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Post by cuda on Sept 1, 2014 12:49:24 GMT -5
I have both for now going to just use bushings from now on. But with the vent liner when it gets to .035 we throw them away. But now some are starting .035 bushings and then some using .040 bushings just seems a little different. Why go bigger than .035 what others discard just a little hard to figure. At .035 the groups got bigger you would think the .040 should not work at all. You would think that a .030 or smaller would be way better over all right? And it will let more fine powders go right through the hole. So if you do not have a spent primer in when you load the gun fine powder can go right into the firing pin hole. And then you have a chance of trouble firing the gun. The .030 vent line would fire the powders we use before so why go any bigger now? Just wonder why you would want to go bigger to do the same job now?
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Post by Deleted on Sept 1, 2014 14:23:43 GMT -5
The majority of guys using .45 SMLs are using a very quick burning powder like 4198. That powder is very easily ignited by any primer, right? Then a guy like Richard (and a lot of others) use a booster load and get even better ignition and ES's. Now look at the guys who tried using IMR3031 with a .030" bushing and no booster. They had a hard time igniting it. So they used a booster to remedy that. A .040" bushing has a surface area that is ~ 2 times bigger than a .030" bushing. So it allows ~ 2 times the flame through the bushing hole for ignition. If anyone wants to use a slow burning powder like 3031, 4350 or 4831 in a .45 SML with a .030" bushing or a LRM primer, and not have the load be pressure starved, they can remedy it a number of ways. 1) use a heavier bullet to help the load create pressure 2) use a booster to help the load create pressure 3) use a bullet that is sized very tight to help the load create pressure. That's how I first got Retumbo to ignite in the .416's with 209's and a .016" x 1 hole bushing. Break out the mallet!  4) use a wad, that might even help with some of the slower powders But if you are going to stick with a very quick burning powder like 4198, or a boosted load, that can be ignited by smacking 2 rocks together, you probably don't need a .040" bushing. You can always have a custom .029" x 2 hole bushing made ( that has ~ the same surface area as a .040" x 1 hole) if you're worried about having powder fall down through the bushing hole. |
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Post by longrange on Sept 1, 2014 14:33:30 GMT -5
That explains the ignition, but what about the accuracy issue? Is it a matter of the flash hole staying the same size? Richard said that his groups didn't open up even when his his vent liner opened up to .044.
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Post by Deleted on Sept 1, 2014 15:22:03 GMT -5
That explains the ignition, but what about the accuracy issue? Is it a matter of the flash hole staying the same size? Richard said that his groups didn't open up even when his his vent liner opened up to .044. I haven't had an issue with accuracy with the .040" bushings. But the pure tungsten bushings stay the same size for many hundreds of shots So your thoughts are probably correct in regards to the vent liners opening up with various powders and loads over the course of 20-25 shots or so. Richard would be an expert on this I'd say. |
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Post by Deleted on Sept 1, 2014 16:05:23 GMT -5
My take on it is that once a vent starts eroding out to .035 then more accelerated erosion will take place each shot and then you are essentially shooting a different gun and poi will shift.....Vents are cheap so why not change it...? Probably time to clean the flame channel out while you are at it....It's just breachplug maintenance... IMO the sabotless game has been the root of all improvements because the pressures just went up at least 10,000ft/lbs....from 33,000 for saboted rounds to 43000+ sabotless.....
With Richards gun he has been shooting the same bushing at last count ICR is 500+....Earnhardt send him a .040 and tell him NO duplexs,lol.....The ANSR bushing is what I call it very major breakthrough here by Earnhardt's xtreme testing temp and load's...he knows smling... |
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Post by Dave W on Sept 1, 2014 16:16:47 GMT -5
My reason for tossing the vents at .035 is the accelerated erosion of the vent and the ES starts to widen once the vent gets larger than .035. I have shot good groups at .037 but the group starts to take on a more vertical shape than horizontal.
Would like to see an .035 bushing available.
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Post by Richard on Sept 1, 2014 16:23:17 GMT -5
Expert? No!...........Having a lot of experience? Yes!
What happened was this: On a number of occasions I would start my range day out with a new vent that I had drilled with a .031" bit. I would use the same bushing for the complete sessions which would run between 30 and 40 shots. I had many of the groups at the end of the session be of equal or sometimes smaller size than when I started? When I got home and pulled the vent to measure it, I found...........WOW!..............038, .041, .0445 and many other sizes in between! So, in my experience I was seeing no difference in loads from .031 up to .0445" AND, I was using Clays boosted loads with mainly H-4198.
Due to Labor Day, I will not get the .040" bushing from Earnhardt and test it until next week. I reserve one day a week to play at the range.
