Can dirty barrels cause keyholing?

[EcHo]

On Thursday I took my new M&P 15-22 to the range to test it out. After about 250 rounds of CCI Blazer, the bullets started keyholing. It was a very quick onset. One magazine went perfectly fine and the next one and every subsequent one keyholed. After 20-30 rounds of non-stop keyholing I called it a day and left. The guy at the range said a dirty barrel is probably the cause of the keyholing. It this possible? I was under the assumption that most keyholing is caused by bullet weight/twist rate mismatches. When I tried to clean the barrel after getting home it was FILTHY. The cleaning rod wouldn't fit for the last 2 inches of the barrel (I inserted the rod from the muzzle end) and even now after soaking for 48 hours in Hoppe's No. 9 solvent there is still one good chuck of lead stuck on the inside of the barrel.

Any tricks for getting stubborn chunks of lead out of a barrel? I'm not shooting this thing again until its clean because I'm sure its not good for the barrel. Needless to say I'm not using Blazer anymore since they make the gun inoperable due to lead buildup after 250 rounds.

 

[Big Daddy 45acp]

They do make lead cleaning kits. The kit uses a small bronze screen to help scrape out the lead.

 

[Scrivener]

On Thursday I took my new M&P 15-22 to the range to test it out. After about 250 rounds of CCI Blazer, the bullets started keyholing. It was a very quick onset. One magazine went perfectly fine and the next one and every subsequent one keyholed. ...When I tried to clean the barrel after getting home it was FILTHY. The cleaning rod wouldn't fit for the last 2 inches of the barrel (I inserted the rod from the muzzle end) and even now after soaking for 48 hours in Hoppe's No. 9 solvent there is still one good chuck of lead stuck on the inside of the barrel.

Which suggests that your problem was DEBRIS in the muzzle; perhaps from jacket separation. A mere 250 rounds should not foul a clean bore.

 

[EcHo]

They do make lead cleaning kits. The kit uses a small bronze screen to help scrape out the lead.

The kit I have has a bronze spiral attachment to help scrape out lead, but it doesn't actually do anything to the deposits. Is there a stronger solution I could get that would just dissolve the lead away?

Which suggests that your problem was DEBRIS in the muzzle; perhaps from jacket separation. A mere 250 rounds should not foul a clean bore.

There are no jackets on this ammo, its the Blazer 525 bulk pack stuff.

 

[drgrant]

Which suggests that your problem was DEBRIS in the muzzle; perhaps from jacket separation. A mere 250 rounds should not foul a clean bore.

It will if you are using remington thunderbolt ammunition.

-Mike

 

[Scrivener]

There are no jackets on this ammo, its the Blazer 525 bulk pack stuff.

No plating?

I haven't shot Blazer .22 in years, but never had a problem with it in any of my 3 Rugers.

Assuming you did NOT have a piece flake off, you either have some seriously crappy ammo or, perhaps, a burr/tooling mark in your bore. Once you actually get it clean, examine it with a bore light.

 

[EcHo]

No plating?

I haven't shot Blazer .22 in years, but never had a problem with it in any of my 3 Rugers.

Assuming you did NOT have a piece flake off, you either have some seriously crappy ammo or, perhaps, a burr/tooling mark in your bore. Once you actually get it clean, examine it with a bore light.

Yeah its the getting it clean part that's been killing me. Do you happen to know of anything better than Hoppes 9 and a bronze scrubber for getting lead out?

 

[Bugs100]

Tetra Copper and lead remover works good. But first I would go to Ace Hardware and buy some Chore Boy Copper pads and take a some strands from it and wrap it around the brass bristles, dip it in Hoppes and start brushing it with that. That always works for me and it's a lot cheaper than a Lewis lead remover.

 

[Gammon]

I am amazed. I have fired thousands of Blazers through several different 22s and have only needed to run a patch soaked with solvent through the bore. I think there may be something wrong here; either the ammo or the barrel, probably the ammo. I would try some quality 22 LR ammo and see if it makes a difference. I have had good luck with Shooter's Choice Lead Remover (available from Brownells).

 

[wolf223]

i've fired hundreds of CCI (lead nose) Std Velocity through my 10/22 between cleaning and no issues.

my M&P15-22 has seen about 500(ish) rounds of CCI mini mags and it's still plinking.... i have YET to clean it....

good luck

 

[hedgehound]

It will if you are using remington thunderbolt ammunition.

-Mike

Is it the one that looks like a truncated cone on the cylindric bullet body? Or I am talking about Yellow Jacket? Those did produce lots of lead shavings, but I did not see any keyholing. I saw Keyholing only on Aguila SSS.

 

[97serpent]

It will if you are using remington thunderbolt ammunition.

-Mike

You've got that right. I thought I would need a new barrel in my P22 after 50 rounds of that crap.

 

[center442]

Since the rifling imparts the spin to the bullet, I suppose it is possible that a badly fouled bore could cause keyholing. If the grooves in the bore become heavily fouled you will be firing, in essence, a smoothbore. The result is that the bullet will not be properly spun to stabilize it. At least that is my understanding. If you're looking for an easy way to remove leading from the bore I would suggest something like an Outer's Foul Out system. It's amazing how much crud it can remove from a bore without any scrubbing. If you go that route, follow the directions carefully for best results.

I would avoid that ammo, at least in that particular gun. I've fired many thousands of cast bullets (my own reloads) and have gotten some leading with certain combinations but never to that extent.

 

[Uncle Fester]

It will if you are using remington thunderbolt ammunition.

-Mike

This.

Thunderbolt is total crap.

