Could Use a Little Help on a TC Hawken - Cleanout Screw

[Jeff H]

I am removing a stuck cleanout screw from a TC Hawken and need to know if anyone knows what size they are.

I have drilled to a number 31 and see no threads in the wall of the hole yet and am hesitant to drill much larger without knowing what the threads are so I don't go larger than the proper tap drill size.

Next problem will be finding a cleanout screw because I didn't see anything on TC's site. If it's a common size, no problem.

Yes, in hindsight I probably could have left it alone. I don't know that it's actually necessary for cleaning but since the holes are there and there are threads in them in my other MLs, I remove it when cleaning anyway.

Thanks.

Jeff

[fouronesix]

IIRC it's 6x32. Once you get it out, easy enough to check with a 6x32 screw. At this point you might try a little heat, add Kroil during the cool down then an EZout or tapered/squared off cut nail when completely cool.

[Jeff H]

Thanks, fouronsix, Kroil has been in the mix for several days so far and soaking again now.

6-32 makes me wonder why I haven't gotten into threads already but that's why I stopped there. I started with a small center drill to get started and worked up to a number 31 ten or so thousandths at a time. I have to be close, so I doused it with Kroil and left it for the night.

Thanks, fouronsix. I will grub for a 6-32 hex cleanout screw in the "parts bin."

[tomme boy]

It really is not a clean out screw. You should have left it alone. Thats why they grind it off on all of the newer ones. It is not meant to be taken out.

[fouronesix]

300-400 deg heat with a torch won't hurt a thing but that's just me so understand the reluctance to do it. An alternative to the torch would be a solder gun with a small tip. You can touch the tip to the screw and apply direct heat to it then a couple of drops of Kroil as it's cooling down.

OK update. Don't know what I was thinking. I have a T/C Hawken here that has the clean-out screw. Pulled it out of the safe and checked. It is very close to 8x32. I assume your's would be the same. So you should still be OK with the #31 pre-drill. Now to get the old one out and check with an 8x32 screw to make sure. But at this point there may not be enough left to get ahold of.

I really don't know the hardness of that original screw. If it is not too much harder than the bolster then you could very gingerly try running an 8x32 tap in since the #31 drill should be acceptable for the 8x32 tap.

[Jeff H]

It really is not a clean out screw. You should have left it alone. Thats why they grind it off on all of the newer ones. It is not meant to be taken out.

Yeah, I know it's not a cleanout screw but that's what people call it and for the sake of clarity and brevity I call it that too because wasting my breath telling everyone who calls it a cleanout screw would get tiresome and it annoys people unnecessarily.

It's a hole drilled to complete a flash channel and then threaded to plug it. Cheap, easy, facilitates the process.
Since they left a hole and then threaded it, I have always made it a habit to remove them for cleaning so nothing starts growing where they left the threaded hole - not specifically to clean the flash channel. If they are cleaned properly, they will come out. Whoever owned this one didn't. So, the screw becomes permanently fixed - problem solved? No. Maybe if it were intentionally fixed with thread locker but I don't consider rust an appropriate thread locker.


Thought I had precluded unnecessary admonition in my mention of "hindsight."

[Jeff H]

300-400 deg heat with a torch won't hurt a thing but that's just me so understand the reluctance to do it. An alternative to the torch would be a solder gun with a small tip. You can touch the tip to the screw and apply direct heat to it then a couple of drops of Kroil as it's cooling down.

OK update. Don't know what I was thinking. I have a T/C Hawken here that has the clean-out screw. Pulled it out of the safe and checked. It is very close to 8x32. I assume your's would be the same. So you should still have clearance for the pre-drill. Now to get the old one out and check with an 8x32 screw to make sure.

That makes more sense and for going to the trouble to check. I was hesitant to chuck up the next size drill until I had an idea.

I have not tried heat yet but it may be in order when I get back to it. I do have a soldering iron tip that will be perfect - the thought had crossed my mind and I will keep that in my back pocket. What's left in the hole may be solid enough to back out with an easy-out but I will have to see if I can round one up tomorrow.

[John Allen]

I would try heating like the other guys have said now that it is drilled out some it should start moving.

[fouronesix]

I'm glad I gave the thread and my post a second thought and look! I don't know why 6x32 was stuck in my mind but I may have worked on a ML a month or two ago that did have a clean-out that was 6x32??

The screw I just took out of the T/C here most certainly measures 32 pitch but the diameter is about .002-003" under nominal size 8. But I'm certain it is 8x32 and not 6x32. Still, worse case would be to have to drill and tap for size 10 screw which would work fine also.

[Jeff H]

I would try heating like the other guys have said now that it is drilled out some it should start moving.

That's what I am hoping for. Should have about .010" wall left and the steel is not overly brittle so I should have enough to turn the five or so threads after they have had time to soak. The heat won't hurt a thing so I may just start out with it tomorrow.

[Jeff H]

I'm glad I gave the thread and my post a second thought and look! I don't know why 6x32 was stuck in my mind but I may have worked on a ML a month or two ago that did have a clean-out that was 6x32??..........

That's the same reason I stopped at #31. I have a ML with a metric thread that is smaller - about like a 6.

[OverMax]

I hate firing channel screws. Oh their just too enticing to use a screwdriver on. Don't feel bad Jeff H. Many have made the same mistake. And I'm sure you won't be the last fellow to do it. __So here's my Tip: Center punch the screws head prior to drilling. A cobalt drill bit is my preference for its drilling. If you have or can find someone who has a drill press. That's the best way to drill them out. Otherwise free handed works too. A screw that small. Just be patience with its drilling and drill straight. If I were involved with its drilling I would drill it twice. Once dead center with a smaller drill bit size to use as a pilot hole for the larger drill bit size. Good luck Sir.

