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Post by Deleted on Mar 13, 2015 4:57:36 GMT -5
Jeff, your new plug appears to have a slightly larger gap between the last thread and the shoulder, compared to your old style plug. Unless it's an optical illusion. Was curious, if there is a difference, is this something that was done as an improvement when you built the new plug? Maybe to get a better seal or plug to barrel fit? Or maybe it's just an illusion.. Second, will we see your plug with the option for 209's? Sure be neat to compare lrmp and 209 in the same exact system/gun, for testing/development sake.
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Post by gar on Mar 13, 2015 6:29:11 GMT -5
He wouldn't change the plug he would make the change on the primer module by adjusting the primer pocket. Awful short flame travel for a 209 IMO.
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Post by Deleted on Mar 13, 2015 6:38:38 GMT -5
He wouldn't change the plug he would make the change on the primer module by adjusting the primer pocket. Awful short flame travel for a 209 IMO. primer modules was what I was referring to.
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Deleted
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Post by Deleted on Mar 13, 2015 7:05:36 GMT -5
He wouldn't change the plug he would make the change on the primer module by adjusting the primer pocket. Awful short flame travel for a 209 IMO. But if LRMP's are far more hotter and superior to 209 primers why do they need such a short flame path to travel through to reach the powder?
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Post by Jon on Mar 13, 2015 7:26:07 GMT -5
Good question. Just my 2cts. worth. I like the plug with a nose just enough that you could create a labyrinth seal before the threads. I liked Jeff's test but it was not apples to apples. It was a constant pressure. When the test was made with the plug backed off and still no leak it kind of proves that although a leaky seal the threads do create a seal? If I'm not mistaken if you change direction of flow the flow is reduced? I don't have the formal education but I did spend some time working with air flow and fluid flow if I remember correctly a fitting with a hard 90 compared to a sweeping 90 is more restrictive? Just observations and questions? Like Dave W I have a gun with a SMI plug and have had no problems so your design is perfectly fine and proven. For instance the threads where the lock ring holds in the vent bushing see a lot of pressure and no one if worried about it? Like on the rear seal plugs there is very little area for the pressure to flow into. not like the Savage plug. If anyone remembers the 5/8th. plug that RB made only had a short nose. Just my uneducated observations? I would like to try a primer module with a fully supported 209? The original ML1 used 209 but in a module but had a long flame channel. Again not apples to apples.
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Post by edge on Mar 13, 2015 7:41:39 GMT -5
SNIP. A lot of us were using a .242" "C" drill bit to open up the primer pocket to make it easier to close the bolt with a new primer. DO NOT DO THAT ANYMORE! You want the primer pocket as snug as tolerable to aid in sealing and supporting the primer. SNIP. Have you considered a taper pin reamer? The taper is a bit course ( 1/4 inch per foot ) but if you only went in say 0.050 that would taper the mouth 0.001 if you went 0.100 deep that would be 0.002 wider at the mouth which is probably a bit too much. You might be able to make the bottom even a little tighter and still have the primer enter the BP easily. They are fairly cheap, an import will run less than $25 They are fairly long since they are designed for assembling and disassembling components. That means you need to cut the front of the reamer off that you are not using but they are HSS so any grinder or even a dremel would work. Taper pin reamers unlike a regular reamer do not need a precision cut on the end since that is not the part doing the cutting. edge.
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Chris
Button Buck
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Post by Chris on Mar 13, 2015 7:51:01 GMT -5
Hi, I have been lurking here mostly reading this board for some time BUT the topic of thread sealing has given me the motivation to post. Unless someone is making there breech plugs using NPT or NPTF thread the thread does nothing for sealing the gas from blowing back. Where I work we build gas compressors so I feel I know a little about it. The only thread that I can see would be able to do such a thing would be NPTF, is there such a plug being produced? I can't imagine there is because of the way they are designed it couldn't work in this application IMO.
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Post by edge on Mar 13, 2015 8:03:36 GMT -5
Hi, I have been lurking here mostly reading this board for some time BUT the topic of thread sealing has given me the motivation to post. SNIP. Chris, your thinking is incorrect! Your idea of a seal is something that completely PLUGS up a hole, and NO ONE is saying that is what they are doing! Non contact seals are open and at low flow do not hold back anything since they are not closed. Seals used on steam turbines are designed to reduce the flow by making the flow bend back upon itself. The front door at Walmart lets you and thousands of people in everyday, but only one or two at a time. Go there on Black Friday when they open the doors and and you have hundreds trying to get through at the same time it slows down to a crawl. That is what a labyrinth seal does. A ML BP does not need to hold back pressure indefinitely, but instead it needs to hold it back for a few milliseconds at a a time! Think 5 people trying to get through that door at Walmart. edge.
