I think it would be more interesting to do it with the rifle clamped in a true full bench rest. That way you'd be seeing the actual effect of the barrel temp and not differences in the shooter.

Also would be neat to see how different barrel profiles in similar guns perform. So your predator and say, an M77-II VT, and a standard Hawkeye as well. Ya'll need to get some friends together with that sort of collection of gear and then do the test.

 

I agree, I would like to see what bullet mfg use for their loading profiles and Ruger uses to test guns for accuracy. I am sure they are not cheap.

If you do these tests, I would pay more for the temp gauge and get one that would dump data to a computer so you can graph it over time then plot POI deviations on top.

 

It's just my humble opinion, but I believe all of your testing will only show you the particulars of you particular rifle. There are SOOOOOOO many variables in shape, weight, contour, length, caliber ad nauseum. And that doesn't take into account the variable properties of different stocks, receivers and bedding methods - all of which will have some impact on heat transference. Your tests will probably give you more information than you will be able to use about YOUR rifle, but it is unlikely it will be directly relevant to any other rifle. Also, until you have gathered data from some 20 different days of different conditions, all you really know from your testing is what to expect under the precise conditions your tests were conducted and only on that gun.

It's an interesting exercise, to be sure! However, I doubt there will be much of any real use or applicability.

Besides, over the years with lots of rounds downrange, I can tell you this:
Metallic Silhouette is fired at four different animals; 10 rounds each target with a 30 second break between banks of 5 animals - that is five rounds at five Chickens, a 30 second break, then 5 rounds at five more chickens.
Then there is approximately 20 -25 minutes break before the 10 rounds are fired at Javalina. And so on until the last of the four target types have been fired. Firing 40-50 rounds of .270 Winchester on a day when the ambient temperature reaches 115 deg, the barrel of a hunter class rifle gets very, very hot. It gets so dang hot it is uncomfortable to hold it by the forend of the stock for more than a few seconds. Touching the barrel with your bare skin is very painful and has been known to give first degree burns, if not second degree burns. Baby, that's hot! Yet these rifles are often used for several years of competition before they are considered worn to the point that they no longer deliver reliable accuracy out to 500 meters.

To sum it up, if you are trying to satisfy your own sense of curiosity, well, by all means go for it. If, on the other hand, you expect to discover some magnificent principle that will forever impact your rate of flinging lead downrange or the optimum barrel temperature for maximum accuracy..... Well, I think you might be a little disappointed.

Again, JMHO. And worth everything you paid for it!

MC

 

Yes, my mission was to determine how much barrel heating will change the POI for my gun only, not to discover a magic principles.

I am new to reloading and have fired more rounds this year than all years of my life. Until I got into reloading, my knowledge of this sport/hobby was limited to being a hunter buying a box of "whatever", "whenever".

Your story about Metallic Silhouette shooting was very helpful. I had no idea that you could do such shooting with a normal hunting rifle and not damage it. Thanks for the comeback. This is so much fun. I love to learn new things.
I will surf and learn more about silo shooting for sure.

 

Some of the old Milsurps like the old Mosins that are so popular really get hot when fired...I think a combination of metalurgy and the hand guard over the barrel to hold heat in contribute...I have a Mosin that will string shots like a little army marching up the paper as the barrel heats...of course the old Milsurps (unless set up for match) are about "Minute of deer or minute of man" accuracy so not a big issue....the old Mosins will actually burn your hands if you grab the barrel after a session of shooting.

 

Barrel heating and change of POI, as above, is very much a matter of gun type and so on. This is a well known phenomenon to us oldsters. Now and then, however, I''l be at the range shooting one of the guns, waiting for the barrel to cool, when I've been asked by a new shooter if anything was wrong. You'd be surprised at how many shooters don't even know it is an issue for accuracy, not to mention barrel life.

 

My mission is to know my gun, improve my accuracy via learning from the oldsters and trying different setups, loads, timing of shots, etc.

Where heat comes into play for me is load testing a new bullet. I may shoot 30 rounds per powder and maybe two powders. That is 60 rounds. If you have to wait for cool down, what is that wait and how do you measure it by time or temp.

I just thought that time is relative to load and ambient conditions, while temp is something that can be measured. Setting min and max range for temp is where I am now and that could be different for different ranges, i.e. 100 vs 300 yards.

This is a lot of fun. The local ground hogs are paying the price this year for sure.
My goal is 400 yard groundhog shot and a 300 yard crow. With the rolling hills, finding that situation is not easy.

 

I'll tell ya right up front out here it gets down right hot, I suggest taking at least 3 firearms to alternate between series of shots, in order to let the barrels cool off a bit. I've got a mini-14 that is very capable of moa accuracy at 100 yards, however if you shoot too rapidly the groups open up significantly to double that.

I've also got an AR-15 with a 20"bull barrel that is very capable of placing 5 rounds in under a moa, however if you continue to shoot fairly rapidly, that group will also fade into an inch and a half, and I'm sure I'm not doing the lands and grooves any favors by shooting it in an extremely hot barrel.

Last but not least is my bolt action .223 that has a standard hunter barrel, that I've taken on praire dog hunts, and shot quite rapidly, at least as far as I was concerned and found little or no dispersion of the shots, however the weather was fairly cool to say the least.

My .270, 45-70's and 30-06 I haven't shot them until the barrel got too hot to touch, as I only sight them in just before the season starts and once more when I get to the place I'm about to hunt. Any way like somebody else already mentioned, every rifle is an entity on to itself.