Story, concern and question on M70 scratched barrel

[Wyo7200]

My Mod 70 is fouler. It takes 5-6 shots to get back to being under moa and then I have about 8-10 shots before it starts opening up again. I am the rifles third owner, and I suspect there is under 150 rounds through it. The first owner only shot two boxes through it. My bother shot the other two. They didn’t save any for me so I have shot hand loads. After a few days of trekking in the high mountains of SE Wyoming in wet-cold weather chasing elk, I deep cleaned my Model 70 to prevent any rusting. I used KG-12 copper killer on a .30 cal mop to dissolve and remove all of the fouling I put on for the hunt. After 45 minutes of scrubbing, the barrel was clean enough for me. Patches were clean and I didn’t see any copper on the rifling. Dried it out and ran the oil patch down the hole.

Before putting it in the safe, I looked at the crown again and didn’t like what I saw. I found some irregular scratches in the barrel that I have no idea where they came from. They look like someone used a stainless steel brush at some point or if I just cleaned it well enough this time to see them all.

Before I start gathering information for the custom turret, I want to make sure that I won’t have to change components any time soon. I’m not sure if the barrel was ever broken in. I’m going to see what the Dave Tubbs Final finish system can do before I look at getting another barrel.

Has anyone else experienced a scratches barrel like this or experience with using the final finish system?

 

[Guy Miner]

I used the Final Finish system on a 7mm Rem mag that was fouling pretty bad once.

Not sure it helped the fouling problem much, but good grief, that rifle turned out to be accurate as all get out. Should have kept it!

I dunno what to say about your scratches...

Guy

 

[Wyo7200]

Thanks for the info-

I think the scratches came from the mop jag insert... I twisted it when I squirt more KG-12 on the mop part and I must not have been thinking at that moment that it would scratch the barrel... freakin a.

 

[hellrazor]

I doubt a jag could scratch a barrel that easily. Are you sure it isn't residue coming from the jag itself?

 

[Wyo7200]

Im pretty sure. I took a q tip with some solvent on it and scrubbed it for a few seconds with all the hope in the world only for it to be crushed. I'm thinking it was the metal part of the mop jag that did it.

 

[Wyo7200]

Got my finish today and started loading. First bullet I pulled out of the box and seated was a .308! the rest are .284. Emailed Mr. Tubb to let him know. I don't think loosing one will make that much of a difference. I am using FC cases that came with the rifle when I bought it and I don't expect to get more than 2-3 loads out of them so not too worried about any case damage/ case loss.

 

[Wyo7200]

Shot the #3 and #4 today. #5 will be tomorrow or IMG before work. I understand not to pay attention to the groups during the process, but I was happy to see the group shrink. Still takes a lot of passes with a bronze brush to clean but the tooling marks are harder to see, along with the irregular scratches near the crown. Even managed to find an accurate subsonic load for the .300 blkout on the first go around.

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[SJB358]

Looks pretty good. Wondering how it'll shape up when it's all complete.

Thanks for the write up.

 

[Wyo7200]

This was the final step. Been extremely cold and windy since I shot this and haven't had a chance to shoot my accubonds. A lot less fouling with this group.

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[JD338]

Looking good.
I'm anxious to see how the AB's shoot for you and if the barrel will foul less.

JD338

 

[Thebear_78]

I did my 300 rum with the final finish system. It zak ways shot very well and still shot great after the finish. I can't say for sure it helped a lot with accuracy but it made clean up a snap. It was a night and day difference. It is almost a one patch and done clean up now!

I was impressed enough that I bought two more of the finish systems for my 375 rum and a 7mm kit for the would be 280ai I switched to 270 lightweight build.

I guess I'll have to get another one in 277. I should have done the 375 by now but the prospect of running thru 50 on the bench is a little daunting. Takes forever too because those things heat up a barrel fast

 

[Wyo7200]

I wish they'd sell the #3-#5 as a kit option. Really sucks throwing away 20 bullets that you paid for but cant use. It certainly took less effort to dissolve the copper fouling on the last batch. Going to be a few weeks till I can get out and shoot it. Seems that the good weather has synced up with my work days so I'm stuck in the house on my days off.

I did my test in 5 degree pre-blizzard weather. Only took 45 sec- 1 minute between shots for the barrel to cool.

 

[Wyo7200]

Here's the results:

100yards, 160gr AccuBond. 3 shots. I changed my load based the recent discussions about OBT and QuickLoad and... I'm happy. Time to collect drop data and get my custom turret.

 

[DrMike]

You have every reason to be pleased with that group. Congratulations.

 

[SJB358]

Wow. Congrats on that load.

What is your load and what were the predictions?

 

[Wyo7200]

Thanks! Sorry for the terrible blurred photo. didnt look so bad on the iphone. Not bad for a Wal-mart special eh?

Before I ran the Final Finish system I was loading 65gr of R22. Since evaluating all my loads with the OBT theory in mind, I dropped the charge to 64.5 R22. I tweaked the burn rate in QL based on chrono data and landed on node 5 in the 26” barrel OBT table.

160gr AccuBond, 64.5gr R22, 3.280 oal, Fed 215 starter cap. QL estimate of 2993 fps.

 

[truck driver]

That worked out very well. I was always leery of trying the bullet lapping kits after reading how they could do as much harm as good. But if I need to fix a barrel I might give them a try.

 

[efw]

Have you fired it at least a hundred times?

If so I'd say it was broken in !

In all seriousness, I have a couple foulers & am installing Ultra Bore Coat this winter. It's a polymer coating that is supposed to help quite a lot, allowing many shots before copper becomes an issue.

I'll report back here & let ya'll know.

 

[SJB358]

Have you fired it at least a hundred times?

If so I'd say it was broken in !

In all seriousness, I have a couple foulers & am installing Ultra Bore Coat this winter. It's a polymer coating that is supposed to help quite a lot, allowing many shots before copper becomes an issue.

I'll report back here & let ya'll know.

My plan as well on a few rifles..

 

[preacher]

I used both NECO and Tubb kits through the years. I like them for the foulers too, they do a good job. I did tried a product called "EezOx", which is a polymer/specialty oil that works wonders. Initially, I will clean a barrel ( even a new one, heck, especially a new one!) down to bare metal, soak the bore with a good coating and let sit overnight. Next day, I run another mop through the bore with it and then it sits until my next range day. At the range, I run a Boresnake through to dry it out, and start shooting. I found that I can achieve essentially barrel break in in 5rds ( just running the Boresnake between rounds with more EezOx on it). Afterward, fouling is a non issue! I don't deep clean again until accuracy falls off. I'm sure there are other products out there that do the same thing, I don't get paid by EezOx, ha. Now I only use firelapping if the bore has a lot of tool marks in it.