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Post by flyingzebra on Apr 14, 2020 22:27:46 GMT -5
Looking good!
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Post by Lee Martin on May 14, 2020 21:14:18 GMT -5
Main Springs & Primer Seating – Fire Control _____________________________________________________ I recently experienced misfires when working up new .30 Stingray brass. At first I assumed the bullet wasn’t jammed far enough into the lands. Fire forming blows the shoulder out 10 degrees and pushes it forward 0.040”. Hard jam seats the case firmly against the bolt head and the firing pin does the rest. Without jam, there’s excessive headspace. But after re-adjusting my seater stem, the problem persisted. Not every round hung. I’d say 2 or 3 out of 20. And the primer would always ignite on the second attempt. I pulled the bolt apart and checked the main spring. When putting the gun together, we cut a couple of coils to take a 28 lb Remington short action spring to 23 lbs. After 10,000 rounds it had lost some force, scaling just over 20. I always have spare Wolff Blitzschnell springs and installed a new one. But this time I didn’t trim the length. Wolff spring ends are closed and precision ground to provide flat seats. While my cut spring shot fine, I decided to try 28 lbs. Incidentally, my cocking shroud to firing pin collar length is a bit longer than a SA Remington. That uncut spring rates around 26 lbs in my action.  I went back to the range with fully formed Stingrays and still had misfires. By design, pin protrusion mic’d 0.060” so there was plenty of reach. The bolt had also been thoroughly checked upon reassembly. There was no cocking piece, firing pin, or kinked spring rub in the body. Then the lightbulb went off. After the ignition problems in fire-forming, I seated primers flush with the back of the case. Knucklehead move because: 1) I always bottom them out in the pocket and never get misfires 2) CCI BR4s run thicker cups that most other primers. I incorrectly thought by positioning them closer to the bolt face, they’d go off easier when forming 3) This lot of brass has nearly 30 firings on it. The pockets have loosened a hair, giving less purchase on the primer sidewall 4) When bottomed, they sit 0.002 – 0.003” below the rim’s face 5) The first strike fully seated the primer. And that miniscule amount of run, coupled with a hard cup, cushioned the blow. Each went off the second time because they were final seated by the initial hit My secondary findings were more enlightening. The gun shot OK, but occasionally bullets wandered. Those that strayed were with rounds that fired on the first attempt. Those requiring a second strike shot great. I’m convinced that flush seating in older brass causes two problems. First, you can’t consistently fix primer depth unless your tool has a stop or you're bottoming in the pocket. Second, the primer being pushing ahead a few thousandths AND simultaneously going off is an accuracy killer. Now for the sake of transparency, the bullets weren’t flying out an inch. As best I could tell, it caused a 1/4" worth of stray. Something you’d never notice with a hunting rifle but do with a BR rig. Lessons learned: 1) Change the main spring every 5,000 rounds or so 2) Always bottom the primer in the pocket 3) I was reminded how critical fire control is in benchrest shooting A week later I returned with the same brass and fully seated primers. They all went off on the first pull. The new Brux barrel is also showing promise. After playing with the tuner, I found a setting I liked. With only 9 rounds left, I put 4 into the sighter. That group measured 0.102”. I used the last 5 to run the score target and wiped out every X. I’m eager to see what it’ll do in a match. Four shots – 34.0 grs of LT30, Martin 114 gr bullet seated jam-0.010”. Neck tension = 0.002”, freshly annealed brass. For reference, the circle you see is 0.500” and the bullet tears a 0.308” hole, give or take.  Subtract the bullet diameter and the group measures 0.102”.  -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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Post by Rimfire69 on May 15, 2020 8:26:48 GMT -5
Incredible accuracy, looking forward to seeing the results from your next match Lee.
