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We all know how you break down the word Assume.
When I built up my rig, I put all the components together, ordered a brake, mounted one of my scopes. Installed the brake. Loaded up some ammo after considering what I wanted to try. Went to the range and shot some really bad groups, but harvested some good ballistic data. Two trips later and a lot of fussing about my dies and the same results. More fussing with the resizing die led to this egg-on-face confession in someone else' thread.
At that point, in the face of a lot of ho-hum groups and I started questioning whether I wanted to work the die problem out or not as I was questioning the merits of this caliber as a choice for what was supposed to be a fun project. After crunching the latest ballistics data from Saturday's outing, I decided to zoom out and consider the bad groups as an issue separate from the die debacle. What hadn't I tried? From shot one, I never tried shooting without the brake on, though having purchased 3 others like it in different calibers that ran like clockwork, I never doubted this one. There's that assume thing again. Anyway, I had 10 more HBN'd 100gr Nosler Ballistic Tips left from the last run, loaded them with the charge that had the best SD from earlier trials and headed over to the range today with just my front rest, rear bag and some targets I usually give away at the range when someone shows up without any of their own.
I set up a 5-up target at 100 yards and shot 3 times at the top left bull. Same miserable group in the making. I took off the brake and shot 2 more. First off, boy is that brake effective. I could hardly believe the increase in rifle jump without it, but strangely no holes in the target. I walked down with a sharpie and some more targets and boxed in my original target while marking the other holes in the board. Back to the bench and shoot two more times. No holes in any of the targets. Put the brake back on and two more members were added to the bad group. Took the brake off and shot my last round. I spied a small crescent in the left edge of the top left target paper adjacent to a dime size hole just off of it. I walked down stopping short to take this picture with my Nextel I had with me since it's my weekend for being on call.
See the group without the brake? I was aiming at the center bull below and to the right of the one with the bad group. I went home and removed the brake, cleaned it in the parts tank and examined it under the stereo micro-viewer. There on the last baffle was a telltale crayon smudge of copper, built up. When I commissioned Ross to make it for me, I specified against his advice to have the brake bored extra tight to caliber with only .0065 clearance on any side of the bullet, or .277 total if you'd rather. I wanted to benefit as much as possible from as little as possible gas leaking around the bullet. An experiment I always wanted to try. He reluctantly made the brake without having my barrel there to check registration and it was off a little. Please don't slam his quality. This problem is on me 100%. If I had let him bore it to .284 as he wanted, I would not have wasted a couple of outings, boxes of bullets, powder, primers and most importantly my own self confidence.
Things I ignored in my haste to get some range time:
1) I sighted in with the brake on instead of off at first.
2) It didn't bother me that I had to adjust my turrets way off of where I had bore-sighted to before my first outing. Figured it was just me interacting with the rifle.
3) Failed to not recognize the fact that I never shoot that many bad groups without exploring why. I was too tunneled in on the chamber/die controversy.
4) I should have inspected the brake after my first outing. It really never occurred to me since I associate contact with the brake making bullets fly off into the wild blue yonder, not just throw off a little to one side and open up groups.
5) Any other self-deprecating observations I missed.
The weekend is over and bad weather is said to once again be approaching. I reamed the brake bore to .284 and will give it another try on the next outing. The copper smudge was around 10 oclock which is consistent with my shots going low and right before I adjusted it out with the turrets, hence high left when I took the brake off. Given the offset is about 1 foot by 1 foot, that should return my turrets to the mid point of their rotational range again.
In the aforementioned thread, I spoke that I had "hit and miss" luck with trying to add some neck tension by way of my Lee Factory Crimp Die. I stand corrected. I used it with today's 10 loads and it worked fine restoring the .001 too much that I lapped off of the neck portion of the resizing die. In defense of that mistake, at least the bullets seat easily and the HBN coating is not scraped off where they pass the case mouth. I did inspect one after chambering to make sure I had enough tension not to allow the bullet to move forward into the lands before I shot. I still have a lick of sense, despite this recent lapse.
Live and Learn. Assume nothing. share your mistakes as well as you victories for the sake of others benefit.
