After cleaning barrel - huge pressure spike.

[Bulldog Firearms]

Not sure if this should be in bolt rifle forum or this one since I'm reloading.

Started using RL16 a few months ago in everything from a 6XC to a 30-06AI. Started developing what I thought was a carbon ring in my match rifle, a MPA 6CM. Had some leaking primer pockets after not cleaning rifle and shooting two 60 round matches with some practice in between. Probably around 200 rounds fired total along with 80 factory 108 ELD stuff through barrel. Went back and had 6 rounds of factory Hornady 108 ELD-M, shot it, ended up having a blown primer on last round.

Decided to clean the rifle up, did some research and settled on some JB Bore Paste to get rid of carbon ring. Cleaned rifle per what Bore-Tech recommended with BT Eliminator. Then put some JB Bore Paste on a patch, wrapped it on a 22 cal brush and brushed the bore and then stroked it on first 1/3 of barrel. Ran a patch soaked in BT afterwards followed by dry patches til patches came out clean. I used a bore guide as well.

Same 8lb of powder I've been using, same lot of 500 DTAC bullets, same lot of Hornady virgin brass.

Went out this morning shot 5 rounds and every primer was blown with gross pressure signs. Same load that shot just fine prior to cleaning now going bonkers. I checked bore for obstructions, I ordered a bore scope a few days ago that is due in on Tuesday. Obviously something is left in the bore from that cleaning? I don't know how else you could explain the pressure. Does anyone have any experience with this?

Any help would be great. Thanks.

 

[Supersubes]

You have any velocities to go along with your results, before and after? Was the barrel in the 6cm new when you started?

 

[Deleted member 113831]

Did you patch out the chamber without the bore guide in place? There is always some stuff that gets past the bore guide and ends up in the chamber. That could cause it.

 

[Bulldog Firearms]

You have any velocities to go along with your results, before and after? Was the barrel in the 6cm new when you started?

Velocities went down from 3030 to about 2950.

Did you patch out the chamber without the bore guide in place? There is always some stuff that gets past the bore guide and ends up in the chamber. That could cause it.

I patched out chamber after normal cleaning, but I didn't do it after the JB stuff.

 

[Supersubes]

That’s weird, wouldn’t have expected that. Along the lines of what skookum said, I’ve found that even with a bore guide, usually there is some solvent puddled in the shoulder area of the chamber. I always spin a patch wrapped brush in the chamber after the wet work is done, and prior to that last few dry patches.

Also, when I used JP (I dont any more), I was always surprised how many wets it took to get the black out. Seem like it was half a dozen or so. Maybe you left some in there.

 

[Deleted member 113831]

Velocities went down from 3030 to about 2950.

I patched out chamber after normal cleaning, but I didn't do it after the JB stuff.

That could very well be your cause right there.

 

[arm017]

That could very well be your cause right there.

agree- I bet it's the jb. Especially for all 5 cases to show pressure concurrent w/ velocity drops.

I try to force myself to clean a rifle while having something else to do so that I end up having to leave the rifle brewing with my magic carb remover- CLR. First I'll take one of those long handled cotton swab dipped in CLR and let it soak into the neck for at least an hour, then take it out and flood the bore w/ CLR- nylon brush x 10 strokes and let it sit another hour and then it usually patches clean within 2-3 patches.

And I can do it in the house and it's super affordable and available

 

[Precision Underground]

Wet or cruddy chamber will def do it. Make sure everything is wiped very clean and dry with bore guide removed.

 

[FatBoy]

This bit me once, H4350. I cleaned and dried the barrel and chamber but the lug recess had wipe out pooled in it I didn't see. (Old AI 6 lug single shot) During transport it migrated up into the chamber and a 6.5x47 went WAY over pressure. Took three rounds before my dumb ass figured out what was going on. Once it cleared, smooth sailing.

Any slickness at all on the cases?

