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odugrad
11-02-23, 16:59
Finally getting around to replacing my BCM kmr rail with an mcmr but I'm having trouble getting the cross bolts off. I've snapped 2 provided torx wrenches and 2 bits.

I know the one without the star comes off first.

Any advice?
Stickman
11-02-23, 17:04
Finally getting around to replacing my BCM kmr rail with an mcmr but I'm having trouble getting the cross bolts off. I've snapped 2 provided torx wrenches and 2 bits.

I know the one without the star comes off first.

Any advice?

Throw it in the freezer and let the aluminum shrink down more than the steel components. If that doesn't work, it may have an thread locker which would need heat.
mexica
11-02-23, 17:06
I think it's the other end. Are you talking about the one that looks like gears?

Sent from my SM-S916U using Tapatalk
markm
11-02-23, 17:09
I know the one without the star comes off first.


NO! The one with the STAR comes off after the first bolt. The star notches are what lock it in position when the first bolt tip pokes through.
odugrad
11-02-23, 17:12
Yeah. That's what I meant. The one with the star is locked in position by the first bolt. That's the one I'm trying to remove.
grizzman
11-02-23, 18:29
I've removed and installed KMRs, MCMRs, and QRFs quite a few times and have never come close to breaking a bolt or bit. Either you're still doing it backwards and trying to remove the bolt that's locked by the other one, or the bolt has thread locker installed.

I guess my next question is.....do you know how to remove a fastener that's got thread lock on it?
odugrad
11-02-23, 20:06
I have applied heat using a hair dryer but that still didn't work.

I'm definitely not trying to remove the wrong bolt. I've contacted BCM but have yet to hear back.
Disciple
11-02-23, 21:55
I have applied heat using a hair dryer but that still didn't work.

A hair dryer isn't nearly hot enough unless it's choked so much it's melting. Try a temperature controlled soldering iron.
HKGuns
11-03-23, 06:32
I have applied heat using a hair dryer but that still didn't work.

I'm definitely not trying to remove the wrong bolt. I've contacted BCM but have yet to hear back.

http://wonderfulengineering.com/wp-content/uploads/2015/11/Best-Butane-Torch-4.jpg
odugrad
11-03-23, 07:14
So BCM responded and confirmed there is loctite on the bolts.
markm
11-03-23, 08:43
So BCM responded and confirmed there is loctite on the bolts.

That's annoying. There's a chemical method of removal that Iraqgunz swore by. I have the product in my Amazon wish list, but never needed it. I had torching my guns.
joedirt199
11-03-23, 08:51
A heat gun is enough to remove loctite and a cheap tool to have on the bench.
Disciple
11-03-23, 09:00
A heat gun is enough to remove loctite and a cheap tool to have on the bench.

Why not use the focused heat of a soldering iron?
Uncas47
11-03-23, 09:09
I have defeated loctite by applying a soldering iron to the head of the bolt or screw. You need patience but it's a real nice feeling when it lets go. It's worked very well for me a number of times.
odugrad
11-03-23, 09:20
I could try those methods. But BCMsaid I could send it to them and they'd remove the kmr and install the mcmr. I'm thinking of going that route.
joedirt199
11-03-23, 10:51
With a heat gun, I put the allen key in the bolt and apply slight pressure while I heat it. You can feel when it starts to let go. With a soldering iron, you are heating a very small tip vs heating the bolt and the part around the bolt. It takes longer and harder to feel when it is ready to let go.
hotrodder636
11-03-23, 11:01
As I recall with my KMR and MCMRs, the cross-bolts only had blue loctite, so I am surprised that torque alone is not effective. I have never had an issue removing mine and definitely never had to use heat. I just find this interesting.
Disciple
11-03-23, 11:13
With a heat gun, I put the allen key in the bolt and apply slight pressure while I heat it. You can feel when it starts to let go. With a soldering iron, you are heating a very small tip vs heating the bolt and the part around the bolt. It takes longer and harder to feel when it is ready to let go.

Interesting. I hadn't considered applying torque while heating. The small tip of a soldering iron is a boon for folding knife pivot screws where I do not want to distort or discolor the scales or cook off all the lubrication.
SteveL
11-03-23, 11:56
As I recall with my KMR and MCMRs, the cross-bolts only had blue loctite, so I am surprised that torque alone is not effective. I have never had an issue removing mine and definitely never had to use heat. I just find this interesting.

Same. I've never come across blue loctite that I couldn't break with just a little force.
joedirt199
11-04-23, 06:39
Mine is a 2 speed from Lowes. Just an over powered hair dryer. First speed is usually enough but second speed gets so hot it throws sparks.
prepare
11-04-23, 08:13
That's annoying. There's a chemical method of removal that Iraqgunz swore by. I have the product in my Amazon wish list, but never needed it. I had torching my guns.

Whats the product?
SteveL
11-04-23, 14:07
Whats the product?

I'm pretty sure it was this.

https://www.amazon.com/Bob-Smith-Industries-BSI-161H-Debonder/dp/B0166FFC96/ref=sr_1_2?crid=3P7J0ZW15U8D4&keywords=bob+smith+industries+un-cure&qid=1699124792&sprefix=bob+smith+un%2Caps%2C100&sr=8-2
georgeib
11-04-23, 14:20
Loctite has their own branded Loctite remover/solvent too.
HKGuns
11-04-23, 14:55
I've never had much luck using a heat gun to remove thread locker from threads. It heats up a larger area than necessary and takes longer. I don't have the patience for a soldering iron approach.

The heat applied with a small torch is easier to control and direct into the area desired and isn't going to hurt anything unless you go ham on it.

I own a heat gun and always reach for my small butane torch first, applying torque while heating.