Hot Barrel Accuracy

[WoolSocks]

Hello. Took my new (to me) browning x-bolt 300 prc to the range today. First three groups of 3 were great, sub MOA, if not a little better. After those 9 shots, the groups opened up to 3 MOA or so. I stopped shooting at 20 rounds cause it wasn’t getting any better.

Is is typical? The barrel is floated and fluted. which I thought would help with the hot barrel inaccuracy.

[Fidelk]

Not any kind of expert but how long between shots? When I'm shooting from a bench rest and going after a tight group, I use a watch and wait 2 minutes or more between shots to allow a bit of cooling. Good news is when hunting, your most effective shot should be coming out of a cold barrel.

[WoolSocks]

Probably 1-2 min between shots. I take my time when sighting in.

Did check the barrel after 15 rounds or so. It was pretty hot. Not hot enough to burn ya, but on the edge of uncomfortable to keep your hand on.

[Fidelk]

I feel my barrel (Rem 700 Long Range, .300 Win Mag.....bull barrel) when sighting in to see how warm it is.......you are describing a much hotter barrel than I have encountered. Why not try another range session and time 5 minutes between shots. To be scientific about it, if you expanded the cool down time, you should see how 3 x 3 shots compare to your first groups.......then shoot a couple more 3 shot groups. If they don't open up, then heat might be the main factor. The 3 sub-MOA groups is a positive sign.

Is the .300 PRC known to shoot "hot"? Does it have a lot of recoil and could that have you anticipating it enough to open up those groups after a certain number of rounds have been fired?

Again, no expert.......I just go with trial and error. My first outing with my Rem 700, I couldn't even find any holes in the target......someone took pity on me and loaned me a large piece of white cardboard.......my scope was way out of whack.   

[JimmyHoffa]

Copper fouling?

[wheels1]

Prc can be a toasty round  wouldn't shoot more then 5  rounds with 2 to 3 minute break

[Bob33]

Do the same test another day. If the first three groups are good then barrel heat is the likely culprit. If the first group from a cold barrel is 3 MOA then thoroughly clean the barrel, come back another day and try again.

[buckfvr]

  If its your new hunt rifle, first 2 shots same hole or as close as you can get.  Third shot will be starting to move on you, I do 5 minutes between shots when dialing in and checking loads.  If its hot out, even longer.  Between groups, you must let the barrel cool down all the way.  That rifle should do better than moa if you handload or use premium ammo.

[KNOPHISH]

Add the hot weather and it takes longer to cool down. Bring multiple guns to range and switch after a few shots so you don’t have to sit around waiting.

[boneaddict]

The only other thing might be a screw coming loose on a scope mount?   

[boneaddict]

This is the one that always got me...

ot any kind of expert but how long between shots? When I'm shooting from a bench rest and going after a tight group, I use a watch and wait 2 minutes or more between shots to allow a bit of cooling. Good news is when hunting, your most effective shot should be coming out of a cold barrel.
Modify message

My DAD always fouled the barrel when we got on the range to shoot for accuracy or when working up loads.  I always thought to myself, well, I have a cold cleaned barrel when I was putting a drop on something downrange.........

[Farmer72]

This is the one that always got me...

ot any kind of expert but how long between shots? When I'm shooting from a bench rest and going after a tight group, I use a watch and wait 2 minutes or more between shots to allow a bit of cooling. Good news is when hunting, your most effective shot should be coming out of a cold barrel.
Modify message

My DAD always fouled the barrel when we got on the range to shoot for accuracy or when working up loads.  I always thought to myself, well, I have a cold cleaned barrel when I was putting a drop on something downrange.........

I never had a clean barrel when I was rifle hunting. I always shot a fouling round or 2 before we left for a trip.

[OltHunter]

Hello. Took my new (to me) browning x-bolt 300 prc to the range today. First three groups of 3 were great, sub MOA, if not a little better. After those 9 shots, the groups opened up to 3 MOA or so. I stopped shooting at 20 rounds cause it wasn’t getting any better.

Is is typical? The barrel is floated and fluted. which I thought would help with the hot barrel inaccuracy.

Hot barrels due decrease accuracy. From sub to 3 moa, not sure. Might be something loose.

But hunting, big taper, thin barrels do not maintain accuracy as they heat up. 3 shot strings, with full cool between strings is the best way to figure out accuracy at the range. That equals long range trips.

The thicker the barrel, the more you can shoot in a row without an effect.

[dreadi]

At 25yds, 100yds, 300yds, 600yds?
Did you check your base and rings torque between groups?
Were you changing positions? Did you have the rifle locked into a rest?
Could you clearly see the target or was it like a mirage?
Were you getting tired? Shooting in direct sun, getting hot and uncomfortable?

There’s so many factors that have to come together. The only way to get as close to a conclusion is to eliminate as many variables as possible and keep the shooting as consistent as possible.

9 sub MOA shots sounds like a good shoot to me when you’re past and well past 100yds.


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[Fidelk]

This is the one that always got me...

ot any kind of expert but how long between shots? When I'm shooting from a bench rest and going after a tight group, I use a watch and wait 2 minutes or more between shots to allow a bit of cooling. Good news is when hunting, your most effective shot should be coming out of a cold barrel.
Modify message

My DAD always fouled the barrel when we got on the range to shoot for accuracy or when working up loads.  I always thought to myself, well, I have a cold cleaned barrel when I was putting a drop on something downrange.........

I never had a clean barrel when I was rifle hunting. I always shot a fouling round or 2 before we left for a trip.

I've always heard that you NEED to fire a round if you've cleaned your barrel and have used any oil or solvent. Fire a round and that gets burned out of there. If I clean a barrel close to a hunting trip, I'll only use a dry patch.