 

[Bulldog Firearms]

Went and cleaned it, this is after 5 shots, you guys think the residue is remaining bore paste?

That could very well be your cause right there.

 

[Deleted member 113831]

Went and cleaned it, this is after 5 shots, you guys think the residue in remaining bore paste?

It doesn't take much, and it entirely possible that the majority came out with the extracted cases.

 

[Precision Underground]

Went and cleaned it, this is after 5 shots, you guys think the residue in remaining bore paste?

Probably. I also take a large brush and wrap a thick patch around it and spin it in the chamber a few times with no guide to make sure there isn’t any crud left orpind the shoulder or neck if the chamber where the bore guide sits.

 

[Bulldog Firearms]

This bit me once, H4350. I cleaned and dried the barrel and chamber but the lug recess had wipe out pooled in it I didn't see. (Old AI 6 lug single shot) During transport it migrated up into the chamber and a 6.5x47 went WAY over pressure. Took three rounds before my dumb ass figured out what was going on. Once it cleared, smooth sailing.

Any slickness at all on the cases?

I didn't notice any slickness or wetness on the cases when they came out.

 

[FatBoy]

I didn't notice any slickness or wetness on the cases when they came out.

That's odd. Do you have any more that were loaded at the same time that you can pull down and re-measure the powder charge?

 

[arm017]

did you just apply the jb to the throat?

 

[MtnCreek]

What do the necks look like? I would suspect bore paste is in the neck area of the chamber.

 

[Bulldog Firearms]

That's odd. Do you have any more that were loaded at the same time that you can pull down and re-measure the powder charge?

I pulled apart 3x rounds, all 40.58-40.6 according to FX120

did you just apply the jb to the throat?

I applied JB to the entire bore, but focused on stroking the throat area.

What do the necks look like? I would suspect bore paste is in the neck area of the chamber.

I will take a picture of necks when I get back home from work.

 

[wilson1911]

Boretech has an action cleaning rod that I use. Its for cleaning the front of the lugs in your action. You can also remove the roll adapter and replace it with a 9mm brush. The rod does not rotate like a regular cleaning rod. It's solid...so I take boretech's carbon remover and spin it by hand after it sits for several minutes soaking.
Also, you will find that when your boreguide is inserted, it seems to miss the carbon ring at the front of the chamber. Always remove it, there is nothing your going to do that will harm the barrel.

I clean the carbon ring/throat usually every other cleaning. If you shoot your brass 10 thou from max length and not trim it for a couple of loads....it will make the bolt harder to close....hence carbon is there.

Be careful with JB's paste and clean it all out.

As FAtboY said, be careful to make sure there is no "oil/lube" residue on your cases. This prevents the case from grabbing the walls of your chamber to seal properly.

I am a Boretech fan.

 

[shoot4fun]

I have two short plastic rods from Midway; one holding a swab to clean locking lug recess and the other accepts jags/brushes. After every cleaning, no matter what product used, I attach a large bore mop, cover with a 2" patch and push it up into the chamber as far as it will go. Then I rotate until I hear a squeak so I know all the gunk is out of the chamber. That residue from cleaning will spike pressure beyond belief. Also, if you managed to get JB on the hammer walls and "polish" the chamber out you'll get pressure spikes because, as mentioned already, a shiny slick chamber won't "grab" the brass when it's fired.
It's funny to me that a bore can be left wet and never cause a pressure issue but leave even a little in the chamber/throat and you can have big problems.

 

[arm017]

I would scrub the bore out with a standard solvent more so than just BT on patches. You gotta get that Bore paste out.

 

[Bulldog Firearms]

Boretech has an action cleaning rod that I use. Its for cleaning the front of the lugs in your action. You can also remove the roll adapter and replace it with a 9mm brush. The rod does not rotate like a regular cleaning rod. It's solid...so I take boretech's carbon remover and spin it by hand after it sits for several minutes soaking.
Also, you will find that when your boreguide is inserted, it seems to miss the carbon ring at the front of the chamber. Always remove it, there is nothing your going to do that will harm the barrel.