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Post by Lee Martin on May 29, 2020 9:49:23 GMT -5
Match #90 Georgia Mountain Shooting Association, Eastanolle, GA IBS 100/200/300 Yard VFS __________________________________________________________ I shot my first match since March 14th, but had to travel 1,200 miles to do it. As states relax COVID-19 restrictions, events are starting to resume (including mine next Saturday). This was my third trip to GMSA, and like the previous two, the weather was hot. Near 90 both days. Unlike before, the mirage wasn’t too bad. Winds were mild, but the terrain poses a challenge or two. More on that later. I also decided to shoot my back-up .30 Stingray. I built it two years ago and have never used it in a match. Sunk $5,000 into building it, so the time had come. BAT DS action, Dixie stock, Lederer 1:18 barrel, Bix trigger, and a 50x March scope.   Flag setting Friday afternoon:  40 guns showed up. Considering a few states on the east coast still have travel restrictions, the turnout was solid. We began with 300 yards early Saturday morning. That distance isn’t my strong suit, but I took 21st place. We then moved to 200 yards where I landed in 15th. My 200/300 agg finish was 17th. Short of two shots I wish I could redo, the gun performed very well at those yardages. My good friend’s daughter Tori Allen @ 200 yards. She won IBS rookie of the year in 2019:    GMSA’s range is built on a hill with berms at 50, 100, 150, and 200. As the air quarters left to right or gives straight head wind, it hits the berms and actually pushes shots up. It’s very easy to get “caught” in those instances.  Sunday morning rounded things out with the 100 yard leg. I took out every X on the warm-up and record #1. The load was on early, but as the temperature rose, my tune shifted a little. In hindsight, I probably should’ve nudged the tuner. But I found a good hold for a condition or two and finished strong on frame #4 and #5. I placed 9th at 100 yards, giving me 12th in the 100/200 agg. My grand agg was 15th. Not bad for a rifle that had only seen 200 rounds prior to Georgia. -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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Post by bradshaw on May 31, 2020 8:01:43 GMT -5
Lee.... record shots want to track the same wind as your sighters. I can imagine wind curling over the trees to either depress or raise POI----depending on which side (slant of ground) the downdraft strikes. Is uplift caused by wind striking berms more pronounced on the steep end of the berm?
David Bradshaw
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Post by Lee Martin on Jun 3, 2020 9:56:38 GMT -5
Lee.... record shots want to track the same wind as your sighters. I can imagine wind curling over the trees to either depress or raise POI----depending on which side (slant of ground) the downdraft strikes. Is uplift caused by wind striking berms more pronounced on the steep end of the berm? David Bradshaw David - it was more pronounced on the right side of the range (where the berms are higher). As the wind quartered left to right or blew straight in, shots went high. That definitely showed in the sighters. The problem is you can't simultaneously shoot sighters and records....hence sometimes you'd get 'caught'. -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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Post by Lee Martin on Jun 11, 2020 18:32:42 GMT -5
Match #91 Black Creek Gun Club, Mechanicsville, VA IBS 100 Yard VFS ______________________________________________ If I didn’t know the value of tuners before Saturday, I do now. For the second match in a row I shot my backup .30 Stingray. Conditions were hot and humid, but the winds were mild. The warm-up target was a mixed bag. I clipped 4 X’s but didn’t like how they landed. A test group in the sighter box gave a glob. Probably a 0.250 – 0.300” spread with a bit of vertical and horizontal. So before the first official target, I bumped the tuner out an eighth of a turn. Three test shots went into the same hole. It looked solid until I went to the records. There was dispersion around the X, however I believed I got 3 or 4 out of 5. That is until the target came back and I scored it. I only hit one, narrowly missing three (two of which needed the reticle). Dug quite a hole for myself and was sitting in 13th place out of 15 after the first frame. For target #2, I bumped the tuner out another 1/8th and like before stuck three in the same hole on the sighter. I was able to take 3 Xs but I still wasn’t happy. Prior to target #3, I moved the tuner out a full half turn and the gun came alive. I center drilled all five X’s on the 4th and 5th targets. I left things alone for target 5 and almost took all the X’s again, only missing one (which was missed by thousandths of an inch). So after a disastrous start, I finished 3rd on the day. Had I only got the tune right on warm-up, the gun could’ve been a winner.    -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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Post by bradshaw on Jun 11, 2020 20:35:27 GMT -5
Lee.... sounds like you cranked out the tuner 3/4-revolution between targets #3 and #4. Just about a roll of the dice. At the start, if I hear right, you had a touch vertical AND horizontal on the same tuner setting----after looking tight. As you say, a lost shot dosen’t come home. What I see here is COMMITMENT----commit to a change in the middle o0f a match and HOLD TO IT. Unless I read it wrong, this comes under the heading of sharpshooting.
To commit in match, whether a sight picture, a sight adjustment, a position adjustment, or a tune, is less a gamble than a distillation of experience.
David Bradshaw
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Post by Lee Martin on Jun 15, 2020 19:21:41 GMT -5
David - yes, I rotated the tuner a full three-quarters. In hindsight, here's what happened. The previous match in Georgia was shot under similar conditions - 90 degrees and 60% humidity. I figured that tune would hold for Black Creek. It wasn't off by much and likely was on the edge of the node. Instead of moving the tuner out, I should've nudged it in. The first turn out bumped it off the node. The same movement in would've re-centered it. But I committed to going out and ended up on the next node. When I tuned the gun initially, nodes were about 3/4 of a turn apart. This match confirmed that. -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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Post by Lee Martin on Jun 22, 2020 19:10:08 GMT -5
Rail Gun _________________________________________________ Jay Young built me this rail platform in 2018. I’ve been so busy shooting matches and making bullets, I never took the time to finish it. But it came together last week. I'll get it dialed in on paper soon. • Design – integral block with a Delrin sleeve. I’ll start with 30 in/lbs on the bolts and go up from there to see if it changes the tune (but not higher than 60 in/lbs) • Action – Kelbly Panda with TG ejector • Barrel – 1.45” Lederer, 13.5 twist • Scope – March 48x • Trigger – Jewell       Haven't scaled it yet, but I'm guessing it weighs 40 - 50 pounds. -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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Post by kings6 on Jun 23, 2020 10:18:54 GMT -5
Lee, I am ignorant on this. Is that a platform to test load development or is there a rail gun style competition?