 

[bostonasphalt2]

GO get some CCI minimag, I have not had a problem through my 15-22 yet with it. I can always give ya a sleeve or two if you want.

 

[sig2009]

They do make lead cleaning kits. The kit uses a small bronze screen to help scrape out the lead.

Chore Boy copper cleaning pads are cheaper,do the same thing. Cut some and wrap around a barrel brush.

 

[Gammon]

This.

Thunderbolt is total crap.

I am not endorsing Remington Thunderbolt 22 LR, but I have run thousands of this stuff through my Marvel conversion with not a lot of trouble. The only real problem I had was that the bullets had a lot of wax on them which would occasionally cause a feeding problem. Cleaning was simple, just run a patch soaked in solvent through the barrel.

 

[Len-2A Training]

Thunderbolts jammed up one of my Wife's guns so bad that I bent a cleaning rod and destroyed 2 brushes clearing out the lead (with Chore Boy's help).

In >30 years of shooting .22LR, I never saw such a mess in my life and hope never to see it again.

 

[rattletrap1970]

Many things can cause keyholing. Severely fouled bore, damaged crown, improper velocity, damaged/deformed bullets, improper bullet weight for rifling twist.

 

[EcHo]

Many things can cause keyholing. Severely fouled bore, damaged crown, improper velocity, damaged/deformed bullets, improper bullet weight for rifling twist.

Well the first 250 rounds went perfectly, so that leads me to believe the twist rate is appropriate and the crown is in good condition. I also examined the crown and it is in good condition.

 

[dhuze]

Many things can cause keyholing. Severely fouled bore, ................. damaged/deformed bullets, ..........................

It sounds like one causing the other in your case.

If you have a problem with the brush getting stuck 2" from the end of your barrel That would be where the keyholing starts. It must be disrupting the spin right there. You shouldn't be having a problem at only 2" from the end of any barrel. I would seriously look into this. Maybe a defect in the barrel or it had something stuck in it. 200 rounds of crappy ammo shouldnt cause that problem.
As far as cleaning it. I only use Hoppes and a brass brush and sometimes a little JB bore paste. I spent 3 hours cleaning a lead fowled barrel I bought recently. I was starting to wonder if it really even had any rifling. Barnes also makes a copper and lead remover, but it also eats away your brush.

 

[rattletrap1970]

There is an old school lead removal method, it is not practiced very much anymore. With the proper care and handling mercury can be worked with safely (gloves, ventilation, goggles, you know the drill).
Degrease the barrel very very well, the lean will not amalgamate to the mercury through oil.
Plug the barrel well (silicone cork or some such plug).
Fill the barrel with mercury while held securely.
Leave overnight.
Pour out mercury and clean barrel out very well (the mercury can be kept in a plastic jar, I don't use glass in case it falls it will go everywhere) it can be reused.
I resort to this only in the most extreme cases of leading. I find a properly lapped barrel that is cleaned regularly will not lead up as much as a rough bore the is never cleaned.

Hope this helps.

 

[EcHo]

It sounds like one causing the other in your case.

If you have a problem with the brush getting stuck 2" from the end of your barrel That would be where the keyholing starts. It must be disrupting the spin right there. You shouldn't be having a problem at only 2" from the end of any barrel. I would seriously look into this. Maybe a defect in the barrel or it had something stuck in it. 200 rounds of crappy ammo shouldnt cause that problem.
As far as cleaning it. I only use Hoppes and a brass brush and sometimes a little JB bore paste. I spent 3 hours cleaning a lead fowled barrel I bought recently. I was starting to wonder if it really even had any rifling. Barnes also makes a copper and lead remover, but it also eats away your brush.

I don't know if it matters, but its 2" from the breech and not 2" from the crown.

There is an old school lead removal method, it is not practiced very much anymore. With the proper care and handling mercury can be worked with safely (gloves, ventilation, goggles, you know the drill).
Degrease the barrel very very well, the lean will not amalgamate to the mercury through oil.
Plug the barrel well (silicone cork or some such plug).
Fill the barrel with mercury while held securely.
Leave overnight.
Pour out mercury and clean barrel out very well (the mercury can be kept in a plastic jar, I don't use glass in case it falls it will go everywhere) it can be reused.
I resort to this only in the most extreme cases of leading. I find a properly lapped barrel that is cleaned regularly will not lead up as much as a rough bore the is never cleaned.

Hope this helps.

Thanks for the tip. I actually looked at getting some mercury (by opening many old thermostats) to fix the problem, but fortunately last night I got it out without too much effort. After hours of scrubbing with M Pro 7 (this after hours of Hoppes #9) it still wouldn't come off. I took the backside of your average dish sponge and ripped pieces off of it. I put these pieces (maybe .5" x .5" squares) on the end of a 3/16" wooden dowel and scrubbed the hell out of the inside of the barrel. The backside of the sponge is some plasticy/fabric material so it wouldn't damage the barrel. Other people recommended Chore Boy scrubbers, but I couldn't find a retailer in MA who sells them. Maybe I didn't look hard enough... I can't seem to find anything else to blame the problem on other than filthy ammo causing lead buildups, so I guess I'm not shooting anymore unjacketed ammo through this gun.

I didn't see any burrs or nicks or anything abnormal in the barrel after it was clean, so I really don't know

 

[Len-2A Training]

Chore Boy is available in every supermarket, it's with the steel wool, etc. I think that Home Depot and Lowe's probably carry it as well with their cleaning supplies.

It's not a "gun shop item".

 

[rattletrap1970]

Once you get it clean, read up on using Bore Paste and clean up the finish inside the barrel. Might help keep it from fouling as bad next time. Also with regular cleaning it will continue to get better.