A few BP/Duplex Q's

[HollandNut]

CZ550 458 Lott 21.5" barrel

Me thinketh a full BP load in this case will most likely spew a lot of unburned powder with the short barrel , right or wrong ?

Will the duplex do a better job of burning all the BP ?

There is a few other questions , but dang I forgot them ..

[Nobade]

No unburned powder, it will pretty much all go away. But the point of duplexing is to control the fouling so you can fire multiple shots without wiping the bore. You sort of miss out on the "authentic" experience, and usually duplexing can't quite equal the accuracy you can get from straight black loads, but for a rifle like yours I would most certainly duplex load it. More fun to keep shooting than have to remove the bolt and wipe or blowtube every shot.

Last weekend I tried shooting a bunch of 45-70 duplexed loads through my Marlin cowboy rifle. Used a LDPE and a cork wad, and a paper patched boolit. No lube at all in those loads. Fired 25 and it was still grouping quite well, and when I cleaned it there was just starting to be a fouling buildup near the muzzle. With lubed grease groove boolits I can shoot it as long as my shoulder holds up and never have to wipe. I'll do that sometimes at the cowboy levergun matches just to make some noise and smoke for the boys.

-Nobade

[bigted]

I completely agree with Nobade in this. you will have an overage of fun with the duplex and your 45-2 7/8ths" express rifle. the short barrel should do great with these loads and im bettin it would do for anything walking or crawling with some heavy boolits belching outta that short tube. do post photo's of the targets and monster.

[HollandNut]

My BIG PLAN is to start a thread on the whole process/idea and keep it updated along the way .. Duplexing is new to me ..

We will see how it goes

I have some j's that I have shot that will take down any loose mastadons roaming the area ..

[bigted]

indeed so. those rascals have roamed here before and im ready for em again when they decide to wrestle their way outta the ice.

do you have a thought as to where you will begin your quest?

[MT Chambers]

My use of duplex loads and Bp features 10% 4759 and the rest 2fg Goex, barrel does not need blow tubing or wiping between shots, velocity is higher by about 50 fps but recoil is much higher IMHO.

[HollandNut]

I'm not certain , I have two boolit moulds that shoot great already , a Postell ( Ken's , that I am long overdue to return ! ) and a Lyman 4 cav 462560 .. I also have a couple hundred 413g and 425g LBT's as well as some PP , none of which I have moulds for ..

Thinking the Postell and 462560 as the main ones and doing some full BP as a baseline to proceed from ..

Any thoughts on Fg over FFg ?

I have plenty of 4227 , so thinking that will be my smokeless

[oldred]

My use of duplex loads and Bp features 10% 4759 and the rest 2fg Goex, barrel does not need blow tubing or wiping between shots, velocity is higher by about 50 fps but recoil is much higher IMHO.


I recently started duplexing my 45-90, 10% H4198, and I had also noticed recoil to be somewhat milder, at least it seems so. I was expecting it would probably be higher than straight 2FF if any different at all, since my crono went south (nope I didn't shoot it! :mrgreen:) I can't say what the velocity is vs straight black. At a weight of 14 1/2 lbs recoil is very mild anyway and is kind of a non-issue even with 500 grainers.

[Larry Gibson]

Might want to read Spence Wolfe's book Loading Cartridges For The Original .45-70 Springfield Rifle And Carbine. He has a very well written section on duplexing 45-70 loads; the why and the how. I shoot a lot of duplexed 45-70 cartridges in my target TD, my H&R OM TD and my H&R carbine. They work excellently in controlling fouling. In one test more than 100 duplexed 45-70 loads were fired through my TD carbine w/o cleaning or wiping in one day. the bore was not fouled or leaded at all and accuracy remained excellent from the first shots to the last.

If you want to duplex 45-70 loads and keep the psi's with in TD limits then Spence's book is a must read. This wheel has already been invented.

Larry Gibson

[bigted]

""A few BP/Duplex Q's



CZ550 458 Lott 21.5" barrel

Me thinketh a full BP load in this case will most likely spew a lot of unburned powder with the short barrel , right or wrong ?

Will the duplex do a better job of burning all the BP ?

There is a few other questions , but dang I forgot them .. ""


guess I had it wrong with wanting some help ... didn't realize you had it figured out!

[HollandNut]

not trying to re invent the wheel , I know it's nothing new to many folks , but BP is a whole lot easier to find that smokeless around here , and a whole lot more funner to boot ..

I been done figured all that out Ted , but Thanks anyways

forgot I also have two NEI's that throw 450 ish and 525 ish

[Larry Gibson]

With the CZ 550 strength of the action isn't a problem as with TDs. I'd opt for a "bulky" smokeless powder that was relatively fast burning and easy to ignite. SR 4759 would be my 1st choice. I'd start with 10 gr of the SR 4759 over the primer and then fill the case full enough with FFg so there was about 3/8" compression of the BP with a compression die or with the bullet when seated. A BP bullet lube will still be needed BTW.

What smokeless powders do you have to use?

Larry Gibson

[HollandNut]

smokeless that I use in the 480 , mainly 4227 , tite group , lil gun and H110 , as well as W296 ..

I had read that SR4759 is a good choice as well as RX7

I use Bullshop's Speed Green and my version of Darr's as well

[Larry Gibson]

Of the powders listed I'd go with the 4227. 4759 and RL7 are the usual choices these days because they ignite easily and provide the bulk.

If you look down the bore from the breach after shooting BP loads only you'll notice large streaks of black fouling; that is the residue from the charcoal in the BP. That's what you want the smokeless to "blow out". With 4227 I'd start with 7 gr and fill the case as mentioned with FFg. Increase the 4227 1 gr at a time while decreasing the BP an equal volume of the 1 gr. Fire 3 shots w/o cleaning or wiping the bore with each load then inspect the bore for the fouling. You should see a gradual movement of the fouling toward the muzzle. When you've reached a load that blows the streaks of charcoal residue all the way out that's it.

Larry Gibson

[HollandNut]

Thanks I was wondering if any amount of smokeless worked or not .I presume it's still OK to use a filler over the BP if needed ??

[Larry Gibson]

Filler should be ok as long as powders do not migrate.

Larry Gibson

[Grapeshot]

CZ550 458 Lott 21.5" barrel

Me thinketh a full BP load in this case will most likely spew a lot of unburned powder with the short barrel , right or wrong ?

Will the duplex do a better job of burning all the BP ?


There is a few other questions , but dang I forgot them ..

Using a duplex load has been around a long time. Before there was smokeless the old timers would use 4Fg under the main charge of 1Fg or 2Fg to insure that the entire charge was burned. I used 4Fg under any load that used Pyrodex and I never had any unburned grains in the tube. This was true for my .45/70 Sharps as well. I'd use at least 10 grains of 4Fg and add the balance of 2Fg before seating Bullet.

[missionary5155]

Greetings
I have been very pleased with using straight 3F in some cartridge rifles. Started with 50-95 and as small as 44WCF with no problems and little fouling.
I plan on eventually switching to 3F comepletely when my last cans of 2F are used up.
Mike in Peru

[Starvnhuntr]

The last time I bought powder the person I talked to at buffalo arms recomended 3f for more velocity. I have not shot enough of it to decide if it burns cleaner than 2f or goex cartridge. I will check it out and follow up.