ShtrRdy
Well-Known Member
Copy.
I'll see if he has instructions available online.
I'll see if he has instructions available online.
Concentricity Question
- Thread starter Deputy819
- Start date
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Deputy819
Well-Known Member
Okay, here we go (I read the directions that came with it AND the ONLINE directions too. As it turns out they were the same. +1 for consistency)Copy.
I'll see if he has instructions available online.
After zeroing a fired/unsized case and inserting one of my handloads afterwards this is the reading I get. Instructions say headspace clearance of handloads should NEVER be greater than .002. So, please "school" me on exactly what .001 means in this case. Is the shoulder on this particular round right at the "ragged edge"?
Deputy819
Well-Known Member
Upon taking more readings of SIZED cases some of them actually went to .002 and .0025 IN variation from the "zeroed" fired/unsized case. So, some inconsistencies in my brass I conclude? So, my next step is to use the body die in conjunction with this gauge and start bumping back all cases .002 from the original zeroed fired/unsized case yes?????
It can take 3-4 firings for brass to completely stretch out to chamber dimensions. I would mark the cases somehow and fire them again and remeasure if it was me. Keeping track of where they are. Soon on this thread guys are going to start talking about annealing to you (me too), so prep for that
Deputy819
Well-Known Member
"Dr Vette" already hit me with that one. Ugh. But, answer me this. In taking fired case headspace measurments I actually saw variation anywhere from .02 all the way down to -.08. Yep....that's a negative sign before that number. Surely THIS is one of the things thats been causing my inconsistent groupings?? The "feel" method of closing the bolt on a resized cartridge is something I obviously CANNOT DO.....It can take 3-4 firings for brass to completely stretch out to chamber dimensions. I would mark the cases somehow and fire them again and remeasure if it was me. Keeping track of where they are. Soon on this thread guys are going to start talking about annealing to you (me too), so prep for that
If you zeroed your gauge on a fired case, and then got a measurement of 0.02 (I bet it was 0.002) and -0.08 (which I bet was -0.008) is telling me that your brass has not all fully expanded to your chamber size. You need to fire it all a couple more times before you can bump the shoulder back with any consistency. If I was playing with your new "toy" (that looks cool) I'd find the most positive case and set the die to bump that measurement down 0.002 and run all the brass through and fire ALL OF THEM and then measure again. Or find a handful that measure long and size them down and see if this solves your problem. But you will not get anywhere until they have all stretched out to chamber size.
Deputy819
Well-Known Member
Yes...sorry. Didn't type in enough zero's. What I did so far was set that gauge's "zero" to a case I fired out the back door a couple days ago and THEN measure all my fired brass. Admittedly some of that brass was "once fired" and some was "3rd-4th fired". The headapace variation in all that brass measured anywhere from .002 to -.008. The ones that were actually at "zero" got bumped back by .002. I now have 15 cases (out of all that I was able to measure and bump back) that all have the same shoulder headspace and within close enough weight to shoot together. Please tell me I'm on the right track .
Deputy819
Well-Known Member
I see what you're saying though. The case I "zeroed" on may not have even stretched to my chamber dimension yet, right?
Dr. Vette
Well-Known Member
Or it was one you previously bumped back?
Remember, you said that sometimes you were doing that, sometimes you weren't.
I'd take the "longest" few cases, set those as your zero point, then go back 0.002 from those...after you anneal.
Deputy819
Well-Known Member
Ha! There's that dreaded
Ha! There's that dreaded "A" word again. Yeah, I would only do that when my bolt wouldn't close anymore, but didn't have a way to measure how much I was actually bumping it. I do now thanks to your recommendation. Pretty cool little tool. Now I just have to weed through all the brass I messed up.
Ha! There's that dreaded "A" word again. Yeah, I would only do that when my bolt wouldn't close anymore, but didn't have a way to measure how much I was actually bumping it. I do now thanks to your recommendation. Pretty cool little tool. Now I just have to weed through all the brass I messed up.
Dr. Vette
Well-Known Member
How much brass do you have?
Deputy819
Well-Known Member
Only to sort through about 50 pcs or so of fired brass. Have a couple unopened boxes on the shelf.
just country
Well-Known Member
morning, I shoot a 6mmAI, 95gr. bergers. 4831sc. fed. large rifle
primer, Winchester brass. shoots .250-.500 groups all day
long. the .500 r from mirage in summertime TX. heat.
the rig is #7 contour shilen barrel. SS. I do not check
cont. I work with bullets, seating depth, primers, brass
last of all myself. GBOT TUM
question, why r u using 4451.
the norm for me is bullet make and weight, make my
decision on the powder. justme!
primer, Winchester brass. shoots .250-.500 groups all day
long. the .500 r from mirage in summertime TX. heat.
the rig is #7 contour shilen barrel. SS. I do not check
cont. I work with bullets, seating depth, primers, brass
last of all myself. GBOT TUM
question, why r u using 4451.
the norm for me is bullet make and weight, make my
decision on the powder. justme!
Deputy819
Well-Known Member
Morning, Sir! Thanks for your input on this thread as it is much appreciated. Have tried several powders for this rifle to include RL19, IMR 4831, and H4831 SC. Still have yet to try RL22 as it is still unopened on the shelf. Honestly, I've seen the best numbers (S.D./E.S) and, generally speaking, the best groups at 200 yards with IMR 4451 and BR2 primers. Still playing around though as I'm pretty sure some of my issues have to do with inconsistent handloads! I'll throw myself right under the bus on that one.
