Bolt knob modification help

[Bigdude]

A long time ago I sent my bolt handle (Remington 700) to Badger Ordnance so it could be modified to accept their Tactical Bolt Knob. Well, recently I decided that I would like to switch out the bolt knob for a carbon fiber bolt knob. After removing the Badger Ordnance bolt knob and putting on the carbon fiber one, there is approximately .17” of exposed thread on the handle. Now, do I attempt to grind down the bolt handle or lengthen the inside of the bolt knob by drill/tap? Or is there a third option that I am not seeing such as filling in the gap with JB weld or something? Any advice would be appreciated, thanks.

 

[...]

can you post a picture of the threads?

i can tell you that you arent going to be able to drill and tap the bolt knob deeper without fucking up the threads.

you might be able to just cut down the threads on the bolt handle about an 1/8"

personally what i would do is just make a little plastic spacer that takes up the space.

 

[Servo93]

Just grind it down.

Find a nut that threads on to the bolt handle and then grind the threads down with the nut on the threads. When you finish grinding take the nut off the threaded bolt handle.
Just an old mechanics trick to clean up threads after you ground down a bolt to make it shorter.

 

[Bigdude]

can you post a picture of the threads?

 

[Bigdude]

can you post a picture of the threads?

i can tell you that you arent going to be able to drill and tap the bolt knob deeper without fucking up the threads.

you might be able to just cut down the threads on the bolt handle about an 1/8"

personally what i would do is just make a little plastic spacer that takes up the space.

Agreed, drilling and tapping the knob would not work and would definitely destroy it.

 

[Bigdude]

Just grind it down.

Find a nut that threads on to the bolt handle and then grind the threads down with the nut on the threads. When you finish grinding take the nut off the threaded bolt handle.
Just an old mechanics trick to clean up threads after you ground down a bolt to make it shorter.

I think that's what I am going to do. Will it be an issue that I do not have access to a bench grinder? I was planning on using a cut-off wheel.

I am just hesitant for fear of some how ruining the entire bolt.

 

[FourT6and2]

I'd rather destroy a knob, than the bolt. Which one is easier/cheaper to replace or fix?

 

[lash]

I think that's what I am going to do. Will it be an issue that I do not have access to a bench grinder? I was planning on using a cut-off wheel.

I am just hesitant for fear of some how ruining the entire bolt.

A cutoff wheel and a hand file will work just as well. As long as you have a nut threaded onto the bolt handle prior to doing the cutting, you should do fine.

Just spin on the nut past the part you want to remove. Use the cutoff wheel, then clean up the end with a hand file. Remove the nut, which will clean up any minor nonconformity in the threads and you should be fine. Just make sure that when you start the new bolt knob onto the newly cut handle threads, you are careful and don't cross thread or otherwise bugger up the threads.

 

[Bigdude]

A cutoff wheel and a hand file will work just as well. As long as you have a nut threaded onto the bolt handle prior to doing the cutting, you should do fine.

Just spin on the nut past the part you want to remove. Use the cutoff wheel, then clean up the end with a hand file. Remove the nut, which will clean up any minor nonconformity in the threads and you should be fine. Just make sure that when you start the new bolt knob onto the newly cut handle threads, you are careful and don't cross thread or otherwise bugger up the threads.

Ok, thank you very much. What kind of hand file do you recommend? I have to purchase one so I might as well get the correct one.

 

[Servo93]

Edit: what lash said, he was quicker off the draw than I.

With the cut off wheel just go slow, you don't have much to take off. If you don't feel comfortable just practice on a few scrap fasteners.

There is a good chance that the insert in the carbon fiber knob is already bottom tapped. Meaning you can't make the threads much deeper.

 

[...]

also, before you start cutting, make sure that the thread length is actually the problem.


take a bolt and thread it into the knob, and mark where it bottoms out.....then compare that length to the threaded portion on the handle....if the threads are the problem, your threaded portion will be longer than the bolt you marked.

because it looks like your handle is not 100% threaded, and it looks like the bolt knob is stopping right where the threading stops........so even cutting down the threads wont fix it.

