Re: AR Building, Accurizing, Tips & Tricks
Quote:
Originally Posted by
RXM
There are a few things that you can do to increase accuracy out of your gun (removing the shooter as a variability).
1. Quality barrel
2. Upper receiver that has a tight fit to the barrel extension. The barrel extension should not easily slip in and out of the receiver.
3. Bolt
4. Free float rail
To get precision out of the gun, the shooter has to become consistent and a good trigger will help you do that.
Good tip if you want to check your rifle's accuracy. If you're doing a 5-round group (as you should be doing), put a cheap 6th round in there and pop it off into the berm before you do your grouping. Part of precision is consistency and this allows the BCG to cycle the same from 1st to 5th round. This was taught to me by a guy that knows a thing or two about murdering things from far away.
One piece I've wondered about since I got the AR bug is the bolt. I ask this out of genuine curiosity & not to start an argument.
I understand how you can increase the precision of your rifle by using a better barrel, free float tubes & better trigger etc. I know a better fit & options on the upper / lower / stock can make life easier through better controls (or by just making it prettier). But I do wonder, how does a more expensive bolt actually affect the chambered round to increase accuracy? I get that it should be machined well & close tightly. Does a more expensive bolt close tighter or more straight somehow? I thought some of the coatings were essentially to make them easier to clean & need less lubrication.
Re: AR Building, Accurizing, Tips & Tricks
Quote:
Originally Posted by
theunrulychef
One piece I've wondered about since I got the AR bug is the bolt. I ask this out of genuine curiosity & not to start an argument.
I understand how you can increase the precision of your rifle by using a better barrel, free float tubes & better trigger etc. I know a better fit & options on the upper / lower / stock can make life easier through better controls (or by just making it prettier). But I do wonder, how does a more expensive bolt actually affect the chambered round to increase accuracy? I get that it should be machined well & close tightly. Does a more expensive bolt close tighter or more straight somehow? I thought some of the coatings were essentially to make them easier to clean & need less lubrication.
I have a nib coated bolt that I run wet and lubricate prior to each range session. After only about 150 rounds the coating has already started to wear where it contacts the upper receiver. I will post pics later of it, but a good quality phosphate MPI bolt is better than most new age treatments.
Re: AR Building, Accurizing, Tips & Tricks
Headspacing and bolt lockup. If you want to go the extra mile you can also check the bolt carrier to make sure it moves freely in the upper and doesn't meet resistance at any point during the cycling (minimal friction). The whole name of the game is consistency.
Most folks will be just fine with a bolt that is held to tight tolerances. Tolerance stacking is no bueno when it comes to trying to get consistency out of a gun.
Re: AR Building, Accurizing, Tips & Tricks
You really don't need MPI unless your material is in question. Any manufacturer that's worth it's weight have material that's been tested before it leaves the mill. With the vacuum arc remelt process, it's real hard to get crap material. Not everyone used VAR metal. That doesn't mean the metal is crap, but if it's not VAR, you may want the MPI to make sure.
As far as the bolt being machined better, yes it does matter, but there is no easy way to get it to fit more flush like you would on the bolt of a Remington 700 by lapping the lugs. The best way would be to see how much run-out the lugs have compared to the others lugs. Over time, they will peen and conform a little better. Almost like lapping. You can alleviate a lot of this by buying a good bolt.
Now the tricky part...how do you know who makes a good bolt vs someone who makes an expensive bolts? For the most part, you don't, but there is a quick way to check. Each company has specific verbiage to set them apart from the next guy. I have looked at and measured quite a few of my bolts (Rainer, LMT, BCM, Core15, FN and the ones I currently run). I can say the bolts that I run now are within a tighter spec and they are of higher quality material, as well as process. You can identify them by the relief cuts from behind the lugs. Don't believe me? Compare them to anyone else's bolts out there, even the fancy 'enhanced' ones.
I tend to think there are very very few people that will be able to tap into any potential results by matching a bolt. I could be wrong, though. You'd have to be an excellent shot and have everything else on your rifle in check and even then, I'm not so sure it would matter. Heck, I've shot bolts that fail on the No-Go gauge with great luck and no worries (we're talking about a .003-.004" difference from go to no-go). A field gauge is way more lenient.
I'll also be posting some AR10 stuff up on here.
Re: AR Building, Accurizing, Tips & Tricks
Quote:
Originally Posted by
animalmother85
You really don't need MPI unless your material is in question. Any manufacturer that's worth it's weight have material that's been tested before it leaves the mill. With the vacuum arc remelt process, it's real hard to get crap material. Not everyone used VAR metal. That doesn't mean the metal is crap, but if it's not VAR, you may want the MPI to make sure.
As far as the bolt being machined better, yes it does matter, but there is no easy way to get it to fit more flush like you would on the bolt of a Remington 700 by lapping the lugs. The best way would be to see how much run-out the lugs have compared to the others lugs. Over time, they will peen and conform a little better. Almost like lapping. You can alleviate a lot of this by buying a good bolt.
Now the tricky part...how do you know who makes a good bolt vs someone who makes an expensive bolts? For the most part, you don't, but there is a quick way to check. Each company has specific verbiage to set them apart from the next guy. I have looked at and measured quite a few of my bolts (Rainer, LMT, BCM, Core15, FN and the ones I currently run). I can say the bolts that I run now are within a tighter spec and they are of higher quality material, as well as process. You can identify them by the relief cuts from behind the lugs. Don't believe me? Compare them to anyone else's bolts out there, even the fancy 'enhanced' ones.
I tend to think there are very very few people that will be able to tap into any potential results by matching a bolt. I could be wrong, though. You'd have to be an excellent shot and have everything else on your rifle in check and even then, I'm not so sure it would matter. Heck, I've shot bolts that fail on the No-Go gauge with great luck and no worries (we're talking about a .003-.004" difference from go to no-go). A field gauge is way more lenient.
I'll also be posting some AR10 stuff up on here.
Thanks for that info. My gut feeling was that the bolt on an AR would be pretty low on my list for accurizing, as long as it's of decent material & in spec. Of course, that's one of the many fun benefits of handloading; the headspace can be adjusted to fit your bolt / chamber combo more precisely.
Re: AR Building, Accurizing, Tips & Tricks
Quote:
Originally Posted by
theunrulychef
Thanks for that info. My gut feeling was that the bolt on an AR would be pretty low on my list for accurizing, as long as it's of decent material & in spec. Of course, that's one of the many fun benefits of handloading; the headspace can be adjusted to fit your bolt / chamber combo more precisely.
No problem. I have a little more insight than some on these things being an industry insider so I do my best to share what knowledge I can. There are lots of options out there and it's easy to get confused. Marketing is king for moving product. If your marketing blows, you don't sell as well, even if you do have the best product.
Once I started looking at a lot of these different parts through tool scopes, I had no idea just how shoddy the work from a lot of these premium manufacturers really ways. Their marketing killed it though, so they sold tons of product. As far as their products whent, a lot of the slop I did see were in places where it didn't matter, or after the part was worn it, it didn't matter. Some parts it did matter.
Yeah, if you fire form then neck size, but then you start having interchangeability issues of said ammo with other rifles. I do love hand loading for bolt guns, though. Chasing loads can be fun, when you don't spend a century doing it. It can go from love to loathe in about two weekends of pursuit.
Re: AR Building, Accurizing, Tips & Tricks
Here is something I did today;
Every time I'd open the safe, my SAM-R would blind me with it's shinyness. I got tired of the luster and made it comform more with what I like by bead blasting it.
Before
http://i166.photobucket.com/albums/u...psmzhr3hd6.jpg
After
http://i166.photobucket.com/albums/u...ps0peyqknh.jpg
Now it goes back together and gets a suppressor.
Re: AR Building, Accurizing, Tips & Tricks
Here is the bit I use to dimpled for gas blocks. I'd rather cut then press;
http://i166.photobucket.com/albums/u...pstzmwq0gz.jpg
What it looks like when done;
http://i166.photobucket.com/albums/u...psqpecng4c.jpg
Re: AR Building, Accurizing, Tips & Tricks
Following up on that...
I've read that clamp on gas block are better than the set screw type. The reason being, the clamp on type seal completely around the barrel where a set screw type actually pulls away from the barrel on the bottom meaning there is more chance of gas bleed.
Re: AR Building, Accurizing, Tips & Tricks
Quote:
Originally Posted by
unclejumbo
Following up on that...
I've read that clamp on gas block are better than the set screw type. The reason being, the clamp on type seal completely around the barrel where a set screw type actually pulls away from the barrel on the bottom meaning there is more chance of gas bleed.
Also there is talk about a chance of actually causing a shape change in the barrel from the set screws. That is only from what some ARFCOMers have said and then proceeded to shove pinning and Adco down everyone's throat (no offense against Adco). I love clamp blocks for ease of installation and strength, but a majority will not fit under the thinner rails.
The Mk12 uses a set screw gas block. That's gotta be worth something. I have only had self induced issues with the set screw block (which is why I always test fire before listing something). Other than that, I find the set screw blocks just dandy.
I was "stupid" when I bought tools to start putting them together. I bought the BRDE jigs for pinning a low profile block (good for only Vltor blocks unless you mill it out) and the FSB pinning jig. Neither has been used yet. Maybe some day.