fixing threading in body for main screw

[SR_matt]

ok long story short my friend has a nice mag he got in a trade a while back... only issue is that the person he got it from didnt mention the main screw threading was starting to strip out and during normal maintenance it stripped the rest of the way.

helicoil it? nutsert it? just tap it larger? we both have decent size tap sets so that is no issue but every helicoil kit i saw is running like 25 plus for a new set. has any one had this issue and how did you fix it or what do you think we should do? he is rather cheap at this point (he needs a new car and is moving soon so money is tight for him so he needs to get this gun up as cheap as possible to play a game coming up).

he is thinking to just tap it to a larger size screw, i guess the next size up is about a 1/4 20 or 1/4 28. is this realistic or not?

-matt

[secretweaponevan]

Tapping for 1/4-28 would be the cheapest if you do it right. Tapping stainless is tough for me.

1/4-28 would give you 100% threads according to this chart:

http://www.shender4.com/thread_chart.htm

Perhaps finding a local proshop that can helicoil it might be the best/least risky, option.

[maniacmechanic]

do it right & heli-coil it if you go to a larger size you will have to drill out the trigger frame , then you will lose all resale on the body & the frame , how long was the allen screw he was using ? you may still have good threads at the very bottom of the hole & by custom cutting your screw length you may be able to get by for a while

[SR_matt]

do it right & heli-coil it if you go to a larger size you will have to drill out the trigger frame , then you will lose all resale on the body & the frame , how long was the allen screw he was using ? you may still have good threads at the very bottom of the hole & by custom cutting your screw length you may be able to get by for a while

im pretty sure it was the correct length screw.

secretweaponvan its an AL body so its not going to be any were as bad as SS, and 2 things with the get a local pro shop A) none of the pro shops around do that, the biggest repair they may do is replacing a noid on a newer electro and B) most of the shops have shut down.

by that chart i get the 100% thread thing but would 12 32 work (if we went that route) since while its not 100% threads the thread would still be deeper than what was originally there, or do you still just have to worry about cross threading a lot more?

is there a cheap break off tool that i can get separately and then just buy a few helicoils. my friend and i have both worked with metal and done pretty in depth things on markers so doing it our selves is not a worry and heck at this point if i could find the tool for cheap i may just buy it for my self to have since he is to cheap to get it (but seeing as i am going into metal working for the concentration of my degree i have an excuse too)

-matt

[punkncat]

You should be able to find a helicoil kit that will come with the drill bit and tap you need to perform the entire action.
Even the coils themselves (at least used to) have the recommended drill bit and tap size to repair on the box. So that way if you already have some nice bits and taps you will need nothing else.
I have never seen the coils come in a "one" pack, there are normally several in it. You may come out better calling a local machine shop to have them repair it.

[SR_matt]

You should be able to find a helicoil kit that will come with the drill bit and tap you need to perform the entire action.
Even the coils themselves (at least used to) have the recommended drill bit and tap size to repair on the box. So that way if you already have some nice bits and taps you will need nothing else.
I have never seen the coils come in a "one" pack, there are normally several in it. You may come out better calling a local machine shop to have them repair it.

i do understand that but dont you need a "break off tool" or some special tool to get the coil in?

between my friend and i we have what ever bit and tap and i dont mind shelling out a few bucks for a pack of helicoils (just dont want to buy 100s) but i thought i needed another tool for it too.

-matt

[punkncat]

i do understand that but dont you need a "break off tool" or some special tool to get the coil in?

between my friend and i we have what ever bit and tap and i dont mind shelling out a few bucks for a pack of helicoils (just dont want to buy 100s) but i thought i needed another tool for it too.

-matt

I don't recall having anything special to put it in with. Its been a while since I used one, but iirc I just used the threaded bolt it was sized for, and some loctite.

[SR_matt]

o ok, i guess it was for custom sized ones. ill have to let him know that before he goes a head and taps it out (im betting knowing him hes going to wait until the day before the game to do it so i have a good while but ill let him know)

now another question, what length ones should i get then, i see .285 and .190 lengths, i dont have access to a mag until the day before the game si i cant check it my self

thanks
-matt

[SR_matt]

screw it (pun intended), im getting a little kit. found one at a local bolt shop for like 23 bucks with he tools and 5 coils. ill reply in 2 weeks with how it works out
-matt

[SR_matt]

ok well update

tried to put a helicoil in, first problem the tap wont go very far in so my friend ended up having to drill into the breach to tap it, coil wouldnt stay in... some how the threading totally stripped out again. so he jamed the coil in the hole to have some grip on the body, electrical taped the gun together and we played the first day of the scenario to day. has worked fine so far, of course its not what we really want but hey its working for now.

now we just have to figure out how to fix it. i asked a machinist friend from another team that used to be on my team and he sat there and thought for a few mins and replied with "i really dont know what to tell you, if it keeps stripping out im not sure what will fix it"

so ya, we might try and retap it at a much larger screw or something.

-matt

[athomas]

Fill the hole with metal filler or bronze. The metal filler (JB weld or similar will work). Then redrill the hole and retap. Go as deep as you can with a regular tap and then finish with a bottoming tap to get the maximum depth on your threads.

[SR_matt]

Fill the hole with metal filler or bronze. The metal filler (JB weld or similar will work). Then redrill the hole and retap. Go as deep as you can with a regular tap and then finish with a bottoming tap to get the maximum depth on your threads.

will the fact that he ended up drilling/tapping into the breach be an issue for this?

with bronze? how so?

would using something like marine tec work and if so does the taking a screw, coat it with a lubricant and twist the screw in the filler to create the threads work? (i know this is supposed to work on some things but im not sure if this is too fine of a threading to do that)

-matt

[MANN]

Use a larger screw. If that doesnt work scrap it. Marinetech while absolutely the most wonderful thing in the world will not fix a stripped hole

[SR_matt]

Use a larger screw. If that doesnt work scrap it. Marinetech while absolutely the most wonderful thing in the world will not fix a stripped hole

well the hole is totally stripped out to the OD of the helicoil. im not sure if you meant to use a longer or a wider screw.

and with the amount of metal left there still i think "just scraping" a rarer body is frankly stupid (heck even if that whole part was gone there are many ways to get around just scrapping it). we may resort to going to a machine shop and seeing if they can fix it, i know you can double helicoil but i dont want to risk tapping it out more unless we can get a very good grip in the metal

-matt

[athomas]

will the fact that he ended up drilling/tapping into the breach be an issue for this?

with bronze? how so?

would using something like marine tec work and if so does the taking a screw, coat it with a lubricant and twist the screw in the filler to create the threads work? (i know this is supposed to work on some things but im not sure if this is too fine of a threading to do that)

-matt

A hole drilled into the breach won't affect it. The hole will be filled with grip screw, plus the bolt will be past that location when a ball is fired anyway.

Bronze is melted into the hole with a torch. Then you drill and tap. It might be difficult since there is a hole all the way through.

I'm not sure how a lubricant would react with the marine tec. If it is an acceptable means of preventing adhesion, then it should be a good way to get new threads without tapping. If it is a problem, use a nylon machine screw. It should come right out of the hardened metal. If it doesn't then you can easily drill it and run a tap into the preformed threads.