View Full Version : Bolt swap?
How many of you check headspace when replacing a bolt? Do most just throw it in and run it, or check it?
Chromed 5.56 chamber or?
If the former, the only thing I know of is the field gauge specified in the armorers manual which would indicate excess headspace. The only thing adjustable in that scenario is trying new bolts.
If the latter, then it may be something that needs to be checked and have some potential for reaming the chamber to correct if the bolt won't close on a go gauge.
I just run it. I mean it's a good idea to check headspace especially if it's a higher mileage gun.
I just run it. I mean it's a good idea to check headspace especially if it's a higher mileage gun.
Yep. If it's a reputable manufacture (barrel and bolt), just run it. If it's got 20k rounds, not a bad idea to check head space.
Honestly naw. It could eff up on you but usually doesn’t if it is well made. LMT enhanced bcgs exist
Honestly naw. It could eff up on you but usually doesn’t if it is well made. LMT enhanced bcgs exist
Yes they do! I have two in weapons and two more as spares dipped in EWL and wrapped in a gallon ziplock bag.
Chromed 5.56 chamber or?
If the former, the only thing I know of is the field gauge specified in the armorers manual which would indicate excess headspace. The only thing adjustable in that scenario is trying new bolts.
If the latter, then it may be something that needs to be checked and have some potential for reaming the chamber to correct if the bolt won't close on a go gauge.
Thanks! It’s a chrome lined 5.56
Yep. If it's a reputable manufacture (barrel and bolt), just run it. If it's got 20k rounds, not a bad idea to check head space.
Well I don’t know about the upper being reputable. It’s a PSA premium upper with alleged FN barrel from 2012. MPI bolt that planned to replace with a Sionics or SOLGW.
It’s got MAYBE 3,000 rounds through it, tops. I don’t mess with it much, but looking to eliminate all the parts in from PSA. Probably shoot it ‘til it breaks, but didn’t want to throw another bolt in there if it’s not recommend
Doc Safari
03-08-19, 17:55
Supposedly people will tell you that with modern manufacturing, and the nature of how an AR is designed, makes excess headspace not too likely, but I'm the paranoid type.
( I may have to come back and edit this. I'm tired and not phrasing things too clearly).
Edited my reply to markm above with more info.
Supposedly people will tell you that with modern manufacturing, and the nature of how an AR is designed, makes excess headspace not too likely, but I'm the paranoid type.
( I may have to come back and edit this. I'm tired and not phrasing things too clearly).
My general understanding is exactly what you wrote. Like has been said, if it's got beaucoup rounds through it then yeah, a headspace check would be in order.
I've always assumed that headspace was more important to pay attention to in a platform like the M14 or M1 Garand.
Well I don’t know about the upper being reputable. It’s a PSA premium upper with alleged FN barrel from 2012. MPI bolt that planned to replace with a Sionics or SOLGW.
It’s got MAYBE 3,000 rounds through it, tops. I don’t mess with it much, but looking to eliminate all the parts in from PSA. Probably shoot it ‘til it breaks, but didn’t want to throw another bolt in there if it’s not recommend
Their premium stuff is pretty good. Worst thing I have seen/read about is gas blocks installed with no dimple. Front sight bases are taper pinned and phosphates before pinning.
I think if there was anything inherently wrong with your bolt it would have shown by now. That kind of issue tended to show up quick in 2012 era if something got cranked out substandard. Keep a spare on hand and shoot the original till you lose a lug, etc.
Well I don’t know about the upper being reputable. It’s a PSA premium upper with alleged FN barrel from 2012. MPI bolt that planned to replace with a Sionics or SOLGW.
It’s got MAYBE 3,000 rounds through it, tops. I don’t mess with it much, but looking to eliminate all the parts in from PSA. Probably shoot it ‘til it breaks, but didn’t want to throw another bolt in there if it’s not recommend
I have gauges, so I would remove the ejector and extractor and see if it closes on a field gauge.
Unless you have a specific reason for wanting to replace the bolt (not sure if you are talking bolt or BCG - I tend to just buy BCG's) I would just run it until it gives you problems, or, if you want to be on top of it, at about 5,000 rounds.
In other words if it is working, why mess with a part that is working in your rifle.
I have gauges, so I would remove the ejector and extractor and see if it closes on a field gauge.