 

[lash]

I personally just use an 8" single cut mill bastard file, which is a good general use all around file.

Some will get all fancy and use a set of needle files, but it's not necessary.

 

[lash]

also, before you start cutting, make sure that the thread length is actually the problem.


take a bolt and thread it into the knob, and mark where it bottoms out.....then compare that length to the threaded portion on the handle....if the threads are the problem, your threaded portion will be longer than the bolt you marked.

because it looks like your handle is not 100% threaded, and it looks like the bolt knob is stopping right where the threading stops........so even cutting down the threads wont fix it.

You make a good point. I went back and looked closer. It may be that the badger knob has relief cut into it to cover the unthreaded portion of the knob.

 

[z98]

Can we see the inside of the bolt knobs? Possibly looks to be stopping at the end of the threads not bottoming out. Maybe you need to chamfer the inside of the new bolt handle.

Also use calipers to measure the depth on the handle and the shank.

 

[buffybuster]

From the pictures, my WAG is you need to have a relief in the new bolt knob for the unthread part of the handle. But other than aesthetics, what does the new knob get you? The old knob was professionally installed and probably looked alright. IMO you're going from "If it ain't broke don't fix it" to "fix it until it's broke".

 

[Bigdude]

Can we see the inside of the bolt knobs? Possibly looks to be stopping at the end of the threads not bottoming out. Maybe you need to chamfer the inside of the new bolt handle.

Also use calipers to measure the depth on the handle and the shank.

I took the following measurements with Mitutoyo calipers:

Badger Ordnance bolt knob depth: .6925”
Carbon fiber bolt knob depth: .6175”
Threaded portion of handle: .5680”
Entire exposed handle: .6880”

Here are pictures of the new bolt knob (carbon fiber):

[IMG2=JSON]{"data-align":"none","data-size":"full","height":"300","src":"http:\/\/i1377.photobucket.com\/albums\/ah69\/bigdude011\/CF-1_zpsyp6yshsh.jpg"}[/IMG2]

[IMG2=JSON]{"data-align":"none","data-size":"full","height":"300","src":"http:\/\/i1377.photobucket.com\/albums\/ah69\/bigdude011\/CF-2_zpsx3yei0r9.jpg"}[/IMG2]

Here are pictures of the old bolt knob (badger ordnance):

[IMG2=JSON]{"data-align":"none","data-size":"full","height":"300","src":"http:\/\/i1377.photobucket.com\/albums\/ah69\/bigdude011\/BO-2_zpsh0hlircs.jpg"}[/IMG2]

[IMG2=JSON]{"data-align":"none","data-size":"full","height":"300","src":"http:\/\/i1377.photobucket.com\/albums\/ah69\/bigdude011\/BO-5_zpskn3ap0gd.jpg"}[/IMG2]

[IMG2=JSON]{"data-align":"none","data-size":"full","height":"300","src":"http:\/\/i1377.photobucket.com\/albums\/ah69\/bigdude011\/BO-1_zpsjbdhrg1g.jpg"}[/IMG2]

[IMG2=JSON]{"data-align":"none","data-size":"full","height":"300","src":"http:\/\/i1377.photobucket.com\/albums\/ah69\/bigdude011\/BO-4_zpsfqrde8bj.jpg"}[/IMG2]

 

[hamstur]

Eyeballing all your pics, my bet if you wont get the carbon knob to fit because the exposed unthreaded portion on the handle is clearly same/larger OD as threading. The Badger knob had internal relief. It's similar-ish to how an AIAE barrel won't work on AW/AT/AX. Personally would just stick with the Badger knob, else send off the someone like PTG for an entire handle replacement.

 

[...]

I would just drill out the first 1/8" or so of the threads on the carbon knob

 

[lash]

I agree, but based on his measurements, he still will need to shorten the threaded part of the handle by 1/16"+ to get a clean fit and look.

So all in all it's not just a plug and play bolt knob swap.