I clean the carbon ring/throat usually every other cleaning. If you shoot your brass 10 thou from max length and not trim it for a couple of loads....it will make the bolt harder to close....hence carbon is there.

Be careful with JB's paste and clean it all out.

As FAtboY said, be careful to make sure there is no "oil/lube" residue on your cases. This prevents the case from grabbing the walls of your chamber to seal properly.

I did my best to scrub out chamber, I'm going to run some carb cleaner through the chamber and barrel just to degrease it in case there might be some left.

I am a Boretech fan.

I have two short plastic rods from Midway; one holding a swab to clean locking lug recess and the other accepts jags/brushes. After every cleaning, no matter what product used, I attach a large bore mop, cover with a 2" patch and push it up into the chamber as far as it will go. Then I rotate until I hear a squeak so I know all the gunk is out of the chamber. That residue from cleaning will spike pressure beyond belief. Also, if you managed to get JB on the hammer walls and "polish" the chamber out you'll get pressure spikes because, as mentioned already, a shiny slick chamber won't "grab" the brass when it's fired.
It's funny to me that a bore can be left wet and never cause a pressure issue but leave even a little in the chamber/throat and you can have big problems.

I would scrub the bore out with a standard solvent more so than just BT on patches. You gotta get that Bore paste out.

I scrubbed this bore. I'm not a huge fan of RL16 after this, I was hoping to not have to do much cleaning and this scrubbing crap has been more cleaning than I've done in years on a rifle.

 

[shoot4fun]

I scrubbed this bore. I'm not a huge fan of RL16 after this, I was hoping to not have to do much cleaning and this scrubbing crap has been more cleaning than I've done in years on a rifle.

I use RL16 in 6 Creedmoor. Testing and real world results tell me it's the best option for my rifle. My dial ups have been more consistent than with H4350 and the accuracy node was the widest I've seen with any powder and any cartridge; well over 1 grain. As for clean up, I use 4 patches with BT C4 and follow up with about 8-10 passes with a nylon bore brush. Four more wet patches finishes the job. Then I take a 2"patch or a piece of old white tee shirt, place over a Brownell's bore mop (oversized) and wipe out the chamber and throat. Always inspect with my bore scope to make sure no carbon ring is building. I don't think you need to scrub til a clean patch comes out.

 

[Supersubes]

I scrubbed this bore. I'm not a huge fan of RL16 after this, I was hoping to not have to do much cleaning and this scrubbing crap has been more cleaning than I've done in years on a rifle.

I’m with shoot4fun on this, it isn’t the powder. I’d choose it over h4350.

 

[Deleted member 10043]

It's important to use Kroil with JB paste. You may have fire lapped that barrel unintentionally . 50/50 Kroil and #9 with a bronze brush would have cleaned it just the same. We've all done something like this at some time or another.

 

[Clearlight]

Sounds like you had some JB in the chamber . I dont clean much , except in the big magnums which
run quite dirty . When I clean , I use the Pro Shot action cleaning kit to get any solvent out of chamber
and bolt lug recesses . There is this tampon wad thing that the kit has , which is perfect for getting into
most lug recesses . There’s also a stick you can screw a mop onto for neck and leade cleaning .

I use a little automotive brake cleaner on the tampon and mop , to ensure traces of solvent or JB are
removed from action , after doing this a little brake cleaner goes on a patch down the bore , followed
by a dry patch . Result is squeaky clean gun guts ready to go . Brake cleaner will evaporate in 30 - 60
seconds .

 

[Deleted member 10043]

Clearlight, the first thing we do is rattle spray paint our expensive rifles in custom cammo patterns. Brake cleaner not good on our war paint.

