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+--- Thread: Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge (/showthread.php?tid=16181)
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Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - Deplorable - 05-08-2018
Hi guys, I have a Kies Custom .264 LBC upper with the stainless steel barrel. I've measured the bolt face depth at 0.125", and it does not close on a go gauge (either with the bolt in the bolt carrier, or with the bolt removed from the carrier). It also doesn't close on a no-go gauge. Maybe it could be forced closed on the go gauge but I figured that would damage the chamber or gauge.
I checked the headspace because it often fails to extract the case from the chamber--but the extractor grips the case firmly, the gas system just doesn't have enough "power" to get the case unstuck, and indeed it's very hard for me to work the charging handle to get a fired case out. Additionally, the fired brass often has a very faint groove that I can't really feel with my finger as it's not at all deep, but still attracts light. (This only with Hornady A-max or Wolf MTP brass, no steel-cased stuff). I've tried cleaning out the chamber with a brush to no avail (gauge still doesn't fit), and can't see any obvious obstructions. I have also played with the adjustable gas block although I understand that sometimes it gets clogged to the point that opening it fully still doesn't supply enough gas.
Do you guys think that I have the wrong bolt (that I should have a 0.136" bolt?)? Is it worth buying a 0.136" bolt to see if it closes on a go gauge? I couldn't see an obvious place on the upper that would say whether it's a Type I or Type II chamber, any idea where to look? (Do I have to take off the handguard and look at the bbl? I'm a bit of an AR noob and not sure if I should since it's a free-floated handguard). Or should I look for a pro who can re-ream the barrel? Any recommendations of guys who specialize in Grendel?
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - NugginFutz - 05-08-2018
Simply put, call the vendor and ask which bolt they require. That will allow you to determine your next trouble shooting step.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - VASCAR2 - 05-09-2018
I know joeboboutfitters used to sell Kies Fierarms products. JBO does not list Kies as a company they currently use. It is possible Kies is out of business. I found the info Ill post below but if you cant get into contact with Kies I suggest you contact Joe Bob Outfitters. I suspect someone at JBO can advise if Kies is still in business.
Kies Firearms
804 Laurel Street West
Stillwater, MN 55082
Phone: (612) 803-3487
Web: http://www.kiesfirearms.com
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - grayfox - 05-09-2018
A group buy bolt is only $58 shipped and it's a great, GEN-you-wine grendel bolt, 0.136 face depth.
If the mfr isn't in business and the GB bolt doesn't fit it's ready for the next barrel/build you'll be doing... lol.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - Deplorable - 05-09-2018
Thanks guys. VASCAR2, yeah, Kies is out of business now...but used to use JoeBob as their distributor.
Grayfox, so would a 0.136" bolt work in a .264LBC chamber? (As long as the headspace is checked to be good with said 0.136" bolt?) And do you think there is any chance that it would have excessive headspace, even if the 0.125" has too little headspace? It's just so strange to me that a gun manufacturer could get something as basic as the headspace wrong.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - VASCAR2 - 05-09-2018
I used the google custom search and got several threads in regards to Keis 264 LBC barrels. You might use the custom search feature and see if any threads mention which bolt was used with the Kies upper.
https://cse.google.com/cse/publicurl?cx=016368947416500061353:paqd_0xcu1o&hl=en
If you used a .136 bolt with with a barrel chambered to use a .125 bolt there could be excessive head space. If you fired one round with excessive head space the spent piece of brass would fire form to the shape of the chamber. In essense the shoulder of the brass case could be moved forward. Similar fashion as fire forming 7.62X39 brass to 6.5 Grendel.
If you try a .136 bolt with the Kies barrel you could check the barrel with go no gauges. I can’t remember which bolt Kies were chambered to use. I remember when JBO sold them but not much else.
I looked at several old post and everything I read indicated the Kies was made to use 7.62X39 bolt with .125 bolt face depth. The post indicated the Kies barrels in 264 LBC sold by JBO were not supplied with a bolt.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - bj139 - 05-09-2018
I just bought a .125 bolt in case I get an LBC. I figured I would check your situation since this question often comes up.
