Help with scoping an M1A

[pmclaine]

I came across a Brookfield mount in the PX that I'm planning to use on my GI grade M1A.

It's not intended to be a clone of anything but will be in the spirit of an issue rifle.

I have a spare Leupold green anodized from the M40 commemorative line I intend to use as a scope. Zero the cross hairs for 100 yards than have 5 mils of hold for anything further away seems like a pretty functional setup.

I'm partial to Badger rings.

Considering the Leupold is probably close to an ART dimension wise anyone got suggestions for height, diameter, model number of the Badger rings to use? Probably 6 screw front, 4 screw rear?

Thank you for doing what I am being too lazy to do - research.

 

[jetmd]

That scope would be 1” correct?

Badger choices would be 306-12 with any 30 mm ring set.
306-24 USMC M40A3
Or 306-39 USMC M82A2 which would be way higher than what you would need.

 

[jrhtx]

Not sure what receiver you are mounting to but if you haven't mounted the Brookfield go SLOW and be very careful when you are tightening the mount to the receiver. I think Sadlak(?) sells some pins to check if your mount/receiver is in spec.

Friend was mounting a Brookfield to a Springfield Armory receiver and the stripper clip mount part of the receiver broke. He was like WTF.

Sent it all to Springfield for inspection. They wanted $450+ to replace the receiver. He told them to ship it back and sold it for parts.

 

[pmclaine]

Yes 1” tube. Scope is actually Redfield name made at Leupold.

I own a bunch of Badger 306-24 and love them but wondered if they would be taller than necessary with the BPT mount. Guessing they also need inserts.

Scary about the out of spec issue and snapage of the clip guide mount.

The instructions that come with the mount certainly detail a process of tighten A than attach C before tightening B loosen A and remove C while turning B to 1530 but no more than 1635.

 

[jetmd]

And Red high strength Loctite is required not optional if you plan to actually shoot it much.

I would assemble everything, verify you can properly zero as windage adjustment is a big issue when mounting these.

I have had several receivers that were out of spec along the left side interface of the receiver groove.

This includes both Springfield and Armscor receivers.

If everything fits and zeroes perfectly then disassemble and apply Loctite and reinstall.

Enjoy

 

[nn8734]

And Red high strength Loctite is required not optional if you plan to actually shoot it much.

I would assemble everything, verify you can properly zero as windage adjustment is a big issue when mounting these.

I have had several receivers that were out of spec along the left side interface of the receiver groove.

This includes both Springfield and Armscor receivers.

If everything fits and zeroes perfectly then disassemble and apply Loctite and reinstall.

Enjoy

Both Springfield M1As i used to own were out of spec...My LRB isn't and from what i've heard/read, only those and Fulton are reliable when it comes to meeting the orig USGI blueprints.

The instructions that come with the mount certainly detail a process of tighten A than attach C before tightening B loosen A and remove C while turning B to 1530 but no more than 1635.

Have you seen Tony Ben's video on scope mount checking and install? It's sufficiently detailed to help you through the process if you're not sure, etc.

 

[pmclaine]

Both Springfield M1As i used to own were out of spec...My LRB isn't and from what i've heard/read, only those and Fulton are reliable when it comes to meeting the orig USGI blueprints.


Have you seen Tony Ben's video on scope mount checking and install? It's sufficiently detailed to help you through the process if you're not sure, etc.

Have not but I will look it up.

Don’t know if it’s a sign of things to come but I did try to install a dummy selector/sear trip bar on the rifle and it would not fit. Receiver seemed fat and it would not install without drama so I decided the hole in the GI stock was not that big of a deal.

On the plus side if my BPT mount becomes a thing of drama they are not going down in price any time soon if I have to move it on.

 

[nn8734]

Have not but I will look it up.

Don’t know if it’s a sign of things to come but I did try to install a dummy selector/sear trip bar on the rifle and it would not fit. Receiver seemed fat and it would not install without drama so I decided the hole in the GI stock was not that big of a deal.

