PDA

View Full Version : corelokt



6schwab6
12-01-2006, 03:45 AM
I'm using a 26" encore in 300 winmag. I'm trying to find reloading data for the 180gr corelokt to no avail. need help!!! sorry, the corelokt is a pspcl

kg42
12-01-2006, 08:58 AM
Hi 6schwab6

These are data from the pre-Hodgdon IMR free Handloader's Guide, Rifle section:

300 Win. Mag.
Win. case, Win. 8 1/2-120 PR
REM 180gr PTD.SPCL
24" bbl, 3.250" col

IMR3031/58.5/2900fps/53700cup
IMR4064/62.5/2995fps/53800cup
IMR4895/59.5/2950fps/53900cup
IMR4320/60.5/2920fps/53700cup
IMR4350/71.5/3100fps/54000cup
IMR4831/75.5/3105fps/53700cup(compressed load)
IMR7828/74.0/3050fps/53900cup

IMR suggest to start 10% below these loads.

kg

versifier
12-01-2006, 06:04 PM
You can safely substitute data for any 180gr jacketed bullet as long as you start at the minimum charge and work up. What powders do you have to work with? I have always been leery of sources that publish one load for a powder/bullet combination because I never know without some research where that load falls on the pressure curve. I have the same data source as kg42 and this is what I learned comparing them to the listed loads with those powders in my Sierra manual:
IMR3031:not listed
IMR4064:not listed
IMR4895:not listed
IMR4320:not listed
IMR4350:64.0-71.4Max
IMR4831:67.2-73.8Max
IMR7828:72.3-76.8Max
Next, I looked it up in my Lee manual:
IMR3031:51.8-58.5Max
IMR4064:55.2-62.5Max
IMR4895:52.5-59.5Max
IMR4320:53.5-60.5Max
IMR4350:63.6-67.8Max
IMR4831:65.4-69.7Max
IMR7828:74.5Min & Max
So, this is what I learned about the IMR data:
IMR3031:58.5 Max load
IMR4064:62.5 Max load
IMR4895:59.5 Max load
IMR4320:60.5 Max load
IMR4350:71.5 Over Max on both other sources
IMR4831:75.5 Over Max on both other sources
IMR7828:74.0 Mid range in Sierra, below starting in Lee
All of which tells me that it's a good thing they suggest starting at 10% below the loads they list. Just because it is listed as a Max load, that doesn't mean it will necessarily be a Max load in your rifle. Some rifles will show pressure signs well below listed Max, others will not even when the listed Max is exceeded in small increments. Start low and work up, watching the primers of your fired cases for pressure signs. When they begin to flatten, that shows you're getting hot. When they begin to crater (totally flattened and metal flows around the firing pin forming a raised cup) you have exceeded the safe maximum for that particular rifle and you should back off the charge at least to the point where you noticed they began to flatten, or preferably one increment below. You will almost never find the best accuracy at the high end of the pressure curve, but I admit there are occasional exceptions. Pushing the pressure limits with a magnum cartridge will greatly shorten the working life of the barrel by eroding the throat. Some shooters try to compensate for this by loading longer bullets and seating them out as far as they will feed through the magazine, or single loading them in extreme cases, but I think the practice is a foolish one, especially when simply loading in moderation will avoid the problem to a great extent. (This is not to be confused with the similar standard practice of loading bolt action and single shot cartridges out to their maximum functional length to enhance accuracy by minimizing the distance the bullet has to jump between the case mouth and the beginning of the barrel's lands.) Dead deer can't tell the difference of a few hundred feet per second in bullet velocity, and more energy NEVER makes up for a poorly placed shot.

dale clawson
12-02-2006, 12:27 AM
Just for your info check out my and others comments on corelockt in 300 mag in the general section under" wounded deer recovered". Dale

lovedogs
12-05-2006, 03:33 AM
Versifier has it pretty well figured out. I've found the .300 Winney to be a real accurate cartridge. My best results usually come with close to max charges of H4831. If you size the cases to headspace on the shoulder instead of full-length sizing it'll extend case life. The RCBS Precision Mic is real handy for measuring this and getting them sized right. You may find the Core-Lokt to be somewhat inconsistent on the ogive of the bullet which can give you fits if you're trying to measure OAL with tools that measure off the ogive. Set them back far enough and them measure nose-to-base with a caliper and it'll work okay for hunting loads, which is all you'll be using Core-Lokt's for anyway.