7 replies to this topic

[pizzadude]

Hi guys,

I'm sure many of you have long since sold/lost/moved on from your BT16s, but I was wondering if anyone actually found out what the thread pitch was for the buttstocks (AR15/M16/M4?).

If you have one still kicking about and are able to measure for me, that'd be ace.

cheers

[Tomcat]

No.  The thread was specific to the BT-16.  Not the same threading.  Yea that and the placement of the hopper was what killed that model.  I loved mine for a good while.

[pizzadude]

Thanks Tomcat - thought so. I have an aluminium butt tube at my machinist's, but we're metric over here and he's struggling to match the thread pitch - it looks like a decimilized imperial thread...

Any ideas how to find out exactly what it is?

[Jaz]

Perhaps someone at Empire might be able to pull the info.  I had same issue trying to find a stock myself.  I think it's npt 16 but I can't be sure.

[pizzadude]

Thanks for the reply dude - tried Empire previously, they sent me the BT-4 schematic... It took a couple of emails to confirm that I was really after BT-16 info, but they replied that they weren't able to help further.

If I can confirm the thread, we can get hold of the die and run the thread off on the lathe. Without it, my stock tube is a paperweight

[Jaz]

Bring the marker to a tool and die shop, they should be able to tell by a thread tool what it is

[Dadops]

If you get a machenery handbook and a vernier caliper and some thread pitch gages....you can probly figure out what it is.....I get farmers,gocarters,stock car people...asking me what these threads......are all the time!....I would be surprised if it was a taper pipe thread....but then again...Ive seen some pretty werd stuff.

[pizzadude]

Just an update - I've decided to turn down the knurled end of the plug and have that fitted to my butt tube. The thread OD seems to be 1 5/32" (1.156" or 29.4mm) and when/if I identify the pitch, I'll post up. Thanks for all the replies