Tubb final finish bore lapping system

[WalksLikeADeer]

Has anyone tried this system on an old barrel? I have an 35 year old Winchester Model 70 Featherweight .243 that shoots 2"-2 1/2" 100 yd groups with both factory and handloads. It use to shoot 1 MOA but the last 3-4 years accuracy has degraded. I'm guessing it's had 1000-1500 rounds thru it. No hot loads. I've eliminated bedding and scope/mounts as the problem. A new barrel is most of the cost of a new gun. Thought I might try these as a last resort? Thank you in advance.

https://www.midwayusa.com/product/605933/tubb-final-finish-bore-lapping-system

 

[dok7mm]

You really need to have someone check it out with a borescope, to see exactly what you have. My first thought was to try seating the bullet out longer
(closer to the lands) if you have the tools to measure and the lands have not eroded too badly.

 

[WalksLikeADeer]

You really need to have someone check it out with a borescope, to see exactly what you have. My first thought was to try seating the bullet out longer
(closer to the lands) if you have the tools to measure and the lands have not eroded too badly.

That's probably a good idea. I have seated .020, .030, .040, .060 and .080" off the lands and they all shoot bad. This is with Sierra Game Changers 90 gr. I'm pretty sure there is good throat erosion because when the bullets are seated to fit in the magazine they are WAY off the lands. I forget the exact number but it's significant.

 

[WalksLikeADeer]

You really need to have someone check it out with a borescope, to see exactly what you have. My first thought was to try seating the bullet out longer
(closer to the lands) if you have the tools to measure and the lands have not eroded too badly.

The bore lapping system seems to have good reviews and I thought it might be worth a try? Probably less expensive than having a gunsmith bore scope it? I wish I knew a good smith in the Portland Oregon area.

 

[Mustang72]

I haven't tried them yet but it does have instructions in the box for running some of through it when accuracy drops off to polish the throat back up. I don't know how well you have cleaned the barrel but that can make a big difference. Some like it clean but others don't shoot as good after they are clean- can take 10-20 rounds before they start shooting good again. Also sometimes bullet manufacturers make little changes to their bullets and don't tell anyone, so you might try a couple of different loads.

 

[hunter67wa]

I have used Tubbs system and have restored old rifles back and even better than before. I will say I copper stripped first shot still didn't shoot and used Tubbs and shot an Inch. I have done this on 3 rifles now. I am not afraid to use this on a new rifle that wont shoot either with a factory barrel as custom barrels are made better. What do you have to loose?

 

[Orange Dust]

Key to trying this is to start with a really clean barrel, and follow the instructions to the letter. Sometimes the results are amazing. Nothing to lose, barrel won't shoot like it is.

 

[SidecarFlip]

I have 2 bore scopes, a very expensive Gradient Lens Hawkeye (900 bucks) and a cheapo Harbor Freight 49 buck electronic bore scope with color monitor and I use the HF cheapo scope 99% of the time now. Best 50 bucks I ever invested. Resolution on both is equal as is clarity. Only difference is the probe end on the Hawkeye is a bit smaller so it fits where the HF won't.

Nice thing about a borescope and used firearms is, you can look inside before you buy (which I always do now) and walk away or haggle the price if the tube is questionable. I buy used firearms regularly, mostly handguns but long guns too.

Amazing how fast a seller changes his or her tune when the scope reveals a bore that looks like a lunar surface....

 

[Susquatch]

Frankly, I doubt that Final Finish will restore an old bore. But you never know. It certainly won't hurt. In my experience, they are designed to speed up the process of breaking in a new barrel, not renewing an old one. However, they can also be used to improve an old throat by smoothing out the alligator surface that develops over time. If you do use it, don't use the course bullets - just use the last two or three sets.

You say you have ruled out bedding and scope mounts, but I'd be checking your crown and barrel clearance in the forend if I were you...

If you try them, please come back to this thread and let us all know what happened.

 

[stangfish]

I have 2 bore scopes, a very expensive Gradient Lens Hawkeye (900 bucks) and a cheapo Harbor Freight 49 buck electronic bore scope with color monitor and I use the HF cheapo scope 99% of the time now. Best 50 bucks I ever invested. Resolution on both is equal as is clarity. Only difference is the probe end on the Hawkeye is a bit smaller so it fits where the HF won't.

The one HF currently sells has a 8.5 OD(.330"+). Were they smaller than that on earlier models? Thanks

 

[WalksLikeADeer]

I haven't tried them yet but it does have instructions in the box for running some of through it when accuracy drops off to polish the throat back up. I don't know how well you have cleaned the barrel but that can make a big difference. Some like it clean but others don't shoot as good after they are clean- can take 10-20 rounds before they start shooting good again. Also sometimes bullet manufacturers make little changes to their bullets and don't tell anyone, so you might try a couple of different loads.

Yes, I have done a thorough copper cleaning multiple times and have also let the copper build up and neither has helped. Thanks for your reply.

 

[WalksLikeADeer]

I have 2 bore scopes, a very expensive Gradient Lens Hawkeye (900 bucks) and a cheapo Harbor Freight 49 buck electronic bore scope with color monitor and I use the HF cheapo scope 99% of the time now. Best 50 bucks I ever invested. Resolution on both is equal as is clarity. Only difference is the probe end on the Hawkeye is a bit smaller so it fits where the HF won't.

Nice thing about a borescope and used firearms is, you can look inside before you buy (which I always do now) and walk away or haggle the price if the tube is questionable. I buy used firearms regularly, mostly handguns but long guns too.

Amazing how fast a seller changes his or her tune when the scope reveals a bore that looks like a lunar surface....

I will need to get one and probably useful for other things as well. Do you know the diameter of the probe end? Thanks.

 

[WalksLikeADeer]

Frankly, I doubt that Final Finish will restore an old bore. But you never know. It certainly won't hurt. In my experience, they are designed to speed up the process of breaking in a new barrel, not renewing an old one. However, they can also be used to improve an old throat by smoothing out the alligator surface that develops over time. If you do use it, don't use the course bullets - just use the last two or three sets.

You say you have ruled out bedding and scope mounts, but I'd be checking your crown and barrel clearance in the forend if I were you...

If you try them, please come back to this thread and let us all know what happened.

 

[WalksLikeADeer]

Frankly, I doubt that Final Finish will restore an old bore. But you never know. It certainly won't hurt. In my experience, they are designed to speed up the process of breaking in a new barrel, not renewing an old one. However, they can also be used to improve an old throat by smoothing out the alligator surface that develops over time. If you do use it, don't use the course bullets - just use the last two or three sets.

You say you have ruled out bedding and scope mounts, but I'd be checking your crown and barrel clearance in the forend if I were you...

If you try them, please come back to this thread and let us all know what happened.

I have checked the crown and can not see any noticeable flaws but it's possible there could be is some microscopic irregularities. I have increase the clearance between the free float barrel and stock and nothing is touching.

Yes, I feel I have nothing to lose and others seem to have had good results. I will report back if I try them. Thanks.