With the vent liners, I was constantly shooting at various vent openings. With the Tungsten bushing, I will be able to see over a variety of loads what the .040" bushing will do. I will also be opening up the flame channel, which I never did before or at least, never did so and kept a record of what size drill bit I used. Right now, I mainly use a 1/8" bit. I use a larger one to open the primer pocket and keep the primer from bottoming out. Remember, if the carbon builds up too much under the primer, when you cam the bolt closed, you could (and it happened to me on a couple of occasions)ignite the primer and it will scare the be-jesus out of you. For me, my rifle is always on the lead sled when I close the bolt and pointing down range.
Richard
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Post by ET on Sept 1, 2014 16:45:09 GMT -5
What is often overlooked is the shifting of the sweet spot for a given load and bullet.
By altering the level of thermal energy injected into the powder for ignition you are in effect altering the mass consumption rate of the powder in a given time frame enough to alter the acceleration rate of the bullet. This should in turn alter the bullets time in the barrel.
With a larger vent orifice a larger volume of powder should be ignited at the start of the burn because of the injection of more thermal energy. This would be more noticeable with faster burning powders whereas the slower burning powders need additional thermal energy to establish a good self perpetuating burn.
This is the way I see it.
Ed
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Post by Deleted on Sept 1, 2014 17:17:58 GMT -5
What is often overlooked is the shifting of the sweet spot for a given load and bullet. By altering the level of thermal energy injected into the powder for ignition you are in effect altering the mass consumption rate of the powder in a given time frame enough to alter the acceleration rate of the bullet. This should in turn alter the bullets time in the barrel. With a larger vent orifice a larger volume of powder should be ignited at the start of the burn because of the injection of more thermal energy. This would be more noticeable with faster burning powders whereas the slower burning powders need additional thermal energy to establish a good self perpetuating burn. This is the way I see it. Ed The way I saw it in Kentucky was that 78gns of I4198 was consumed fully with prejudice on the 275mh's....with the .040 hankins ignition.......And Earnhardts getting great ignition and CLEAN .....no fouling in the bp......Fire er up Richard...... Ed I get what you're saying...until somebody does it we don't know.....That why TGinPa has been invaluable again PRICELESS for ALL he has done.....Its getting cooler ...we are fixting to be trying some loads out LIVE....Everyone be safe and bring back some some good stories........
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Post by Deleted on Sept 1, 2014 17:27:31 GMT -5
Richard...
When you get the .040 bushing are you going to enlarge your flame channel in increments or go to 14/64ths immediately... I've got a .040 bushing plug coming so I 'm interested in what your doing... I won't be shooting the big boomer loads...around 2700fps.. I'm thinking in opening mine up to 14/64ths and be done with it...Anybody got any input?
Zen
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Post by ET on Sept 1, 2014 18:17:18 GMT -5
SML
The service TGinPA has graciously provided is indeed invaluable. Knowing the pressures for given loads has contributed as much to the 45 pioneering as any research being done.
Don’t get me wrong because many others have also made noted major contributions in the pioneering aspect of ML’ing. TGinPA has removed a blindfold that has added safety value that is priceless IMO also.
Ed
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Post by longrange on Sept 1, 2014 18:42:28 GMT -5
Would peak pressures change with a .040 bushing compared to a. 030 ventliner or bushing??
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Post by Richard on Sept 1, 2014 20:01:40 GMT -5
Zen................Earnhardt suggested I go with 5/32" at first with my duplex loads. So that is what I will start with next week. Actually, the Fed-Ex tracking notice indicates I will not get it until Wednesday so next week I will put some shots down range with that combination.
Longrange..........? I had also noted that with the larger opening, my velocities remained very similar to with the smaller opening??? Since I have been shooting a lot of 5/60, 5/65 duplexes with bullets from 200 to 300 gr. I should be able to get a good comparison shooting the same loads at a constant .040".
Richard
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Post by longrange on Sept 1, 2014 20:42:41 GMT -5
looking forward to seeing your results
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Post by cuda on Sept 4, 2014 9:16:52 GMT -5
Well no one has added for a few days so. I was wondering what others do about powder falling through when using the larger vents and other powders?
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Post by rambler on Sept 4, 2014 9:19:27 GMT -5
I have just used the .040 tungsten liner with IMR4198 and no powder fell through. I was careful to look for this as I've been following this issue closely on the board.
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Post by linebaugh on Sept 4, 2014 10:08:33 GMT -5
Just a thought I had on powder falling through the larger hole. The stick type powders would obviously need to be in the right position before they could get through. In addition I kind of think if you are loading with any compression at all on the powder with your bullet this should also keep the powder captive. Since this is done prior to priming we may be overthinking the concept to a degree.