Hoot
When I built up my rig, I put all the components together, ordered a brake, mounted one of my scopes. Installed the brake. Loaded up some ammo after considering what I wanted to try. Went to the range and shot some really bad groups, but harvested some good ballistic data. Two trips later and a lot of fussing about my dies and the same results. More fussing with the resizing die led to this egg-on-face confession in someone else' thread.
At that point, in the face of a lot of ho-hum groups and I started questioning whether I wanted to work the die problem out or not as I was questioning the merits of this caliber as a choice for what was supposed to be a fun project. After crunching the latest ballistics data from Saturday's outing, I decided to zoom out and consider the bad groups as an issue separate from the die debacle. What hadn't I tried? From shot one, I never tried shooting without the brake on, though having purchased 3 others like it in different calibers that ran like clockwork, I never doubted this one. There's that assume thing again. Anyway, I had 10 more HBN'd 100gr Nosler Ballistic Tips left from the last run, loaded them with the charge that had the best SD from earlier trials and headed over to the range today with just my front rest, rear bag and some targets I usually give away at the range when someone shows up without any of their own.
I set up a 5-up target at 100 yards and shot 3 times at the top left bull. Same miserable group in the making. I took off the brake and shot 2 more. First off, boy is that brake effective. I could hardly believe the increase in rifle jump without it, but strangely no holes in the target. I walked down with a sharpie and some more targets and boxed in my original target while marking the other holes in the board. Back to the bench and shoot two more times. No holes in any of the targets. Put the brake back on and two more members were added to the bad group. Took the brake off and shot my last round. I spied a small crescent in the left edge of the top left target paper adjacent to a dime size hole just off of it. I walked down stopping short to take this picture with my Nextel I had with me since it's my weekend for being on call.
See the group without the brake? I was aiming at the center bull below and to the right of the one with the bad group. I went home and removed the brake, cleaned it in the parts tank and examined it under the stereo micro-viewer. There on the last baffle was a telltale crayon smudge of copper, built up. When I commissioned Ross to make it for me, I specified against his advice to have the brake bored extra tight to caliber with only .0065 clearance on any side of the bullet, or .277 total if you'd rather. I wanted to benefit as much as possible from as little as possible gas leaking around the bullet. An experiment I always wanted to try. He reluctantly made the brake without having my barrel there to check registration and it was off a little. Please don't slam his quality. This problem is on me 100%. If I had let him bore it to .284 as he wanted, I would not have wasted a couple of outings, boxes of bullets, powder, primers and most importantly my own self confidence.
Things I ignored in my haste to get some range time:
1) I sighted in with the brake on instead of off at first.
2) It didn't bother me that I had to adjust my turrets way off of where I had bore-sighted to before my first outing. Figured it was just me interacting with the rifle.
3) Failed to not recognize the fact that I never shoot that many bad groups without exploring why. I was too tunneled in on the chamber/die controversy.
4) I should have inspected the brake after my first outing. It really never occurred to me since I associate contact with the brake making bullets fly off into the wild blue yonder, not just throw off a little to one side and open up groups.
5) Any other self-deprecating observations I missed.
The weekend is over and bad weather is said to once again be approaching. I reamed the brake bore to .284 and will give it another try on the next outing. The copper smudge was around 10 oclock which is consistent with my shots going low and right before I adjusted it out with the turrets, hence high left when I took the brake off. Given the offset is about 1 foot by 1 foot, that should return my turrets to the mid point of their rotational range again.
In the aforementioned thread, I spoke that I had "hit and miss" luck with trying to add some neck tension by way of my Lee Factory Crimp Die. I stand corrected. I used it with today's 10 loads and it worked fine restoring the .001 too much that I lapped off of the neck portion of the resizing die. In defense of that mistake, at least the bullets seat easily and the HBN coating is not scraped off where they pass the case mouth. I did inspect one after chambering to make sure I had enough tension not to allow the bullet to move forward into the lands before I shot. I still have a lick of sense, despite this recent lapse.
Live and Learn. Assume nothing. share your mistakes as well as you victories for the sake of others benefit.
Hoot
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