RGR
07-08-2006, 04:24 PM
Howdy all from Arizona- first post-
I want to tell you about a very small experiment I conducted last week to take a look at the springyness of the model
95 Marlin in 45-70. I prodeeded as follows:
A loaded round with primer below flush is placed on a
granite surface plate and, useing the height guage with
carbide scribe, a line is scribed on the case about .150"
below the case mouth. The height guage is left undisturbed
while the round is fired, then the de-capped case is returned
to the surface plate and a second line is scribed. The
distance between the two lines is then measured with a
high magnification hand-held optical comparator.
I've beel loading Keith's old load of 53 gr. IMR 3031
under the 400 and 405 gr. bullets for about 40 years,
but have become interested in Hodgdon's "new" H4198
and loaded eight single rounds with it, carge weights
ranging from 46 gr. to 50.5 gr. under Remington 400 gr.
bullets and useing the above procedure, got the
following results:
53 gr. IMR 3031 1820 fps .005" stretch
46 gr. H-4198 1859 .005
48.5 1955 .007
50.5 1981 .010
Note that jumping from 48.5 to 50.5 does not produce
much gain in velocity, while case stretch increases to .010".
Like I said, a very small experiment.
I'm kinds liking that 48.5 load generating only .002" more
stretch than the 3031, which is probably OK.
I could certainly tell the difference when firing the rifle.
Gad! Maybe I'm actually going to change my load!
Hope this is of some interest.
Best regards,
RGR
I want to tell you about a very small experiment I conducted last week to take a look at the springyness of the model
95 Marlin in 45-70. I prodeeded as follows:
A loaded round with primer below flush is placed on a
granite surface plate and, useing the height guage with
carbide scribe, a line is scribed on the case about .150"
below the case mouth. The height guage is left undisturbed
while the round is fired, then the de-capped case is returned
to the surface plate and a second line is scribed. The
distance between the two lines is then measured with a
high magnification hand-held optical comparator.
I've beel loading Keith's old load of 53 gr. IMR 3031
under the 400 and 405 gr. bullets for about 40 years,
but have become interested in Hodgdon's "new" H4198
and loaded eight single rounds with it, carge weights
ranging from 46 gr. to 50.5 gr. under Remington 400 gr.
bullets and useing the above procedure, got the
following results:
53 gr. IMR 3031 1820 fps .005" stretch
46 gr. H-4198 1859 .005
48.5 1955 .007
50.5 1981 .010
Note that jumping from 48.5 to 50.5 does not produce
much gain in velocity, while case stretch increases to .010".
Like I said, a very small experiment.
I'm kinds liking that 48.5 load generating only .002" more
stretch than the 3031, which is probably OK.
I could certainly tell the difference when firing the rifle.
Gad! Maybe I'm actually going to change my load!
Hope this is of some interest.
Best regards,
RGR