I replaced it in a Grendel barrel and with a Hornady Custom Grendel round the bolt will not close at all.
I slammed it home several times and still no go by a lot. Not even close.
I think you just have a slightly tight chamber if you are able to shoot it with the .125 bolt.
A new round may be several thousands smaller than your go gauge.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - Deplorable - 05-09-2018
VASCAR2 Wrote:I used the google custom search and got several threads in regards to Keis 264 LBC barrels. You might use the custom search feature and see if any threads mention which bolt was used with the Kies upper.
https://cse.google.com/cse/publicurl?cx=016368947416500061353:paqd_0xcu1o&hl=en
If you used a .136 bolt with with a barrel chambered to use a .125 bolt there could be excessive head space. If you fired one round with excessive head space the spent piece of brass would fire form to the shape of the chamber. In essense the shoulder of the brass case could be moved forward. Similar fashion as fire forming 7.62X39 brass to 6.5 Grendel.
If you try a .136 bolt with the Kies barrel you could check the barrel with go no gauges. I cant remember which bolt Kies were chambered to use. I remember when JBO sold them but not much else.
I looked at several old post and everything I read indicated the Kies was made to use 7.62X39 bolt with .125 bolt face depth. The post indicated the Kies barrels in 264 LBC sold by JBO were not supplied with a bolt.
Thanks VASCAR, all I could find was that they use a "7.62x39" bolt, does that necessarily indicate 0.125"? Were there ever any 0.136" "7.62x39" bolts for Grendel/264 LBC?
If my chamber is headspaced for 0.125" and just a bit tight or off-spec, should I get a gunsmith to re-headspace it?
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - grayfox - 05-10-2018
Deplorable Wrote:Thanks guys. VASCAR2, yeah, Kies is out of business now...but used to use JoeBob as their distributor.
Grayfox, so would a 0.136" bolt work in a .264LBC chamber? (As long as the headspace is checked to be good with said 0.136" bolt?) And do you think there is any chance that it would have excessive headspace, even if the 0.125" has too little headspace? It's just so strange to me that a gun manufacturer could get something as basic as the headspace wrong.
The bolt with 0.136 (or 0.135 dep on tolerances) bolt face depth can work fine in a 264 LBC if that LBC was headspaced for the 0.136 bolt face depth. The difference for an LBC primarily is in the throat area which is not measured by go/no-go gauges or chambering/head space. As another example, if you have a "308" set of gauges you'll notice that they work for .243, 7mm-08 and 308.
Unfortunately yes mfrs should not be making such elemental mistakes as wrong bolts ('course - disclaimer - to be fair I don't know Kies nor the facts behind your setup so may be due to some other issue), I guess that's just shows Murphy is still alive and well, and heavily employed.
Verify verify verify, it's your face behind the bcg.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - Klem - 05-10-2018
Deplorable,
You should be able to use a .136" bolt.
On the SAAMI spec chart there is a safe tolerance range between min and max Grendel chamber headspace. The chamber specs in the attached picture is the bottom half of the diagram;
1.2201" Min
1.2301" Max
The difference between min and safe max SAAMI is .01". The difference between a .125" and .136" bolt is .011". Those two differences are practically the same.
If you can only just close the bolt on that factory ammunition and you use SAAMI's .01" of safe stretch as a guide then you will be fine swapping out bolts. SAAMI's specs will be conservative so you have a little more on top of that before it gets dangerous. Loading short ammo in a long chamber is OK as long as the neck tension is good. How short before the case ruptures is the question and will vary depending on the brass and load.
https://www.google.com/search?q=6.5+grendel+saami+drawing&tbm=isch&source=iu&ictx=1&fir=k0zYmdAvou84FM%253A%252CrPuY2ZNxLmCIMM%252C_&usg=__cs2lXVK3XwSkrtIoixmGhODbpZs%3D&sa=X&ved=0ahUKEwjau-HIgvnaAhWBv7wKHU5sCRAQ9QEIKTAA#imgrc=k0zYmdAvou84FM:
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - VASCAR2 - 05-10-2018
Usually with a short chamber a gunsmith can use a finish reamer to get the chamber closer to spec. There have been numerous BCA barrels recently with short chambers. Most reamer rental companies advise against using their reamer on surface hardened barrels which are typically referred to as Melonite, Nitride, Tennifer or QPQ.