Unless you have a specific reason for wanting to replace the bolt (not sure if you are talking bolt or BCG - I tend to just buy BCG's) I would just run it until it gives you problems, or, if you want to be on top of it, at about 5,000 rounds.
In other words if it is working, why mess with a part that is working in your rifle.
I have it in my head to replace the bolt and possibly the whole bcg since they came from PSA. It works fine now, so I could just have a new bcg on standby for when it fails. Once I have the new bolt and carrier, do I check to see if that bolt closes on a go/no go gauge?
I have gauges, so I would remove the ejector and extractor and see if it closes on a field gauge.
You HAVE TO get the gauge that's rebated so you don't have to remove bolt parts to check.
You HAVE TO get the gauge that's rebated so you don't have to remove bolt parts to check.
Is there a brand you recommend? The USGIs are a bit expensive when you can find them.
Is there a brand you recommend? The USGIs are a bit expensive when you can find them.
I don't know of any other than the USGI. With precision gauges, you're not usually getting off cheap.
I don't know of any other than the USGI. With precision gauges, you're not usually getting off cheap.
I was afraid you would say that. Is there a good source for the USGI ones? I got one from Bill Ricca at one point, but it grew legs while I was deployed.
RVTMaverick
03-09-19, 07:56
Hey OP, FWIW: IMHO.... There is Nothing wrong with "Most of" PSA's Quality nowadays. Also, it's the 1st AR to go 5,000 rounds without breaking via the guys of "AK Operators union"... https://www.youtube.com/watch?v=yvAz185Z6-I
Plus they've run other firearms from PSA through the war...
IF You've got something wrong with your PSA... They'll fix it.
You have to be pretty lazy not to do it. It takes maybe 10 minutes to KNOW what the situation is.
You have to be pretty lazy not to do it. It takes maybe 10 minutes to KNOW what the situation is.
Yea if you have the right tools. I plan to check it when I get a new bolt.
Yea if you have the right tools. I plan to check it when I get a new bolt.
I don't know if you've decided to replace your PSA bolt out of hand of not, but if you have, there's no reason to. Just run out till you either wear out the barrel, or you break the bolt. Chances are very remote that the bolt will break before the barrel wears out.
What you should replace is the extractor spring. I suspect PSA uses an M16 spring which is too weak and isn't as durable as the correct M4 spring. Replace the extractor spring with a Colt or Sprinco spring with the black insert. Do not use an O ring.
Mr McSimon
03-09-19, 11:13
I don't know if you've decided to replace your PSA bolt out of hand of not, but if you have, there's no reason to. Just run out till you either wear out the barrel, or you break the bolt. Chances are very remote that the bolt will break before the barrel wears out.
What you should replace is the extractor spring. I suspect PSA uses an M16 spring which is too weak and isn't as durable as the correct M4 spring. Replace the extractor spring with a Colt or Sprinco spring with the black insert. Do not use an O ring.
Why not use an O ring?
I tried measuring a 6920 vs. PSA extractor spring, but couldn't get the calipers on the center (ends are flattened so meaningless). Eyeball and what little I could get the calipers in, the 6920 may be a couple thousandths thickets diameter, but the PSA was longer. Both have black insert, PSA has the Viton ring.
I don't know if you've decided to replace your PSA bolt out of hand of not, but if you have, there's no reason to. Just run out till you either wear out the barrel, or you break the bolt. Chances are very remote that the bolt will break before the barrel wears out.
What you should replace is the extractor spring. I suspect PSA uses an M16 spring which is too weak and isn't as durable as the correct M4 spring. Replace the extractor spring with a Colt or Sprinco spring with the black insert. Do not use an O ring.
I appreciate the advice
I though with a CL barrel, odds are you’d need a new bolt before the barrel is shot?
This is a CL hammer forged barrel. Never been confirmed but word was when I bought it that FN made these for PSA
Why not use an O ring?
I'm not Mistwolf, but it is not needed with the stronger Colt copper-washed, Sprinco, and BCM enhanced springs. It is much harder to assemble the bolt with an enhanced spring and o-ring, at least in my expirience.
Andy
Mr McSimon
03-09-19, 14:15
I'm not Mistwolf, but it is not needed with the stronger Colt copper-washed, Sprinco, and BCM enhanced springs. It is much harder to assemble the bolt with an enhanced spring and o-ring, at least in my expirience.
