history.
https://www.pbase.com/halp/schuetzen_measures
https://www.reloadingtool.com/ideal-...owder-measures
Last edited by M-Tecs; 10-04-2023 at 11:47 PM.
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
Can duplexing powder charges be done in a flint or cap lock muzzle loader?
Some use BP under Blackhorn 209 in sidelocks. I have been planning to use BP/Blackhorn 209 in my ROA for a hunting load but I have not gotten around to any serious testing yet. On flinters and cap lock I would think flash hole location might be an issue.
https://castboolits.gunloads.com/sho...in-a-side-lock
Last edited by M-Tecs; 10-05-2023 at 12:50 AM.
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
Anytime I tell ya grains it is weight not guesstimate
why? get your patch lube right in a muzzle loader - only time you need to clean it is when you done shooting for the day, clean it, put it back in the safe
Is there a general starting ratio of BP & smokeless to start off at?
These men and their hypnotized followers call this a new order. It is not new. It is not order.
My old side caplock TC rifle was used when purchased about 35 years ago and is meant to use long cylindrical 54 cal slugs. Does not shoot patched round balls accurately. I am guessing because of the twist.
I was asking because I was interested to see what the answers might be.
Actually right now I have no black powder and have found no percussion caps locally.
For fouling issues we use the next faster BP. Such as going to 3F where 2F was not burning clean enough.
If desiring to stay at the same 2F velocity Less 3F will be needed.
All we have ever used is Goex. Good to read it is getting back up in the supply line.
"Come unto Me, all you who labor and are heavy burdened, and I will give you rest." Matthew 11:28
Male Guanaco out in dry lakebed at 10,800 feet south of Arequipa.
NO! You'll blow your fool head off.
Posting Permissions
| BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
| BR | Bench Rest | M | Magnum | RN | Round Nose |
| BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
| C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
| HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
| PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
| LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
| GC | Gas Check |
Reply With Quote
Chill Wills