Setting Headspace

[Joshm28]

OK guys. I just set the headspace on my 6.5-284 build. I resized (full length) two pieces of brass. I put a piece of tape on the first piece that measured .0020 in thickness. Put it in the chamber, closed the bolt and screwed the barrel down till it was touching. I tightened the barrel nut and then took the second piece of brass, which i put a piece of tape that measured .0040 in thickness in the chamber and tried to close the bolt. The bolt will only close about 10% in rotation. I then took a loaded shell (Nosler) and took the gun outside and the nosler ammo loads without issue. Should I still rent a no go gauge to ensure the headspace is correct or call it good?

Thanks

[Patch700]

Probably get differing opinions on this and here is mine... I don't classify tape as something to be used as an instrument.

People say "This tape measures .020" " or whatever the case may be , problem with that is tape compresses so are you getting true measurements using tape? Not to mention just because you F/L resized that brass do you know what the shoulder was pushed back too?

If you have a Go gauge you should have a No go... Made of steel... In my opinion.

Good luck

[fgw_in_fla]

That's great question to start a heated debate with. The last one was 8 pages long I think...

I think I'll sit on the sidelines since I'm a scotch tape head spacer....

By the way, the off brand scotch tape is a wee bit thinner compared to the name brand stuff. Govern yourself accordingly.

[drybean]

Hummmmmm, SAAMI spec tape

[BillPa]

I think I'll sit on the sidelines since I'm a scotch tape head spacer....

I'll join ya. Got any beer?

Bill

[drybean]

I Have plenty, plus I just stuck a hog in the ground,
should be done in about 18 hrs

drybean

[Poor Shot]

Well, watching this should give me something to do until the pig is done.

[fgw_in_fla]

I Have plenty, plus I just stuck a hog in the ground,
should be done in about 18 hrs

drybean

Did you remember to light the fire this time?
And stop making fun of my SAAMI scotch tape. It's worked fine all these years.
Usually.

[Patch700]

Lol , yes these topics do tend to be entertaining... Quick question , what instrument does one use to both measure the thickness of this tape and then deduce what the headspace value is??

I've had "A couple" barrels replaced over the years and not for nothing but if the machinist\gunsmith told me he setup my headspace to scotch clear tape specs...... lol

[fgw_in_fla]

You mean you're supposed to measure it???

[drybean]

Did you remember to light the fire this time?
And stop making fun of my SAAMI scotch tape. It's worked fine all these years.
Usually.

sure did, please do forget your bib

[fgw_in_fla]

Don't need a bib.
I got sleeves.

[BillPa]

Quick question , what instrument does one use to both measure the thickness of this tape

I use a digital C clamp.

[Patch700]

I use a digital C clamp.

.....lol..... And then you re-mike the tape (or should I say re-digital C clamp) after it's been used just to back up your measurements?.... Seems legit. In all honesty I thought someone would've said they used their digital sliding salad tongs and measured from base of taped case to shoulder.

[joeb33050]

OK guys. I just set the headspace on my 6.5-284 build. I resized (full length) two pieces of brass. I put a piece of tape on the first piece that measured .0020 in thickness. Put it in the chamber, closed the bolt and screwed the barrel down till it was touching. I tightened the barrel nut and then took the second piece of brass, which i put a piece of tape that measured .0040 in thickness in the chamber and tried to close the bolt. The bolt will only close about 10% in rotation. I then took a loaded shell (Nosler) and took the gun outside and the nosler ammo loads without issue. Should I still rent a no go gauge to ensure the headspace is correct or call it good?

Thanks

I use the tape method, and use 3 or 4 pairs of fired fl sized cases, no-tape and tape. To answer your question: I would try 5 or 6 of the Nosler cartridges. If they chamber without problem, I'd put 1 layer of tape on the case head and try them. Then 2 layers. If there's resistance to chambering with 1 layer-OK. If there's resistance to chambering with 2 layers, OK. If there's no resistance with 2 layers, I would start over. BTW, I take the ejector and the firing pin assy out of the bolt before any of this. That's my opinion.

[joeb33050]

Probably get differing opinions on this and here is mine... I don't classify tape as something to be used as an instrument.

People say "This tape measures .020" " or whatever the case may be , problem with that is tape compresses so are you getting true measurements using tape? Not to mention just because you F/L resized that brass do you know what the shoulder was pushed back too?

If you have a Go gauge you should have a No go... Made of steel... In my opinion.

Good luck

Do you classify shim stock as an instrument?

[snowgetter1]

Tape all the way!

[earl39]

I use the tape method, and use 3 or 4 pairs of fired fl sized cases, no-tape and tape. To answer your question: I would try 5 or 6 of the Nosler cartridges. If they chamber without problem, I'd put 1 layer of tape on the case head and try them. Then 2 layers. If there's resistance to chambering with 1 layer-OK. If there's resistance to chambering with 2 layers, OK. If there's no resistance with 2 layers, I would start over. BTW, I take the ejector and the firing pin assy out of the bolt before any of this. That's my opinion.

The thing to remember no matter what you use to set your headspace is to never use factory ammo or new unfired brass BECAUSE it tends to be on the small side and COULD cause problems with your reloads if your dies will not resize the brass that small. Use a gauge or once fired brass sized in your dies and enjoy the little things in life.


Is the pig done yet?

[BillPa]

.....lol..... And then you re-mike the tape (or should I say re-digital C clamp) after it's been used just to back up your measurements?

This is my 280 GO....BTW,that's not the roll of tape I use. BTW, the bushing on the butt end of the gauge is bored exactly .100" deep so add .100" to the measurement. I use them for repeatable alignment in the the caliper.


The same gauge shimmed with Scotch Transparent tape which measures .0022"-.0024" as measured with my digital C clamp.


A GO gauge is used to check/set a chamber "Equal To or Greater Than" it's length. A NO GO, "Less Than" it's length. If the action cannot be locked to battery on the NO GO, in the case of the 280, the chamber length must be something less than 2.104", 2.103" or less.

By shimming the GO .002" that tolerance is reduced .002" so the chamber would be between 2.100" and something less than 2.102", 2.101 or less!

Close enough for government work!


Bill