First borescope experience - 28 Nosler carbon ring

[Mule3006Elk]

I use the Boretech C4 for carbon and Boretech CU+2 for copper. I've ditched Montana Extreme since running Cu+2. But I agree, you can't just run eliminator. I generally go with C4 for Carbon first, CU+2 for Copper, then C4 for any carbon under the copper for my last patches. With a 6.5 SAUM I clean every couple hundred rounds. Other stuff I rarely clean or after a dirty match.

Same. Boretech works really well IME.

 

[Formidilosus]

500’ish (?), but I don’t have the exact round count in front of me.

I‘ve never run a brush through it.

 

[Harvey_NW]

I don’t know. I do know that I/we don’t chase the lands, don’t work up loads that are right on the bleeding edge when the barrel is new/clean, and in general do not use temperature sensitive powders.

If you do load work up with the bullet seated close to the lands “cause that where accuracy is”, and go until you see pressure signs- well First your already over pressure at that point generally, and then yeah I could see issues popping up as the throat got fouled. My answer to that is- don’t do that. With most of the bullets people are shooting now, seating depth has very, very little to do with group size.

I do all the same, typically seat the bullet so bottom edge of bearing surface is at the neck/shoulder junction, or make sure I'm at least .050" off and go from there. Typically don't even load up to or over book max. The pressure spike I experienced in this rifle was with a Berger 180 seated .060" off the lands, with a middle of the book specs charge 87.5gr H50BMG. initially I was shooting CCI250's, I threw a Fed 215M in and got a 160fps increase in velocity with excessive recoil at the same charge weight. It was pretty erratic with that combo so I ditched the H50 thinking maybe it's too slow and decided to clean it completely as a baseline to restart testing with a new powder.

Not doubting you either, just wondering the same as @ID_Matt on why some people seem to experience it, and others don't.

 

[Formidilosus]

I do all the same, typically seat the bullet so bottom edge of bearing surface is at the neck/shoulder junction, or make sure I'm at least .050" off and go from there. Typically don't even load up to or over book max. The pressure spike I experienced in this rifle was with a Berger 180 seated .060" off the lands, with a middle of the book specs charge 87.5gr H50BMG. initially I was shooting CCI250's, I threw a Fed 215M in and got a 160fps increase in velocity with excessive recoil at the same charge weight. It was pretty erratic with that combo so I ditched the H50 thinking maybe it's too slow and decided to clean it completely as a baseline to restart testing with a new powder.

So you were fine with one load, then changed primers and saw issues?

Not doubting you either, just wondering the same as @ID_Matt on why some people seem to experience it, and others don't.

I don’t have an answer. I can say that every person that had issues that I’ve seen, when I went back with them and redid their load work up, they no longer had any issues.

 

[Harvey_NW]

So you were fine with one load, then changed primers and saw issues?

Yes. I attributed the primer swap to the pressure spike, but I made a post asking if anyone had ever seen that level of volatility from doing only that. No one said they'd seen much more than maybe 50fps. But that load was erratic with other primers too.

I don’t have an answer. I can say that every person that had issues that I’ve seen, when I went back with them and redid their load work up, they no longer had any issues.

Well I'm starting with a new powder and a clean slate, so maybe I won't have any issues by doing it the same way you do. I'll update when I settle on a load and track it from there.

 

[Formidilosus]

Yes. I attributed the primer swap to the pressure spike, but I made a post asking if anyone had ever seen that level of volatility from doing only that. No one said they'd seen much more than maybe 50fps. But that load was erratic with other primers too.

Primers in some combinations can certainly make a difference, however that is at the upper end of what I’d expect.

Well I'm starting with a new powder and a clean slate, so maybe I won't have any issues by doing it the same way you do. I'll update when I settle on a load and track it from there.

 

[Ryan Avery]

There is a difference, and maybe is matters... However @Ryan Avery and I, as well as couple dozen others I know all shoot larger magnums without cleaning, do not have pressure issues, and get the same barrel life. That’s on most/all brands of barrels, and with cartridges from 6mm with 65gr of powder to 300 and 338’s with more than 100gr of powder.


Bore scopes are another distraction path for people to go down that has nothing to do with shooting or hitting things.





No. No matter how much you shoot them, copper nor carbon will fill the lands of grooves. By just measuring the bore diameter, you can’t tell whether a barrel has 50 or 100 rounds on it, or 10,000.

I have burned down more than a few 300 RUMs, a 300 terminator, and a 28 Nosler, and I have just over 1000 rounds on a 6.5 PRC. I never cleaned them, and I haven't bore-scoped them. I keep waiting for my barrel to blow up.