[Jeff H]

I hate firing channel screws. Oh their just too enticing to use a screwdriver on. Don't feel bad Jeff H. Many have made the same mistake. And I'm sure you won't be the last fellow to do it. __So here's my Tip: Center punch the screws head prior to drilling. A cobalt drill bit is my preference for its drilling. If you have or can find someone who has a drill press. That's the best way to drill them out. Otherwise free handed works too. A screw that small. Just be patience with its drilling and drill straight. If I were involved with its drilling I would drill it twice. Once dead center with a smaller drill bit size to use as a pilot hole for the larger drill bit size. Good luck Sir.

There was no mistake made. That screw has (had) a slot in it. I did not originate the idea of removing the clean out screw when cleaning the gun. That it was seized indicated that there was rust in there, which should come out. I appreciate the tip but the hole was already drilled before I started the thread.

[OverMax]

Oh I see. "That it was seized indicated that there was rust in there, which should come out." Well at least I understand your logic now.

[Jeff H]

Oh I see. "That it was seized indicated that there was rust in there, which should come out." Well at least I understand your logic now.

You got it - vile, insidious RUST[smilie=b: Thankfully not enough to compromise the safety of the bolster. It's out now and everything looks good.

I can't fault the young lady who brought it to me because she just got it after it had been stored for something like fifteen years. Can't fault the fella who gave it to her because he had passed away - which was why it was in storage. Had this been for someone who had simply been lazy - it wouldn't have become my problem.

I ran a #29 through it today and could see deformation on the walls of the hole where the threads were hiding on the other side and picked up a small ez-out today to break up the first one or two. I picked the rest of the threads out and chased with a 8-32 and everything looked good.

Now, I just have to find a screw and I'll have a new black powder buff shooting her own rifle next weekend. She shot mine this past weekend and the bug bit hard. She was all smiles. She's excited about the prospect of putting her grandpa's ML back into action in the deer stand this year.

Thanks for the help and support, guys.

[fouronesix]

Good deal! Always nice to hear positive results. The replacements now use a regular plug screw for allen head instead of the slot head. A regular slot head would work of course but the allen type probably has a little better chance of not buggering up in the future. I use either synthetic grease or anti seize on those and the nipples after cleaning.

Oh and one thing to check. If the replacement clean out plug screw is too long sometimes it will interfere with the full depth seating of the nipple. Easy enough to trim the new plug to length if needed.

[Jeff H]

Good deal! Always nice to hear positive results. The replacements now use a regular plug screw for allen head instead of the slot head. A regular slot head would work of course but the allen type probably has a little better chance of not buggering up in the future. I use either synthetic grease or anti seize on those and the nipples after cleaning.

Oh and one thing to check. If the replacement clean out plug screw is too long sometimes it will interfere with the full depth seating of the nipple. Easy enough to trim the new plug to length if needed.

All good info - and I had picked up a pair of "set screws" (Allen head) when in town the other day but realized I grabbed a pack of 10-32s someone had misplaced in the 8-32 bin. I'll go through my parts drawers again and see what I can find. I had actually chased the threads with a bottom tap in hopes that the threads stopped in time to not interfere with the nipple threads but they just kept going. Without a head, like on the drum screws, it can easily be run in too far and interfere so I may use a crew with a head to keep her out of trouble. Even if there had been some taper left in the female threads would have been nice but the screw doesn't seat against anything.

I have never used anti-sieze compound on any of mine but may try it. I have always just slathered the threads with TC Bore Butter after cleaning and then NOT snug the screw (or the nipple) until I get it out to shoot again.

[fouronesix]

Yes, there is no "bottom" to the clean out plug hole. If you look at the T/C bolster it is a single cast piece. The hollowed breech plug is integral to it and is called a patent breech. That clean out plug hole is actually the way the flash channel is drilled.... connecting the nipple to the chamber part of the patent breech. Then it is plugged and flush filed on some guns or in the case of T/C and others they decided to put a removable plug in so it could be used as a clean out. No problem using a plug screw with a head to act as a stop.

And as to the anti seize like the specialty product sold in auto parts stores. Just an idea for the plug screw because it may help in the long run as many times the clean out is not removed on a regular basis during normal cleaning whereas the nipple usually is. Heavy automotive grease will work about as well.

[Jeff H]

The screw on my Lyman bottoms out but has no head. Not sure if it's because of thread taper or if the threads just stop but it's convenient.

[fouronesix]

Don't know about the Lyman but I imagine that the flash channel was drilled with a smaller diameter drill than the minor/pilot drill for tapping the clean out plug screw seat. Or possibly, on the Lyman, a standard tap was used with a tapered tip and when they ran the tap in they stopped before running the full/major diameter of the tap on into the nipple seat hole... thus creating a tapered "stop" to the end of the plug screw portion.

[Buzzard II]

I know this is an older thread but it still is important. I just got a NOS T/C .45 barrel and the nipple came out hard (no anti seize and tightened by a gorilla). It finally came out, and it was DRY. I guess the slotted screw in the "clean out hole" is OK to leave in and just use a pipe cleaner to clean out the channel from the nipple to the main charge. I'm not drilling this one. Replacement screws are available for the "clean out hole" but I think I'm going to stop work right here and just shoot the gun after drying out the Kroil. I'm glad I found this as I'm RELIEVED. Who says you can't teach an old geezer new tricks (I'm 68).