Settling in a rifle using Cast

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  • Last Post 19 November 2013
Thomassen posted this 17 November 2013

I'm new to shooting cast. I had a great first time out last week. I've read here and other places that folks take 1 or 2 fouling shots before their rifle settles in. Why is this? Anyone know the science behind it? I'm familiar with the concept when shooting muzzleloaders with BP. But why here?

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joeb33050 posted this 17 November 2013

It's what's called “The Knurlman Effect". The gun doesn't know what you're shooting in it for a few shots, and because it is confused, scatters the first few shots. As the gun gets used to the bullets and load it settles down and clusters the shots together. Discovered by Ivar Knurlman, love child of H. Pope and Lotte Linya.

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grouch posted this 17 November 2013

I can't speak to the science, but one of my rifles very reliably throws the first shot of the day about 3” high. Some do, some don't. Grouch

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muley posted this 17 November 2013

each rifle is different, as we are. some say a fouling shot is needed and some call it a shot to warm the barrel. my pistol takes one shot after cleaning or between strings to shoot for score. the first shot, cold, is @ 11'oclock outside edge of the 9 ring. some guns may need as much as 3-4 shots.

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Ken Campbell Iowa posted this 17 November 2013

in my years of shooting rimfire benchrest, ( which i always thought of as little cast bullets .. ) i don't think i ever saw a rifle that didn't require a few ” conditioning ? ” shots ... some as many as a dozen .. some only 2 or 3 ... i played with lubes, a lot with moly ...maybe some were better, but non beat the need for conditioning ..

also noted ... conditioning shots almost always go high ...hmmm ...

during a 25 shot match ...if you delay too long, your impact can start walking away ...dangit !

just some trivia ..

ken

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onondaga posted this 17 November 2013

As usual, I disagree with everybody so far on this phenomenon because I have a method that works 100% for me and my rifles with cast or even jacketed bullets. It can work for you too if you don't get creative or invent shortcuts and make substitutions.  I have had first shot high or or first shot out and vertical stringing of hits cured every time with this one time bore polishing method combined with timing 3 minutes between shots and pulling a clean BoreSnake through every 5 shots. Of course, your cast bullets must fit the throat of your rifle and be suitable hardness for your load level or you are only tempting reality and relying on a lot of variables to somehow all align up for you. Gary

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swed6.5 posted this 17 November 2013

we all have oppinions, and for many that shoot to many diff rifles will never master this,Ive shot a lot of bench rest type comps and unless the firearm was fired and not cleaned prior to shooting a string or group we all have shifts of groups. A good hunter will know mainly where the 1st shot POI will hit. Even when you think you got it figured out a climate condition can change it. Onondaga has gone even farther into this than most, time between shots can change things too. Mainly caused by barrel temp fluctuations,

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Thomassen posted this 18 November 2013

Thanks for all the feedback.

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billwnr posted this 18 November 2013

A lot of times the issue is powder fouling. The rifle shoots best with some fouling but not too much. I have one that takes about 6 shots before it's fouled enough to go to POA. Then it holds it to about the 25th shot and starts rising one bullet hole at a time each shot.

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highstandard40 posted this 19 November 2013

As stated by others, each gun is different. I have an XP100 chambered 7TCU that I use for IHMSA silhouette. I use the RCBS 145 bullet with FWFL. At a recent match, after 65 shots, it still held 1 MOA accuracy. I clean only with Kroil.....a soaked patch, 5 passes with a brush, another wet patch, then I dry patch it till I get a clean patch. Using this method, I need no fouling shots........first shot from a clean bore is dead on. I don't know if this will work for anybody else but it works for me in this gun.

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billglaze posted this 19 November 2013

My Model 52B Winchester always--always, placed the first shot at 2:00 half-way out in the 9 ring. It was so dependable, that if the first shot was elsewhere, something was wrong with the sight setting. Didn't make any difference if it had sat for a half hour, all week , or all month. (A rarity>)

Bill

In theory, there's no difference between theory and practice. In practice, there is. My fate is not entirely in Gods hands, if I have a weapon in mine.

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onondaga posted this 19 November 2013

I'm familiar with the problem and your 52B does what mine did and I fixed it. Re-visit my post #6 up the page. Even if the rifle has had thousands of rounds through it, it  sounds like it has always suffered from a break-in error or bore flaw that didn't shoot out. A good bore polish will fix that 52B first shot out problem. Gary

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Ken Campbell Iowa posted this 19 November 2013

speaking of different guns ...some of the match 22 lr rifles would put the first shot or two right on the crosshairs ... then start walking ( uphill ) then walk back onto the crosshairs . then if you shoot often enough would keep that placement.

just interesting.

ken

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