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Post by gar on Mar 13, 2015 8:07:59 GMT -5
45 omega, I don't know that one is superior to the other, just different. From my understanding, and I may be wrong, the 209's have more force behind them and the LRP's have more heat. Not better just different. Jeff's plug has a channel that comes close to the primer kinda like a mini powder chamber in the plug for lack of a better description.
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Deleted
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Post by Deleted on Mar 13, 2015 8:12:42 GMT -5
Hi, I have been lurking here mostly reading this board for some time BUT the topic of thread sealing has given me the motivation to post. Unless someone is making there breech plugs using NPT or NPTF thread the thread does nothing for sealing the gas from blowing back. Where I work we build gas compressors so I feel I know a little about it. The only thread that I can see would be able to do such a thing would be NPTF, is there such a plug being produced? I can't imagine there is because of the way they are designed it couldn't work in this application IMO. OK, then why did my gun fire with only the threads as a seal? The velocities were exactly the same as they were with the shoulder sealed against the barrel. A shoulder-less plug will help us determine how much the threads actually seal up the chamber on a SML.
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Post by hankinsrfls on Mar 13, 2015 8:21:01 GMT -5
Jeff, your new plug appears to have a slightly larger gap between the last thread and the shoulder, compared to your old style plug. Unless it's an optical illusion. Was curious, if there is a difference, is this something that was done as an improvement when you built the new plug? Maybe to get a better seal or plug to barrel fit? Or maybe it's just an illusion.. Second, will we see your plug with the option for 209's? Sure be neat to compare lrmp and 209 in the same exact system/gun, for testing/development sake.
REPLY MOVED TO" A NEW hankins plug ": dougsmessageboards.proboards.com/thread/17120/nother-new-plug
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Post by hankinsrfls on Mar 13, 2015 8:27:58 GMT -5
Hi, I have been lurking here mostly reading this board for some time BUT the topic of thread sealing has given me the motivation to post. Unless someone is making there breech plugs using NPT or NPTF thread the thread does nothing for sealing the gas from blowing back. Where I work we build gas compressors so I feel I know a little about it. The only thread that I can see would be able to do such a thing would be NPTF, is there such a plug being produced? I can't imagine there is because of the way they are designed it couldn't work in this application IMO. OK, then why did my gun fire with only the threads as a seal? The velocities were exactly the same as they were with the shoulder sealed against the barrel. A shoulder-less plug will help us determine how much the threads actually seal up the chamber on a SML. If you had a shoulder less plug, what would stop it from just screwing in and or out. You must have some positive stopping point, be it on the insideĀ using the snout or the shoulder of the newer style plugs.. If you shoot your gun with a loose plug it will leak and eventually cause gas cutting and erosion of the plug threads and in the barrel... That is a fact and has been written here on this board probably a hundred times... So lets move on and get over the loose thread thing,, we have more important things we should be doing..
Don't worry,, Be happy.
Jeff Hankins.
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Post by Richard on Mar 13, 2015 18:28:04 GMT -5
Amen!.....................Whewwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww!
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Post by hunter on Mar 13, 2015 19:25:42 GMT -5
A shoulder less plug, now that would make head spacing a breeze
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Post by rossman40 on Mar 13, 2015 22:56:06 GMT -5
Edges comparison of the labyrinth seal with the doors at Walmart is a good one. But to understand it to the point that I think ET is trying to explain we need to take it further. We will start off with the one thousand people pushing and shoving on black Friday wanting to get thru a 8' door but think of the door more as a entrance to a 8' wide hallway. Then 12' in they have to make a 90 degree turn to the right, then go 12' more and then have to make a 90 degree turn to the left. Now with all the people pushing thru the door we are going to see a lot of people face planted into the first wall. Now the amount of direct pressure from the crowd is less after making the turn so the number of people face planted into the wall at the second turn is going to be less. This is nothing new, we even use the concept for roadblocks/checkpoints. It's easy to blow thru a checkpoint at high speed if it's a straight shot, but if you have to weave between closely spaced obstacles like M1 tanks it makes it tough.
You have to remember the Savage breechplug setup is a production design, machine time is money and so is the number of tools used (tool cost, sharpening/replacement, tool setup). As Jeff can tell you the time to switch tools even on a fancy CNC machine can be longer then to make the cut with the tool. For what it is designed for the Savage plug IMO is a pretty good piece of engineering. But now we are pushing the limits pressure wise as we travel down different paths with different performance goals.
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Post by Dave W on Jan 13, 2016 10:49:32 GMT -5
See somebody has decided to copy the plug. Looks like you have a target on your back Luke.
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Post by edge on Jan 14, 2016 11:54:29 GMT -5
When a thread is moderated please do not bring back posts that were moved or deleted...thank you!
edge.
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