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Post by Deleted on Jan 18, 2017 13:56:38 GMT -5
I plan to get everything together and posted this evening. The results were not what I had expected due to previous claims but I am not at all surprised and am very pleased.
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Post by gd357 on Jan 18, 2017 16:14:26 GMT -5
Cool! Can't wait to see some of you findings! Thanks!
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Post by Richard on Jan 18, 2017 17:18:12 GMT -5
Jerry...........You might try comparing results with those of TG to see how close you come. When I was running them, I always seemed to be 10,000 psi lower than his readings. Supposedly there is a way to adjust your readings. At the time, I was so unfamiliar with this technical stuff I just wanted to send it back to Jon.
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Post by Deleted on Jan 18, 2017 21:39:57 GMT -5
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Post by Deleted on Jan 18, 2017 21:52:47 GMT -5
Wow, that's really cool Jerry!!!!
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Post by jimmykip on Jan 18, 2017 21:53:22 GMT -5
Interesting. Based on my limited (very limited) learning on the subject, the pressures are higher than what I would have guessed. Jimmy
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Post by longrange on Jan 18, 2017 22:01:06 GMT -5
I'm looking forward to more traces. Are you planning on tracing 3031 with 275 grain bullet and lrmp?
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Post by hillbill on Jan 18, 2017 22:06:29 GMT -5
A GREAT start Jerry! looking good..
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Post by Deleted on Jan 18, 2017 22:24:59 GMT -5
Interesting. Based on my limited (very limited) learning on the subject, the pressures are higher than what I would have guessed. Jimmy The pressures are relatively close to TG's traces given temperature differences, etc. In a rifle that must engrave the bullet, expect about 2-3 more thousand psi than the LRMP traces. The LRMP 70 gr 4198 300 sst traced above was around 48.5kpsi. In a rifle cartridge it would have been around 51kpsi. We really are shooting much hotter loads than we realize.
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Post by Deleted on Jan 18, 2017 22:30:45 GMT -5
scat, these are cool traces. if there's anything i can do to contribute to the cause let me know.
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Post by jimmykip on Jan 18, 2017 22:36:15 GMT -5
Lots of learning here. Great stuff. Hopefully, I'll be getting my barrel back soon and trying out my first SML shooting. Was going to try 55 of I4198 w/275be for starters. With LMRP. If a little extrapolation is anywhere near correct,I'd think I'd be high 30ish. As high as comfortable with a break action. Jimmy.
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Post by mike on Jan 18, 2017 23:19:56 GMT -5
Very interesting data. I haven't carefully reviewed this type of data before. What is "rise"? Thank you for your time and effort performing the tests.
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Post by mike on Jan 18, 2017 23:24:21 GMT -5
Also, what level of pressure is considered safe in a #17 28" Brux barreled bolt gun? How about a 25" Bergara on a CVA Apex break-open rifle?
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Post by Deleted on Jan 18, 2017 23:34:14 GMT -5
Very interesting data. I haven't carefully reviewed this type of data before. What is "rise"? Thank you for your time and effort performing the tests. The following is the definition given by the pressure trace manufacturer. "Rise (Rise Time) is calculated as the time in microseconds it takes for the pressure to rise from 25% of the peak value to 75% of the peak value. This can be taken as an indication of the powders burn rate." If you notice on the straight load traces. The LRMP rise time is 130 and the 209 rise time is 140/160. Also, the LRMP pressure avg is 48504 psi and the 209 pressure avg is 45866 psi. This tells me that the lrmp ignition accelerates the powder burn, developing a higher peak pressure along with much increased velocity vs the 209 ignition with the exact same load.
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Post by mike on Jan 18, 2017 23:46:10 GMT -5
Thank you for the explanation, scat. Really very interesting data.
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Post by linebaugh on Jan 19, 2017 7:32:16 GMT -5
Most excellent work Jerry. I realize this is a rather small sampling and not 100% conclusive but this seems to confirm what I have always thought about the LRMP vs 209 system, that there is no gain in velocity/pressure using a 209 system. Assuming you are using the same bushing orifice size on both guns??? Couple this with the fact that many of the lrmp systems use a larger orifice size on the bushing and I would expect to see even more gains and a more excellerated ignition timing.
Can't thank you enough for doing this.
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Post by schunter on Jan 19, 2017 7:51:48 GMT -5
Great start for sure. How long between shots?
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Post by Deleted on Jan 19, 2017 8:27:16 GMT -5
Way to go Jerry...This testing your doing will keep us safely shooting unknown loads in the future....Imo Tg is smiling from up above....
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Post by Richard on Jan 19, 2017 10:28:52 GMT -5
Jerry..............This will be an added feature on Hank's. Thanks for doing that. Also, and I know there is a lot involved with this project but...........Had you thought of a system to keep track of the traces much like on Doug's? Either in numerical order as you do them or is there a way (I don't do spread sheets) that one could "put in a powder/bullet" search and retrieve info for a specific. I know this can get complicated...........but maybe we have a member who is good at this sort of thing that could help you? Just thinking out loud. Maybe Hank could set up a "sticky" just for the traces?
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Post by Deleted on Jan 19, 2017 12:02:48 GMT -5
I'm very happy your doing this because it should give us ideas on loads.
If you decide to make a "pressure trace" post where you place all your findings would you take a suggestion?? One thing I don't like is how unorganized the one on Doug's is. If you were to make one on here could you or who ever places them on the forum make a section for each individual bullet weight and caliber? When searching for a load it's very hard to find what your looking for when it's just thrown on the page. I realize it could be a pain but if we start out that way then it shouldn't be difficult to at least start that way.
If not I understand you are all ready doing a lot for this board and I thank you and appreciate your efforts!!
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