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Why Does This Happen.....Any Thoughts
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I have a 260 Rem sporter built on a trued Remington short action, Tubbs Speed Lock firing pin, Rifle Basix trigger set at 2 lbs. The barrel is a 1 in 8 twist # 4 taper Krieger finished at 23". The rifle is pillar bedded in a Bell and Carlson Carbolite stock. This rifle will shoot consistently low .4's to the low .5's or a little less occasionally with several different bullets. The 90 gr. TNT, 120 Sierra ProHunter, 120 Nosler B.T. and the 140 gr. Sierra GameKing.

Here is the question. The 120 gr. Nosler B.T. averages in the mid .4's for 5 shot gorups. I was shooting up some ammo left over from the hunting season, and the rifle was doing it's usual .4's to low .5's when I fired another 5 shot string that went .076" for 5 shots (100 yards). WHY did it do that. The shots had all broke clean but in firing the strings before that, those shots had as well. I reloaded those 5 pieces of match prepped brass again, the same lot of components, and fired them in the same sequence and got a group was a normal .492". I have seen this happen on occasion before. Does anyone have any ideas why that happens. I use match prepped brass and check all my loads for runout so I shoot ammo that is properly loaded. But taking the same pains with same brass will not produce the same results. Any ideas.

PaPa 260
 
Posts: 109 | Location: Extreme Southwest Indiana | Registered: 14 August 2005Reply With Quote
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PaPa

I have read your post a couple of times trying to figure out what your question is. I keep looking for some hidden message in there but I just can't seem to find it. So, i'm going on the assumption that you are asking a simple "why do I sometimes shoot a big group?"

Ah, if only I knew the answer I would be rich, travelling about the country shooting for money. I assume you are something more than a casual tin-can shooter so I'll forego the usual questions and advice and simply say, "It happens!" I have been a short and long-range Benchrest shooter for a lot of years and have yet to figure out the "why" of those occasional big groups. I have shot with the world's best shooters and believe me, they do the same thing. The difference between me and them is that they do it less often. Benchrest shooters may shoot smaller groups when compared with a varmint or hunting rifle, but there is usually a lot bigger relative difference between the little ones and the big ones than what you have experienced. Going from a low 5 to a mid 7 is not nearly as painful as going from a big 1 to big 3 even though that 3 may look good to most non Benchrest shooters. Sorry I can't give you the magic formula, but there isn't one IMHO.

Ray


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Posts: 1560 | Location: Arizona Mountains | Registered: 11 October 2004Reply With Quote
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Actually what I was asking is why a rifle/load that averages in the .4's suddenly shot a tiny group like the .076" I referred to. Those 5 shots didn't break any better than the previous 5 shots or 5 shots after the tiny group. I guess it could be called an "accident on paper"? Or the planets aligned just right. Any ideas where the tiny group came from or why. Like I said, I have seen it happen a few other times and it always made me wonder why.

Yes I am more than a casual tin can shooter. I shoot F Class competition with several different calibers (260, 260 A.I., 6.5 X 284, 284, and 300 WSM) with some success. Plus I am lucky enough to be able to shoot well past 1K from my back yard. It don't get any better than that. By the way the 260 A.I. is my favorite of all the them.

PaPa 260
 
Posts: 109 | Location: Extreme Southwest Indiana | Registered: 14 August 2005Reply With Quote
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PaPa

I confess that I mis-read your post. I thought you said that you shot a .760 group. But, all of my comments apply just the same, just substitute small for big, where appropriate. Smiler

Ray


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Posts: 1560 | Location: Arizona Mountains | Registered: 11 October 2004Reply With Quote
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Papa 260. I think the answer is statistics! You are shooting 5 shot groups. But before one samples, one has to answer two questions: Error rate and confidence factor. Take your rifle out and shoot 5, 10 shot groups and average the group size. I think you will find that the group size might well be larger than your .4 or .5 inch. In any case, the question when shooting groups is to establish groups of sufficient number (sample) that one has a reasonable confidence that the next shot will be inside that group. That is why I, when I shoot a "magic" group, try to duplicate it. If I cannot, then my confidence is low! In shooting a 10 shot group, you might very well have 4 in the same hole (your .076" group) followed by 6 which will give you the usual group size for your rifle.
Peter.


