Colorado Bear

Post pictures and tell us all about the critters you harvested with your Thumper.

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Re: Colorado Bear

Postby Hoot » Tue Sep 11, 2012 8:38 pm

Caseknife wrote:Ursusj...snip...
Hoot, I'm curious as to how you load the 275 xpb with more powder than the 200. Isn't it usually the other way around in the loading manuals? Or is this something peculiar with the 450. Are the crimp and col the same as the 200?


First off, I rarely load for maximum velocity. More often than not, I load for maximum accuracy since most of our bullets are plenty lethal at speeds below maximum velocity and I don't use my 450b out on the plains, at long ranges, so flatter shooting doesn't come into play for me. Like many different bullets in my 20" 450b barrel, the 200s reach maximum accuracy going down the pipe from 2200-2250fps. It takes more powder to push the 275s to 2200-2250fps than it does for the 200s.

That having been said, there is an error in the image I linked. Those who followed my XPB experiments closely last year may recall me getting a second bottle of Lil Gun in the middle of the testing process and noting that it had ran significantly slower, to the tune of 2-3 grains slower than my previous bottles of Lil Gun did. I eventually committed the remainder of that bottle to the flower bed out back. Something was just not right about it. If you recall that, you recalled better than me, because I quoted the results of that bad bottle in the previous post and I thank you for catching that. Read my reports and you'll find I generally err on the side of caution, sometimes to the point of being chided for it. The correct weights of powder from previous and subsequent bottles of Lil Gun require 39-40 grains (NOT 42-43) to drive the 275 XPBs to 2200-2250 fps, depending upon the crimp you use. In my case a taper crimp, as opposed to a stab crimp. The latter being capable of getting even more velocity at a modest sacrifice in accuracy (my experience).

I am usually more fastidious about posting data from my reloading and I apologize for quoting the exception, not the rule. :oops: I still maintain that I will gladly trade off 5-10% of maximum velocity to reduce my 100 yard groups from 2 inches down to less than one inch. That's just how I'm wired.

Don't ever hesitate to call into question that which rings wrong in you gut, WRT someones loads that they post. I have been know to chide members for working right up to the brink of safe loading practice as they strive to get every fps out of their rifle, so I'm open to that door swinging the other way.

Hoot
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Re: Colorado Bear

Postby Hoot » Tue Sep 11, 2012 8:42 pm

I forgot to answer one of your questions. Both the 200 and 275 are identical in the forward half. The 275 has a longer butt to achieve the additional weight. Since I seat both to catch the front driving band groove with the taper crimp, I seat both of them to the same COL.

Hoot

Edit: Here's a link to the thread regarding the misquoted charge weights.
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Re: Colorado Bear

Postby Caseknife » Wed Sep 12, 2012 11:00 am

Hoot, I recall the batch of powder issues. I have 3 boxes of 275's to work up a load. I'll start with 38 grs and go from there. Thanks for the clarification.
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