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Post by Lee Martin on Jun 25, 2020 16:11:09 GMT -5
Lee, I am ignorant on this. Is that a platform to test load development or is there a rail gun style competition? Robb - rails are shot in unlimited class group competition (100 & 200 yards). A lot of people assume these things shoot dots on demand. They don't. In benchrest, there are 4 variables to contend with: 1) The load (aka 'tune') 2) The flags (wind) 3) Gun handling 4) POA, which is tough under heavy mirage Rail guns only eliminate #3 and #4. If you can't tune loads and time shots to a condition, they'll print big. -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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rWt
.375 Atomic
Posts: 1,567
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Post by rWt on Jun 26, 2020 19:00:59 GMT -5
Fascinating!
Thank you for this thread!
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Post by Lee Martin on Jun 30, 2020 21:36:01 GMT -5
Match #92 Cavalier Gun Club, Montpelier, VA IBS 200 Yard VFS _______________________________________________ Cavalier isn’t an easy range to shoot. The benches have plywood tops on metal bases which aren’t attached to the concrete pad. The sun hits the back of the targets from mid-morning to early afternoon. Bullet holes aren’t always discernable. Mirage seems to be worse at Cavalier too. Then there’s the layout. At 100 yards is a creek which sits 20 feet lower than the firing line. But all that said, I’m starting to like the place. My friend Chris Allen puts on the matches and they’re exceptionally well run. And everything I just listed conditions you to become a better shooter. Don’t bellyache about the surroundings, just gut through them and learn. Take the benches for instance. They teach you table manners quick. Lean in or out on the edge and your reticle moves. That forces you to stay still on follow through. More so than other ranges, lax gun handling at Cavalier will cost you points Saturday was brutally hot. Low 90’s to be exact. The wind was moderate. The mirage was horrific. I shot my back-up gun for the third straight match. I hoped to use my primary .30 Stingray with the new Brux. Unfortunately, that barrel is getting wild. Despite a few one hole groups, the tube isn’t giving me the consistency needed to compete. I’ve sent 400 rounds down it, adjusting charge, seating depth, and tuner settings along the way. For all that, it seems to be getting worse. I pulled it this week and chambered up my third 1:18” Krieger. If it shoots like the first two, I’ll be back in business. As for the match, my gun drilled the sighters all afternoon. The tune was right, the rifle was on. I got caught on frame #2, dropping a 9 on bull #4. Oddly, I held the same as I did 15 seconds earlier when I center punched the sighter X twice. Something shifted and I didn’t see it. I went to bull #5 and did the old “half-hold”. Basically, I held halfway between where the sighters told me the bullet was going versus the hold-off for the previous 9. No luck though. Shot #5 went exactly where bull #4 landed. I did well on target #3 and then the mirage stood up in a big way. No one shot a clean 50 on frame #4. I took 5th out of 10.    -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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Post by Lee Martin on Jul 14, 2020 18:48:50 GMT -5
Match #93 Fairfax Rod & Gun Club, Manassas, VA IBS 100 Yard VFS ________________________________________________ First match for the new Krieger and it brought home a win. The weather dealt us 93 degrees, subtle wind, and workable mirage. I figured the reticle would dance more for all the heat and humidity. Guess we lucked out on that front. The barrel was consistent. Shots went where you'd expect them to for a given condition. The load did show about a half bullet of vertical. Dialing the gun the week before, the tightest groups were with the tuner at 12:00 and 1:00. One o'clock grouped a hair better so I started with that. After the second target, and another 4X score, I bumped it back to 12. On frame #3 I stuck three shots into one hole on the sighter. It was a zero-something. That built confidence and I almost cleaned all five X’s. The one miss landed left, likely due to mild push. My last two targets were 5’s, which I needed to win. Lesson learned – don’t be afraid to move the tuner mid-match. Settling on a ‘decent’ tune will likely give no better than a ‘decent’ finish.   -Lee www.singleactions.com"Chasing perfection five shots at a time" |
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