 

[Bulldog Firearms]

Sounds like you had some JB in the chamber . I dont clean much , except in the big magnums which
run quite dirty . When I clean , I use the Pro Shot action cleaning kit to get any solvent out of chamber
and bolt lug recesses . There is this tampon wad thing that the kit has , which is perfect for getting into
most lug recesses . There’s also a stick you can screw a mop onto for neck and leade cleaning .

I use a little automotive brake cleaner on the tampon and mop , to ensure traces of solvent or JB are
removed from action , after doing this a little brake cleaner goes on a patch down the bore , followed
by a dry patch . Result is squeaky clean gun guts ready to go . Brake cleaner will evaporate in 30 - 60
seconds . View attachment 6930084View attachment 6930084

So I have one of these, not the exact brand but a non rotating short rod that takes some tampon looking patches that are supposed to go into lug area. I used that and mopped up as much as I could.

Anyway here are some pictures of throat area after cleaning with a borescope. I'm not sure what I'm looking at and I can 't fit the mirror attachment in bore to look perpendicularly to bore. Anyone who knows something about how bores are supposed to look, maybe they can make something of these?

 

[Bulldog Firearms]

What do the necks look like? I would suspect bore paste is in the neck area of the chamber.

Image of the case necks.

You can definitely see on a few of these that they were being rammed backward because the rim is bent and gouged.

 

[Bulldog Firearms]

Shot it this morning. Back to normal, 3020ish. Seems like nothing got messed up.

5 @ 1K

 

[Milo 2.5]

Image of the case necks.

You can definitely see on a few of these that they were being rammed backward because the rim is bent and gouged.

I think your brass is oversized also, you have gassing on the shoulders of your brass, most likely in chamber too by the looks of the cases.

 

[Bulldog Firearms]

I think your brass is oversized also, you have gassing on the shoulders of your brass, most likely in chamber too by the looks of the cases.

Brass I was using was virgin Hornady. No prep beside inspecting for burr.

 

[Milo 2.5]

Brass I was using was virgin Hornady. No prep beside inspecting for burr.

I'd check headspace or chamber sizing then.

 

[JeffLebowski]

Clearlight, the first thing we do is rattle spray paint our expensive rifles in custom cammo patterns. Brake cleaner not good on our war paint.

Spray paint is cheap.

 

[Bulldog Firearms]

I'd check headspace or chamber sizing then.

I used a no go and it didn't close, and it closed on a go. So I think it is headspaced correctly.

 

[Milo 2.5]

I used a no go and it didn't close, and it closed on a go. So I think it is headspaced correctly.

You have something going on where you are not getting a seal off, is your powder charge too low.

 

[Bulldog Firearms]

You have something going on where you are not getting a seal off, is your powder charge too low.

I think chamber was slick when I fired those and combined with bore paste in bore caused a huge over pressure ramming those casings back.

 

[Milo 2.5]

I think chamber was slick when I fired those and combined with bore paste in bore caused a huge over pressure ramming those casings back.

Yes, I have not read the whole post, hope you get it nailed down.

 

[Bulldog Firearms]

Went out and shot a match today, ended up crushing extractor spring somehow, some over pressure loads showed up. Caused my rifle to go down 2 stages in. Wouldn't extract case.

I still can't figure out what has been going on, thought I don't have any more virgin Hornady 6 CM brass left, the once fired stuff I do have is 1.925" case length. I don't know what max length is, but that is over .01 to .015 the trim to length depending on what reloading manual you look at. I have some Alpha Munitions brass that came in that is 1.9" Could this long brass be causing over pressure issues?

 

[Deleted member 113831]

Went out and shot a match today, ended up crushing extractor spring somehow, some over pressure loads showed up. Caused my rifle to go down 2 stages in. Wouldn't extract case.

I still can't figure out what has been going on, thought I don't have any more virgin Hornady 6 CM brass left, the once fired stuff I do have is 1.925" case length. I don't know what max length is, but that is over .01 to .015 the trim to length depending on what reloading manual you look at. I have some Alpha Munitions brass that came in that is 1.9" Could this long brass be causing over pressure issues?

