Free floated my barrel - Results

[IDHUNTER]

A while back I had asked about the possible negative effects of removing the factory pressure point and free floating a barrel because i was getting significant POI shift from one shooting session to the next...presumably from the wood shifting/swelling/shrinking etc.

Most responses of pressure point removal were positive so i went ahead and got my barrel floated and action bedded by a good gunsmith and took it to the range this weekend.

I shot 5 rounds of factory ammo (previously could shoot under 1" with this) and 5 rounds each of three different hand loads with .5 grain powder charge differences in each. (73, 73.5, 74 grains H4831SC)

All of them produced around 4" groups. There really wasn't one that shot any better or worse than the others.

Is this something that needs to be addressed on the rifle by putting the pressure point back in or do i just need to keep tinkering with my hand loads?

This is a late 60s German 7mm WBY Mag shooting 140 grain partitions.

 

[30338]

What scope are you using? Really never had a centerfire shoot 4" groups unless the scope was shot.

 

[OXN939]

Yikes. Pics of the bedding job? If it's well done and your action screws are torqued correctly, you should be doing much better than that. Always worth taking a close look at the crown.

 

[Cahunter805]

You can test this easily. Fold a business card up and wedge it under the barrel where it meets the forend and shoot some more groups. If they tighten up you can have a pressure point bedded in the barrel channel.
I personally free float all my rifles and bed them before starting load development.

 

[IDHUNTER]

Scope is a 1 year old Leupold VX3i. Shot great pre-float.

Cant get a pic of the bedding job right now but i saw it upon completion and it looked great and the gunsmith who did it is very reputable and does excellent work.

I got sub 1" groups prior to this with factory ammo which i would think indicates a good scope and crown. Only issue was POI change between range sessions.

I'll try the card/shim next time out to see if that tightens things back up.

Thanks for the replies.

 

[Antares]

Sounds like something is loose to me. Action screws, rail, rings, etc.

 

[Aaron Warpony]

Whenever i've been stumped with a gun I start from the beginning. take the stock off and inspect the gunsmiths job, put stock back on (easy, usually just 2 bolts). Torque to spec. clean barrel really well, torque scope mounts and rings, then shoot 10 rounds through it, then start worrying about groups. this has always solved my problems. Once was an issue with copper fouling in the barrel, just needed cleaned after 400 rounds or so, and other was a loose scope ring. brought the gun back to zero. good luck

 

[Unclecroc]

I would start with the low hanging fruit give it a once over make sure everything is tight, barrel is clean and ammunition is in good order. Then I would pursue more costly and time consuming options if it didn’t shoot well.
My experience is that free floating most of the time makes the rifle shoot better and more consistent. My guess is that the barrel harmonics were changed and now a load that previously shot well now does not agree with the new harmonics. I would go over the basics and then try new load development from scratch.

 

[Antares]

I would start with the low hanging fruit give it a once over make sure everything is tight, barrel is clean and ammunition is in good order. Then I would pursue more costly and time consuming options if it didn’t shoot well.
My experience is that free floating most of the time makes the rifle shoot better and more consistent. My guess is that the barrel harmonics were changed and now a load that previously shot well now does not agree with the new harmonics. I would go over the basics and then try new load development from scratch.

You're totally right that free floating will change barrel harmonics, but that shouldn't result in 4 MOA groups (assuming OP is shooting at 100 yards).

 

[30338]

I had a 9.3x62 that went from half inch groups to 6" groups just all over the place. The formerly rock solid Leupold 6x42 had let loose inside. Replaced it with a different brand and groups went back to half inch. Had similar things happen on several rigs over the years. Easy one to rule out by a simple scope swap.

 

[30338]

Sounds like something is loose to me. Action screws, rail, rings, etc.

Reticle, etc.