06-15-2011, 10:29 AM
pinzgauer Wrote:at the risk of sounding like a smartass, if you have to ask you are not ready.
Minimum prerequisites:
- Proper clamps/blocks for holding the upper. There are a couple of good ones... I use a DPMS claw based on local smith input, but the Brownell's one LR1995 suggested a while back would be my new pick. (But the claw works find)
- Good Armorer's wrench (for barrel nut and flash hider). Again, DPMS actually makes decent one. There may be better available, but of all the ones I've handled / used I like theirs. Shame the rifles are not as nice!
- Torque wrench (and knowledge to use it, how to hold, etc) Make sure it fit's your armorer's wrench!
- Good understanding of how the uppers go together. Barrel nut to receiver relationship, gas tube, etc. Lot's of good how-to's with photo's out there. Look at your own rifle
- one of 3-4 different anti-seize or grease choices. Entire villages have been destroyed in the flame wars on which anti-seize to use. Just pick one of the known good choices.
- angle gauge or some other method to index the flashhider properly. You can eyeball it, but getting it right is not hard or expensive.
For Grendel's normally the bolt comes with the barrel and will be properly headspaced. Some will tell you to check headspace regardless, but that's not set by you, it's the mfg when they install the extension on the barrel. So buy as a pair from a quality mfg and it will be set properly.
Some will tell you that it's OK to homebuild for plinkers, but to get an accurate rifle you have to have it build with secret sauce. That has not been my experience.... the AR design itself does not allow for much fitting. IE: Barrel & component quality has a much larger impact.
And the few items in the upper you can fit can be done yourself with inexpensive tools if you decide it's important. (Like making sure the upper receiver to barrel interface is square)
Unless you are buying a premium barrel, optics, upper receiver, etc, the secret sauce fitting stuff won't make as big of a difference as the barrel upgrade will. And a trigger upgrade follows the barrel in priority.
Again, you'll know when it's time. If you have not already, start with assembling a lower or full kit. It's actually a bit more involved in terms of steps, but none of them are quite as "major" as installing the barrel is.
Back to your "factor"- I'd say 6 or 7 max assuming top notch components & proper tools. It actually takes less time than assembling a lower, just less fiddly stuff. I found that top tier components are not really any more expensive. And I'd avoid Delton, generic, DPMS, etc. Colt, Daniel Defense, etc are readily available. Though I don't like their rifles as much, Rock River loose parts were quite good and easy to get.
Torquing the barrel sounds very hard, but the way the AR works you are just torquing to a minimum value (quite low, actually), then tightening till the next gas tube index lines up cleanly. Bit of a PITA to hold the armorer's wrench in against the delta ring spring, but not hard. Overtorquing decreases accuracy most have found.
Flash hider is not hard, just make sure your compression washer is facing the right direction. (Peel washers are more of a pain). Hard to screw up, and cheap to fix if you do. Just order extra compression washers of good quality! Also, make sure your armorer wrench fit's your flashhider flats. The proper way to install is to use two hands and avoid torquing the barrel like would occur if you just used a wrench. Like using a two handed lug nut wrench.
This all assumes a non-pinned gas block/front sight base. If you want to use the traditional FSB you'll need another jig to do it right. (Though some drill them without the jig/block) Some barrel mfg's will provide a drilled barrel & loose pinned FSB for you.
Only one point of contention with this post. Aside from extra long wait times for product shipping, I have yet to hear anything bad about Delton, and the rifle kit I purchased from them (though with a pre-assembled upper) is seriously pretty and is shooting near MOA through a cheap Bushnell red dot. Somewhere down the road that thing is going to be wearing a 6.5 barrel and I won't worry a bit about it.
As for assembling an upper, except for the angst of the torquing and the need for the block, I'd call it a 4, as the only really fiddly bit is the gas block alignment and pinning.