David d....Pete's breech plug

[Richard]

Dave.....One of our board members, "Jon" sent me his ML for stock work and to put on his new PacNor .45 barrel. He has one of Pete's stainless breech plugs! This is the first time I have seen one. They are really nice! I might, however, offer a suggestion. Just my opinion mind you.
The neck of the plug (the part that protrudes into the barrel) is thick and flat. Picture pouring the smaller charge of a duplex load down the barrel (and not bouncing the gun) and having some of the powder "hang up" on that lip! Then pouring the slower charge in. A certain amount of the fast charge would not be in the BP recess.
But also, think of the flame propagation coming from within the plug? There will be powder on that "ledge" shielded from the initial flame. Am I making much out of nothing? I have included a picture of the modification I do on the standard plug alongside Pete's plug. Just a little bevel will allow the powder to feed into the plug recess and also allow the flame to "spread" to all the powder equally. Actually the bevel on mine could be even steeper!
Just a thought and a simple additional cut.
Richard

[ET]

Kind of reminds me of putting a chamfer on the primer hole inside a brass casing for better groups.

Ed

[Dave W]

I feel if you shoot duplex, you should bump the butt on the ground or tap on the barrel to settle the booster in case any sticks to the barrel walls.

[Richard]

DW......I did mention "bouncing the rifle!" And whats your thought on the flame propagation and that area shielded by the Ledge?
Richard

[Deleted]

sounds like a good idea Richard, I have one of petes plugs also, when I take it out for the new barrel I will try that mod myself. I cant see that it could do anything but help......Bill

[smokeeter]

Richard, do you feel that a normal charge will fill beyond the bored out portion of the plug, if so any build up on the shelf wouldn't be a concern IMHO. No doubt your chamfered edge with help direct the powder into the cavity more easily.

[Dave W]

Paul, I have a RB recessed plug that is recessed pretty deep, the recessed area only holds about 9gr of N110, and though I have not seen one of Pete's plugs since he redesigned it supposedly is less deeply recessed than what I have. Can you verify Rich?

As far as the shelf Rich, with a OEM plug there is always powder in the corners not in align with the flame path so I don't know how much of an advantage a chamfer will be, but as Bill said, certainly cannot hurt for peace of mind, which is a big part of shooting .IMO

[dave d.]

:)richard i will give pete the suggestion and see what he thinks.thank's

[Harley]

Dave W, I have both the Pete and the RB; you're right, the RB is much more deeply recessed.

Harley

[fletch]

Does anyone use a drop tube to load powder? I have one that I bought a few years ago and it is just a hollow brass rod with a funnel soddered on top. Just something picked up from traditional ML days.

[edge]

It is an interesting question.

You always have a "tee" shaped powder column.
Personally I have never "bounced the rifle" after loading the fast powder before adding the slower one.

Obviously, if the fast powder fills the hollowed out breechplug there is no harm, but let's assume that it does not. A funnel shape added may help and in manufacturing it might actually be easier.

If the question of is it better comes up, then that may be hard to tell.
1st, IMO the primer emits a jet of superheated gases straight up the center of this powder and a fair amount of slow powder starts before the faster powder due to a quenching effect of the normal design.
2nd, lets assume that some fast powder does sit on the lip. That may in fact be a good thing...or not!
The burning powder needs to "go around" this blind corner. Would a faster powder not be beneficial in that location?

Personally, the only way to really test the theory would be to use two plugs ( in the same rifle with the same load ) and the shooter not know which one was being used, a blind study, fire one or two shots one way, one or two the other way and keep flip flopping the breechplug until it became obvious which one was more accurate.
This all assumes an accurate rifle to begin with and probably using a dead sled type rest to eliminate shooter bias, real or perceived!

edge.

[jims]

Fletch: To answer your question I use a copper drop tube I made with help from my father in law. One for my .50 and one for my .375. The .50 tube probably is not needed as I have enough room to pour the powder but the .375 is easier with the tube.
It may not really help but I think I am getting all of the powder down by the breech and not hanging up along the barrel, especially if the barrel is dirty.
The tubes are copper water line tubing. The 1/2 inch was too big to get down the bore of the .50 so it was chucked in a lathe and "turned" down with some grit/emory type flexible sandpaper to get it small enough to fit down the bore. A metal funnel was then soldered to the tube and it works well.
The .375 used smaller tubing. It came in a coil and it had to be straightened first to work. That was the hardest part.

[fletch]

I actually got mine at October Country and use it on the bench as one of my loading procedures. It might be a perceived thing but I think it helps. Especially with duplex loads. www.octobercountry.com/products3.php?productid=150
Another thing I do but not with the duplex is to drop a copper BB down the barrel and I think this causes the primer flame to expand around the BB igniting the powder more fully and before the sabot can be pushed off the power. I have noticed a more consistent velocity when shooting over the Chrony doing this.

[nic58]

I use a drop tube with both of my ML's. They have different barrel lengths so I have a drop tube for each of them. They are made out of Easton aluminum arrow shafts with a small funnel epoxied to the top. Cut them to length so they will just clear the powder column once it's poured into the barrel.

[whyohe]

richard this is very interesting. my question is how will the pressure and heat effect the thinner and sharp edge of your chamfored plug. edge has a good point too and looking forward to what everyone thinks.

[Richard]

Smokeeter..........Definitely a normal single powder load will come up over the snout of the BP. Some of my concern was the "directing" of the flame into the charge so the powder hidden by that shelf gets the blast.
As far as the depth, I did not measure it, but it appears similar. However, I believe Pete's plug has a narrower opening, hence the fatter shelf than the factory plug.
I have been using the same chamfered plug since I got my replacement from Savage about 700 shots ago. There is NO semblence of any wear and tear on the snout.
By the way, my modified plug holds 11 gr. of N-110 to the end of the snout. Most of my 300 gr. duplexes incorporate around 10 grains of booster which pretty well fills it.
All I can say is this.......when I did my first plug, I looked at it in the lathe and said to myself.........Self, that thing need to be chamfered to direct the booster! And I doubt it can hurt anything?
Richard

[rbinar]

Jan 17, 2009 20:42:55 GMT -5 Dave W said:

I feel if you shoot duplex, you should bump the butt on the ground or tap on the barrel to settle the booster in case any sticks to the barrel walls.

I'd have to disagree. Now don't get me wrong it won't hurt a thing and if you like to do everything possible to make the load perfect, it's just one more step.

I've never done it and don't think it makes a wing doddle. Hey I've been wrong b4. It's just a personal preference.

Duplexes are not near as picky as might be thought. You'd be surprised the number of shots I fired before I ever told anyone I was shooting a duplex. Some times I'd mix powder on purpose because so many thought any powder mixing would be a danger.

In fact I fired the loads inverted and completely mixed to ensure safety but along the way I learned you don't have to be at all neat for the load to work well." As long as the booster is near the bottom and the primary near the top", is what I've said for accuracy.