Size of CVA ML scope mount screws?

BerdanSS · February 23, 2013, 06:13 PM

Does anyone know the size of the scope mount screws for a CVA staghorn?

<EDIT> Just went to menards and bought one from 3mm-6mm and 8-10 32.

The 4mm fit pretty good

**Unclenick** · February 24, 2013, 06:03 PM

The scope mount screws are 8-36 and made of hardened steel. That is a UNF (unified thread FINE) standard size, not UNC (Unified thread COARSE), which is what most hardware stores sell. It is finer so that recoil doesn't loosen them as easily.

4 mm screws have a 0.7 mm pitch standard, which is 36.3 turns per inch, and is why that 4 mm screw seemed to turn in OK. It will be compressing the receiver threads a little. The 4 mm screw is a little narrower. The tables in my copy of Machinery's Handbook suggest a minimum dimension 4 mm screw in a maximum dimension 8-36 female thread will engage about 1/3 less thread than the right screw does, so it will be a weaker attachment and pulling on the receiver threads harder. Also, the 4 mm screw may not have the same heat treatment as the right scope screws, so it also risks breaking off in the holes. I would not be trusting it, personally, and would get the right screws.

If you call CVA, they might send you some of the right ones. 770-449-4687.

BerdanSS · February 25, 2013, 02:44 AM

I will eventually get some of the OE screws..in the mean time I'm not mounting a scope, just dealing with set screws to fill the scope mount holes of a used rifle I bought that was missing all of them. Thanks for the number, I'll call them tomorrow and see if I can get an owners manual as well

BerdanSS · February 27, 2013, 05:19 PM

Sure enough....called them and they have a new set of screws and a owners book for it on it's way, free of charge

Thanks again for the number sir!

**Unclenick** · February 27, 2013, 05:57 PM

I thought that might happen. Glad it worked out for you.

February 23, 2013, 06:13 PM	#1
BerdanSS Senior Member Join Date: April 3, 2011 Posts: 581	Size of CVA ML scope mount screws? Does anyone know the size of the scope mount screws for a CVA staghorn? <EDIT> Just went to menards and bought one from 3mm-6mm and 8-10 32. The 4mm fit pretty good Last edited by BerdanSS; February 23, 2013 at 09:17 PM.

February 24, 2013, 06:03 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 9,164	The scope mount screws are 8-36 and made of hardened steel. That is a UNF (unified thread FINE) standard size, not UNC (Unified thread COARSE), which is what most hardware stores sell. It is finer so that recoil doesn't loosen them as easily. 4 mm screws have a 0.7 mm pitch standard, which is 36.3 turns per inch, and is why that 4 mm screw seemed to turn in OK. It will be compressing the receiver threads a little. The 4 mm screw is a little narrower. The tables in my copy of Machinery's Handbook suggest a minimum dimension 4 mm screw in a maximum dimension 8-36 female thread will engage about 1/3 less thread than the right screw does, so it will be a weaker attachment and pulling on the receiver threads harder. Also, the 4 mm screw may not have the same heat treatment as the right scope screws, so it also risks breaking off in the holes. I would not be trusting it, personally, and would get the right screws. If you call CVA, they might send you some of the right ones. 770-449-4687. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Patron Member

February 27, 2013, 05:57 PM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 9,164	I thought that might happen. Glad it worked out for you. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Patron Member

February 25, 2013, 02:44 AM	#3
BerdanSS Senior Member Join Date: April 3, 2011 Posts: 581	I will eventually get some of the OE screws..in the mean time I'm not mounting a scope, just dealing with set screws to fill the scope mount holes of a used rifle I bought that was missing all of them. Thanks for the number, I'll call them tomorrow and see if I can get an owners manual as well

February 27, 2013, 05:19 PM	#4
BerdanSS Senior Member Join Date: April 3, 2011 Posts: 581	Sure enough....called them and they have a new set of screws and a owners book for it on it's way, free of charge Thanks again for the number sir!