That's only .005" over max length. But it's a definite possibility.

 

[MtnCreek]

See if a bullet slides freely into your fired, unsized cases. If it doesn’t, the bullet is pinched in the case. That could be due to case length or an obstruction in the chamber (like carbon or bore paste).

 

[Bulldog Firearms]

I haven't checked that but my neck tension is .002 to .0015 with the Hornady Brass.

See if a bullet slides freely into your fired, unsized cases. If it doesn’t, the bullet is pinched in the case. That could be due to case length or an obstruction in the chamber (like carbon or bore paste).

I'm going to get in there and try this rifle with Alpha Munitions brass because this Hornady batch I have has been disappointing.

 

[Bulldog Firearms]

See if a bullet slides freely into your fired, unsized cases. If it doesn’t, the bullet is pinched in the case. That could be due to case length or an obstruction in the chamber (like carbon or bore paste).

Bullet slides freely in and out of a once fired casing.

 

[MtnCreek]

Was it one of the cases that showed over pressure?

 

[Bulldog Firearms]

Was it one of the cases that showed over pressure?

No.

Update. Went and shot again. Shot 20 rounds of Hornady brass with no pressure issues til last round which popped primer. Shot a single round of Alpha Munitions brass loaded at 38.3 of RL16 and it popped primer with a velocity of 2927 and broke ejector, mangled roll pin retainer, and required me to use a drill bit to get spring out.

Went home, measured with Hornady OAL Gauge. Carbon ring is definitely there. Red flags came up, OAL gauge measures 2.24 BTO, my loaded ammo measures 2.24BTO. Rifle started at 2.26 BTO in my notes as measured with OAL Gauge.

Went and cleaned gun this time with Iosso Bore Cleaner (4x patches wrapped on worn 6mm nylon brush, stroked 20x each) followed by Boretech eliminator cleaning instructions til rifle came clean.

Now rifle measures 2.269 BTO. Loaded up some new ammo (RL16 & DTACs), 39, 39.2, 39.4, 39.6, 39.8, 40, 40.2 @ 2.249 BTO. I will see what this new ladder does. .003/100rds seems very reasonable for a rifle like this with roughly 300 down the tube.

I've never had this much trouble with a damn rifle.

 

[spife7980]

You didn’t notice it was hard to close the bolt when chambering a round? I shot a pound of rl16 to test and towards the end of that pound the first thing I noticed, even before it was enough to give feint ejector marks, was that some bullets were giving a little resistance on dropping the bolt handle. Seems like it grew up quick and out of nowhere. After a bit more I started to get serious ejector marks and it finally clicked in my mind why my bolt was resisting dropping closed.

And since then I’ve seen lots of reports with 16 and carbon rings. Excellent powder for speed and accuracy but I would clean much more frequently using it than I am with h4350 after that experience.

I’d soak another patch with boretech and just let it sit on that throat, I bet after a couple hours you could get some more. Maybe run a bronze brush through it, actually try and scrape some up. Though isso should have sanded it pretty good I still trust metal scraping to remove more than grit sanding to polish. Leave a bit of it there and you’ll get it back very quickly so try and make sure it’s all gone. Mine took two weekends to unfuck because I didn’t do enough the first. You’re already past that.

 

[Bulldog Firearms]

You didn’t notice it was hard to close the bolt when chambering a round? I shot a pound of rl16 to test and towards the end of that pound the first thing I noticed, even before it was enough to give feint ejector marks, was that some bullets were giving a little resistance on dropping the bolt handle. Seems like it grew up quick and out of nowhere. After a bit more I started to get serious ejector marks and it finally clicked in my mind why my bolt was resisting dropping closed.

And since then I’ve seen lots of reports with 16 and carbon rings. Excellent powder for speed and accuracy but I would clean much more frequently using it than I am with h4350 after that experience.

