My 6br went 'shotgun' on me.

[Tesoro]

I decided to take my Mod7 lightweight 6br out of its h-s stock and put in a lss mdt chassis. Why? because I have always wanted a chassis. The shilen barrel is 21.6 in and .620 at the muzzle. Light sporter profile I guess. Anyhow this rifle shot lights out when in the stock. Now it shoots patterns with the same 30.5g varget and 105 bergers. I even loaded a batch at 30.0 g and same inconsistent patterns. So looks like there is no 'powder tune' fix.
In the old stock the barrel was floated past the shoulder. So I assume that this lightweight barrel is just picking up too much vibration in the aluminum stock?
I sold the h-s stock so reverting back is not an option. I dont want to try a tension tab. What is the other option? A heavier barrel is assume?

 

[dantiff2]

I decided to take my Mod7 lightweight 6br out of its h-s stock and put in a lss mdt chassis. Why? because I have always wanted a chassis. The shilen barrel is 21.6 in and .620 at the muzzle. Light sporter profile I guess. Anyhow this rifle shot lights out when in the stock. Now it shoots patterns with the same 30.5g varget and 105 bergers. I even loaded a batch at 30.0 g and same inconsistent patterns. So looks like there is no 'powder tune' fix.
In the old stock the barrel was floated past the shoulder. So I assume that this lightweight barrel is just picking up too much vibration in the aluminum stock?
I sold the h-s stock so reverting back is not an option. I dont want to try a tension tab. What is the other option? A heavier barrel is assume?

A muzzle device such as a tuner or brake or even a suppressor would likely help. Some of those skinnier profile barrels do like to be held (bedded out in front of recoil lug) a little bit

 

[Tesoro]

thx. Good idea. I would hate to waste that barrel as has lots of life left and shoots bugholes.

 

[Tesoro]

Double check the front action screw length if you haven't already. Make sure it isn't too long & bottoming out before getting tight.

It cranked down to torque spec

 

[Eagle Six]

I doubt this is what's happening, but it's easy to check/ rule out/ fix before chasing other rabbits. A known 6BR shouldn't turn into a scatter gun by simply bolting it into a quality chassis, regardless of barrel profile.

This ^^^^ first.

Then, I'm sure you have double checked, but just throwing things out....

What else did you do when switching over, double check, to assure it isn't some thing other than the chassis.

Receiver screw torque and sequence from one bedding to the other are not always equal and you may have to make some adjustments.

I recently switched from an H-S Precision stock to an KRG Bravo stock/chassis. I used their provided receiver screws and torqued them by their specifications. The first time out was a bit disappointing. I didn't expect any improvement in rifle precision, but thought I would have an improvement in accuracy. I spent a lot of time dry firing before the second range session to get comfortable with the chassis. Second round went well and I got the improvement I had expected and more. We are all different, so good luck with it.

 

[TaperPin]

I must be the only guy ever that can’t get a rifle to shoot well with a bipod - if you have a fancy bipod it would be worth at least padding the feet up off the bench or hard dirt, or use a normal rest.

 

[Bill Norris]

A quick & easy fix for bi-pod bounce. Carpet samples are free at Lowes or Home Depot.

 

[Eagle Six]

I must be the only guy ever that can’t get a rifle to shoot well with a bipod - if you have a fancy bipod it would be worth at least padding the feet up off the bench or hard dirt, or use a normal rest.

I don't remember @Tesoro mentioning anything about a bipod, although I would think he is. I would also think if he is he is using the same bipod he used to previously shoot bugholes.

 

[NZ_Fclass]

It may be worth skim bedding in the chassis. The action may not be so "round" Also check that the recoil lug isn't bottoming out and contacts the chassis correctly.

 

[Mastershot]

My guess, is bedding and the recoil lug not fully seated against the stock.

 

[Tesoro]

Thx - i’ll check bedding n measure screw hole length vs screw. Same everything else. Well I did swap scopes but NF to NF so I doubt that is issue. They beat them on a hard rubber mat and check them before boxing! I have shot this rifle probably 400x and it has never grouped more that .5 during load development. It has done .5 moa at 1000. So not barrel or my ammo.

 

[ballisticdaddy]

MPA makes a gadget called a lug lock and believe this occurs with many chassis types

I have no idea if this would work in your MDT chassis and might be quicker and easier to bed it yourself

 

[whatsupdoc]

The MDT LSS is a lightweight chassis that does not normally need any bedding. The chassis has two raised areas on the sides of the action screw that contact the action and I have had a couple of actions in mine and they shot as expected.

The chassis is lightweight thin and very flexible, the forend twists easily and you need to treat it
differently than a heavier stiffer stock or chassis setup. My MDT ESS chassis is very stiff where my LSS gen II is not.

When I first shot the LSS with a very heavy barrelled action in it and a bipod it seemed to shoot like crap but after a few outings I got the hang of it.

Its now the home for my Vodoo and it works very well.

Di you have the Gen 1 or Gen 2?

 

[Tesoro]

The MDT LSS is a lightweight chassis that does not normally need any bedding. The chassis has two raised areas on the sides of the action screw that contact the action and I have had a couple of actions in mine and they shot as expected.

The chassis is lightweight thin and very flexible, the forend twists easily and you need to treat it
differently than a heavier stiffer stock or chassis setup. My MDT ESS chassis is very stiff where my LSS gen II is not.

When I first shot the LSS with a very heavy barrelled action in it and a bipod it seemed to shoot like crap but after a few outings I got the hang of it.

Its now the home for my Vodoo and it works very well.

Di you have the Gen 1 or Gen 2?

Gen2 Bipod

 

[X-Caveman]

I would swap the scopes back, too. Just because it’s a NF doesn’t mean it can’t be the problem. Minimize variables.

 

[Tesoro]

I would swap the scopes back, too. Just because it’s a NF doesn’t mean it can’t be the problem. Minimize variables.

Nah the scope is fine. I has held zero 3x in a row for diff shooting sessions.

 

[jkohler]

check And make sure the recoil lug isn’t bottoming out Before the action is down on the v-block. I had a chassis that had that problem in the shop last year. If your action screw is to long it with come up to far and hit the bolt not the barrel threads.

 

[Tesoro]

Thx everyone..I know what i need to check now but just realized I also need to use rifle as is for close range brush deer hunting over the next week starting tomorrow. 1 moa is fine. After that I'll post my findings. I think all is good but the barrel is too pencil and getting vibes off the stock so need weight at the end. Those light alum stocks do weird stuff. The first thing my gunsmith friend told me was to brace the barrel to find out. He knows after 40 years of working rifles. He was one of original PacNor guys and not fond of chassis cause he hears the 'ping' sounds as he aways shoots suppressed.

 

[jkohler]

make sure the bolt handle isn’t hitting the chassis also

 

[Idaho-Lefty]

I built, a 6 XC "RemAge" Rem 700 with, a Criterion Barrel and Bedded it to, an H-S Precision Stock and it,.. "BugHoles" !
I put, a "Toe Rudder" on the stock, ( a Bag Rider ) for GREAT, "Tracking" !
I'd NEVER sell my, Aluminum Pillars, Glass Bedded,.. H S Precision Stock !