On the plus side if my BPT mount becomes a thing of drama they are not going down in price any time soon if I have to move it on.

If you find that your receiver is out of spec, you can always throw a Basset Machine mount on it (i had one that I used on my Springfield M1As (one Standard model and one "Loaded" model) and save the Brookfield for a Fulton or LRB-based build later.

I'd also run BO's low 30mm rings with LaRue 1" inserts or 1" BO low rings, assuming they make them. I have USO low 30mm rings holding my SWFA 12x42mm and those, when paired with Triad's stock pack, give me good height for my cheek weld relative to the scope center line.

 

[Atomic_Lobster]

Is the Brookfield mount better than the Sadlak
I have a M1a Match made back in the 70's
Thanks

 

[nn8734]

Is the Brookfield mount better than the Sadlak
I have a M1a Match made back in the 70's
Thanks

Depends on what you mean by "better"....Better in what way?

I have a Sadlak Airborne and it's a great mount; SEI and ARMS also make really good mounts (I think the ARMS #18 is out of production but could be wrong...). I believe they are all based on the original Brookfield Precision mount.

 

[jrhtx]

I assume this would work with BF mount?

Receiver Inspection Kit | sadlak

Receiver Inspection Kit - Part No. 140400We’ve taken the trial and error out of the mounting process by developing an Inspection Kit that includes detailed colored instruction sheets with diagrams, plus two sizes of precision ground inspection pins. The simple, at-home, self inspection procedure...

www.sadlak.com

 

[Stevo86]

Someone was making a mount where u pulled the rear sight base and it mounted between the ears , had a tension screw on the front… I had one but I sure can’t remember who made it. Worked damn well.

 

[camocorvette]

Gotta show pictures and targets when done. Sounds like a fun gun and project.

 

[jetmd]

The problem that I had ran into is the interface grove on the left side is not parallel with the bore of the receiver itself.

I mount the barreled action in my mill and use a test indicator and sweep the groove from front to rear.

If this groove doesn’t run true there is no good fix.

LRB’s in my experience are good quality.

The receiver inspection kit will not help with determining if this groove is parallel and true.

I hope this makes sense?

 

[Random Guy]

I own a bunch of Badger 306-24 and love them but wondered if they would be taller than necessary with the BPT mount. Guessing they also need inserts.

Here's a BPT with medium height 30mm Leupold rings. The main issue to be aware of is the clearance b/t the rear sight aperture and the rear ocular bell of the scope. Here one can see it's very close with the hooded NM rear aperture. (You'll likely need to keep the rear aperture at the bottom of the elevation adjustment). An ad hoc cheek rest is also recommended for best ergonomics.

The medium BO rings with 1" inserts would be the 306-24 (M40A3 rings). Alternatively the 306-20 (Medium) with 1" inserts would also work. Fwiw, I have not had any mounting issues with SAI M1A receivers and my 3 BPT mounts. (The BPT mounts are 'correct' for some replica M14 snipers, like this Desert Storm era replica of a Navy M14 sniper)

A Navy M14 sniper w/ BPT mount circa Feb 1991 outside Kuwait City (note the improvised cheek rest):

 

[ODCMP]

I came across a Brookfield mount in the PX that I'm planning to use on my GI grade M1A.

It's not intended to be a clone of anything but will be in the spirit of an issue rifle.

I have a spare Leupold green anodized from the M40 commemorative line I intend to use as a scope. Zero the cross hairs for 100 yards than have 5 mils of hold for anything further away seems like a pretty functional setup.

I'm partial to Badger rings.

Considering the Leupold is probably close to an ART dimension wise anyone got suggestions for height, diameter, model number of the Badger rings to use? Probably 6 screw front, 4 screw rear?

Thank you for doing what I am being too lazy to do - research.

In selecting rings, just be aware that the BPT mounts used Weaver mount specs rather than Picatinny. The Badger mounts I tried to use on one Weaver base would not fit. Some narrower Picatinny rings might work in either, but it's best to check before you buy.