Gunsmithing Closing on the bolt on the Go gage......how tight?

[223Rem]

Scenario #1: Bolt closes on the Go gage with some force and does not with the No-go gage.

Scenario #2: Bolt closes on the Go gage with less force than scenario #1, but starts to close on the No-go gage.

Which do you choose?

 

[Neo]

Re: Closing on the bolt on the Go gage......how tight?

I'm no gunsmith but after watching the one I use chamber a barrel I would say it shouldn't take anymore force to close the bolt on a go gage as it does with an empty chamber.

 

[GasLight]

Re: Closing on the bolt on the Go gage......how tight?

sounds like you are headspacing with a recoil lug? I personally if I had to choose on the two above, I would take the bigger recoil lug, and hone it down with a sharpening stone until it won't close on the no-go. Then I would reload with only a shoulder bump. I would measure the lug repeatedly with a good micrometer to make sure I wasn't honing it crooked. I would also hone only on the side that goes toward the barrel. That is just me...

Dave

 

[PCR]

Re: Closing on the bolt on the Go gage......how tight?

Scenario #1 - If you can feel the Go when closing the bolt , you are at about zero headspace and need to cut .002" more. So .002" over Go is where you want to be. Hope this makes sense.

Sceario #2 - If you can feel the Go when closing the bolt, you cannot almost close on the No-Go. The bolt will start to fall, then stop dead on the No-Go.

Edited to say: This is assuming that you have stripped the bolt before using the guages.

 

[mcfred]

Re: Closing on the bolt on the Go gage......how tight?

Also, is the barrel tight when you're doing this? I like to have it a touch loose when test-fitting on the lathe because I know it will tighten up maybe 0.001" when the barrel is torqued.

 

[mcfred]

Re: Closing on the bolt on the Go gage......how tight?

Oh, so I'd choose #2 on the lathe and #1 with the barrel torqued.

 

[AZHUNTER]

Re: Closing on the bolt on the Go gage......how tight?

Scenario #1 sounds perfect to me, but im no smith, remember brass gives, the steel on a go gauge doesnt. I think you will find that with scenario#1 that your brass chambers just fine, and with minimum headspace should be accurate and easier on your brass if you reload.

 

[wnroscoe]

Re: Closing on the bolt on the Go gage......how tight?

You just want to "Feel" the go guage when you close the bolt. Some smiths chamber and set headspace anywhere from +.001" to +.003" over a go. I chamber mine from .000" (no feel) to just being able to feel the guage.

IMHO, anything over +.0005" is too much.

 

[STR]

Re: Closing on the bolt on the Go gage......how tight?

I agree with William, if you care about accuracy, which is what we are all after.

 

[GasLight]

Re: Closing on the bolt on the Go gage......how tight?

Assuming the OP is chambering the barrel, I agree 100% with William and Suarez.

wnroscoe and STR, which would you take if he is using a pre-chambered barrel like with the AAC .260 barrels? My previous answer was based on my assumption that he has 2 recoil lugs and they are giving him the results #1 and #2.

Dave

 

[Clark]

Re: Closing on the bolt on the Go gage......how tight?

Some bolt bodies kick up when closed on something tight.

If the ammo does not kick it up on chambering, it will on firing, and the bolt body will wag it's tail. I don't know if that rattling gets started before the bullet exits, but it could affect accuracy.

 

[Glen Seekins]

Re: Closing on the bolt on the Go gage......how tight?

.000" head space isn't always a good thing. Also, most factory brass is under by quite a bit so why would it matter if you went .002 over? There is zero proof that its better, just "good in theory". When you tighten the barrel down you will loose just a bit more, so chambering to 0 will equal less than zero when torqued down. If you reload you adjust your die to bump the shoulder back and that adjustment is based on the depth of your chamber. Too tight in headspace and you might run out of room to bump your shoulder back on your die. Not feeling your bolt when chambering a piece of brass is a must at a comp where running the bolt is important. Thats about .001 clearance, or at least on every gun i have i bump the shoulder back .001 to make everything butter smooth.

Just for reference, a piece of paper is .0035" thick...

 

[wnroscoe]

Re: Closing on the bolt on the Go gage......how tight?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: heatseekins</div><div class="ubbcode-body">.000" head space isn't always a good thing. </div></div>

What I described and how the gauge is "Felt" on closure is when the barrel torque is to 100 ft lbs. In the lathe after chambering and prior to barrel to receiver tourque, it's about +.001" to +.0015" over a go.

I just want to feel the gauge while not forcing the handle closed. I’ve seen rifles chambered with +.003” on headspace blank primers on the 6BR when new brass was used.

 

[Glen Seekins]

Re: Closing on the bolt on the Go gage......how tight?

whew

I assumed it was about how a gauge felt when in the lathe, chambering.

 

[wnroscoe]

Re: Closing on the bolt on the Go gage......how tight?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: heatseekins</div><div class="ubbcode-body">whew

I assumed it was about how a gauge felt when in the lathe, chambering. </div></div>

That would be an issue and too tight IMHO.

I just wanted to clear up what I meant/said so the wrong impression wasnt given.

 

[sharac]

Re: Closing on the bolt on the Go gage......how tight?

One question regarding custom made barrels (finished with chamber). Is it viable (in terms of accuracy in measurement) to have a barrel blank made for a rifle without actually having action in hand. I understand that you can measure action, threads and give this data to barrel manuf. to ream it and thread it however i'm pretty sure (maybe mistaken?) that for top accuracy one needs to have barrel and action mated and measured when chambering/finalizing build as measuring can be off and tolerances we're aiming for are extremely small.

I was talking with Lothar guys at the fair in Salzburg and they said they can easily make barrel/chamber/threads for my rifle even without me sending them my action, only i should measure (aka gunsmith with lathe and precision tools not me with my thumb) depth, threads and give them this data.

 

[tross]

Re: Closing on the bolt on the Go gage......how tight?

If you know any one that makes bullets get the lead wire that comes from when they are making cores. You can use this when checking head space by taking the bolt apart, removing the ejector pin so that there is nothing touching the head space gauge. Use a small piece of the lead wire with a small bend on on end. Put it in the firing pin hole and close the bolt on the gauge. This will flatten the lead wire and you can measure the wire to see how much head space you have.