C.O. Shooter
Well-Known Member
Fred,
How would you compare the 28 Nosler vs 7LRM?
How would you compare the 28 Nosler vs 7LRM?
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D
Deleted member 46119
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The recipies are there with the velocity/pressure reports.
D
Deleted member 46119
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I have not been able to find the dimensions of the 7LRM. Know where I can get information on this chambering?
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I don't know where the dimensions are but I think the case capacity of the 28 Nosler is about 13% more than the LRM.
D
Deleted member 46119
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What is it based on?
D
Deleted member 46119
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Ok, based on what I see, the 7LRM is a worked over 375 Ruger. Fine format.
However, yes the 28-Nosler will have ~10grains more usable capacity. This should allow for 100fps more velocity from the 28.
However, yes the 28-Nosler will have ~10grains more usable capacity. This should allow for 100fps more velocity from the 28.
Dick Tinsley
Well-Known Member
case water capacity was established with a new 26 Nosler case necked up to 7mm and no other changes .......
a dry empty case with a live WLRM primer was weighed and then case was filled with water to top of case .... I repeated the water weight 20 times and 370.1 gr was the most constant at 14 times, the other 6 weights showed 370.0 gr ..... 100 gr of h20 capacity to top of case neck, right in line to what the Quick Design program showed --- 99.7 gr .....
a dry empty case with a live WLRM primer was weighed and then case was filled with water to top of case .... I repeated the water weight 20 times and 370.1 gr was the most constant at 14 times, the other 6 weights showed 370.0 gr ..... 100 gr of h20 capacity to top of case neck, right in line to what the Quick Design program showed --- 99.7 gr .....
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Deleted member 46119
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Testing day
Load data
Bullet: Matrix VLD 190
COAL: 3.648
Powder: Reloader 33
84 grains, 91% case capacity, 2896fps, 54501psi
85 grains, 92% case capacity, 2941fps, 54954psi
86 grains, 93% case capacity, 2960fps, 56294psi
87 grains, 94% case capacity, 2994fps, 58537psi
88 grains, 96% case capacity, 3021fps, 61027psi
89 grains, 97% case capacity, 3056fps, 62992psi
90 grains, 98% case capacity, 3076fps, 63617psi
I this is pretty much max. Ejector marks, flat primer, heavy bolt lift but this is one of those darned R700 actions
This is my first time using Reloader-33. The estimates by QL were within a couple feet for the closer to 90% loads but fps at closer to capacity, slowed by ~50fps compated to predicted. Perhaps is slows quickly when dirty. This indicates to me that the Final Finish treatment may improve the barrel.
Load data
Bullet: Matrix VLD 190
COAL: 3.648
Powder: Reloader 33
84 grains, 91% case capacity, 2896fps, 54501psi
85 grains, 92% case capacity, 2941fps, 54954psi
86 grains, 93% case capacity, 2960fps, 56294psi
87 grains, 94% case capacity, 2994fps, 58537psi
88 grains, 96% case capacity, 3021fps, 61027psi
89 grains, 97% case capacity, 3056fps, 62992psi
90 grains, 98% case capacity, 3076fps, 63617psi
I this is pretty much max. Ejector marks, flat primer, heavy bolt lift but this is one of those darned R700 actions
This is my first time using Reloader-33. The estimates by QL were within a couple feet for the closer to 90% loads but fps at closer to capacity, slowed by ~50fps compated to predicted. Perhaps is slows quickly when dirty. This indicates to me that the Final Finish treatment may improve the barrel.
That is an uncalibrated pressure trace though, correct?
My thought is if the RUM case is setup for a SAAMI max of 65K I would not want to expect sticky bolt swipes heavy primer flow below that pressure or is this typical? I know in other loads where I actually had true ref ammo that was piezo tested with the exact same barrel config ( reamer and button) we did not see heavy swipes or sticky bolts until we got above max PSI.
Doesn't the maxtrix bullet also have more bearing surface area than bergers hybrids
My thought is if the RUM case is setup for a SAAMI max of 65K I would not want to expect sticky bolt swipes heavy primer flow below that pressure or is this typical? I know in other loads where I actually had true ref ammo that was piezo tested with the exact same barrel config ( reamer and button) we did not see heavy swipes or sticky bolts until we got above max PSI.
Doesn't the maxtrix bullet also have more bearing surface area than bergers hybrids
D
Deleted member 46119
Guest
Correct, uncalibrated.
Relative shot to shot not actual.
Nosler brass is way soft so pressure shows early.
R700 action is stretchy compared to the Weatherby shows sticky sooner.
But, uncalibrated, I get ejector mark at ~56k psi across all the sensors.
Someday I will make some xx-Nosler brass from R-P RUM brass. When I sectioned them both the Nosler was ~.022 thick and the R-P RUM was ~.026. I don't have a hardness tester (yet, he he he) but R-P "feels" harder.
JfSeaman,
I know what you mean about some brands of brass being soft. Here is an interesting article where several brands of brass are compared using a X-Ray Fluorescence Spectrometer. Unfortunately Nosler brass is not in the test.
X-Ray Spectrometry of Cartridge Brass within AccurateShooter.com
I know what you mean about some brands of brass being soft. Here is an interesting article where several brands of brass are compared using a X-Ray Fluorescence Spectrometer. Unfortunately Nosler brass is not in the test.
X-Ray Spectrometry of Cartridge Brass within AccurateShooter.com
D
Deleted member 46119
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Just when you think you've read everything on a site...
Nosler is Norma. I have found Norma head stamp in my 300 RUM Nosler packages.
That explains why R-P primer pockets give up so quickly in the hot RUM/Edge loads and why the case wall thickness is .020 in Nosler/Norma and .026 in R-P.