I’d soak another patch with boretech and just let it sit on that throat, I bet after a couple hours you could get some more. Maybe run a bronze brush through it, actually try and scrape some up. Though isso should have sanded it pretty good I still trust metal scraping to remove more than grit sanding to polish. Leave a bit of it there and you’ll get it back very quickly so try and make sure it’s all gone. Mine took two weekends to unfuck because I didn’t do enough the first. You’re already past that.

Never noticed a change in resistance closing the bolt.

 

[Bulldog Firearms]

You didn’t notice it was hard to close the bolt when chambering a round? I shot a pound of rl16 to test and towards the end of that pound the first thing I noticed, even before it was enough to give feint ejector marks, was that some bullets were giving a little resistance on dropping the bolt handle. Seems like it grew up quick and out of nowhere. After a bit more I started to get serious ejector marks and it finally clicked in my mind why my bolt was resisting dropping closed.

And since then I’ve seen lots of reports with 16 and carbon rings. Excellent powder for speed and accuracy but I would clean much more frequently using it than I am with h4350 after that experience.

I’d soak another patch with boretech and just let it sit on that throat, I bet after a couple hours you could get some more. Maybe run a bronze brush through it, actually try and scrape some up. Though isso should have sanded it pretty good I still trust metal scraping to remove more than grit sanding to polish. Leave a bit of it there and you’ll get it back very quickly so try and make sure it’s all gone. Mine took two weekends to unfuck because I didn’t do enough the first. You’re already past that.

Rifle lasted about 30 rounds before blowing primers again. Even dropped load 1.3 grains to next node down, blew primers today. Guess I need to get in there and go bonkers to get rid of that carbon ring.

 

[spife7980]

You can always shove a patch in the throat, squirt some bore tech or engine carb cleaner in and let it sit for a bit flooded and soaking. Then a few spins with a bronze brush for good measure. Hell, jb will scrub it out. Just get the jb out after...

And that’s if it’s the problem. A bore cam would be handy right now. I’ve been wanting to get one but Ive been able to get it back under control with a good soaking and scrubbing. Since I’ve gone back to h4350 from rl16 for awhile now that ring doesn’t seem to be creeping up like before. You can’t see any scrapes on the bullet? My ring gave me ejector marks only and I could feel it easily. Yours are blowing the shit out of them from the earlier pics.

Edit: Wait. You said you ordered a bore scope and it would be there many tuesdays ago. Take a peek.

 

[Bulldog Firearms]

Filled bore with Bore-Tech eliminator. Going to let it sit overnight see what happens then. Noticed some hard bolt closes on the stuff I had seated deeper. As in going from 2.8 to 2.785. So carbon ring is definitely getting bigger lol.

 

[Bulldog Firearms]

You can always shove a patch in the throat, squirt some bore tech or engine carb cleaner in and let it sit for a bit flooded and soaking. Then a few spins with a bronze brush for good measure. Hell, jb will scrub it out. Just get the jb out after...

And that’s if it’s the problem. A bore cam would be handy right now. I’ve been wanting to get one but Ive been able to get it back under control with a good soaking and scrubbing. Since I’ve gone back to h4350 from rl16 for awhile now that ring doesn’t seem to be creeping up like before. You can’t see any scrapes on the bullet? My ring gave me ejector marks only and I could feel it easily. Yours are blowing the shit out of them from the earlier pics.

Edit: Wait. You said you ordered a bore scope and it would be there many tuesdays ago. Take a peek.

Filled bore with Bore-Tech Eliminator, let it sit for 2x days. Cleaned out/dried out bore with some patches. Packed a nylon brush full of Iosso, stroked bore 50-70x and short stroked throat area a lot more. Cleaned bore again to get out Iosso. Stroked bore 8x with a bronze brush soaked in Bore-Tech followed by 4x dry patches, followed by 8 strokes w/ soaked bronze brush every 4x patches. Top is first patches, bottom is end patches.

Keep cleaning?