Gunsmithing Mechanical Reasons for Vertical?

[mdesign]

Is there anything about the mechanics of a bolt action that can cause a rifle to have vertical? A guy was asking me about his factory R700 in 7RM that has a problem with vertical stringing.

He has added a Timney trigger and replaced the j-lock firing pin assembly. Also has a B&C or HS stock which has been skim bedded over the alum block.

It appears to be well bedded (action does not move when screws loosened)and I wondered if there was something else he should look at. I asked him if had swapped out the scope to see if that was it but he had not tried that.

 

[maccrazy2]

Re: Mechanical Reasons for Vertical?

Viagra!!!
Just kidding
Seriously, I would swap scopes. I verify everything is tight first and if nothing is found swap in a known good scope.

 

[nso123]

Re: Mechanical Reasons for Vertical?

Is he shooting hand loads? Vertical stringing can be the result of a load that does not work with the rifle.

 

[ugsly]

Re: Mechanical Reasons for Vertical?

I agree with NSO, if hes using handloads he needs to try tweaking or rework a new load and see where that gets him. He can mess with the bullet jump .005 increments at a time and see if the groups tighten.

Kc

 

[Ledzep]

Re: Mechanical Reasons for Vertical?

Another consideration may be free floating barrel (especially when the front of the stock is resting on something or under load of a bipod ). Stock fore end rigidity.

 

[LRI]

Re: Mechanical Reasons for Vertical?

Failure to hold elevation can typically be traced to one/all of the following:

1. Shooter can't hold it well
2. Parallax
3. Poorly prepared ammunition
-powder charge/seating depth/neck tension issues
4. Reticle out of focus
5. Bedding problems
6. Shot cadence too fast for given barrel contour/cartridge choice
7. Shooting a sporter rifle like its a br gun, different process required on the bags.

 

[Bugholes]

Re: Mechanical Reasons for Vertical?

<span style="font-weight: bold">7. Shooting a sporter rifle like its a br gun, different process required on the bags.</span>
start here

 

[mdesign]

Re: Mechanical Reasons for Vertical?

Thanks for the good feedback guys....

He is using handload, so I gave him some pointers on load development, we'll see, I kind of wondered about this after talking. The barrel is floated, I checked that too.

I have not seen him shoot so there might be an obvious shooter issue but the rifle has some weight to it and a good pad so it should not be too bad.

<span style="font-weight: bold">Question regarding shooting a sporter like a br gun.</span>

Can either of you explain the different bag process more? I guess I did not realize there was difference or some watchout's in how it was done.

 

[Twisted300Win MAG]

Re: Mechanical Reasons for Vertical?

Slow down. thinner barrels will heat quicker then heavier contour barrels. Shooting mechanics are important fallow through being key to help with vertical strings. Also try shooting some different factory loads and see if group orientation(vertical string vs horizontal ect) changes. Just my thoughts.

 

[Bill Larson]

Re: Mechanical Reasons for Vertical?

I don`t know what kind of accuracy you`re looking for......but with a factory rem. barrel and anything below 2" MOA is resonable....
I know guys who have sent back a 3"-5"MOA rem. and were told it was within factory specs.
There are exceptions.....but if you get a 1" or below factory rem.you are lucky.
bill larson