BeeKay

Just curious about what the inside story is on bolt production. It seems like it's a part with very exact tolerances and metalluryy specs so they must come from a central source .... Just guessing. I'd be interested in finding more info on that.

So - At this stage of the game, I can say that this particular Barrel / BCG / Bolt combination, Positively has excessive headspace.. It's a .308 / 7.62x51 Barrel / BCG from the same manufacturer bought at the same time, but not as a package, as they don't offer a Barrel BCG package. Fired less than 50 times I performed the following tests and this Barrel / BCG Combo failed them all #1 ) Go / No-Go Gauge test : the bolt closes on the No-Go Gauge #2 ) Tape on the No-Go gauge - Adding .002" thickness - Bolt still closes #3 ) Light Primer Strikes #4 ) Firing a new case with primer only, reveals primer protrusion of .010" I tested my Go/No-Go Gauges in the chamber of another gun (Browning) and the test indicated results for a proper headspaced chamber. In that same chamber a neck sized case from my AR won't allow bolt closure. I have four AR-.308 Barrels - And I found one that has better headspace test results. But I haven't had a chance to take it out and fire it yet. So I'm looking forward to seeing how that goes. One of the things that I'm looking for is to be able to share neck-sized Reloaded Ammo with my .308 Browning lLever Action . That may be expecting too much,though. I won't name the manufacturer unless someone asks, I've mentioned that in previous posts and I'm hoping that the company will correct the problem, so I don't want to sour my relationship with them.... I'm thankful that I followed some of the headspacing threads and decided to follow this step, because there are issues that came to the surface which would have been a source of future problems.... Another point of interest is that, The least expensive Barrel / BCG Combos that I have, passed the headspace test - BCA. We'll see how they shoot. I would have just broke down, and bought a new Barrel / BCG from Wilson, but I have four already. Learning new things - Thanks for the helpful info

I learned some tinngs about the sequence of events when a bullet is fired in a chamber with excess headspace, by building a TC Contender in .30-30 Ackley Improved. The A.I. chamber has parellel walls so the case clutches the chamber under pressure. Ackley himself fired a round in a rifle ( in the lab ) with the lugs removed from the bolt, to demonstrate that. Excess headspace with that cartridge means stretching at the web . But if loads are fired, that don't have enough pressure to stretch the case, then the primer protrudes until the bolt face stops it. Or the breech face. But clutching the chamber walls doesn't happen with a tapered chamber, so there are different signs of excess headspace.. That may be relevant ?

I'm busy too - Otherwise I would have been done with this years ago I'll be patient - Thanks

Do tou suggest that I send JBMatt a P.M. ? I did fireform some cases and it would be interesting to hear what someone who knows their stuff has to say. Because now I have more questions. Reloading brass is interesting and especially with rifles there can be a lot of details that make successful vs mediocre reloads.

Excellent - Thank You I need to fireform some cases, because my .308 brass got mixed together between 3 different rifles, so it's hard to know for sure what I'm measuring . But out of about 100 fired cases, I didn't see any that had proud primers. I'm looking forward to following through on this. With luck I'll get things dialed in to the point where I can share reloaded ammo between 2 or 3 different rifles with acceptable accuracy and reliability

I have a home-made comparator now - It works well - I get repeatable results within .0005" , so it doesn't jiggle or go off center and create errors. When I use the comparator to measure my No-Go vs a new unfired case, the No-Go is only .001" longer - So that tells me something. I'll dig thruogh my fired brass and see what I can find. I have three .308s so it will be interesting to sort it. Thanks for helping to keep this project moving in the right direction.

Wolff AR-10 springs are on backorder so I ordered some from Tubb I'll post on how they work when they arrive It's surprizing to me that AR-15 mag springs are so abundant and AR-10 mag springs are next to non-existent.

