A question of base screws

[jsali]

For all those more knowledgable than me. I am mounting a Sightron SIII 6-24x50 scope (20.4 ounces) on a Farrel (no recoil lug I think) 20 MOA base with TPS TSR "W" 30mm rings. Do I need to have the reciever and base redrilled and tapped for #8-40 screws or are the standard ones adequate? Thanks,

-John

 

[Fiftydriver]

John,

What is your rifle chambered for? This is not an overly heavy scope but it will depend on the recoil level of your rifle.

Kirby Allen(50)

 

[jsali]

Oops sorry, .300 win mag. I though I put that in there. Goes to show read the post.

 

[jsali]

What do the gunsmiths think?

Any 'smiths like to comment. I sure would appreciate it.

 

[jsali]

Re: What does anybody think?

Boy hard to wrangle an answer out of somebody here these days. Alright I'll try this. Is anyone here using a tactical style scope, base and rings? If so, are the base screws 8-40 or 6-48? If they are 6-48 have you had any problems with them. If you could describe the scope/ring/base setup along with the caliber that would be great. Thanks.

-John

 

[daveosok]

Re: What does anybody think?

I wasnt here yesterday or the better part of today to answer your question.
I have a 300 wsm with a 26 in barrel 1 in muzzle diameter and a laredo style winchester stock, It has a muzzle break and is somewhat heavy. The base is a Ken Farrel no moa slope, the rings are IOR Valdada medium height. The scope is a Night Force 8-32 X 56.
I followed the instructions from the Farrel base and "glued" the base to the action and then installed the rings, made a ring lapper for 30mm scope tube diameter and lapped the rings. Installed the scope and havent had any probelms with it moving. This rifle is not of factory sporter weight standards and is more along the lines of heavy varmint or a tad over it.
The scope hasnt moved and the base is held on with the stock screw holes the 6-48 or whatever thread pitch they are but they arent 8 series. I torqued them down to the recommned value and removed the excess "gluing compound" it doesnt have a recoil lug for the base.
For extreme use 8-32 screws offer a tad bit more security but imo, unless your dropping out of a c-130 halo style and are going to hike it 20 clicks to your destination in the mountains of Afganistan I dont think it matters much.
If you have a good scope, good and proper set-up on your base and rings your scope shouldnt move with the 300 win mag but this is just my opinion and you know what they say about those.

 

[jsali]

Re: What does anybody think?

Thanks for responding. What did you glue the base down with?

-John

 

[daveosok]

Re: What does anybody think?

Some sort of 3m product for steel on steel adhesion with a slow cure time and toughness. Search your local Lowe's or Home Depot and read the backings of the glue for applicable usage.
I cant remember off hand as the tubes leaked and I threw them away.
You could call Ken Farrel and ask what he recommneds.

 

[jsali]

Re: What does anybody think?

I there a way to release the glue or is it a permanent deal. What if a guy wanted to change up bases?

What about bedding the base would that work the same?

-John

 

[chris matthews]

Re: What does anybody think?

The 6-48s will hold it fine.
A base can be bedded to the action for removal if you apply a release agent to the action-paste wax, light film of grease, etc.... to the action before you screw the base down.

 

[daveosok]

Re: What does anybody think?

I second Chris's response and if you want a removable base then by all means apply a release agent.
I kept mine permantly afixed (per say nothing is for ever) since I dont ever see myself removing the base.
Ken Farrel products are top notch and high quality.

 

[jsali]

Re: What does anybody think?

Thanks to those who responded for your help it is appreciated.

-John

 

[Pete Lincoln]

Re: What does anybody think?

Personaly i prefer the 8-40. Now the 6-48s will certainly hold in most situations, and on a normal hunting rifle with a typical leupold attached then i can't see you having any bother. A different matter alltogether is one of these bid heavey European scopes that weigh in about 2lbs +. combine that with a heavey recoiling rifle, and then ad a moderator and we have a different ball game perhaps.
I don't know why manufacturers continue to use the 6-48 size exept for the fact it gives us smiths some room to play with when re drilling and tapping holes that come of centre from the factory.
Whichever thread size, its a good idea to bed the base to the rifle, I like to glue mine in place with Devcon. Bedding the base gives several advantages, 1. it takes up any minor differences in fit between base and reciever/action. 2. when glued in place it certainly helps the base stay put. 3. it prevents the ingress of moisture under the base causing rust. Don't forget to lock the screws with some form of thread lock, but make sure its a thread lock with the correct grade and not a super glue cos if you super glue the screws in the sods will probably have to be drilled out, which is a common occurance i find on rifles where the owner has treid to do the right thing to stop the screws shooting loose by glueing the screws in.
Pete

 

[Stugotz]

Re: What does anybody think?

Just my opinion, but why take the chance of this being the weak link. I use Five #8 screws on Near bases. If your base doesn't have a built in "recoil lug", seems like a little extra meat in the screws would be a good idea. Do you "NEED" them, probably not, but for what's involved in upgrading, I think the insurance is worth it.