 

[BobinNC]

I bought a bolt knob that was much shorter than the Badger Ordnance it replaced. I had a good 0.20" of threads exposed, as the new knob was so much shorter than the old one. Rather then cutting and grinding the threads, which might break, and drill my new knob was not an option, I made a sleeve out of a Closet Maid end cap to fill the gap. I cut the end off the end cap and used a black permanent marker for color blending after I slid it on. It's not a pretty as doing it the right way by cutting and grinding, but this way I leave all options open.

http://www.homedepot.com/p/ClosetMai...1016/100095946

 

[z98]

I would just drill out the first 1/8" or so of the threads on the carbon knob

I agree

 

[z98]

Also my only concern is the pressed in threads will break loose from the carbon if you attempt to drill it out. So take it super easy.

 

[Bigdude]

Thanks to everyone who provided advice/instructions. Overall, it was much easier than I anticipated.

 

[2c1fr]

Glad it worked out OP!

 

[z98]

Looks great!

 

[Danny1788]

Where did you get the carbon fiber bolt known from that looks slick

 

[Bigdude]

Where did you get the carbon fiber bolt known from that looks slick

tacticalworks.com

 

[Griz44Mag]

Just an observation, but it seems Badger has devised a method to try and keep other brands of knobs off bolts that they have worked on...??

 

[lash]

I think that it has more to do with the geometry of the standard R700 bolt handle. It only allows so much threading to be done and then you still need to cover up the remainder of the handle to get the right bolt knob fit.

So, rather, I think that Badger took the time to make sure their bolt knob was designed to work on a standard production R700 handle and that carbon fiber knob was not as well designed.

 

[GTGunner]

Sometimes it is best to leave well enough alone since there was nothing functionally wrong with the Badger bolt knob. In this case your carbon fiber knob looks better. Nice work.

 

[Bigdude]

Sometimes it is best to leave well enough alone since there was nothing functionally wrong with the Badger bolt knob. In this case your carbon fiber knob looks better. Nice work.

Thank you

 

[Downtown]

Perhaps I'm missing something, but could you not simply shorten the threaded part of the bolt handle a bit?

 

[lash]

Perhaps I'm missing something, but could you not simply shorten the threaded part of the bolt handle a bit?

Read the first page of the thread and you should see why that would not be the answer.

 

[Downtown]

My apologies. I read too quickly and didn't realize I was on page two. I'll be quiet now.

 

[lash]

No apology necessary. It happens.

 

[Bigdude]

Sometimes it is best to leave well enough alone since there was nothing functionally wrong with the Badger bolt knob. In this case your carbon fiber knob looks better. Nice work.

I changed the bolt knob for two reasons. First, I wanted it to match the barrel (which is carbon fiber as well). Second, it is significantly lighter than the Badger Ordnance knob, 13 grams (.46 ounces) vs 35 grams (1.23 ounces). I will shave weight off where ever I can. So changing the bolt knob was completely worth it for me.

 

[Bigdude]

I think that it has more to do with the geometry of the standard R700 bolt handle. It only allows so much threading to be done and then you still need to cover up the remainder of the handle to get the right bolt knob fit.

So, rather, I think that Badger took the time to make sure their bolt knob was designed to work on a standard production R700 handle and that carbon fiber knob was not as well designed.

The Carbon Fiber bolt knob is just a generic bolt knob with 5/16" X 24 TPI thread. According to the manufacturers description of the knob, it was not designed specifically for any model firearm. Nowhere does it state "Remington 700" or "R700".

 

[lash]

Okay. I'll buy that, but my response was to the comment that Badger was trying to keep other brands from replacing their knob through clever design. I was pointing out that it has more to do with a design specific to the R700 and not to handles that they have worked on.

 

[Bigdude]

Okay. I'll buy that, but my response was to the comment that Badger was trying to keep other brands from replacing their knob through clever design. I was pointing out that it has more to do with a design specific to the R700 and not to handles that they have worked on.

Oh, ok..Got ya. I misunderstud your post.