Barrel warm up and accuracy?

lngbw111

Active Member
Joined
Dec 11, 2011
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26
I am a first time poster to these threads but a long time viewer. I am sorry if this topic is covered in another thread. If so please direct me there.

Here is what I have,

I have a FN mauser action, ER Shaw barrel, Bell and Carlson Medalist stock, Huber concepts trigger, Leupold varixIII, and Leupold mounts and rings. Chambered in .284 Win.

Barrel is free floated.

I have loaded and shot 140 grain Nosler partitions, Berger VLD hunting, and 168 grain Berger VLD hunting bullets.

I have achieved the best groups with the Berger VLD's. During load development I went to the range and shot very nice groups and found the seating depth I wanted with the Berger 140's. 0.41 inches at 100 yards with 3 shot strings.

Here is the problem...
Before I shot the three shot strings I actually had to shoot a warm up shot and then waited exactly 4 minutes in between every shot for the three shot group. POI change from the first shot and the three shot strings ranged from 1-1.5 inches. I attributed this to being able to keep the barrel temp very consistent etc. Didn't think much of it.

I got some of the rifles favorite length loads loaded. I decided to go back and zero my rifle using 1 shot groups with 20 minutes in between. They were all over the map! 2-3 inch groups.

I will only be using this rifle for hunting purposes and the first shot obviously is the one that counts.

Am I not waiting long enough (20 min.) for the barrel to cool down in the one shot groups? Or is there another issue? I have not tried waiting an hour etc.

Very disheartening as the rifle and myself are capable of shooting 1/2MOA once it warms up!

Sorry for the novel just wanted to let everyone know the whole story.

Thanks for any help of direction?
 
I would bet your rifle has a stock or bedding issue and epoxy bedding the action to the stock would help. I would also make sure the barrel is indeed free floated a good amount, especially when warmed up and with the forarm resting on the bags, or bipod.

It also could be an issue with a stress point in the barrel it self that reacts rapidly to heat. But I am betting on a fresh bedding job and free flost improving your rifles accuracy across the board.

Jeff
 
I agree with the prior post that it could be a bedding issue. The other question I would ask is about whether the barrel was cleaned between the two sessions. I have had rifles that needed multiple shots through the bore to settle in and give good cold/hot bore results. I then left them uncleaned for hunting and had good results.
 
Well something sure is wrong here.

Your cold bore shots (hour wait) should be 1/2 MOA or better unless something is loose.

I'd suggest bedding as the above posters did, but I'd also say you need to look at your scope rings and mounts as well.

That much movement between cold bore shots tells me something is loose somewhere and/or binding.
 
Thanks guys.

I agree that it is somthing. The stock is alluminum bedded but could easily be epoxy bedded.

The barrel was not cleaned in between sessions.

The mounts and could have worked a little loose too. Rings are fine however

I will also check the float off the bags and bipod.

I guess i will try all of them and hopefully it works.

Thanks again...anything else that jumps out to anyone let me know your thoughts.

Eric
 
The stock is alluminum bedded but could easily be epoxy bedded.

I suspect this is your issue, assuming all scope hardware ends up being solid.

I'd highly recommend bedding that action and then trying again. The aluminum is a fine base but a bedding job is what it really needs.
 
I suspect this is your issue, assuming all scope hardware ends up being solid.

I'd highly recommend bedding that action and then trying again. The aluminum is a fine base but a bedding job is what it really needs.

Yup, and I bet when you remove the stock you will see where the action has been wollowing all around in there and leaving gaul marks.

Jeff
 
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