Cold Bore test idea

[Immike]

I was struck with a idea while waiting for a deer yesterday. We are always concerned about starting a match or shooting game with a clean bore so I thought of a test to prepare ourselves for the inevitable. Here it is :
Prepare a 5 bull target with each numbered 1-5 and load 25 good rounds. With a clean bore shoot each once in the order they are numbered. Stop and clean the rifle thoroughly and repeat until each has been shot 5 times. This should show grouping capabilities and elevation changes all in one test. This of course could be expanded to more bulls. We have a 2 sighters only matches at our club with no fouling period so this will be a test I plan to conduct in the spring.

 

[mikecr]

Is this thread about cold bore, or clean bore?
Keep in mind that with hunting you actually are at cold bore, with no sighters, fixed ranges, or bench rests.
With this, there is really no way to consider 'starting a match or shooting game' in a correlating sense.

 

[stool]

for my 20 shot matches at 200 yds( 20 plus 2 siters are allowed)..i go to the range at the same time the match would be shot and shoot two shots ,noting each one. occasionally a rifle will take three but most are on target after two....and then at the real match i simply compensate for the first 2 or 3 shots.

my opinion is that hunters should do this and if the bbl does not shoot dead on for 3 shots, they need to know what their rifle is doing.

 

[finnaddict]

This is a good reason to keep a log and plot sheets. From this data you can determine where that cold bore shot goes each time. You must note all varibals incl weather, wind, humity, alt to name a few. My cold bore shots are 90% of the time X rings. Then it changes slighty.

 

[Immike]

Is this thread about cold bore, or clean bore?
Keep in mind that with hunting you actually are at cold bore, with no sighters, fixed ranges, or bench rests.
With this, there is really no way to consider 'starting a match or shooting game' in a correlating sense.

That's right mikecr, if you want to sight in for cold weather then do it on a cold day. I do start matches in the early morning with a clean and cold rifle. I will run my test with the same conditions for that reason and didn't feel something so obvious needed mentioned. This test is just a suggestion (idea) and will have other aspects to be considered.

 

[jlow]

Apart from the clean/cold bore thing, I have noted a third parameter which may affect your study which is how long your bore has been cleaned. I have found that if you clean the rifle just before you shoot it, it is not the same as shooting a cleaned rifle that has been sitting around for a few days. Anyone else find this?

 

[kelbro]

The scope on my deer rifle is set for a cold, lightly seasoned bore. Five or six shots through it before the start of the season. One or two days between firing those five or six. Clean after the season ends.

 

[stool]

my guess would be, that the bore was not clean....

Apart from the clean/cold bore thing, I have noted a third parameter which may affect your study which is how long your bore has been cleaned. I have found that if you clean the rifle just before you shoot it, it is not the same as shooting a cleaned rifle that has been sitting around for a few days. Anyone else find this?

 

[Immike]

lmmike -

I respect the reasoning for such a test !.!.!
But in my opinion would have to be shot in pristine conditions, not to be faulted by mother nature, do to the length of time such a test would take.


Donovan

Excellent point and that would mess with the grouping results. A complete cool down period would be needed for the elevation to be confirmed so this will take awhile. The information may (or not) provide predictable measurements for making adjustments from the sighters if it proves consistent. This may require separate targets for each cold start for accuracy or logging each string carefully. I think it is a simple test worth the time and possibly save the start of your match day. I have always started at the top of the 10 ring and gave it my best guess with no testing of this nature. With the do or die in competition today a competitor can leave no stones unturned.

 

[finnaddict]

Apart from the clean/cold bore thing, I have noted a third parameter which may affect your study which is how long your bore has been cleaned. I have found that if you clean the rifle just before you shoot it, it is not the same as shooting a cleaned rifle that has been sitting around for a few days. Anyone else find this?

Yes. I have. Just as you describe. I do not clean prior to shooting anymore. Just before does change it.

 

[6BRinNZ]

In NZ we only ever shoot two sighters. I used my Magneto Chrony on club days to "MAP" out the fps change from first shot through to subsequent strings. This allows me to map it over the seasons as well.

Depending on what distance you will be shooting at you could well find that 500, 800 and 900 yard targets give you that extra leeway that its all ok on paper. (I'm talking FO). I'm only speaking to holding the 10 ring.

I will be interested to see if you think the exercise is worthwhile when all is said and done.

 

[jlow]

my guess would be, that the bore was not clean....

Apart from the clean/cold bore thing, I have noted a third parameter which may affect your study which is how long your bore has been cleaned. I have found that if you clean the rifle just before you shoot it, it is not the same as shooting a cleaned rifle that has been sitting around for a few days. Anyone else find this?

Well no bore is 100% clean or should be as that type of cleaning can damage your bore.

But that is a seperate point. What I am saying is if you clean your bore and let it sit a few days before shooting the sighters, you get one type of departure form the "normal" POI when you shoot the sighters. If you clean the bore again the same way (and degree) and shoot it immediately, the departure from the "normal" POI is different.

 

[Immike]

What I am saying is if you clean your bore and let it sit a few days before shooting the sighters, you get one type of departure form the "normal" POI when you shoot the sighters. If you clean the bore again the same way (and degree) and shoot it immediately, the departure from the "normal" POI is different.

I will definitely keep a eye on that observation. I am going to test it with(put away) clean and not just a light cleaning. I am listening when you make a point and will look for a difference in the first string compared to the rest. Thank you.

 

[jlow]

Thanks for listening.

I honestly don’t know the cause. I clean and dry my bore out real well and am hard press to think that it was still wet. The only thing I came out with is some liquid got into the gas port (this was an AR) and that stuff came out but even then it does not make sense as I usually have the barrel pointing up in storage and so one would think that any liquid would go down the gas tube and not into the barrel. Thinking more, perhaps when I drop the bolt…?

Anyhow, just more of a head’s up and would be very interested in what you find as that is of course one of my pet peeves….