[NE450N02]

What sort of accuracy are you getting at 100 yards, with what ammo???

 

[mariodesmo]

I've shimmed the barrel band, clearanced the handguard,
and ferrule, installed a SEI piston, Sadlack op rod guide, and
clocked the key to tighten up nice and tight at 6 o'clock.

With the above mods, I managed a sub MOA with 168 gr. FGMM
matchking BTHP, 308 ammo. Each shot I took the time
to cool the barrel after each shot, for 5 shots.
I did that once.

Then I shot a 1.25 MOA that same day, rapid fire, same ammo
same everything, just shot it quicker as I was getting ready to go home.

Last weekend I shot it again, and shot a 1.25-1.5 MOA again with the same
FGMM 308, ammo. Rapid fire, same conditions. With mil surp MEN NATO
I shot 2 MOA rapid fire.

Before I did the accurizing above, it would shoot 5-6 MOA at 100 yards.
The accurizing mods really much more accurate. The shimming of the barrel
band did the most good. I was disappointed with its accuracy out of the box,
but I knew it could do better. I learned about the mods here on the forums.

Here's a pic of the shots

 

[charlie98]

Before I did the accurizing above, it would shoot 5-6 MOA at 100 yards.
The accurizing mods really much more accurate. The shimming of the barrel
band did the most good. I was disappointed with its accuracy out of the box,
but I knew it could do better. I learned about the mods here on the forums.

That's what I found with my Socom16, and made basically the same mods (shimmed gas lock, Sadlak piston and spring guide.) It tightened up my groups considerably.

Many knock the Socom series, accuracy out of the box being one of the primary criticisms. I would agree to a point, but most folks would shim the gas lock on any M1a to increase gas lock lockup and improve accuracy, I don't know why they bust the Socom's chops over it.

After seeing your bolt's photos, I think I'll pull my bolt, hose it off and see what the wear patterns look like... GI1

 

[SAPPNASTY]

Mario,

Very nice accuracy. I did a few of the same mods on my Socom II and got close to the same results. However, I will not be able to test the true accuracy of my Socom II until I put a little glass on her. Sub MOA is impressive and that just goes to show all of the Socom haters that a little love can go a looooong way. Thanks again for the post and nice shootin'!

 

[charlie98]

Sub MOA is impressive and that just goes to show all of the Socom haters that a little love can go a looooong way.

I'm waiting for the Socom vs Everything Else debate to be a banned topic like cast vs forged... GI2

 

[mariodesmo]

Mario,

Very nice accuracy. I did a few of the same mods on my Socom II and got close to the same results. However, I will not be able to test the true accuracy of my Socom II until I put a little glass on her. Sub MOA is impressive and that just goes to show all of the Socom haters that a little love can go a looooong way. Thanks again for the post and nice shootin'!

Thanks,
Yea, I should say those gorups were with a scope, from a bench. I
mounted a Redfield Revolution 2-7x32 with a SAI Gen 4 Al mount, that I put
on for testing purposes. The ammo was 308 FGMM 168gr.

I have been shooting the Socom with a scope to see if I prefer it best with
or without a scope. My eyes tell me to use a scope, my ego tells me to
shoot irons, like I used to years ago... But I just can't focus on the front
sight like I used to and the scope puts me back in the game!

I'll be up in the mountains this weekend in one of our local National Forests,
way out back. I plan to do some long range shooting for fun. I'm making up
some (big) targets, and polishing up some ammo!

 

[Wayne M]

The bolt looks good from here; I wouldn't hesitate to begin putting a heavy round count on it.

 

[2336USMC]

Looks to me like your bolt has formed a great friendship with your receiver, rock on!

 

[rickyleru]

SOCOM 16 mods

Mario,
Please explain the 'details' of the mods you made to your SOCOM to a new owner. My groups are similar to what your's were initially. The gas cylinder and op rod are self explanatory, the other mods aren't quite as clear to me.
Many thanks for sharing your knowledge!
rl

 

[mariodesmo]

Mario,
Please explain the 'details' of the mods you made to your SOCOM to a new owner. My groups are similar to what your's were initially. The gas cylinder and op rod are self explanatory, the other mods aren't quite as clear to me.
Many thanks for sharing your knowledge!
rl

Here ya go...

