Cold bore groups?

[boiler_house7]

You might post on sniper hide, these guys take the 1st shot seriously and may can give some good advice. I know I chased that same thing for a while and some on the hide recommended the tubbs coating. Bill

 

[alf]

alf, I'm struggling to make a correlation in your post to the subject of cold barrel accuracy in hunting trim.
To me, your test here demonstrated low ES(possibly), and producing .86moa of precision(with 3 shots off a bench & benchrest).
So what was the cold bore shot accuracy?
In other words, what was your 1st shot POI w/resp to your POA?

The other two shots didn't matter, you only get one.

I'm not sure why you're struggling with my post.

I was testing my drops at 1K, and first cold bore shot, dead center hold, was a killing shot on a coyote sized target. I shot two more to prove it wasn't an accident. I don't remember which impact was the first one, nor do I care......

 

[mikecr]

It's fine shooting alf, I didn't mean to imply otherwise.
And since you posted pics to represent 'accurate enough to kill coyotes at 1kyd', it seems an opportunity to define the real accuracy in it.

There are three terms to consider here, which are completely separate and different things:
Accuracy - defined with single shots, or more; POA to POI
Trueness - defined by a multi-shot mean POI of shots about a POA
Precision - defined by a multi-shot agreement in POI, regardless of POA

While trueness can represent a quality in build or load, accuracy is still all that matters in single hunting shots.
Precision, means nothing in hunting.

If your furthest cold bore impact was 6" from center of mark(POA), then:
Your cold bore accuracy at 1kyd was 0.57moa (really good)
The 9" of precision was 0.86moa (not really good)
Trueness looks about ~0.25moa (really good)

Definition examples with 1moa bull about center dot:

 

[mikecr]

Many times I can sense members fixating on grouping -even with hunting guns. And grouping is the overwhelming measure at a non-hunting site like this.
I wouldn't be surprised if some are completely missing the potential(accuracy-wise) in their hunting guns.

alf's posted results show potentially low precision(grouping), and yet his gun is plenty accurate. Good hunting gun.
I'm sure his grouping is better normally & up closer, but it don't matter one bit.
I'm also sure that most folks, including gunbuilders, either never run this test, or dismiss the results before them.

 

[steve-o]

in the sniper world we talk about copper equilibrium, if your client is interested in cold bore shots he does not need to clean the bore as thorough as the benchrest guys do nor as often. for cold bore shots a fouled barrel to some degree will shoot consistant reliable groups better than a pristine squeaky clean barrel. now if you are making him a heavy magnum gun then it will tend to copper foul more than say your non magnum guns so it's kind of a catch 22 there, usually at some point we will chemically go after the copper fouling, but we will fire a few rounds to re-foul the barrel so that the next time you have to use the weapon you can count on the cold bore shot going where you want it to.

There's a guy named Rex if you are really interested in extreme long range shooting. he goes into detail on a lot of things but youtube sniper101 and he has some kind of dinosaur name, there are 60-70 videos he talks in detail including burn rates of temperature of bullets effecting muzzle velocities, how to set up nice ballistics cards etc...

 

[MQ1]

Ryan,

I have a hunting rifle that fits the description of what your customer is looking for, and it was built by a very respected Benchrest gunsmith. Trued, lapped, a great shooting Hart barrel in a lightweight McMillan Edge stock...bedded...blah blah blah...

I have been testing my cold bore shot once a weekend, to determine the best amount of cleaning and where to sight in for optimum hunting performance.

Every cold bore shot is done on a different day, with different conditions...different temperatures, different humidities, etc. it is not realistic to guarantee a rifle that will produce the exact same point of impact in such varying conditions.

My rifle is top notch, and realistically holds about half to 3/4" cold bore "groups," which is more than capable of shooting any pig, deer, elk, and coyote as far as reasonable. This rifle has shot a couple one hole groups, but guess what...they were shot immediately in succession, in the same conditions....

Educate your customer about what is realistic in a hunting situation. If he is not capable of understanding the implausability of his request for a perfectly performing rifle in less than equal conditions, then send him on his way...your customer has unrealistic expectations and assumes the equipment can be made to make up for his lack of experience.

FWIW

MQ1

 

[mikecr]

I didn't see an implication that the customer wanted the same hole everyday, if that's what your suggesting 'the same spot' means.
He could have meant a 1moa bullseye(his spot) at x-range, everyday, from cold bore, and this is reasonable.

The only thing that sets a gun apart in accuracy is it's verified performance in this regard.
Not the parts, and not the builder.
In other words, I would not take a 600yd shot on a groundhog because Mike Bryant built my gun with the best in parts. I would do so because I knew through prior testing with that gun/load, that I could make the shot.

 

[steve-o]

I have ballistics charts from different temperature conditions and different barometric conditions. my charts are set up for first the barometric pressure, then has ballistics information from 0 degrees F to 100 degrees F out to the maximum supersonic range.
I set my zero at 100 meters and range in 10 meter increments from 200 meters on out.
I keep my rifle at copper equilibrium (fouled).
basically I range the target 3 ways, GPS, Mil-dot and laser. I then look at my krestel and surroundings for weather conditions, barometric pressure, wind speed at gun, temp, wind direction at gun, then I look about 60% down range at the wind and direction then at the target, average those out, look at my ballistics table for the conditions, adjust or hold off and fire the shot.
Temperature and pressure will effect most shots.

