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Post by ET on Jan 23, 2011 8:51:23 GMT -5
Hmmmmmmmmmm...I have not figured out how to get those OBT markers on my graph? Any help? Richard Richard On the bottom left hand corner of your barrel setup form my understanding is that you need to fill in Bullet Diameter, Overall Barrel Length and Cartridge Case Length that is then used with the velocity readings to calculate OBT. With a previous trace I would open the file and try adding this information to see what happens. Also expanding the trace to a longer time frame say 2.0 milliseconds to make sure the OBT markers are not masked as your traces seem to have a longer ignition delay. Ed
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Post by Richard on Jan 23, 2011 20:28:42 GMT -5
Thanks Ed...............I will have to look at that again. I know I put in barrel length from the bullet shoulder to the muzzle. I thought I had put the bullet diameter in also?? I'll check when I fire up the lap top. By the way, last night when I got in bed, I was thinking about he discrepancy on the pressure readings between TGinPA and mine? This is what I am thinking just might be the reason: The recessed breech plug! When you think of it, there is 11 gr. of powder inside that plug. This like cylinder inside the barrel. Any pressure exerted on the walls of this cylinder is not exerting on the walls of the barrel............ ? Could this be absorbing some of the barrel stress that effects the strain gage??? So, what I am doing tomorrow (we are shooting Monday since Tuesday is supposed to rain and snow) is installing a standard breech plug and shooting a group with the 50 gr. N-110 powder and see if it effects the pressure reading. Also, thanks to a couple of PM's with DBinNY? ? I finally figured out how to convert the Trace files to JPG's!!! Thank you Dan! Edge also gave me directions but I did not want to pester him for some clarifications. Dan painted the picture a little clearer. Man I learned something new on the computer ;D I might have to get a job with the GEEK SQUAD ;D Savage Shooter... Yes, the N-130 has given me more velocity than H-322. While I have quite a bit of N-130 on hand (maybe 6 lbs.) it is not readily available.......Actually, I think VV has discontinued it. It was the new and up and coming benchrest powder for the 6PPC until N-133 came on the scene shortly thereafter. I happened to get a deal on what I have from a store who has had it since 1997! So, I can't see doing too much testing if guys can't get ther hands on it! Richard
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Post by DBinNY on Jan 23, 2011 22:38:24 GMT -5
Richard, it was the least I could do for all your fine work with the traces. Glad I could help. I think you may be on to something with your recessed plug theory. I'm thinking that initial pressure with a recessed plug would actually be higher because the powder is burning in a more confined space but you are probably right about having more steel surrounding it. It will be very interesting to see how your standard plug tests measure up.
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Post by edge on Jan 24, 2011 8:48:43 GMT -5
If nothing else it will push the powder column out further and should place the center of the powder near the PT gage. It will be interesting to see if it makes a difference.
edge.
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Post by ET on Jan 24, 2011 8:52:13 GMT -5
By the way, last night when I got in bed, I was thinking about he discrepancy on the pressure readings between TGinPA and mine? This is what I am thinking just might be the reason: The recessed breech plug! When you think of it, there is 11 gr. of powder inside that plug. This like cylinder inside the barrel. Any pressure exerted on the walls of this cylinder is not exerting on the walls of the barrel............ ? Could this be absorbing some of the barrel stress that effects the strain gage??? So, what I am doing tomorrow (we are shooting Monday since Tuesday is supposed to rain and snow) is installing a standard breech plug and shooting a group with the 50 gr. N-110 powder and see if it effects the pressure reading. Richard Richard This one I follow with keen interest to see what a recessed BP vs a non recessed BP will produce with trace results. Looking forward to see what affect it has on the Rise Time. Also will be interested in seeing if what appears to be ignition delays is reduced. I would be surprised to see a large difference in pressure but then again I’ve been surprised before on unexpected results. Just part of the learning curve. Ed
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Post by TGinPA on Jan 24, 2011 11:02:01 GMT -5
Richard: I have been shooting a recessed breech plug for all my trace tests I suspect that it is the same configuration you have been using. One thought I had about comparing pressures from two different breech plugs: the ventliner orifice between the two may be different and have an effect on pressure readings. It might be helpful if the ventliner orifice on both was as close to being the same as possible. I will also try to compare the effect of different plugs and give the orifice measurements as part of the data I include in my report. Savage Shooter: As one who has been there and done that your comments are helpful and much appreciated. We need all the help we can get. No need to reinvent the wheel here!
