Barrel Cleaning…data

[Dobermann]

Never tried the Vortex podcast and not interested.

I can't recommend it.

A couple of years ago, prompted by one or another Vortex fail, I took one for the team and listened to hours of their podcast to try to get a sense of who they really were, what they knew, and why they did what they did.

It was like walking into a bar full of Fudd-lore marketing hype-sters ... people full of themselves, who had no idea what they were talking about. Actually kinda disturbing, but it did answer a lot of questions about them as a company.

In other words: very instructive, but hours of my life that I can't get back.

 

[mxgsfmdpx]

I can't recommend it.

A couple of years ago, prompted by one or another Vortex fail, I took one for the team and listened to hours of their podcast to try to get a sense of who they really were, what they knew, and why they did what they did.

It was like walking into a bar full of Fudd-lore marketing hype-sters ... people full of themselves, who had no idea what they were talking about. Actually kinda disturbing, but it did answer a lot of questions about them as a company.

In other words: very instructive, but hours of my life that I can't get back.

Without saying “too much” higher up in Vortex product and project management is incredibly toxic. As in, block new “players” from gaining access to certain OEMs toxic.

 

[Harvey_NW]

I think a lot of issues reloaders encounter are accidentally self induced by riding the edge of unsafe pressures after development, and not understanding the pressure dynamics, or how certain changes can effect things.

Things like virgin vs once fired, new barrel vs stabilized, powder temp sensitivity, jump, lot to lot variability, etc. all have to be explicitly accounted for before blaming fouling for a pressure related issue.

In the podcast they also joked about a 6.5 PRC (IIRC) shooting something like 850 rounds without ever being cleaned or presenting issues, which I find ironic.

 

[Ryan Avery]

@Ryan Avery- do you remember if N150 was the powder that was blowing bolt shrouds and primers three years ago?

Pretty sure it was N150. That also popped primers, but that was not my .223.

The funniest part is I told him there was an issue, but he didn't believe me till I fired a shot, and the bolt shroud hit him in the leg. HAHA!

 

[Formidilosus]

Pretty sure it was N150. That also popped primers, but that was not my .223.

The funniest part is I told him there was an issue, but he didn't believe me till I fired a shot, and the bolt shroud hit him in the leg. HAHA!

I believed that was the powder, and looked- N150 is what I have written down.

@Marbles N150 was blowing primers and multiple bolt shrouds from multiple T3’s. The load was under book max. Two rifles were brand new- first rounds fired that day. 2x were heavily used. Ironically the same ammo was fine in gas guns.

 

[Harvey_NW]

Things like virgin vs once fired

I figure since I brought it up it may contribute to the discussion by expanding on this, this is data I've collected from my rifle.

The rifle is a T3X 6.5 PRC that's been touched up with an AW2 reamer and throated for 143's to be .040" off the lands with boat tail edge seated to neck/shoulder junction. It had 180 rounds fired on it when it was touched up and cut down to ~21", rethreaded, and a dedicated suppressor screwed on. New lot (100pcs) of ADG brass, N565, Rem 9 1/2 Magnum primer. All components are the same lot through testing.

Did the Painless Load Dev method in Aug in almost 90° temps. These are my pressure ladder test results, as I took a conservative approach having never used VV powders. 54-59gr in .5gr increments.


No pressure signs on brass, smooth extraction, but velocity said 59 was spicy. Loaded 10 at 58 and recorded this.



Loaded the rest of the lot for hunting season. Yesterday I shot my last 7 loaded rounds to get an idea of temp sensitivity and check zero for another thread. I realize these aren't valid data sets, but I found the results very impressive for ammo being exposed to elevations from sea level to 8k', and temps from 90° down to -20°ish.


Prepped brass yesterday and loaded 10 at 58gr to verify everything was good today. Even though new brass was very close to my chamber by bolt feel, performance was measurably different on the second firing. I noted that 1.651" from case head to datum with a .420" comparator insert was "tight on close", and average case dimensions were ~1.648" on the new brass. I set my sizing die up to bump shoulders back to 1.648" for ~.002-3" shoulder bump. These are the results of 58gr in 38° weather. This load now had noticeable bolt lift, and slight ejector marks on the last 5 shots.


The only thing I didn't do was let the test ammo from this morning fully acclimate to ambient temperature, but it was in the cold truck/exposed to the elements for 20-30min while I drove out to the range (less than 2 miles from home) and got setup. So given it was still fairly cold, there was an increase of 14fps avg speed at 50° lower temperature.

Couple that with a new lot of powder, and that barrel could really pose an issue from not cleaning and maintaining it!!

 

[B_Reynolds_AK]

@Ryan Avery- do you remember if N150 was the powder that was blowing bolt shrouds and primers three years ago?