There was a guy who posted here a few years ago, and he showed a pic of his bolt and the lugs were chewed up and his question was : Is this normal wear for a few hundred shots ? Everyone said : That's DAMAGE not WEAR - That's the situation I'm trying to avoid So - It sounds like excessive headspace by + 003" or so - Won't destroy my bolt - But will cause case stretching or fireformed cases that can't be reloaded and shared with other rifles with a SAAMI spec chamber . Do I have that right ? I didn't mention that I'll be reloading the brass Thanks for taking the time to clarify this stuff

Yes - The KAK / KAK Bolt combination does close on the No-Go Gauge . I tried creating a thread a few weeks ago, And It's a fine line between NOT PROVIDING ENOUGH information and PROVIDING TOO MUCH info, and then creating confusion . I've made guns that are chambered in Ackley Improved and Herrett wildcats, so I understand some basic things about headspacing issues. But those builds were single shot, folding action guns using the .30-30 as the parent cartrige... So it's time to expand my education At this point : I need to get a comparator and check the length of a fireformed case. The thing that I'm uncertain about at this stage is : How Much Excessive Headspace Is Tolerable ? I guess I'll find out after I fire it and measure a fireformed case Additionally - I have a couple other barrels and bolts and I've tried checking the headspacing on those, using the Clymer gauges, and the bolt would close on the GO GAUGE - and NOT close on the NO-GO GAUGE .

I inquired about this earlier but due to weather / acts of nature conditions and other situations, the thread began to get confusing. I bought some .308 Winchester headspace gauges recently and they're Clymer Go/No-Go gauges 1.630"/1.633" I have three uppers, including dedicated BCGs of various chamberings, which I may end up referring to, but I'd like to focus on my .308/7.62 KAK Barrel/BGC combination. Prior to this, I haven't measured headspacing because the word online seems to be - If the bolt and barrel are from the same source, they're probably Ok. But there are others online who say - Measure It Anyhow. So what I have is a KAK Barrel and BCG that I've measured using my new gauges and that particular chamber has loose headspacing. I emailed KAK and his only questions were "Did you buy it from us ?" and "Have you tried firing it ?" Then he just told me it's probably okay - Keep using it. I'll add - I tried chambering the Clymer Go/No-Go Gauges in a couple of other chambers and the bolt would close on the Go Gauge - But won't close on the No-Go But this KAK Barrel/BCG is apparently loose - What should I do ? I'm somewhat familiar with headspacing, but not on rifles with bolts using locking lugs... So I'm aware of the case stretch issues etc ... I'm seeing that a check for a protruding primer is a good check and using a comparator to compare a fired case to the gauge ? I'm not sure what the next step should be - I wish the tech guy at KAK would have been more helpful.

Hey, Sorry - I ended up making those posts here because I thought this was a thread that I started We had some power failures here over the past 3 weeks and it caused confusion. But there's good info here anyhow Not trying to hijack this thread

ALSO: All of the barrels I have have been fired numerous times . I've fired the .308 barrel the most . I had all 3 barrels but only one upper and BCG so I swapped the barrels just to try them out and see how it runs... No real issues, but I decided to have a dedicated upper/BCG for each barrel, so I bought some new uppers and now what I have is the set-ups shown above . The .308 barrel/BCG combo has been fired about 100 times and the two .358 barrels have been fired about 50 times each, using the same BCG as the .308. I'm not seeing any wear patterns that show possible damage. I haven't measured fireformed brass for stretch yet.

Thank You There was someone awhile back who posted pics of his bolt and the lugs were all rounded off and chewed up and burred, and the question was : Is this normal wear after 200 rounds ? The reply was "That isn't wear, it's damage" ... I don't want that to be me after a few hundred rounds . So I appreciate the help !

Okay - I have more homework ahead But I tried swapping bolt/barrel combos and here's what I got Barrel #1 ) .308/7.62 KAK - Barrel #2) .358 KAK - Barrel #3) .358 KAK Bolt A) KAK - Bolt B) Bear Creek - Bolt C) Bear Creek Barrel #1 + Bolt A - Bolt closes on No-Go Barrel #1 + Bolt B - Bolt closes on No-Go Barrel #1 + Bolt C - Bolt closes on No-Go Barrel #2 + Bolt A - Bolt Closes on No-Go Barrel #2 + Bolt B - Bolt closes on Go - Doesn't close on No-Go Barrel #2 + Bolt C - Bolt closes on Go - Doesn't close on No-Go Barrel #3 + Bolt A - Bolt closes on No-Go Barrel #3 + Bolt B - Bolt closes on Go - Doesn't close on No-Go Barrel #3 + Bolt C - Bolt closes on Go - Doesn't close on No-Go So apparently my KAK .308/7.62 Barrel and KAK Bolt are loose in headspacing - not sure how much The headspace gauges are - GO 1.630" - NO-GO 1.634" What Next ?