Andy
I guess I was thinking about the O ring with the normal spring instead as opposed to the upgraded spring. I had a BCM BCG that gave me a few issues until I installed the O ring they ship their bolts with, and that seemed to do the trick. The Geissele URG-I near clone also ships with a "mil spec" BCG that has an O ring.
I'll admit it seems better to use the upgraded spring as opposed the O ring, but I'm curious as to any reason there'd be not to run an O ring.
I appreciate the advice
I though with a CL barrel, odds are you’d need a new bolt before the barrel is shot?
This is a CL hammer forged barrel. Never been confirmed but word was when I bought it that FN made these for PSA
Decent chance the bolt would need to be replaced before that barrel. If it is their premium bcg, it is supposed to have had all the milspec testing done. They list different atrributes for different items they sell which usually isn't something a company trying to pull a fast one is going to do. Odds are, a kaboom is the only reason you would ever have to replace the bolt carrier.
They state which barrels are FN made and the description is the same as other people selling CHF CL barrels from FN. They have openly stated that for years so not likely FN would let that go if not true.
I guess I was thinking about the O ring with the normal spring instead as opposed to the upgraded spring. I had a BCM BCG that gave me a few issues until I installed the O ring they ship their bolts with, and that seemed to do the trick. The Geissele URG-I near clone also ships with a "mil spec" BCG that has an O ring.
I'll admit it seems better to use the upgraded spring as opposed the O ring, but I'm curious as to any reason there'd be not to run an O ring.
If you are facing super cold conditions with your AR then you probably not put the O ring on. I have BCM and my BCG does not have the O ring on. Never had any issues.
I was afraid you would say that. Is there a good source for the USGI ones? I got one from Bill Ricca at one point, but it grew legs while I was deployed.
Bill Ricca was the only source for them I'm aware of and as I recall the one I bought didn't come cheap. Last I checked he was sold out of them though.
I'm curious as to any reason there'd be not to run an O ring.
If the extractor spring needs an O ring, the spring is weak and needs to be replaced.
Using an O ring with the proper extractor spring will put too much tension on the extractor. With too much tension, it becomes too difficult to snap the extractor over the case rime when chambering a new round.
I though with a CL barrel, odds are you’d need a new bolt before the barrel is shot?
Six to one, half a dozen to the other. The only way to find out is to shoot the rifle until one or the other- or both- fails.
RVTMaverick
03-13-19, 07:38
I appreciate the advice
This is a CL hammer forged barrel. Never been confirmed but word was when I bought it that FN made these for PSA
You're correct, the CHF barrels that PSA sells are made by FN..
Barrel: A proprietary blend of Hammer forged chrome molly vanadium made by FN that is referred to as "Machine Gun Steel" by virtue of its required use in FN's M249 and M240 weapons. The hammer forging process work hardens the steel, making it more durable. In addition, the chrome process for the bore allows for a lining almost twice as thick as a standard M16 for enhanced durability.
The FN barrels are solid, but PSA liked (likes) to drill redonkulously oversize gas ports in them. If that is or becomes a problem, the easiest/cheapest fix is a restrictor in the gas block/FSB.
Andy
thegreyman
03-13-19, 10:13
Honestly naw. It could eff up on you but usually doesn’t if it is well made. LMT enhanced bcgs exist
You replace BCG not just bolt - correct?
You replace BCG not just bolt - correct?
Yeah if I need to. Mostly just the bolt. Like I have not had a bolt carrier mess up on me ever. I just get the full LMT package if I need a BCG. Otherwise just the bolt.
RVTMaverick
03-13-19, 11:59
The FN barrels are solid, but PSA liked (likes) to drill redonkulously oversize gas ports in them. If that is or becomes a problem, the easiest/cheapest fix is a restrictor in the gas block/FSB.
Andy
Hey Andy,
FWIW: (I guess I've been Very Lucky?) I've got a couple of PSA's AR15 Uppers and a complete AR10 from PSA, with what I consider to be a "Perfectly Gassed" a 10.5" in 5.56, and so far whatever brand of ammo I've run through it. the spent rounds eject 3:30 to 4:30.
My AR10 with a S/S 18" barrel is amazing, and when you think about the price I paid for it, it's just flat out Incredible!
And BRT has Definitely got the hook up for any Over gassed barrels.
Peace Jeff
It's good to know about the 10.5", mine is a 16" carbine.
Also good news about the AR-10 barrel
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.