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Post by Savage Shooter on Jan 24, 2011 11:48:18 GMT -5
Richard: I have been shooting a recessed breech plug for all my trace tests I suspect that it is the same configuration you have been using. One thought I had about comparing pressures from two different breech plugs: the ventliner orifice between the two may be different and have an effect on pressure readings. It might be helpful if the ventliner orifice on both was as close to being the same as possible. I will also try to compare the effect of different plugs and give the orifice measurements as part of the data I include in my report. Savage Shooter: As one who hasd been there and done that your comments are helpful and much appreciated. We need all the help we can get. No need to reinvent the wheel here! I am wondering if the primary may still be a touch fast for the .45 bore. I have not seen where anyone tried going with a bit slower powder for primary. It just stands to reason that as well as the H322 has performed in the .50 that a slower powder would be more optimum in the .45. I see Richards increased velocities with N130 and think along this path. Have to wonder if a burn rate along the lines of Benchmark, H335, N133 OR maybe even SLOWER would be best as primary powder for the .45. I also have seen posted that the 15/55 n110/h322 load has shown zero temp sensitivity down into single digit temps, I would think that a optimum load combo SHOULD show at least a bit of fps fall off in these temps. Also shows up by .45 blowing sabots sooner and a bit more than in the .50. You have to really get the barrel warm on a .50 with the n110/h322 to make it blow a sabot. All just thoughts to ponder. Of course barrel length matters here a bit also but not as big a factor as burn rates.
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Post by Savage Shooter on Jan 24, 2011 12:54:05 GMT -5
Just spent a long time reading thru all of Richards results and am even more confident that there would be better main powder for .45 duplex than H322.
I see were he tested a 10/60 N110/N133 load that develops 2694fps, but not a 15/55&60 load, I would think this should be closer to optimum and increase speed and still reduce pressures a bit.
Now there was some testing done at 15/60 with 5744/N133 that shows 2771 and I know this will go faster with N110 as booster.
I would revisit the loads using N133 as primary with more booster using N110. Sweet spot should be at either 15/55 or 15/60 using N110/N133.
Don't see any speeds with 2015 in these load weights either. It would be slightly better than H322 but would again have to use N110 as booster. Again charge weight should be at 15/55,,,, as 15/60 could be bit stout with 2015.
Just caught myself pondering again, going back to sleep now.
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Post by Dave W on Jan 24, 2011 19:12:03 GMT -5
Just spent a long time reading thru all of Richards results and am even more confident that there would be better main powder for .45 duplex than H322. I see were he tested a 10/60 N110/N133 load that develops 2694fps, but not a 15/55&60 load, I would think this should be closer to optimum and increase speed and still reduce pressures a bit. Now there was some testing done at 15/60 with 5744/N133 that shows 2771 and I know this will go faster with N110 as booster. I would revisit the loads using N133 as primary with more booster using N110. Sweet spot should be at either 15/55 or 15/60 using N110/N133. Don't see any speeds with 2015 in these load weights either. It would be slightly better than H322 but would again have to use N110 as booster. Again charge weight should be at 15/55,,,, as 15/60 could be bit stout with 2015. Just caught myself pondering again, going back to sleep now. 17gr N110/53gr 2015 was in the mid 2900's in my #1.
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Post by Richard on Jan 24, 2011 20:03:56 GMT -5
The next traces I plan on getting on this evening will surprise you as much as me concerning N-110 being faster than 5744??? I have done a number of various tests and it seems N-110 was always faster Richard
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Post by Savage Shooter on Jan 24, 2011 20:34:30 GMT -5
The next traces I plan on getting on this evening will surprise you as much as me concerning N-110 being faster than 5744??? I have done a number of various tests and it seems N-110 was always faster Richard That has been my experience also which is why I said some of the old loads you worked on in the past with 5744 that were slower than desired deserve a new look with N110. It is not unusual for duplexes to be 150fps faster with n110 instead of 5744 for booster, I would think this would manifest even more in the .45 than what I saw in the .50. Especially as you get to close to upper end speeds.
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