Me and a friend have been doing a lot of benchrest shooting lately. I was wondering if anyone has done any studies on barrel temps effecting accuracy.

We all know that its best to let your barrel cool down between shots for best accuracy, but to what temperature?
If the outside air temp is 90 degrees, and after your first shot, your barrel is at 110 degrees 5 seconds later, should you let your barrel cool down to the same temp as outside air and start over for the next shot in order to get the best results?

I know, that's going a little far out to prove a point, but shooting 220 swifts at 300 yards, it would seem to me that that's one of the outside influences that effect accuracy on the bench.

We've been playing around with a digital temp gauge attached to the barrel to figure out just that point.

For all of us purists out there, lets say the outside air temp is 90 degrees but you know that your rifle shoots best at a barrel temp of 100 degrees. You could wait between shots until the barrel is exactly that temp. You can even have the sensor audibly alert you when to "pull the trigger"

You could also permenantly mount the sensors inside the forearm with a digital readout on the stock of a benchrest rifle.

We know that there are internal causes effecting accuracy such as clean barrel, bullet/load uniformity, trigger pull, good release, but there are also external causes for inaccuracy such as: wind, weather, and barrel temperature.

This wouldn't make a hoot of difference in a hunting situation, but when you're trying to shoot a dime sized group, it makes a difference.

These are the kinds of things I think about when I'm having a slow work day, but any input is appreciated.

Shoot most of the year in ambient temps of 90 deg+ (lots of the time over 100*). Little things I've learned to do in such conditions to keep the groups from spreading:

1) Bring enough firearms with you to the shooting session that will allow barrel cooling when the tube gets warm enough to be uncomfortable to hold in your hand for several seconds.

2) ALWAYS open the action immediately after firing to allow whatever temp air to circulate down the bore as you scope the shot group.

3) Find a shady place to rest the firearm, with as much of the barrel exposed to the air, as possible and with the muzzle up (natural convection of heat rising and cold air settling).

4) In the dead heat of summer (115*+), I'll pre-freeze handtowels wrapped in foil (don't use plastic wrap) or large sized baggies that will fit into a 12-pack cooler. At the range, when the barrel is too hot to hold onto, a towel is opened and draped the entire barrel length, plus the chamber area of the receiver, and left for a minute or so to soak up some of the heat. BE SURE THE ACTION IS OPENED. The towel is returned to the cooler until the next need. When it no longer is cold enough to effectively cool the rifle down in the mentioned time span, it gets draped around the neck for personal cooling and the next frozen towel is hauled out of the cooler.

BTW, also keep my ammo in plastic boxes stored in the cooler to keep the rounds cool, too!

5) Take along a buddy to visit with to pass some time between barrel cooling.

Does this help, Tom? :D

Spend a good bit of my time for years trying to shoot tiny groups. Think the key is a uniform temeprature...not just too hot, the frist rounds from a "cold " (ambiant) barrel are for the spotter. Some folks like to wait out the wind, mirage, light conditons and only fire when the same variables come back around again...takes a lot of patience and a lot of time between shots.


When the condtions shift, but seem to have a dominate pattern of variables, some people would try to rapid fire shots for as long as that set of condtions lasted (assuming you guessed what was dominate correctly to start with)...this kind of shooter may sit and watch for a good bit, but them shoot rapidly.

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Now I mention this becaseu I've had rifles that would vary very little over a pretty high range of temperatues...and have had other barrels that would not handle nearly the temperature range....so i kind of adjusted my shooting to fit the personality of the barrel.

The question of barrel temperature is interesting, at first my gut reaction is it depends on what the fire arm is to be used for. If hunting a cold barrel, if competition the what the rules allow, if you must shoot 5 shots in 5 minutes then allow the barrel to cool accordingly.

That is different than what will give the best accuracy. I supose that if we accept the arguement that consistancy leads to accuracy then we should let the barrel cool completely, but I think there are other factors like shooter endurance, light position, and returning to position after a long wait, to name a few.

This is an interesting experiment waiting to happen.

Regards,
Gene