Many years ago a local PD bought some Olympic AR-15’s which had very tight chambers. The chambers were at least minimum spec or less but the barrels were accurate. A gunsmith Friend of mine got a finish reamer and after he had worked on the chambers they would shoot any factory ammunition reliably. After he used the finish reamer the barrels didn’t loose any accuracy. These particular Olympic barrels were unlined chrome moley 1:12 twist. The Olympics were purchased in the early 90’s when there were Colts, Bushmaster and Olympic. If I remember correctly DPMS was still just selling AR-15 parts.
There are companies that rent finish reamers and there have been a couple of post discussing this recently. Here is a link to a reamer rental for a SAAMI spec 6.5 Grendel Finish reamer. This company uses Pacific Tool & Gauge reamers so they might rent 264 LBC finish reamer. Just another option and will end up being about the same price as buying another bolt.
https://www.reamerrentals.com/ProductDetails.asp?ProductCode=6%2E5GB%2Ef
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - bj139 - 05-10-2018
If you change to a .136" bolt depth you may get misfires.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - Deplorable - 05-12-2018
Interesting point, bj. Maybe I should get a gunsmith to rechamber the gun then? Can anyone recommend someone who knows 6.5 Grendel?
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - bj139 - 05-13-2018
What would you think of a wooden dowel and some 600 grit sandpaper to polish your boltface until the go gauge will fit.
If it takes more than a touch, the firing pin may need a few swipes.
It sounds like you are very close since factory ammo chambers and fires fine.
Your boltface might be slightly out of spec.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - grayfox - 05-13-2018
Bj don't know about OP but it sounds a little risky to me. Would that take away the hardness layer? Don't know. If he was to do that, might be better to start with more like 1000 or even 1500, I found some at Home depot over in the paint section. How to do, stick a circle onto the end of the dowel w/ dbl-sided tape (ejector and extractor removed) and swish it by hand against the face? be sure to rinse out any grit afterwards...
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - Sticks - 05-13-2018
Lapping compound on a steel rod close as you can get to the dia of a 6.5 case head.
Best bet is to have the chamber reamed.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - 204 AR - 05-13-2018
So was the upper completely built by Kies? If so I would have to think they used the correct bolt.
I've never used a headspace gauge, but is it necessary to remove the ejector and extractor first?
And if I understand correctly, it will chamber a factory round? It's just difficult to extract when fired or is it difficult to extract unfired also?
A close examination of the chamber is what I'd recommend, and polishing it if necessary.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - bj139 - 05-13-2018
Has your barrel been nitrided? Could this add to the chamber walls?
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - VASCAR2 - 05-13-2018
Nitride does not add thickness to the steel, Nitride nitro carbonization goes into the steel a few microns. The Kies barrels were sold around 2012 before there was as many Nitride/Melonite/QPQ barrels on the market. One of the first rifles to use many Nitride parts was the MagPul Masada/ACR, just as a reference to when Nitride started being used in firearms.
Headspace Issues? 0.125" bolt on .264 LBC doesn't close on go gauge - bj139 - 05-14-2018
I had some feeding problems related to a 458 Socom bolt face.
The edge was a bit sharp and would dig into the brass case head and jam it while feeding.
I just sat in front of the TV with a thumbsize piece of 600 grit paper and the bolt and did a bit of smoothing on the face and edges.
No more feeding problems.
I should do this on every barrel extension I have. It was easy peasy.
OP, you could also get some JB bore paste and a cleaning rod chucked in a drill with a chamber size brass brush wrapped with paper towel with the paste and polish. It should make it work better overall. This is why they function better after many rounds shot. All the rough spots are worn down.