13/64 drill bit for a 1/4" WL liner

[Eric Krewson]

Looking through my stock of collected stuff before I put a WL liner in my C weight barrel I found a 3/8" WL liner with drill and correct tap, a correct drill for a 5/16 liner and tap but no liner, and a 1/4" WL liner with tap but no #4 drill bit which is .2090. The closest I have is a 13/64" bit that is .2031. Suppose the 13/64" drill bit is sufficient to use to run a 1/4/32 tap into?

The 3/8 liner is a little big, I like 5/16 liners but don't have one so I was going to use the 1/4" liner that I do have.

There is a TOW WL clone liner in the kit, it is so rough I wouldn't put it in my rifle on a dare.

 

[Kansas Kid]

I’m sure you meant .209 on the #4. I would be ok with the .203 since it will probably drill a Thousands or two over anyway. The barrels are as soft as butter and using a quality tapping fluid you may get 75 to 80 % thread.

Those 32tpi series taps are pretty heavy and tough also. Just break your chip often. Try it on a scrap if you want.

 

[Eric Krewson]

The .209 size is off a drill bit chart for a #4 drill bit along with the metric size.

4

.2090

5.309

 

[Kansas Kid]

Yes I understand that and have been a machinist for many years. You did post .0290 IIRC in your OP.

 

[user 34300]

Go to harbor freight and get a set of bits. HF bits are not great, they are cheap. Pre drill smaller. The final bit will drill to size regardless of the point not being evenly sharpened. I get the one below every few years. The cheaper sets make holes too.

https://www.harborfreight.com/cobalt-drill-bit-set-115-pc-61886.html

 

[Kansas Kid]

Tap drill charts are (suggested) size not an absolute.

 

[Eric Krewson]

It was a typo, I corrected the size when I saw it. I type poorly with club fisted arthritic hands, 27 years of working osage bow staves with a drawknife does that to one.

This is my 5th WL liner install so far. I have a set of fractional bits from Harbor freight, 29 piece set for $9.95 on sale, they wouldn't drill butter when I got them but I have a Drill Doctor, properly sharpened they ain't half bad.

I have a drawer full of drill bits, a good set of fractional bits and the Harbor Freight set, I just didn't have a #4 number bit.

 

[Nameless Hunter]

McMaster Carr has 5.3mm drill bits if you want to be exactly 0.209. Personally, I think 0.203 is more than close enough.

 

[LawrenceA]

Close enough.
You are gping slightly under rather than over and will probably use thread sealer. So you saved on thread sealer!

 

[pooch156]

Go to harbor freight and get a set of bits. HF bits are not great, they are cheap. Pre drill smaller. The final bit will drill to size regardless of the point not being evenly sharpened. I get the one below every few years. The cheaper sets make holes too.

https://www.harborfreight.com/cobalt-drill-bit-set-115-pc-61886.html

I bought a set of number drills from HF. My experience with them is that they are junk. Some are slightly bent, not at all sharp and there are duplicates. I checked a lot of them with a "Starrett" micrometer. Don't go by what the drill index says! Their letter & fractional drills seem to be OK but not the number drills.

 

[ZUG]

Your drill press runout and drill will either drill an accurate size hole for 75% thread engagement or larger never smaller. With a fine thread you don't want an undersize hole that will give you a very tight thread fit (90%) and bind half way in. If you have a piece of cut off barrel do a test hole and tap it to see if will be good or not. I would not use Harbor Freight drill bits - go buy a brand name drill bit it will be ground to a much closer tolerance which will drill a much true to hole size .

 

[Eric Krewson]

Well the saga continues, I have two 13/64th bits, one American made, one Harbor Freight, although the chart cays they are .2030 my bits both measure .1960. I have a Swedish made a Brown and Sharp digital micrometer that is dead nuts on. I checked it against two American made feeler gages, dead on with any shim I checked.

Fastenal has a outlet close by, I checked online and it said my local store may have a #4 in stock or may not. They do have a #5 which is .2055, I will run by tomorrow and see.

 

[Zonie]

Sounds like you need to remark those bits to say, 9.
A #9 bit is .1960 in diameter.

 

[1950DAVE]

Precision Machine Supply in Muscle Shoals
Dave

 

[Eric Krewson]

I thought they had gone out of business, I think I went there looking for a number bit for 5/16 liner and they didn't have one. Fastenal is only about 1/4 mile down the same street. I did buy some really nice small files from Precision machine supply a few years ago. They let me go back and pick what I wanted out of their bins. Recently I wanted to buy more files and the lady at the counter wouldn't let me go past the counter to look at the files and she didn't know one file from another, she said she couldn't help me.

 

[Flintfan69]

Just go to to McMaster Carr or MSC and buy the correct drill bits. Buy some American made TIN coated ones, or a close second are German made Guhring drill bits. You only need screw machine length ones for installing vent liners, and there is less chance for the short ones to "walk". Buy a good center drill if you don't have one yet either.

 

[pooch156]

Just go to to McMaster Carr or MSC and buy the correct drill bits. Buy some American made TIN coated ones, or a close second are German made Guhring drill bits. You only need screw machine length ones for installing vent liners, and there is less chance for the short ones to "walk". Buy a good center drill if you don't have one yet either.

McMaster-Carr is my go to place!

 

[Eric Krewson]

Well folk, I appreciate the advice but, I will only use this bit to drill one hole and probably never use it again. I step drill liner holes starting with a much smaller bit first.

My best option would be to pick up bit in town, my barrel has already been marked with a punch and has been on the cross slide vise on my drill press, I would hate to have to wait for a mail order bit but will if I have to.

 

[Eric Krewson]

Zonie, I think these HF bits are miss-marked, the next step up in the set is 7/32, it measures a perfect .2090 and appears to be exactly what I need, even though I have a very good set of calipers and this bit appears to be correct, I am going to buy a #4 bit just to be sure. Picky, picky that is me when it comes to this stuff.

 

[Eric Krewson]

Fastenal had one for $7, a good quality American made one at that. It measures .208 on my micrometer.