35 Whelen---Vertical String

[Bill,SC]

I have a load that is dead on with a cold barrel.  However, as the barrel gets warm/hot, it will vertical string as much as 6 inches.  Has anybody had this problem?  How do I solve the problem?

Thanks for all help!

[Curtis]

Shoot it without the forearm attached and see if it still strings.  If that solves the problem, then you may be able to simply shim the forearm away from the barrel some.

Curtis

[Coltdriver]

Actually I discovered a long time ago that if you are shooting a shouldered cartridge in your encore/contender that you have to pay a lot of attention to headspace.  If you try bumping the shoulder back a bit you may instantly eliminate your vertical string.

I was plagued by this problem with a Ruger #1 and with my encore.  I discovered that bumping the shoulder back was all that was needed with both.

[surveyor47]

When you say "bumping the shoulder back", do you mean setting back the shoulder to near minimum SAAMI headspace? This would allow the shoulder to expand upon firing, but why would that affect stringing?  I dont understand.

[JustaShooter]

He likely means to bump the shoulder back to give .001-.002 headspace in your chamber, not back to SAAMI specs.  The reason being is that inconsistent pressure of the cartridge head on the frame of break action rifles like the Encore is one of the causes of vertical stringing.

Just a Shooter

[surveyor47]

Ah!  So when the case expands to fill the chamber, it evens out stress on the action.

[Curtis]

Ah!  So when the case expands to fill the chamber, it evens out stress on the action.

Sort of.......... ideally you would size as long as possible without the shoulder to head length stressing the action when it closes.  I had this difficulty with in my early days with 30 Herrett in my Contender.  Very poor accuracy and the action would barely close on some rounds.

Curtis

[Bill,SC]

Thanks guys!

I have tried all suggestions.  It still strings.  I have used a shim, removed excess from forend, used spacers under the forend, and bumped the shoulder.  Nothing works.  I like this round.  I will keep trying.

Bill

[wallypedal]

What is the barrel to frame gap and the barrel to firing pin bushing gap with the action closed? How far are the locking bolts traveling with the action closed? Is it a T/C barrel or something else? There can be other factors at work as well. Don't give up!