As I mentioned, I've shimmed the barrel band, clearanced the handguard, clearance and ferrule, installed a SEI gas piston and Sadlack op rod guide, and clocked the gas lock key to tighten up nice and tight at 6 o'clock. ALL the information here is directly from members here on the forum. I searched for it a little at a time, and I copied the info into a word doc for future reference.

Here is some of what forum members Mr. Art Lupino, and Mr. RAMMAC have to say about accurizing. Some of it is a direct quote, some is edited together on the same topic, and some I've edited myself. I can't remember who exactly said what but it's all very good advice.

You can unitizie the gas cylinder (GC), which is merely screwing the barrel band to the gas cylinder assy so the barrel band doesn't rotate on the barrel, and/or you can shim your gas cylinder as well. Your goal is to get the GC lock to start to tighten up at about 5 o'clock position as you rotate it closed so that at 6 o'clock it clamps the front band tightly between the barrel shoulder and the back of the GC. AND at this point the gas cylinder ports should also be lined up correctly between the GC and the barrel. Also, make sure your barrel band opening edge does not contact the barrel when tightend. There should be a gap between the barrel band and the barrel, where the barrel passes through the band all around.

If your GC lock currently goes past the 6 o'clock position (mine went to about 9:00 o'clock) before such clamping takes place, it is because of the specific thread timing of your particular lock. One thing the shims do is push the front band and GC forward into the GC lock so it tightens up at 6 o'clock lockup and front band clamping. The timing of the threads in the GC lock tends not to be consistent in commercial locks (though it seems to be on USGI locks).

On non-socom rifles, you'll have to remove the front sight or brake to install shims, try removing the GC lock, turning it over and retightening it. Sometimes it will snug up just fine without any shims.

Of course, as RAMMAC points out, moving the GC around affects gas port alignment too; if adding shims improves that, then they're the way to go, but shims can also disrupt ideal alignment, in which case a lock with thread timing correct for your rifle would be better. The ports can be misaligned by as much as half of their diameter but that isn't the preferred setup. Also, the front band should have downward pressure applied to it by the stock ferrule when the stock is in place. That pressure is created by a proper stock fit and trigger group lockup.

The relationship of the front ferrule to the barrel band should include a gap of at least .010" or more between the stock ferrule and the barrel band along the sides, down to the 6 o'clock position at the very bottom. I had to use pliers to pull the sides of the barrel band out to create a gap between it and the stock front ferrule. I adjusted the contact so that ONLY at the 6 o'clock position is there any contact. I check it with a business card by sliding an edge of the card all the way down the barrel band, between it and the ferrule, and having it stop by contact only at the 6 o'clock position.

At that point, it should make contact on a very small area. This allows movement under recoil and allows the stock to settle back to it's natural position after each shot. The contact between the bottom of the ferrule and the barrel band lip should have about 4 to 7 pounds of downward pressure to stabilize the barrel. Contact between these two parts should only be against the lip at the 6 o'clock position. Front contact results in binding which is detrimental to accuracy. Put a touch of grease there too, to help the stock "find" its position after each shot.

Also, the handguard may need to be clearanced. If it touches the stock along the sides. where the two "meet" then you will need to sand down the edge of the handguard on each side. I sanded enough to have a gap between the top edge of the stock and the bottom edge of the handguard, of about 1/32 inch. I can slide a piece of paper along the gap, front to back, to make sure there is no contact between the two all aong the side edges between the handguard and stock. Also make sure the handguard is not "too long" and making contact on the receiver, at the rear of the handguard. You should have at least 1/32-1/16 inch clearance there as well.
Here are some video on shimming the barrel band.

[ame]http://www.youtube.com/watch?v=k5BMTGVXEHQ[/ame]

http://www.topnotchtactical.com/content-product_info/product_id-2593
/sei_m14_gas_cylinder_precision_shim_kit.html

http://www.fulton-armory.com/gascylindershimsetstainlessoneea005010and015.aspx