Be without fear in the face of your enemies. Be brave and upright, that God may love thee. Speak the truth always, even if it leads to your death. Safeguard the helpless and do no wrong;
 
Posts: 10510 | Location: Jacksonville, Florida | Registered: 09 January 2004Reply With Quote
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I think it is just as easy to "pull one" into a group as it is to "pull one" out. I just can't figure out why I pull mine out more often than in.
 
Posts: 868 | Location: maryland | Registered: 25 July 2004Reply With Quote
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Cheechako:
Thanks for the replies, it sure puzzles me. I have shot with the best F class shooters this country and several others has to offer and I know what you mean about it happening a less often to them than to me. I have beaten some of the best and got beat by others not so well known. But that is the fun of it. You are probably right, there isn't an explaination. On the other hand, you know about inquiring minds.

Peter:
Thanks for the reply. Since reading your post I went to the binder that I keep targets and notes for that rifle in. Being somewhat anal about repeatability when it comes to how a load performs, be it a 1000 yard match rifle or a hunting rifle. I wanted to see how many 5 shot groups I had shot with using that load in the sporter. I had shot eight 5 shot groups and the agg. for that primer, powder, bullet combination is .469", which for a sporter weight rifle isn't bad. I will try a couple of 10 shot groups just to see what happens. It will be interesting to know.

eddieharren:
Thanks for your reply as well. I know what you mean about pulling one into the group. Been there did that. Looks good on paper but it still makes me irrate because I borke a bad shot. I have did that in a match with the spotter disc centered up in the X ring. When the trigger broke the dot was at 9:00 just barely inside the the X ring. When the target came back up the spotter hadn't hardly moved. Got lucky on that one. It should have been border line X or a 10 just out of the X ring.

I think we pull more out of group than in the group, is because the rifles we shoot don't shoot out of group often. Hence we are far more likely to pull one out.

Back to the loading bench. I have a 6.5 X 284 Redding micrometer seater die that is giving me fits. Just about ready to throw it in the trash can!

PaPa 260
 
Posts: 109 | Location: Extreme Southwest Indiana | Registered: 14 August 2005Reply With Quote
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Sometimes the good Lord lets us shoot a group that just proves there is someone looking over your shoulder, or in my case I get lucky once in a while. Like when you pull the trigger and you are thinking oh sh##, you look down range and oh S#$#! it went in the same hole as the 4 previous shots.
 
Posts: 869 | Location: N Dakota | Registered: 29 December 2003Reply With Quote
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Maybe something to do with the runout on all shells fired in that screamer group being aligned by accident. For my 1000 yd loads, I sort for less than .002" runout on the bullet, and then make a magic marker stripe on the high side. At the line, I load the stripe up. Can't hurt, is my attitude. More runout sells go into 600 yd, or fouling shot rows. I also seat the bullet halfway, then rotate the case ~180 deg, and seat the rest of the way. Try it.
 
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Try 3X 10 Shot groups letting the rifle cool between shots. That gun might like to shoot with some fouling.
 
Posts: 202 | Location: Santa Fe, New Mexico, USA | Registered: 18 February 2001Reply With Quote
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quote:
Originally posted by eddieharren:
I think it is just as easy to "pull one" into a group as it is to "pull one" out.


Agreed.

quote:
I just can't figure out why I pull mine out more often than in.


Big Grin Big Grin Big Grin

But think about it Eddie...

When you're shooting the size groups that you are, with benchrest gear, there's a whole lot of room to go "out", but very little left to go "in".

Those shooting 2" groups leave lots of vacant space on the inside, yours is all on the outside. Smiler
 
Posts: 2629 | Registered: 21 May 2002Reply With Quote
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There is only one reason for shooting a .076" 100 yard 5 shot group with factory, mass produced hunting bullets. LUCK
 
Posts: 4799 | Location: Lehigh county, PA | Registered: 17 October 2002Reply With Quote
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I have a very plausible answer for you in regards to " Why " certain cartidges seem to go awry .

First consider all components case , projectile , primer , powder , seating depth , Temp , Humidity . You get the picture ,several variables to say the least !.Now consider the TWO You have NO CONTROL OVER ?. Powder and Primer !. Put together a 5 - 6.5 % variable. Out of the SAME LOTS !. Powder is held with in 3 % tolerances , primer ( Match ) are held to with in 2 % mixture consistency . Packaging , freshness adds the other 1.5 % variation . Stop to consider for a moment lets use your car for an example. If Auto makers had any where near the " Quality Control " % wise , You could still be driving the first one you ever bought !. Now I'm a new guy on the block so to speak .Least wise to this forum any way , I've only got 38 years loading experince . I also hold a Ph.D. in Chemistry and a Masters in Structural Composite Engineering . So please believe me when I tell you there are Variables in every aspect of life !!!!!!. Look on the bright side of things Most fire arms aren't capable of those group sizes !. Besides who wants a fire arm that puts all bullets into a single hole ?. All right everybody put you're hands down !. What fun would it be if every fire arm did that !. Face facts we reload to obtain the best group size we can hope to achieve . Perfection is just in the next batch . I know it is least wise that's what I've been telling the better half all these years ... beer
 
Posts: 1738 | Location: Southern Calif. | Registered: 08 April 2006Reply With Quote
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Hello Papa 260,
Do not see any Sierra MK's listed as bullets being used??
Your "ghost" group may well be occuring with the various bullets being used and would advise the Sierra's be given a shot, no pun intended, and also call Sierra and speak to one of their technical people. (More experience there than exists most places on this planet.)

Other than the bullet issue, your reloading program is generally the accepted method for long range shooting but might suggest weighing each completed round and sort accordingly. Remember, all brass even from the same mfg. is not bore equal!! There will be a variance. I also shoot long range, not F class, but from sling/prone position and hold HM classification and only say that, for from a sling w/ micrometer sights, the human factor looms somewhat larger and if my ammo is not the very best I can make it, I have a problem over and above my human errors of which there are many. Might further suggest that you only make one change at a time and then check for results, no matter how small or large that change may be for difficult to assign responsibility otherwise. Again, would chat with the folks at Sierra for excellent advise and guidance. Good Luck! (another factor to consider!!)
 
Posts: 577 | Registered: 19 February 2006Reply With Quote
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onefunzr2: I believe there is a LOT of luck in shooting a .076" with a sporter and hunting bullets hence my comment about it maybe being an "accident on paper" even if it is a custom sporter built by a very good smith. Yes they were mass produced hunting bullets but I seperate all my hunting bullets by bearing surface and weight, as well as run out of the loaded round in match prepped brass. Yeah I am anal.

Dr.K: Count me in the group that wants them all in one hole and it would suit me fine to have it happen all the time. Trying to figure out why they all don't go in one hole has cost me a LOT of money.........lol

driver: My hat is off to you on your HM classifcation shooting off a sling with irons. You guys amaze how you do that. I shot XC until 2 years ago, when I gave it up never made it to HM. Just couldn't see good enough anymore. The smith that builds all my rifles is a Distinguished High Master with a service rifle.

I shoot NOTHING but MatchKings in my match rifles (223, 260, 260 A.I., 6.5 X 284, 284, 308, and 300 WSM) I have tried some of the others but always came back to Sierra quickly. I should buy stock in Sierra as many of them as I shoot. I just haven't shot them in the sporter that did the .076" group. I also use Sierra 120 gr. ProHunters and 140 gr. Sierra GameKings in the sporter that shot the .076" group. It amazes me the accuracay that the Sierra hunting bullets are capable of. Sub .5 MOA consistently with the 120 ProHunter, the 140 gr. GameKing, 150 SPBT, 165 gr. HPBT GameKing, and the 180 gr. SPBT. I am running low on the 142 gr. MatchKings and I am having trouble finding them in the 500 ct. box. According to Sierra they should be avail soon. I sure hope so, I only have 300 left. A good friend friend of mine is a ballistic tech at Sierra. We talk all the time. When I am having a problem with something I always call him for a reality check if you will to see if I am overlooking something.

I do weigh all componets except primers, I quit that about a year ago. I sort and match prep all brass including my hunting brass. I even do that for barrel break in ammo. Like I said above, I am anal.

Thanks for all the replies gentlemen!

PaPa 260
 
Posts: 109 | Location: Extreme Southwest Indiana | Registered: 14 August 2005Reply With Quote
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Hello Papa 260,
I took my HM with long range only, and your 'smith who holds HM/Distinguished w/ a service rifle really needs to be kept very happy and in no way anger him! Just joking, but those who shoot the Serv. Rifle and earn HM are one fine shooters. I shot XC several years and switched to strictly long range, getting to old to keep up with those 20 year old Marines at Quantico. I did make it to Master w/ service rilfe but only when I switched from the 14 to the 15. Less recoil and frankly more accurate. Even at 600, those Sierra 80 grainers would hammer that 10 ring if you read the wind correctly. All through the 70's and 80's I would have not believed any service rifle would outshoot the M14, but have to say that 15 w/ a Krieger 1/7.7 barrel on it is outstanding.

Off topic, but would not know of other steps you could take in your process of reloading for it looks good to me. Primers come in there at about .5gr regardless of brand from my experience but I only use the Fed. 210M's. Damn CCI's have let me down in the past with a string of rapid fire and only have 60 seconds for 10 shots, plus mag change and that dud kills your score. As you probably know, ammo is not an alibi!! You are in good company with Sierra and if anyone could give you good advise it would be them. Favor Center!!
 
Posts: 577 | Registered: 19 February 2006Reply With Quote
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I know what you mean about hanging with those young guys. They are hard as wood pecker lips, and see a lot better than I do. It is truly amazing to see what an accomplished shooter can do with a service rifle. I still remember the first time I saw my gun smith get slung in with an M1A at 1000 yards and just hammer the 10 ring with it. I couldn't believe what I was seeing. Earning the Master classification is no small feat with a service rifle congrats.

What chambering do you shoot in your long line match rifle? After this year, I am going to down size the number of rifles I shoot in F class. Going to standardize with the 6 BR, 260 A.I. and the 284. I will use the 6 BR on calm days. With 260 A.I. using 48.4 gr. of H4831 SC behind the 142 MK, I get 2937 fps. I am giving up VERY little to a 6.5 X 284 with 50% better barrel life. With 284 I give nothing to it again with better barrel life. So that is the plan.

I use both the 210M and the CCI BR-2. Never had a bad experience with either. But you aren't first person that I have heard of that did have a problem with CCI. Maybe I have just been lucky. It depends on the powder I am using what primer I use. I have always had better luck with the 210M when using H4831 SC. With H4350 CCI BR-2 has always been better. With the VithaVouri powders it is a toss up.

Well it is off the loading to bench to turn necks. I would rather get punched in the nose than have to that. Getting punched in the nose is over a lot quicker that turning 300 pieces of brass.

Have a great day, and hold into the wind!

PaPa 260
 
Posts: 109 | Location: Extreme Southwest Indiana | Registered: 14 August 2005Reply With Quote
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Hello Papa 260,

I am pretty much from the old school and almost always use the 308 w/ Krieger barrels, 30" and 1/12 twist. Pretty much standardized on the Sierra bullets and most of the time used the 190's. At 1000 yards, that is all the 308 wants, but it does the job fine. Rem. action, Master Class Stock, Warner Rear or Centre and on the rare occasion use optics, some ranges require you shoot so many round w/ optics, Leupold or Weaver T24. 24 power is a bit on the high side and mirage can mess w/ you a bit plus heart beat issues, but use a mirage band or tube on the scope. My Leupold MK4M1 16x is just about ideal for all around use.

Some years ago, built me a 22-250 w/ 30" barrel, Krieger 1/8 twist and used the Sierra 80 grainers and can tell you that it did very well and my scores stayed up if I did my part. Best score w/ the 22-250 was 197 w/ 12 X's. I have only cleaned the 1000 yard target one time and as strange as it may seem, cloudy overcast, some switching wind, not strong, but switching, and just seemed like the target was very clear that day with the iron sights. I do use a 1.5 magnifier/lens in the front Anshutz globe to see those damn target no's which all seem to run together at that distance.

Notice you are giving some thought to using more than one rifle, and you might want to re think that approach. I did that many years ago and had a lot of fun, but scores never did come out well. Suggest you find the rifle/caliber/load, etc. that you are most comfortable with and wear it out. I know, no one wants to hear advise that limits how many guns one can have!!!! Not fair is it, but only say this as a suggestion. An old saying from the "days of yore...." beware of the man with one gun for he is probably pretty damn good with it. I will say that the 260 as a cartridge is a very fine one indeed and if I were starting all over, believe that is the one I would work with for it has been turning in some impressive scores over the past few years.
Good Luck.
 
Posts: 577 | Registered: 19 February 2006Reply With Quote
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I have a Ruger M77 in .25-06, bedded and Timney trigger. I shot a .19 with it using handloaded Hornady 120 gr HPs--once. The gun always shoots .75 and under with that load, so to answer why do you occasionally shoot a tiny one? Someone said it before--luck.


An old pilot, not a bold pilot, aka "the pig murdering fool"
 
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