Is The Stock Causing Vertical Stringing?

[dvsdev]

This rifle is a Howa 1500 Varmint in 308 with factory synthetic stock. I want to confirm that the stock is causing the vertical stringing. The barrel is not free floating in the stock. There is contact at the end of the forend and the barrel.


Here are shots 16-20 from today's shooting session after zeroing.

Here is where the vertical stringing occurs. My last groups of this shooting session. Shots 26-40, five shot groups. Shots 1 and 2 are shooter error.

ETA:

Bench, prone, over a rest? Shooting from bench.

Bags or biod? Bipod

Rear bag, monopod, fist??? Fist

Different shoulder pressure for each shot? I would say no.

Are you holding it tighter or looser... Looser.

 

[Mike Casselton]

Re: Is The Stock Causing Vertical Stringing?

We need to know more about your set-up.

Bench, prone, over a rest?

Bags or bipod?

Rear bag, monopod, fist???

If a rear bag, is the sling stud making contact with the bag?

Different shoulder pressure for each shot?

Are you holding it tighter or looser...

So many things come into play, so we need more info to help you out.

Right now it's kinda like doing a night drop on your car to the mechanic and the note to him just says "fix it"

 

[dvsdev]

Re: Is The Stock Causing Vertical Stringing?

I edited the OP to add the info.

 

[KeithR41]

Re: Is The Stock Causing Vertical Stringing?

Your barrel is probably heating up.

41

 

[patriotoutlaw]

Re: Is The Stock Causing Vertical Stringing?

I would try free floating it.

 

[Mike Casselton]

Re: Is The Stock Causing Vertical Stringing?

You could be getting tired and (unknowingly) tightening your fist as the sear releases. Realistically it is another version of a flinch. Try a rear bag, but make sure the sling stud does not make contact with the bag.

 

[skeetlee]

Re: Is The Stock Causing Vertical Stringing?

Looks like heat from a sporter weight barrel to me. Yes get the stock opened up to. No good can come from a stock touching a barrel. Lee

 

[Killer Spade 13]

Re: Is The Stock Causing Vertical Stringing?

+1 for K41.

I'd guess heat.

Just for kicks and giggles I'm going to throw something in that's a bit off topic, but you guys will relish in the enjoyment.

Prologue - highschool buddy who has had everything he ever wanted. I got a 30-30 Win., he got a Rem. 742 in 30-06, this is back in 1962. This boy ain't no rifle shot. Jump forward to 1990.

His new trophy-bride buys him a top-of-the-line, paper thin barreled Weatherby in Weatherby 300 Mag.

He gives me a call one day telling me that he's shot 8 three round shot groups and can't get his scope to zero (all in the same range visit).

Lord help him, sometimes that boy just ain't too bright.

 

[Gruff]

Re: Is The Stock Causing Vertical Stringing?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mike Casselton</div><div class="ubbcode-body">You could be getting tired and (unknowingly) tightening your fist as the sear releases. Realistically it is another version of a flinch. Try a rear bag, but make sure the sling stud does not make contact with the bag. </div></div>

^^^THIS^^^

 

[dvsdev]

Re: Is The Stock Causing Vertical Stringing?

It looks like it could be a number of things I wasn't aware of before. I will give it another go with a rear bag.

 

[Country]

Re: Is The Stock Causing Vertical Stringing?

From the descriptions I would say numerous things are wrong.
First off you can not shoota 308 like a 6mmPPC you have to hold onto it and keep it against your shoulder otherwise recoil will push the bags all out of shape and muzzle jump will happen .
Second if the barrel is touching in the forend that could add verticle or inconsistant groups.
Third you may be shooting way to fast and heating up the barrel.
Fourth you may be getting some barrel fouling after 40 odd shots in a group.
Fifth , some of the group is showing you are being caught by wind changes. There is also a verticle componant to wind direction that will add some verticle also .
Slow down and stop just blasting away with too many shots.
Use a five shot group basis and let the barrel cool between shots as you are waiting for the barrel to cool study the wind flags .
Fire each shot when the wind is either at it's lowest velocity point or at a consistant condition .
No rear bag or rest of anykind will not help either especially if you are not holding the gun firm enough.

 

[dvsdev]

Re: Is The Stock Causing Vertical Stringing?

All my shots were done in 5 shot groups. I constantly check the barrel for overheating.

I shot again on Friday night, this time using a rear bag. There was no vertical stringing at all. I was shooting sub-moa groups, but there is definitely room for improvement (shooter and rifle).

 

[Country]

Re: Is The Stock Causing Vertical Stringing?

That's good to hear that you have sorted some of the issues out.
That shows that the gun is ok . We all have room for improvement otherwise everyone would be a world champion shot.
The main thing is that we try new ways of doing things and if it don't improve things go back and try something else.
I have been shooting for over 40 years and I am still learning new things all the time , especially with the internet now that was not available to me until about 12 years ago.