It's a wonder he didn't launch the scope flipping over backwards right into his cranium! Was his name Richard?
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That looks large for a scope mounting screw hole. A 8-48 is only .156 of on the thread. It used to be when dewatting or converting to parade rifles to drill a hole thru the side of the chamber as part of the process. I'm wondering if this barrel was one of these converted barrels. I have seen them returned to "service by puhing a plug in and recutting the chamber, don't recommend it by any means but have seen it done.
Another possible explanation is. The older cup crushers used a receiver with a place to mount a copper pellet, when fired the pressure crushed the pellet increasing dia thus giving pressure information. Could these cases have come from someplace doing pressure testing?
Yes, hopefully they were test cases
http://www.pcb.com/TestMeasurement/P...stic/conformal
and
http://bulletin.accurateshooter.com/...-measurements/
otherwise
YUK and Double yuk!
Time for a new barrel
Mike
Last edited by skeettx; 12-22-2017 at 04:39 PM.
NRA Benefactor 2004 USAF RET 1971-95
I once received a batch of 30-06 brass that was used for pressure tests-- once fired during testing. I have over 10 reloads on them now-- the testing mark gradually fades as the brass adjusts to fit the chamber, and repeated examination (outside and inside) shows no issues.
Hick: Iron sights!
I was thinking the same thing, that the spots look awful large but I can't really think of another thing that might cause such a marking on the case. At least I couldn't until I read the above posts. This sight really is filled with people that know all kinds of stuff.
I Am Descended From Men Who Would Not Be Ruled
Fiat Justitia, Ruat Caelum
Pressure test cases.
I give loading advice based on my actual results in factory rifles with standard chambers, twist rates and basic accurizing.
My goals for using cast boolits are lots of good, cheap, and reasonably accurate shooting, while avoiding overly tedious loading processes.
The BHN Deformation Formula, and why I don't use it.
How to find and fix sizing die eccentricity problems.
Do you trust your casting thermometer?
A few musings.
Pressure testing cases. Mark is from the copper crusher "pill" that starts out flush with the case and is displaced leaving the mark in the case.
These cases work just fine.
I hadn't thought about them being test cases...I do know the brass protrusion sticks up a few thousandths of and inch. Running a few through the full length sizing die didn't manage to squeeze them back down and have a slight "smear" to them...Either way, they are on the reloading shelf as decorations now.
ANother thing to remember on pressure test cases is occasionally the disk in the case is blown up into the crusher channel. SO these spots could be weak areas if full pressure rounds are used.
Not pressure test. Neither CUP or peizo-transducers are used on standard actions. They are used on special fixed test fixtures. Also if either were they would have been mounted in the center of the case powder capacity as per SAAMI or CIP spec. Both are very expensive to own and to use and would not have been mounted on a portable rifle.
The detent in the cases is exactly were the front screw hole would have been drilled through the barrel. I suggest the OP remove the scope and base to determine if such is the case.
Larry Gibson
“Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
― Nikola Tesla
I passed a message to the gentleman I received the cases from. He said he doesn't know for sure who had the rifle in question. Is possible the cases were fired long ago...I laid a one piece base over the receiver of my friends K98 and the hole is in the exact spot under the front hole of the base FWIW...
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |