My rifle shoots 1/2" groups @100 yards all day! Really? Prove it.

Tomochan said:
Nice shooting Jerry - the 0.509 must have sucked eh.

I suppose I shall have to try now that I've piped-up on this thread.
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To be honest, that was not the group I was worried about. A bit of me, a bit of wind but should be fine... Drag out the calipers and WTF - you have got to be kidding.

I thought Group 3 was the out but that one squeaked in - 2nd shot was a zinger, the other 4 made the cluster. Was shooting in the gusty air and figured, big honking bullet should make it through.... apparently not.

groups 4 and 5 I waited for the flags to settle down and things went where they should. Last shot group 5 was an "out". The 4 shots went into a hole that would likely have been in the 0's but the wind came up, I waited, things changed, got nervous and pulled it a schnick low.

Eventually, when things thaw, I am going to try this at 200yds. Not to be a smart A$$ but I think all my fast twist long bullet slinging rifles will settle down better and hopefully produce more stable groups.

I have shot 300m groups smaller then some of the 100yds testing I have done. Frustrating indeed.

But it is practise and trigger time is going to be super important all year.

Jerry
 
Eventually said:
Can someone explain this to me? Perhaps I should start a new thread but if a bullet isn't stable at 100, won't that translate into even worse groups at 200? Does the bullet somehow switch to a more consistent line of trajectory after a certain amount of distance?
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Tomochan said:
Kinda cheating don'tch think ? Thought I'd try with a .308 first and if I fail then I will try with the 6mm !
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Yep, give 'er.
My next barrel is a 7.62x39. Everyone says the cartridge is inaccurate.
Need to get the reamer resharpened and I'll give that a go and put that myth to bed. ;)

By then it should warm up a bit. I'm getting tired of trying to keep warm in zero weather. I'm also convinced that cold weather is responsible for different ignition problems. Noticing more soot on the cases you'd never see in the summer time. I don't usually shoot this much in winter and am realizing how much different barrel temperature swings and powder loads make. A very cold barrel shoots lower so far. I'm seeing some patterns here that are very interesting.
 
Not a whole lot of difference between a 30BR, a 30x44 and the 7.62x39...........so in my books it should be a contendor.......that said.....let me know when your reamer is sharp..........

I shoot 115, 118, and 125's in my 30BR, and the same plus 135's in my 30x44.....a 125 grain in the 7.62x39 with the right powder could be a real winner, I am loading the other cases with a stought load of N135.....and I know it would be a good powder for the 7.62 with lapua cases.

You might look at using a 16 or 17 twist barrel.......my 17 twist 30x44 really picks up at 300 yards and delivers to 600, it was designed for 1-300 yard score but I could never get it to shoot as good as it is supposed to at 100 yards, the 30BR on the other hand covers everything from 1-600 yards with no complaints........10 shot groups at 600 yards under 5 inches from both rifles....now if I tried a little harder on my end I might be able to tighten them up a little more.
 
Shabazz said:
Can someone explain this to me? Perhaps I should start a new thread but if a bullet isn't stable at 100, won't that translate into even worse groups at 200? Does the bullet somehow switch to a more consistent line of trajectory after a certain amount of distance?
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Get Bryan Litz Applied Ballistics Book (got copies if interested) and it will go into this topic. In simplistic terms, long high BC bullets "wobble" for the first 100yds or so. The pattern of flight is not a pure spiral but more like a cockscrew. This dampens really quick but can show up at SR targets as similar size groups as further out.

{all the optical issues and rest issues have been dealt with - this is likely the problem for most shooters}

This is what I am seeing alot in my 7 twist 22cal barrels. Now they may also be tired after seeing a lot of shooting but they were doing great when I put them away in the fall (around 1" at 300m). SO, time for another test as time allows.

Yes, the cold brings a whole bunch of very interesting variables. As does SR shooting. I am really enjoying this experiment.

Jerry
 
Mystic Precision said:
Yes, the cold brings a whole bunch of very interesting variables. As does SR shooting. I am really enjoying this experiment.

Jerry
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Its not really an experiment when you do it right, lots of people need to learn that precision rifles are not multi-bit screw drivers, they might be okay at somethings but perfect at nothing......

You have to build the rifle for the task at hand...short range targets or long range targets. matching the bullet to the twist to the distance you want to shoot are all key players to get the most out of your build, You can build a one rifle does it all...but it isn't going to give optimal performace at everything....

Or so I keep telling myself everytime I decide to rebuild something, or start from scratch...
 
yodave said:
Not a whole lot of difference between a 30BR, a 30x44 and the 7.62x39...........so in my books it should be a contendor.......that said.....let me know when your reamer is sharp..........
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Yep, I know the 30BR is king in VFS, but since I already have the reamer and dies why not give the stock 7.62x39 a go. I'll actually be putting it together for local clubs around here and see what happens. Sounds like the 1-17" is the ticket.
 
Shabazz said:
Can someone explain this to me? Perhaps I should start a new thread but if a bullet isn't stable at 100, won't that translate into even worse groups at 200? Does the bullet somehow switch to a more consistent line of trajectory after a certain amount of distance?
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If its not on line at a hundred, it won't steer itself back towards center at a further distance. Epicyclic swerve (augering), is so insignificant it probaby could not be detected at those ranges.... Bottom line, bullets dont steer. When I shoot a 300M group that is smaller than a 200M group, it has nothing to do with "ballistics"...more likely wind, less parallax, concentration...
 
What I have found is that barrels, powders and primers show much larger changes due to temp changes in the cold then in the hot.

I see more affect of 5C when going from 0C to -5C, then I do from 20C to 25C.

Primers can show a huge difference once you go under 5C. A change that load tuning can't resolve.

Sure there are issues with the shooter being bundled up like a penquin and sometimes shivering BUT I have tried to reduce that variable as much as possible and just focus on how the rifle changes with temp.

Barrels can do funny thing when they are cold - or more accurately, when they heat up from being cold.

The biggest surprise was the bullet. When you are used to having your rifles shoot 1/3 min at 300m and it can't shoot UNDER 1/2 min at 100yds, makes you very frustrated indeed. But that can lead to another very interesting experiment.

I think the 7.62X39 would be plenty accurate. The biggest problem is the taper. I have played with it and it shot well given the platform and barrel BUT the brass died real quick even with neck sizing. Turn it into a 30PPC and you be having some fun...

There are a new range of challenges with SR BR vs LR F class. Alot of fun and a nice change of pace.
Jerry
 
JEC said:
If its not on line at a hundred, it won't steer itself back towards center at a further distance. Epicyclic swerve (augering), is so insignificant it probaby could not be detected at those ranges.... Bottom line, bullets dont steer. When I shoot a 300M group that is smaller than a 200M group, it has nothing to do with "ballistics"...more likely wind, less parallax, concentration...
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Sounds like you are going to like my next test.

Jerry
PS I agree completely with you so far but that is not what my targets are telling me and I have put enough rds downrange to know when something is acting weird with these rifles. So either my barrels are toast (could very well be given the beating they have taken) or there is more to this "going to sleep" nonsense then I would have originally believed.
 
yodave said:
comparing the .708 to the .741 its hard to tell on a computer screen....the white circle of the target is 1 inch, so using that to gauge the outside to outside I would say its in and correct........

Hey Rob...the jurry wants a picture of your calipers laying on the .741 group.........
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Took a few snaps today --- Hope it helps ??? Yodave has already done the " Math " so I'll leave it @ that !! Sent both " just in case " ????

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Well back to some loading & trigger time --------------- Rob
 
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Mystic Precision said:
Barrels can do funny thing when they are cold - or more accurately, when they heat up from being cold.

BINGO!

I think the 7.62X39 would be plenty accurate. The biggest problem is the taper. I have played with it and it shot well given the platform and barrel BUT the brass died real quick even with neck sizing. Turn it into a 30PPC and you be having some fun...
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After 4 to 5 firings trimming necks are in order and I have considered the 30PPC or 7.62x39 IMP. I may go down that road after a time, but for now the SKS round will get full bill for the hell of it as I'm just enjoying it too much.
 
You do realise that this will lead you down the path to.....

CAST BULLET BR.

Now we be having some winter fun...

Jerry

PS looking at an old reloading manual and I see a 30X223. Also called the 30 silhouette. TCU's are another fun family (just got way too much 223 brass to not dream up more trouble) Now I am getting another itch :)
 
6-223 has been taunting me for years.........then one day I dreamt of a 6-222.........oh it never ends Jerry...........
 
but then this post would be very very boring with this post filled with successes even with burnt out PPC's.

30-30 - WHO WANTS TO JOIN THE INSANITY?????

yodave, your deepest desires is a barrel nut swap away. I saw a SR BR built up for the 6-223. It did work ok but that to me is a bit too easy.

25-223 and 270-223 - that is just begging for a bunch of headaches.

there are now a few 115gr match bullets in 270cal....
Jerry
 
I shot with a guy who had a benchrest 30-30.........don't kid yourself that thing could shoot........
I tried the 6.8 spc route......velocity was never there and I couldn't get it either........they make 277 match bullets but they were hard to source in Canada........there is now the odd 270-08 floating around and gathering some serious interest.....
 
Hopefully out this weekend, but why not use ontarget to measure groups. Way easier. Throw some calipers or a ruler on there so you have a base line measurement and easy peasy.
 
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