Just got back from testing out the new mid-length carbine I built on Friday night. Zeroed her in at 50 yards with XM193 and ran about 250 rounds through it to verify everything was functioning properly.
It shot about 2.5-3 MOA at 100 yards with XM193. Like an idiot I packed everything but the Camelbak
. It was getting too hot and the heat was screwing with my eyesight. After about 3 hours in the sun I was happy to keep it all in the black. It's definitely more accurate than me and next time I'll give it a better wringing out with some match ammo when my brain isn't frying in the sun.
Right now it's pretty plain and all it has are irons so I put on the M7 since I didn't want it to look so bare next to it's tactical whore sister.
Here's the component list so far.
1. LMT/Lauer lowerwith Stag/CMT lower parts kit.
2. Tango Down Battlegrip.
3. Magpul trigger guard.
4. CMT M4 upper receiver.
5. Vltor Clubfoot collapsible stock with Vltor receiver extension tube.
6. CMT bolt carrier group with Wolff XP extractor spring.
7. CMT charging handle with PRI Big Latch.
8. Troy Gen III, dual aperture BUIS.
9. LaRue 9.0 FF rail with Tango Down rail panels.
10. Sabre Defence mid-length 16",chrome lined, 1/7 barrel.
11. Old school M7 bayonet, very scary...
12. Profile Tactical CQ90 single point sling on a YHM HK style single point end plate.
I have some cool pics of the build process that I'll post later...
Okay, here's how the build went...
I got my barrel on Friday and when I got home from work I looked over it and I must say
that Sabre makes some nice barrels. The chrome lining looked great, the M4 barrel extension looked really good and the F marked FSB was a bonus!
Before I removed the FSB I wanted to stack things in my favor so I put some penetrating oil on the pins and let it sit while I ate dinner and had a few beers.
After dinner I asked my wife to be my assistant and hold the barrel while I pounded out the pins. I used Troy's method and put a small socket under the FSB on top of small plate of 1/2" steel for backing. I first removed the FS and crush washer then I used a 3 lb hammer and 1/4" punch to start things out.
After a few stern warnings from my wife about how the barrel would become part of my anatomy
if I hit her pretty little hands I was ready to begin.
Sabre uses taper pins and like all other FSB taper pins they come out towards the ejection port side. I started with the front pin and it took two wacks to get it flush with the FSB, I didn't remove it all the way yet as I wanted to get the rear pin started first. The rear pin also took two wacks to get flush with the FSB. I then used a smaller punch and hammer and it only took one tap to knock the pins all the way out.
As mentioned repeatedly by expert FSB removers like mongo you need to make sure your initial strikes are hard and focused. Hit with HATE!
With the pins removed I then put a light coating of CLP on the front section of the barrel to help slide the FSB off. To remove the FSB I just twisted it back and forth and then around a couple of times before pulling it off the barrel.
Now it was time to barrel the upper and install my LaRue 9.0.!
I went a bit WECSOG on this portion and I used two 2x4 pieces of wood as my receiver blocks and two heavy duty 6" C-clamps to hold everything down to my workbench. Note, due to the locking mechanism the LaRue FF rails do not require excessive torque when installing the barrel nut. If I needed to really torque down hard I would have used a DPMS Claw receiver block. In fact I'll probably be adding one to my tool box very soon. Another interesting note is that on my LaRue instruction sheet there's a picture in it where the receiver is clamped sideways in a vice between two pieces of wood.
I also did a couple of things to make sure the receiver would be undamamged. First I cut the bottom section of wood to fit exactly between the pin lugs, I did this to make sure the receiver was properly supported. Next I cut the top section of wood so it wouldn't go over the charging handle cutout, I did this to make sure that only the solid rail section would get the stress when I tightened down my C-clamps. Lastly I used two C-clamps to make sure that pressure was put on evenly accross the receiver.
With the receiver clamped down securely on my workbench I installed the LaRue rail as per their instructions. I put the locking collar on reveiver then slid on the FF tube retainer ring and the barrel nut. I put some Valvoline high-temp, moly fortified disk brake/wheel bearing grease on the receiver threads and then tightened the barrel nut to 35 ft/lbs ensuring that the gas tube holes were properly lined up.
Once the barrel nut was secured down I slid on the FF-tube and used my Craftsman strap wrench to tighten it down. I then verified that the top rail of the recevier was even with the top rail of of handguard before installing the two locking collar bolts. As per LaRue's instructions I put a drop of 242 Loc-tite on the two bolts before installing them.
Next I installed the gas tube into the FSB and slid the whole thing on the the barrel. I lined up the FSB pin holes and verified that the gas tube was properly in place before knocking the FSB pins back in place.
Finally I put the crush washer and FS on and my mid-length upper was finally complete!
Now for the pics...
Here's the Sabre barrel after I pulled it from the box.
Close up of the F marked FSB.
Markings on the other side of the FSB.
Sabre's barrel rollmark.
Another mark near the bottom of the barrel extention. I'm not exactly sure if this just another mark to identify it a 1/7 twist barrel or if it's for something else.
The M4 barrel extension.
FSB sight adjustment marking.
FSB and FS removed.
Gas port.
Getting ready to reinstall the FSB and gas tube.
Here it is after test firing and zeroing. It ran like a sewing machine and ate up 250 rounds of XM193 and about 6 mags of Poly Wolf 62gr. Next range session I will test out some 75 and 77 gr ammo and also some Cabelas MK262.
Cheers!