I don't use any of the duplex stuff so some of the primer powders may not have the above luxury.
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Post by Richard on Sept 4, 2014 13:51:13 GMT -5
Good thinking Line.............! So, how many people with .040" bushings have actually loaded their rifles and then taken a white tissue and held it under the end of the BP, shaken it and observed if anything cam thru? Might be interesting if some would try with different powders? I would just guess that the issue is of little concern.
Richard
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Post by rambler on Sept 4, 2014 14:06:02 GMT -5
I just cranked my off yesterday with the .040 vent liner using IMR4198 and I intentionally looked for any powder coming thru the primer hole. Didn't see nary a granule. I didn't hold any tissue over the hole tho. Richard would you recommend Charmin or some other brand  LOL |
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Post by cowhunter on Sept 4, 2014 23:30:30 GMT -5
Earnhardt that was a great tutorial. You summed up all the ways to create pressure. Panhandle just go ahead and drill out your plug to 14/64 ths. You may as well have it work from the start. Do not use the .040 with a stout load without drilling out your flame channel or you will get nasty blow-up/back/primer/bunging. The worst that can happen is you buy a new plug. You would get to 14/64 ths sooner or later anyway. I think it is funny how I tell my brother in Utah how the .040 bushing and 14/64 ths plug make a difference. He and his mechanic friend looked at things and told me those differences in bushing and plug sizes could not possibly make a difference. Now he believes. It just takes some faith I guess.
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Post by cuda on Sept 5, 2014 8:18:20 GMT -5
Rambler put it in there before you load and you will see powder. Close the bolt to hold it in place while you load the gun. You can just take the powder and measure it and you will know how much smaller it is to the .040 bushing. I had it hang my firing pin with a .030 vent liner and I had IMR4198 powder fall back out of the firing pin hole. I was only 3 pieces but it only takes one to have a FTF. Kleenex will work too. LOL!
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Post by rambler on Sept 5, 2014 9:22:04 GMT -5
Rambler put it in there before you load and you will see powder. Close the bolt to hold it in place while you load the gun. You can just take the powder and measure it and you will know how much smaller it is to the .040 bushing. I had it hang my firing pin with a .030 vent liner and I had IMR4198 powder fall back out of the firing pin hole. I was only 3 pieces but it only takes one to have a FTF. Kleenex will work too. LOL! I will try this.
if in fact is can and will fall thru the .040 hole will a spent primer left in the BP prevent the powder from coming thru?
I have a break open action BTW.
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Post by dannoboone on Sept 5, 2014 9:47:58 GMT -5
So, how many people with .040" bushings have actually loaded their rifles and then taken a white tissue and held it under the end of the BP, shaken it and observed if anything cam thru? Just so they don't shake the whole rifle up & down, or granuals which wouldn't otherwise go through, will....just like the effect of a salt shaker. A few years ago a guy came on here complaining that N110 was falling through his vent liner. It was determined the vent liner hole had not gotten too big, but he had been shaking his ML up & down to "settle" the powder. |
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Post by rambler on Sept 5, 2014 13:59:13 GMT -5
I did a little test a while ago. taped my bp to a powder tube, poured 70 gr of IMR4198 in it and shook it up and down, violently lol
Anyway, I didn't see nary a nibble come thru. Now maybe with a bullet pushed down on it. See my set up and pics below:
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Post by rangeball on Sept 5, 2014 14:29:49 GMT -5
Nice |
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Post by Deleted on Sept 5, 2014 18:22:27 GMT -5
Ok rambler, you need to safen up your workplace. Chainsaws, power tools, gunpowder and a propane tank.... All mixed with alcohol, I should have expected this out of you I guess And firearms, where's the tobacco? Then you can start an agency of your own! |
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Post by rambler on Sept 5, 2014 18:49:01 GMT -5
No tobacco. The only way to smoke at my place is if you're on fire lol
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Post by Dave W on Sept 5, 2014 18:54:24 GMT -5
Good test Rambler- thanks.
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Post by rambler on Sept 5, 2014 19:00:28 GMT -5
Good test Rambler- thanks. Thank you, tonight i may try and tweezer one of the granuals down the vent hole just for grins and i'll try the same test with some SR4759 i have which seems to be a popular duplex load and one i may be using this winter
And also thank you for not admonishing for all the unauthorized paraphernalia I have laying around
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Post by Deleted on Sept 5, 2014 22:39:47 GMT -5
H4198 is smaller though....that's where there can be a problem imo..Bill measured it at .039" a granule....
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LOL
