I wanted to share an experience I had that has opened my eyes to the importance of small details in rifle building being very important to 1/8th minute accuracy. I hope that it helps someone, maybe not directly with the same problem, but in the process of elimination when it comes to fliers or a gun that just won't shoot.
I bought a lightly used gun with a known action and Leonard stock several years ago and, though it would perform decently agging in the mid to upper-2's, it would never give me more than a .180 (and that was very rare) and would spit shots randomly. Once at 100yds it went down and left ~1/2" on the first shot and I was able to chase a .220 out of it - could have been the rest shifting on the pock-marked bench, but there were too many other times it happened to make it a coincidence.
I opened the back of the shroud up as the cocking piece was rubbing and still no improvement. I tried firing pin spring weights from 17lbs to 26lbs with spacers to create the extra spring tension. I turned my necks thinner and brushed them, cleaned primer pockets, different neck bushings, and burned incense while mumbling sacred incantations to the accuracy lords.
3 different barrels, different front and rear bags and tensions on each, bullets, powder, lapped the lugs, a call to the action maker who recommended trying a new scope, and then recruiting a very well known shooter trying to make it all work. Still couldn't get it to make small holes at 200yds in ideal conditions and always had issues with vertical and spit shots. Right next to me using the same bullets and powder this same shooter was drilling small 2's and 3's at 200yds with his setup, but could not repeat it with mine. Another well informed source had told us that a certain spring weight was ideal for this action, and I matched that as well to no avail.
I had taken the thing apart and put it back together again multiple times, the bedding was good, and even tried different triggers - the firing pin flowed freely in the shroud with no pressure, but, on one occasion, I pressed my thumb against the cocking piece, the firing pin spring not in place, and tried to slide the pin down into the shroud. I realized there was some resistance to the pin sliding freely in the shroud. Not a lot, but definitely not smooth.
I lapped the firing pin to the shroud with 600 grit compound, then polished the pin on a buffer, and now I could put as much pressure as my thumb could create and the pin would slide in the shroud with no hesitation. BINGO! somewhere along the line the firing pin had galled inside the shroud. Next outing same shooter drilled a small .3 at 200yds with little effort in changing seating depth and powder charge. I gave him a big hug and thanked him profusely for helping me push to figure this thing out.
I took it home and opened up the first 1/2 of the firing pin guide in the shroud, widened the cocking piece guide (found in Tony's book), and made sure there were no burrs.
Took it out again and drilled a small .1 3 shot group and moved the seating depth a little and hit a zero. Next 5 shot group measured .150 and that is being generous as I know that I would measure small so I have added a good .020.
Went out to 200yds and drilled a .250 center to center in heavy mirage, and it would have been smaller had I not held for a condition. Two 3 shot groups in the 1's (center to center not MOA) at 200yds in opposite conditions with a barrel that wouldn't have thought about less than a .4 previously. Will the load hold up over time who knows, but at least I know the damn thing can do it and, no, three shot groups don't tell the whole story, but I couldn't even get past the first page with this thing before!
I actually got a little misty eyed after the last group was shot and thought I would pass on my experience albeit a bit long-winded.
Hope this helps someone someday and good luck!
Mike
I bought a lightly used gun with a known action and Leonard stock several years ago and, though it would perform decently agging in the mid to upper-2's, it would never give me more than a .180 (and that was very rare) and would spit shots randomly. Once at 100yds it went down and left ~1/2" on the first shot and I was able to chase a .220 out of it - could have been the rest shifting on the pock-marked bench, but there were too many other times it happened to make it a coincidence.
I opened the back of the shroud up as the cocking piece was rubbing and still no improvement. I tried firing pin spring weights from 17lbs to 26lbs with spacers to create the extra spring tension. I turned my necks thinner and brushed them, cleaned primer pockets, different neck bushings, and burned incense while mumbling sacred incantations to the accuracy lords.
3 different barrels, different front and rear bags and tensions on each, bullets, powder, lapped the lugs, a call to the action maker who recommended trying a new scope, and then recruiting a very well known shooter trying to make it all work. Still couldn't get it to make small holes at 200yds in ideal conditions and always had issues with vertical and spit shots. Right next to me using the same bullets and powder this same shooter was drilling small 2's and 3's at 200yds with his setup, but could not repeat it with mine. Another well informed source had told us that a certain spring weight was ideal for this action, and I matched that as well to no avail.
I had taken the thing apart and put it back together again multiple times, the bedding was good, and even tried different triggers - the firing pin flowed freely in the shroud with no pressure, but, on one occasion, I pressed my thumb against the cocking piece, the firing pin spring not in place, and tried to slide the pin down into the shroud. I realized there was some resistance to the pin sliding freely in the shroud. Not a lot, but definitely not smooth.
I lapped the firing pin to the shroud with 600 grit compound, then polished the pin on a buffer, and now I could put as much pressure as my thumb could create and the pin would slide in the shroud with no hesitation. BINGO! somewhere along the line the firing pin had galled inside the shroud. Next outing same shooter drilled a small .3 at 200yds with little effort in changing seating depth and powder charge. I gave him a big hug and thanked him profusely for helping me push to figure this thing out.
I took it home and opened up the first 1/2 of the firing pin guide in the shroud, widened the cocking piece guide (found in Tony's book), and made sure there were no burrs.
Took it out again and drilled a small .1 3 shot group and moved the seating depth a little and hit a zero. Next 5 shot group measured .150 and that is being generous as I know that I would measure small so I have added a good .020.
Went out to 200yds and drilled a .250 center to center in heavy mirage, and it would have been smaller had I not held for a condition. Two 3 shot groups in the 1's (center to center not MOA) at 200yds in opposite conditions with a barrel that wouldn't have thought about less than a .4 previously. Will the load hold up over time who knows, but at least I know the damn thing can do it and, no, three shot groups don't tell the whole story, but I couldn't even get past the first page with this thing before!
I actually got a little misty eyed after the last group was shot and thought I would pass on my experience albeit a bit long-winded.
Hope this helps someone someday and good luck!
Mike
The ignition system is the biggest area that gets taken for granted. 