Wheeler Bore Lapping

[RL338]

I picked up one of these kits to try on the 338 WM. I used the Speer 250gr GS. The bar stock that came in the kit could be a little bigger for me. I did 5 of each grit. After wiping them off the bullets felt rough but didn’t look like the Tubbs FF bullets.

The bore in this rifle is a bear to clean. I fired 5 at 220 grit and the barrel was coppered up good.

Cleaned the barrel again and fired the next 5 at 320 grit. This time the barrel cleaned up easier and quicker.
Fired the last 5 at 600 grit and cleaned the barrel again. Way easier and quicker again.
Now for throat erosion , yes it grew. I used a Nosler 300gr CC for measuring.
Started at 3.480”
3.486” after 220 grit
3.490” after 320 grit
3.493 after 600 grit
I know the Barnes 210gr TTSX shot decent I’ll see if the Speer 250gr GS improve. If all else the barrel does clean up way quicker now.

 

[xphunter]

You have me curious as to the final results.

 

[JD338]

Glad it's helped with the fouling and clean up.
Hopefully the 250 GS shoots better for you.

JD338

 

[TackDriver284]

You have me curious as to the final results.

I second to that, I'm curious as well. My 7 Mag throat and rear 8 inches of the barrel is toasted. There is firecracking and roughness in the breech end after cleaning with about 50 patches and a bronze brush going one way and unscrewing at the muzzle and repeat. Used Kroil, and Bore Tech cleaners.
Maybe that stuff RL338 used may smooth it out a little, just wondering.

 

[RL338]

Throat Maintenance System T.M.S kit 284/7mm Cal

David Tubb's FinalFinish and FinalFinish TMS corrects and improves reamer marks, dimensional uniformity, tool marks and surface finish issues in your barrel providing enhanced accuracy of your rifle in 7mm or 284 caliber.

www.davidtubb.com

This might be worth a look on your 7mm. I have a box of 308 for my 30-378 to try when the fire cracking starts getting worse. Just haven’t shot it much lately.

 

[Yoteklr]

The throat after fire lapping obviously lengthens measurably, ask yourself what dimensional changes happen to the bore diameter. .284 bore fire lapped to remove fire cracking might be .285 or more.

Just a thought.

 

[RL338]

My Teslong borescope die last weekend so I can’t get a visual inspection of the bore. With winter settling this week it will be awhile before I get out to see if there is any changes. It does patch out easier now.

 

[phil]

The throat after fire lapping obviously lengthens measurably, ask yourself what dimensional changes happen to the bore diameter. .284 bore fire lapped to remove fire cracking might be .285 or more.

Just a thought.

I’ve got a barrel or 2 that’s tight or tighter than spec.
Id like to remove a thousandth.
Wish I knew it would work!