new barrel install

[jeto]

i am getting my new bushmaster HBAR 20" barrel tomorrow. i sold my 14.5" barrel. is the anything special i new to get done to it when i stall it. i know how to install a barrel but being that i am switching to a different one, do i need to get anything inspected? my buddy said to get a gunsmith to check the head spacing and something else. don't remember. i thought they were universal and all fit the same and would work with the BCG. :confused:

[jeto]

both barrels are bushmaster. i don't know if that matters.

[polymorpheous]

Will the feedramps machined into the barrel extension match the upper?
Are you using the same bolt? Did you buy a new bolt?

You will be changing gas systems. Coming from a carbine length gas system to a rifle length. You will need the appropriate gastube and you may have to play around with buffer weights. (Assuming you were running the 14.5" upper on a carbine lower.)

Also, headspace shouldn't be too much of an issue, if the parts are of known quality.

[jeto]

the barrel is coming with the gas tube. will be using the bushmaster bolt that was used with the 14.5" barrel. do you have any recommendations on the buffer. i don't even remember which one i have.

[polymorpheous]

the barrel is coming with the gas tube. will be using the bushmaster bolt that was used with the 14.5" barrel. do you have any recommendations on the buffer. i don't even remember which one i have.

How many rounds through the existing bolt?
Regardless, I would recommend a new bolt.

As for your buffer.... Run with what you got.
If it cycles too fast, go heavier. And vice-versa.
Buffers are cheap.

[jeto]

maybe around 250 rounds fired at the most.

[polymorpheous]

You are more then likely OK.
That bolt is pretty much new.

[juliomorris]

I always throw the guages in just to check any time I change a barrel, but I have only had two that didn't check out an Oly which had to be sent back for excessive head space and a kit with mil surp parts from Hess the shop i worked in part time bought a bunch thinking they could make some quik money we ended up sending back all the kits. Most GS have the go, no go guages and won't charge much just to check and it gives you a piece of mind. Just my .02.

[polymorpheous]

I always throw the guages in just to check any time I change a barrel, but I have only had two that didn't check out an Oly which had to be sent back for excessive head space and a kit with mil surp parts from Hess the shop i worked in part time bought a bunch thinking they could make some quik money we ended up sending back all the kits. Most GS have the go, no go guages and won't charge much just to check and it gives you a piece of mind. Just my .02.

While I won't deter the gentleman from checking headspace, Bushmaster is far beyond the quality of Hesse/Vulcan/Blackthorne and Olympic Arms.

[jeto]

my buddy has the gauges. exactly what do you measure.

[polymorpheous]

my buddy has the gauges. exactly what do you measure.

You will have to remove the ejector to check this.

[Tweak]

You will have to remove the ejector to check this.


depending on the gages and the skill of the operator.

[juliomorris]

depending on the gages and the skill of the operator.

Yes depending on what gauge you may have to remove the ejector then you place the go gauge in the chamber and close the bolt eensure that the bolt fully closes then try the same thing with the nogo guage and it should not chamber if it does then you have excessive head space and will probably need a new bolt. But like I said most often you will not need a new bolt. As for Bushmaster not being on the same lower than pond scum level as Oly or hess that is most correct and like I said I do it for peace of mind and will do it no matter who the manufacturer is. Because you never know who was QA that day it might have been Homer Simpson or someone having a bad day.

[C4IGrant]

i am getting my new bushmaster HBAR 20" barrel tomorrow. i sold my 14.5" barrel. is the anything special i new to get done to it when i stall it. i know how to install a barrel but being that i am switching to a different one, do i need to get anything inspected? my buddy said to get a gunsmith to check the head spacing and something else. don't remember. i thought they were universal and all fit the same and would work with the BCG. :confused:

Are you keeping the bolt you used with the 14.5" barrel for the 20" barrel? If so, you might want to get the head space checked (especially if you have a lot of rounds on the 14.5.



C4

[polymorpheous]

Are you keeping the bolt you used with the 14.5" barrel for the 20" barrel? If so, you might want to get the head space checked (especially if you have a lot of rounds on the 14.5.



C4

He's only got 250 rounds on the old bolt.

[jet80tv]

Assuming it was a quality bolt, I would expect it to be fine headspace wise. But being that he's using bushmaster components....who knows, even after just 250 rnds!;)

[polymorpheous]

Assuming it was a quality bolt, I would expect it to be fine headspace wise. But being that he's using bushmaster components....who knows, even after just 250 rnds!;)

Is Bushmaster known for headspacing issues? I've never read about any issue. Poor staking on a castle nut, sure. But headspace is a major issue that the end user can't remedy themselves.

[jet80tv]

Is Bushmaster known for headspacing issues? I've never read about any issue. Poor staking on a castle nut, sure. But headspace is a major issue that the end user can't remedy themselves.

Have no idea as to frequency of headspacing issues involving bushmaster guns and or bolts. I have used a Daniel Defense bcg with two different barrels with no issues and did not use a gauge either. Why use a gauge? Either the bolt will lock or it won't....correct? and as you stated, there is no user remedy other than getting a new bolt or barrel extension.

[Tweak]

if the parts are made to spec then headspace is rarely an issue, but how do you know the parts are made to spec unless you check?

[MistWolf]

You can use an unfired round as a rough check