 

[Drop Port]

With some rifles it's like trying to catch a fart in a wind storm, it aint going to happen. Some barrels just don't do cold bore well. With a quality built rifle your chances are better but still not in stone. All of my rifles are for LR hunting and run from 12# to 17#. I have been through some barrels that are better than others. Knowing what a rifle does on cold bore is important, but even better is not needing to know, meaning it shoots the same hole cold bore as group and that is a real winner.
I have a 6br that shoots same hole cold as it does for group. I have a 338 Norma that shoots cold and clean the same as group only the first shot clean on a kroiled barrel is about 20-25fps slow and most of the time my cold bore hunting shot isn't going to be far enough to matter.
Knowing that your cold bore is not out of group is huge for follow up shots. When I put one on a deer at 600-800 and it is slightly off its nice to know my next shot will be the same and I don't have to factor in cold bore on the correction.

 

[alf]

alf's posted results show potentially low precision(grouping)

Looks as though I should sell this POS of mine, as it's obviously barely capable of hitting elephant sized targets at rock throwing distances......

 

[Jay Christopherson]

alf's posted results show potentially low precision(grouping)

Looks as though I should sell this POS of mine, as it's obviously barely capable of hitting elephant sized targets at rock throwing distances......

I think you are missing his point...

 

[alf]

alf's posted results show potentially low precision(grouping)

Looks as though I should sell this POS of mine, as it's obviously barely capable of hitting elephant sized targets at rock throwing distances......

I think you are missing his point...

I don't think I'm the one missing the point.....

 

[Jay Christopherson]

alf's posted results show potentially low precision(grouping)

Looks as though I should sell this POS of mine, as it's obviously barely capable of hitting elephant sized targets at rock throwing distances......

I think you are missing his point...

I don't think I'm the one missing the point.....

Ok, well if you want to go ahead and be offended, then that's fine. It doesn't really matter to me one way or the other except for the fact that I can see from your post that you were (rightly so) proud of shooting you did, but miffed that someone pointed out that it didn't necessarily demonstrate good (potential) precision, in the context of accuracy vs. precision vs. trueness. However, it's a three shot group, so it's tough to tell much about it overall, except with regards to it's potential, which mikecr was careful to state clearly. Clearly it would result in a dead coyote at 1000 yards though, so that's good.

 

[alf]

However, it's a three shot group, so it's tough to tell much about it overall, except with regards to it's potential, which mikecr was careful to state clearly. Clearly it would result in a dead coyote at 1000 yards though, so that's good.

That's exactly my point. There's no way in hell you can glean that much, or type of statistical information, from one three shot group.

The OP was questioning cold bore accuracy. I showed what I did the last time out, first shot, cold bore, then shot two more, nothing more, with a hunting gun.

 

[Hoier]

I'm with Al that is what cold bore is about in my opinion. First shot with the next two pretty darn close. That is how hunting would be. I don't know many guys who could go out and should only 3 shots and shoot a 9" group right where it needs to be.

 

[mikecr]

When you take the context of my posts into full account, I think you should see that I'm in no way cutting down his gun or shooting. Just the opposite.

alf's posted results show potentially low precision(grouping), and yet his gun is plenty accurate. Good hunting gun.
I'm sure his grouping is better normally & up closer, but it don't matter one bit.
I'm also sure that most folks, including gunbuilders, either never run this test, or dismiss the results before them.

When you purely look at the numbers, nothing about this is untruthful. The numbers are stated in MOA, it's that simple.

You walk into a bar one day and declare your grouping was .86moa today, nobody reaches for a trophy..
When you tell them it was at 1kyds, well now some are pretty interested.
And when you tell them your cold bore accuracy was actually .57moa, they should really wanna know who built your gun and how did you get it shooting so well.
There are differences here that I tried to point out. .86moa grouping -vs- .57moa accuracy.
Of coarse his results are better up close, and so this is taken in MOA. It could have been 200, or 500yds, and tighter just as easily for my point.

The subject is accuracy. Alf provided a great example. I thought the example demonstrates how a fixation with grouping could lead to overlooking the accuracy in it. That's all.
I didn't mean to offend folks in making this point.

 

[expiper]

hey Alf,,,,nice place to shoot and great rifle,,,,that is 3 shots to start the day at 1000yds that you could cover with a ball cap ,,,and right in the middle of the gong,,,,,anybody that doesn't like that has never tried it !!!!,,,,to the OP,,,anybody who thinks you can build/have a gun that is zeroed always at any distance in any weather (temp-alt-humididty-etc) is too dumb to shoot any rifle let alone a good un'...Roger

 

[Drop Port]

alf's posted results show potentially low precision(grouping)

Looks as though I should sell this POS of mine, as it's obviously barely capable of hitting elephant sized targets at rock throwing distances......

I'll give you .50c on the dollar and help you out if you decide to sell
is that a VR-Pic action?
What bullets are you shooting?
Nice range are those cuts from the left and right down range? hard to tell from the pic, if so I see a tough to read cross wind even on a mostly calm day.
Nice shooting!

 

[alf]

I'll give you .50c on the dollar and help you out if you decide to sell
is that a VR-Pic action?
What bullets are you shooting?
Nice range are those cuts from the left and right down range? hard to tell from the pic, if so I see a tough to read cross wind even on a mostly calm day.

Thanks, but I think I'll slum it for a while yet....

Bullets are moly plated Berger 105 VLD's, H-4350, 7 1/2"s, running 3030.

Yes, it's a Bat VRPIC action, #3 Rock barrel cut to 22", McM Classic Edge stock, Seekins rings, and 2.5-10 Nightforce.

It's not a shooting "range", just a place I have permission to shoot. If I add the neighbor's place, and shoot kitty corner across the properties, I have stretched it out to 1925 yards.

 

[Raythemanroe]

I just started working up loads with mine and trying different seating depths and what not. Before each session everyday I shoot five at a hundred yards then move out to 300y for my testing. My (clean) cold bore shots have been half inch or less everyday and I thought that was pretty cool! I feel it adds to my confidence to take cold bore hunting shots!