I believed that was the powder, and looked- N150 is what I have written down.

@Marbles N150 was blowing primers and multiple bolt shrouds from multiple T3’s. The load was under book max. Two rifles were brand new- first rounds fired that day. 2x were heavily used. Ironically the same ammo was fine in gas guns.

What would be your best explanation as to why that would happen? It’s a slower powder than what most use in 223’s, such as Varget, and being below book max. At 2.26 length, capacity is maxed out around 25.5g . It sounds like there may have been other issues at play than just powder choice.

 

[Harvey_NW]

What would be your best explanation as to why that would happen? It’s a slower powder than what most use in 223’s, such as Varget, and being below book max. At 2.26 length, capacity is maxed out around 25.5g . It sounds like there may have been other issues at play than just powder choice.

Spitballing here, but possibly a hot lot? I believe volatility goes up as case capacity goes down, and with a slow burning powder, possible compression, just seems like it could equate to an issue.

 

[Clark33]

I like to clean my barrels just because it makes my office smell good, and cleaning rifles pairs well with knob creek single barrel.

Cant hurt anything, fun to do, gives me an excuse to hide out in my office with whiskey. Why wouldn't someone clean their barrels?

HelI…I clean my barrel twice a day sometimes

 

[Formidilosus]

What would be your best explanation as to why that would happen? It’s a slower powder than what most use in 223’s, such as Varget, and being below book max. At 2.26 length, capacity is maxed out around 25.5g . It sounds like there may have been other issues at play than just powder choice.

We never figured it out, the only thing we could come up with was temperature. The ammo was fantastic in gas guns- that’s what it was loaded for. It was the first time any of us had seen ammo be fine in an AR, but not in bolt guns.

Ryan was telling the guy that his ammo was hot, the guy denied it as it was legit ammo and was working fine in MK12’s. Right after that Ryan shot one and the bolt shroud hit the guy. If I recall correctly, we needed up breaking two bolt shrouds with it.

VV powders have always been finicky, and odd issues haven’t been uncommon. Its wasn’t until N570 and the 6 UM that I would even mess with it.

 

[Marbles]

Spitballing here, but possibly a hot lot? I believe volatility goes up as case capacity goes down, and with a slow burning powder, possible compression, just seems like it could equate to an issue.

In bullets with both listed by VV in 223, N150 has a higher max load than N140, both are compressed. The 77 TMK does not have a N150 load listed, but setting max for N150 the same as for N140 one should be under the true max (N150 loads are first listed for 80 gr bullets). Both N140 and N150 need a drop tube to load at max and tapping the case. Clearly VV knows they are compressed loads and publishes it. I would need real data to accept a speculation that the compressed load is the issue with this combo. Plus, I had put several rounds of this load through the rifle, around 50, but I keep very poor logs.

Few hundred practice rounds of a different load later, I loaded up some more, I think I got through 7 of 30 before I noticed a blown primer. 3 primers had blown and the brass with blown pockets no longer fit in my RCBS shell holder.

I stopped shooting when I noticed the blown primers and pulled the remaining rounds apart and reloaded 0.9 gr lighter. Lost 80 fps, but no more issues. Load is still compressed and needs to be tapped to seat bullets consistently. Velocity loss with the drop in powder charge was consistent with my prior 10 round ladder in 0.5 gr increments to insure no pressure issues.

Velocity difference between the over pressure and load development loads was not impressive.

The load data is for 223 loads, not 5.56, but VV specifies data is for bolt guns and to use caution in auto loaders, so my guess is they are using a liberal max pressure between 60-65k psi.

A post I made the same day.
Post in thread 'Rokslide Special 223 recipe' https://rokslide.com/forums/threads/rokslide-special-223-recipe.335947/post-3665127

Screen shot of VV load data


Chrono data from load development

Chrono data from the blown primers


My big question, is why the confidence that fowling was not the issue? I have freely admitted that other things might have been the cause, but based on everything present so far in this thread, I find the idea that fowling can be ruled out to be unsound.

I have shot some 77 TMK loads that are above book max in different brass with N135 and not had an issue since this, and no cleaning. Which I find interesting and argues against (but doesn't prove) that cleaning was not the culprit.

Perhaps I just got the only 3 out of spec TMKs all in the same batch. Perhaps it was 3 pieces of bad Federal brass (but they had no issues shooting the factory 5.56 load). Perhaps it was bad powder (though the rest of that pound never caused an issue and I think I burned through 2 pounds from that lot).

Perhaps it was a combination of things, one of which was fowling. I don't have a pressure barrel to check the rounds in. Even if I recreate the load and blow primers, and it resolves with cleaning there will be plenty of unaccounted for variables if someone wants a different explanation.