I located a set of Go / No-Go gauges - Clymer. They arrived today. This is interesting. I'm glad I decided to pursue this. So I have 3 uppers and one is a KAK .308 barrel with a KAK bolt - The other two are KAK .358 barrels with Bear Creek Arsenal bolts. On the KAK .308 bolt/barrel combo the No-Go gauge would close... Loose headspacing ? On the .358 KAK barrels with the BCA bolts, the bolt would close on the Go gauge but wouldn't close on the No-Go gauge - I'm guessing that's how it should be... but it seems like that's what every video I've watched tells me.... But on one of those barrel/bolt setups, it was snug on the Go gauge .... It took a tap with the plastic handle of a screwdriver ... I tried feeding a couple of new .358 cases and some handloaded live rounds and they both fed smoothly with no resistance. Any input on this would be appreciated - I may try mixing/matching to see if I can get a good proper fit on all three. Thanks for helping out

I'll update when the Wolff Spring arrives I think that I'll also order a spring from Tubb

I'll buy one and find out It would be a minor hack to make it fit, if the dimensions are close enough Sometimes gunsmithing entails removing a bit of material here or there - When I say 'Hack' that's what I mean I got used to working on my 1911s and quality parts are always tight and take some filing, for a good fit.

Very Interesting - So Wolff doesn't show any pics -. But it says their springs don't work on "new generation polymer mags" I'll probably call there and ask for more info on Monday, but I'm wondering what the difference is that makes their springs not work on plastic magazines. I have a DuraMag steel mag and when I compare the spring the HexMag spring is round on the ends and the steel mag has square ends.... See attached pic. But it seems to fit in the case and if there's anything other than the ends being a different shape it seems to function. Have you tried the Wolff spring in a HexMag ?

I sure do appreciate this forum - My AR would be a hack-job without it. Anyhow, I spent a couple hours last night looking for mag springs that will work in the HexMag SR-25 20rd. The market is flooded with AR-15 mag springs, but I don't see any AR-10. Thanks for the help !

I've ordered what I need We'll see how it goes when the stuff arrives Thanks for the help

Thank You I read cautionary posts on using a bolt that's from a different manufactured source than the barrel. Also I sometimes see pics of damage to bolt lugs, for reasons that are uncertain - Either design incompatibility, or metallurgy. So : Here i am unable to get a bolt from the maker of the barrel - and if it ends up that design incompatibility of the bolt lugs is off the table as being a likely source of problems, then that leaves headspacing as being the main issue with cross matching a bolt to a foreign barrel.... I reckon So I was hoping to find someone who has a .308 W No-Go Gauge in stock and they're unavailable. I think that Brownells had the pair in stock for around $70 - But I'd really like to spend the money on ammo than buy a Go Gauge that I will probably never use. Any help ? Happy New Year !!

I have a few uppers and some extra barrels. So I want to do some swapping around. But there's an issue with bolts not being from the same manufacturer as the barrel. So - I DO UNDERSTAND that it's best to buy a bolt to match a barrel and run those together as a pair. I have also been reading up and watching videos re. headspacing. But here's what's happening - specifically : I have a .358 Win barrel from KAK and I'd like to fit it to a side charging upper from Bear Creek. I thought I'd be able to order a bolt from KAK to fit into the side charging BCG that fits my new Bear Creek upper... Only KAK .308 pattern bolts have been on backorder for months, and there's no word on when they'll be available. What should I do ? If I try to match a bolt to that barrel, it's obvious that damage will occur if the specs of a bolt are incompatible with the barrel extension. But if i can mic a bolt and it has the specs that match would that be okay ? I do have a KAK BCG and I can use that as a reference for checking specs against. And I could also use that BCG with the upper , except it's already run with it's own upper. I'm just trying to find the simplest solution to this problem, and hopefully I've stated this question in a way that's not confusing. To break it down to one simple question : Can .308 headspacing gauges be used to measure headspacing on a .358 W, for the purpose of matching a bolt to a barrel ? I appreciate the level of expertise of the members here and problem solving help Thank You in Advance - Happy New Year !

Thanks - I got it done My greatest worry was that I'd break the drill bit - But Success I'm looking forward to seeing how it runs.

Excellent - Thank You Much - That information is very helpful