RSI Pressure Trace - Initial use report

[royinidaho]

Hijacking own thread to Frontal Ignition from RSI pressure trace test

Here's what I did, not by design but because it was convienent.

Was working up to maximum load w/250gr Sierra Game Kings and RL-25 powder.

Started at 90gr and went to 94.5gr and stopped, not because of pressure but due to achieving 2999 FPS average velocity which was my goal (well, 3000 was really the goal). Still room to go but I figure 3000 MV is enough. Didn't have the RSI connected but would say that another 0.5gr of powder would make pressure signs noticeable.

While loading the 3 94.5gr loads I noticed a case with a flash tube installed so I dumpted 94.5 gr of RL-25 in that one also.

W/o the flash tube the top of the powder came to the base of the shoulder. With the flash tube the powder came to the base of the neck.

My overall cartridge length is 3.041" from base of brass to ogive (0.388 bullet diameter). The base of the game king is right at the base of the neck.

#1 good thing - RL-25 seems to have a good density for the flash tube test. (hey a blind hog stumbles onto an acorn once in a while /ubbthreads/images/graemlins/smirk.gif)

I was a bit concerned about too much pressure at the 94.5gr load due to the case volume reduction with the flash tube and without the tube the load is just below the beginnings of extraction problems and primer pocket expansion. These flash tubes were cut for the Win Mag case and are a bit short for the RUM. Nevertheless with that much powder space reduction I figured pressure was going to be a problem.

Results: All four shots were w/94.5gr RL-25, 250gr GKs & 215M primers.

Velocity
3009
2993
2995
2940 - Flash tube installed.

Its very small data point but seems indicative of something. If this trend continues someone will have to come up with an explanation. /ubbthreads/images/graemlins/grin.gif

 

[bailey1474]

Re: Hijacking own thread to Frontal Ignition from RSI pressure trace test

That's all the tease that you are going to give us???? I expect you to have the Pressure Trace hooked up next time. I want to be sure my contribution to this research project is being used as it should /ubbthreads/images/graemlins/grin.gif.

 

[royinidaho]

Re: Hijacking own thread to Frontal Ignition from RSI pressure trace t

Geez Bill,

Cut me a little slack. I'm old, slow and ugly and not overly bright....

I ran the battery in my H-4 down to zero twice last week and Momma hates for her clean machine to make the trip to the back pasture. /ubbthreads/images/graemlins/crazy.gif Its not the RSI but the computer that does it + the battery may be older than you and I forget to start the machine every once in awhile. /ubbthreads/images/graemlins/frown.gif

 

[bailey1474]

Re: Hijacking own thread to Frontal Ignition from RSI pressure trace t

Just yankin' your chain a little Roy /ubbthreads/images/graemlins/grin.gif!! Get yourself a $40 power inverter and plug the thing into your cigarette lighter. That is what I did. The laptop I was using was so old that I couldn't find a new battery for it and the one I have is nothing more than a good paper weight. I just used the inverter to run it.

 

[royinidaho]

Re: Hijacking own thread to Frontal Ignition from RSI pressure trace t

[ QUOTE ]
Just yankin' your chain a little Roy /ubbthreads/images/graemlins/grin.gif!! Get yourself a $40 power inverter and plug the thing into your cigarette lighter.

[/ QUOTE ]

Yup, I caught on to the chain yanking /ubbthreads/images/graemlins/wink.gif

RE: the inverter. That's what I do/have. It's the battery on my Hummer-4 (read Suzuki Sidekick /ubbthreads/images/graemlins/blush.gif but just wait till I get my airbrush skills up to speed, it'll say H-4/HEMI/Bully Dog/APS on the fender. Then I'll be cool like the young guys /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

I'll do some more shootin today and get a base set of data w/o the flash tube then go to the next step.

 

[41mag]

Re: Hijacking own thread to Frontal Ignition from RSI pressure trace t

Well if your gonna have "H-4/HEMI/Bully Dog/APS on the fender." and "Then I'll be cool like the young guys", then you might as well pick you up a spare battery and mount it in the back so you can run your goodies off it instead of your starting battery. Might as well throw in a heavier duty altinator as well to charge it up quicker, and a solor panel to charge it while you are just sitting there waitin on your barrel to cool.

Just think, then you could have your varmint light, DVD player, lap top, electric ice chest, and even a fan or two set up to keep ya cool. Shoot the accessories are limitless. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif