Couple of AR bolt questions

[Silverlode]

AR guru's lend me your ear.

I want to buy a couple of backup bolt assemblies just to have on hand. Rifle in question a Bushmaster, nothing fancy. I'm going under the assumption that a mil-spec bolt is a mil-spec bolt. So I am looking at what is available on Brownells and Midway and I am seeing comments like this.

...works great, checked headspacing and it was fine...

...lugs were oversized and I had to file them...

Now I am thinking, what the hell? I assumed these are just drop in parts. Do I really need to be concerned with checking headspacing when I get a new bolt (as if I know how). What else do I need to be concerned with?

And my other question is, who makes a good bolt and who is selling them for a reasonable price. Was looking at a Les Bear for about $70 vs the bottom of the line DPMS bolts I was finding for about $45. Is it worth the extra $? What about nickel boron plated high performance... Don't really want to spend $100+, but if it is truly worth it I would consider.

Thanks

 

[boatbod]

I'm sure Chad and others will chime in too, but my view is that you'd want to check headspace any you are swapping in a new bolt on a used barrel/barrel extension. You probably won't have any problems, but it's better to be safe than sorry.

 

[Ooops]

I love brownell's and midway but I wouldn't go to either for bolts. I'd roll with:

BCM(when they are not backordered), LMT, Daniel Defense, Colt (G&R tactical has them from time to time), or Spikes (HPT & MPI and easily available).

Nickel Boron is good for ease of cleaning but don't buy into that no lube crap. You are dealing with metal on metal here.

I'd get that DPMS idea out of your mind right now. No MPI and no HPT equal a no-go on bolts. Period.

 

[X-Factor]

I love brownell's and midway but I wouldn't go to either for bolts. I'd roll with:

BCM(when they are not backordered), LMT, Daniel Defense, Colt (G&R tactical has them from time to time), or Spikes (HPT & MPI and easily available).

Nickel Boron is good for ease of cleaning but don't buy into that no lube crap. You are dealing with metal on metal here.

I'd get that DPMS idea out of your mind right now. No MPI and no HPT equal a no-go on bolts. Period.

Good post and solid advice.

 

[Boom Boom]

Like boatbod, said, talk to Chad. Some Bushmasters, like the Carbon 15 Flat-top, have a non-standard BCG.

 

[clandestine]

I'm sure Chad and others will chime in too, but my view is that you'd want to check headspace any you are swapping in a new bolt on a used barrel/barrel extension. You probably won't have any problems, but it's better to be safe than sorry.

I love brownell's and midway but I wouldn't go to either for bolts. I'd roll with:

BCM(when they are not backordered), LMT, Daniel Defense, Colt (G&R tactical has them from time to time), or Spikes (HPT & MPI and easily available).

Nickel Boron is good for ease of cleaning but don't buy into that no lube crap. You are dealing with metal on metal here.

I'd get that DPMS idea out of your mind right now. No MPI and no HPT equal a no-go on bolts. Period.

Good post and solid advice.

Like boatbod, said, talk to Chad. Some Bushmasters, like the Carbon 15 Flat-top, have a non-standard BCG.

All of these guys are on the money.

If you want spares get them NOW, AR parts are drying up fast, and wont get any easier as the election approaches.

Its best to keep bolts matched to a barrel/barrel extension, so dont switch them from gun to gun because they wear a certain way.

Always check headspace, the gauges are good insurance.

 

[sailskidrive]

Rainier Arms also has a good quality house brand bolt, which is relatively inexpensive. As mysterious as their parts quality and material selection is, unless you're shooting a lot the Bushmaster bolt will probably never give you any problems.

I've given up on BCM, they never have anything in stock. Its like chasing a freaking Unicorn.

Spikes does a much better job at managing demand.

 

[rseymorejr]

All of these guys are on the money.

If you want spares get them NOW, AR parts are drying up fast, and wont get any easier as the election approaches.

Its best to keep bolts matched to a barrel/barrel extension, so dont switch them from gun to gun because they wear a certain way.

Always check headspace, the gauges are good insurance.

If you have a new AR and want a spare bolt, does it make sense to get your spare bolt and swap bolts back and forth and wear them both fairly evenly or does that even matter??

 

[drew_acid]

All of these guys are on the money.

If you want spares get them NOW, AR parts are drying up fast, and wont get any easier as the election approaches.

Its best to keep bolts matched to a barrel/barrel extension, so dont switch them from gun to gun because they wear a certain way.

Always check headspace, the gauges are good insurance.

What gauges do you recommend for an AR?

I have seen .223 and 5.56 - go, no go & field. Should all three be used?

What is the correct repair for a no go? Bolt replacement?

Same for a .300 BLK?

 

[clandestine]

If you have a new AR and want a spare bolt, does it make sense to get your spare bolt and swap bolts back and forth and wear them both fairly evenly or does that even matter??

No just fire it with the one you have in the gun. Once headspace opens the new Bolt Head will tighten things up but you do want to check headspace when making te swap and check wear patterns on the Bolt Head Lugs.

What gauges do you recommend for an AR?

I have seen .223 and 5.56 - go, no go & field. Should all three be used?

What is the correct repair for a no go? Bolt replacement?

I use all 3 for .223 and for 5.56 they have 3. I suggest to buy 3 gauges if you have a .223 AR, if you have a 5.56 AR buy those 3. If you have a 5.56 AR and a .223 AR get all 6. This is not something Im saying a owner should have if they are a Gunsmith, Im saying that even if you are NOT a Gunsmsith you should have these gauges and check you headspace regularly. I do the same on my AK's in 7.62x39 and my guns in .308/7.62 NATO. I also have them for my 7.62x54r. Headspace can open up FAST on any weapon system and without gauges an oener will never notice unless he reloads and sees severe abnormalities in the length of the brass. Primers can indicate when headspace is opening but primer issues can also be related to the barrel throat and chamber pressures as well.

$100,00 for gauges is much cheaper than the hospital bill to remove pieces of a blown up gun from your face/body or the risk of loosing your hand/eyesight or even death in a bad situation. Most often guns that blow are from bad reloads, squibs, using the wrong ammo, and bad headspace.

I dont reload so that removes one variable, I know what a squid feels and sounds like so I stop shooting when it happens, I always load my own mags so theres no chance of using the improper ammo, and I always check headspace when doing maintenance.



Colt has an additional called a Field II Gauge. There is some crossover with specs between the 5.56 and .223 but I dont take shortcuts.

Heres the listing for specs of gauges if you are interested: http://ar15barrels.com/data/headspace.pdf

You can safely fire a NO-GO AR15, its unlikely it will blow, but its approaching
the need for replacement. A Field is what you dont want to fire your gun if it eats the gauge.

You are correct a New Bolt Head "should" correct a NO-GO AR Variant.

If it eats a Field its time to look at the Bolt Head, Barrel Extension and possibly the chamber. FIxing a Field GAuge failing AR BArrel is more costly than its worth. I usually just suggest barrel replacement which has a new extension installed. While I can fix a Field Fail setup the labor involved is not "cost effective"

Same for a .300 BLK?

A seperate gauge is listed for .300BLK, and thats what I use. I have not looked at the specific #'s on a .300 chambering to determine if theres a difference since I havent reamed or roughed in any .300 Chambers. All the .300 barrels I have dealth with are pre chambered and Im just fitting or checking a bolt for headspace.

 

[Silverlode]

I appreciate the help. Probably going with the Rainier Thunderbolt, although I am going to think on it for a bit longer. I'm still considering spending more and getting something that will last forever (at least with how much I will use it).

Any opinions on the J P Enterprised Enhanced bolt? Any other higher end bolts that well worth the price of admission?

And, one last question...

Is there any advantage to buying the entire BCG as one package and keeping those parts together? I can't imagine wearing out a carrier, but in reality I have no idea how long they typically last for normal semi-auto use.

Thank you again all.

Clandestine - One of these days I want to talk to you about some 1911 work and two AR builds, one 5.56 and one 9mm. I wish I lived close by to Scotts I would be in there all the time.

 

[Terpnut]

I'm going through the same issue, keep us posted. I have a M&P 15

 

[clandestine]

I appreciate the help. Probably going with the Rainier Thunderbolt, although I am going to think on it for a bit longer. I'm still considering spending more and getting something that will last forever (at least with how much I will use it).

Any opinions on the J P Enterprised Enhanced bolt? Any other higher end bolts that well worth the price of admission?

And, one last question...

Is there any advantage to buying the entire BCG as one package and keeping those parts together? I can't imagine wearing out a carrier, but in reality I have no idea how long they typically last for normal semi-auto use.

Thank you again all.

Clandestine - One of these days I want to talk to you about some 1911 work and two AR builds, one 5.56 and one 9mm. I wish I lived close by to Scotts I would be in there all the time.

Ill be available whenever you need me my friend.

 

[Silverlode]

Ill be available whenever you need me my friend.

And know that I appreciate it.

Now I am in the process of ordering headspace gauges, and I'm have a real hard time understanding why I need all three. My issue being the field and go gauges....Why do I need both?

If my bolt closes on the go gauge, I am good. If the bolt doesn't close on the no-go gauge, I am good. But the field gauge is the max acceptable headspace, so in theory, the bolt should close on it yes? So why bother with a go gauge. And, I read if the bolt does close on a field gauge, have a gunsmith check it out for other potential problems. It is supposed to close on it right???

So why not just use a field, in which case it should barely close, and a no-go?

Forgive my apparant density on this issue, but there is something I am failing to comprehend.

 

[clandestine]

And know that I appreciate it.

Now I am in the process of ordering headspace gauges, and I'm have a real hard time understanding why I need all three. My issue being the field and go gauges....Why do I need both?

If my bolt closes on the go gauge, I am good. If the bolt doesn't close on the no-go gauge, I am good. But the field gauge is the max acceptable headspace, so in theory, the bolt should close on it yes? So why bother with a go gauge. And, I read if the bolt does close on a field gauge, have a gunsmith check it out for other potential problems. It is supposed to close on it right???

So why not just use a field, in which case it should barely close, and a no-go?

Forgive my apparant density on this issue, but there is something I am failing to comprehend.

The Go just tells you the gun will chamber and allow the locking lugs to fully close/engage. If the gun closes on a live round you "should" be good. Go gauges are best used when you are chambering a new barrel. So technically you dont need one if you have a gun that fires. Bad thing is if your gun is slightly short chambered you may end up getting a gun that fires without the bolt fully closed, this is BAD. WHile the gun may close fully when clean fouling can cause a gun to fail to go into full battery when its dirty. The go gauge tells you wether tou have the proper safe minimum clearances wether the gun is clean or fouled. A gun that dosent lockup is just as dangerous, and possibly MORE dangerous than a gun that has bad headspace.

The No-Go is one that I can live without, you can fire a gun with a No-Go, heck Remington 700P .308's close on a No-Go out of the box and shoot great but they are a bolt action. The good thing about the No-Go is if the gun never closed on the No-Go in the past and then starts it means you are physically seeing wear occur and can keep a closer eye on things.

The Field means the gun is UNSAFE to fire if the bolt closes on it. WHile most guns can handle bad headspace and not blow catastrophically its best NOT to test the mechanical limits of a gun by pushing it outside safety parameters.


For me, if I could only have 2 it would be a Go and Field. But this is like having a fuel gauge that shows Full and Empty. These 2 gauges are what I suggest you have to be sure the gun can close safely and also dosent have unsafe headspace.

 

[Silverlode]

Ah, now it all makes sense. Thank you again for your time and willingness to share your expertise. It is appreciated.

 

[Silverlode]

If you have a 5.56 AR and a .223 AR get all 6.

One last little bit of confusion and I want to make sure I understand correctly before buying.

Quote above meaning if you have two ARs, one of each(5.56 and 223) buy all six? Or if you have one AR that is stamped 5.56NATO/223REM, then I should be buying all six gauges?

 

[clandestine]

One last little bit of confusion and I want to make sure I understand correctly before buying.

Quote above meaning if you have two ARs, one of each(5.56 and 223) buy all six? Or if you have one AR that is stamped 5.56NATO/223REM, then I should be buying all six gauges?

The gun should be oneor the other, some manufacturers list it as both when its a 5.56 because you can fire both .223 and 5.56 out of a 5.56 gun. Without seeing it I would say it 5.56 so get one set if you only have tht one AR, get all 3 if you can afford, if not and can only afford 2, get a go and field.

In a .223 you shouldnt fire 5.56 because the 5.56 has different dimensions.

 

[RW2111]

Wouldnt hurt getting a Fire pin Protrusion gauge also