Need help with barreling a 280 RCBS

[CjC73]

Have a barrel chambered in 280 RCBS, shouldered and not a Remage set up. Can't find head space gages to check it though. Loosely screwed onto the action, the lettering engraved is just above the stock line (see picture). If torqued down, I'm sure it would line up but not going off that to tell me it is headspaced correctly. I do have some fired brass from this barrel.

Can someone either lead me to some gages or a smith for some advice. I asked a couple local smiths and they don't have gages either.

I thought I could use 280 Rem gages since I was told you could shoot factory 280 Rem from this barrel, but want to be sure.

Any advice would be appreciated. Thanks!

 

[shortgrass]

You need a "GO" gauge for the .280 Remington. In this case of the RCBS, the GO for Remington is the NO-GO for the RCBS. You should be able to insert a new .280 Remington case in the chamber and feel a slight 'crush' (resistance) when you close the stripped bolt. That's how cases for the RCBS are formed, by firing .280 Rem. in the RCBS chamber.

 

[CjC73]

You need a "GO" gauge for the .280 Remington. In this case of the RCBS, the GO for Remington is the NO-GO for the RCBS. You should be able to insert a new .280 Remington case in the chamber and feel a slight 'crush' (resistance) when you close the stripped bolt. That's how cases for the RCBS are formed, by firing .280 Rem. in the RCBS chamber.

So what would be my go gage? Piece of fired brass?

 

[SheepSeeker]

No a real headspace gauge that you can buy or rent.

 

[CjC73]

No a real headspace gauge that you can buy or rent.

Haven't found any to rent or buy. Only custom made ones.

 

[shortgrass]

So what would be my go gage? Piece of fired brass?

There is not a "go" that I know of for this. Someone will make you one at "custom cost". It takes experience, the same experience as gauging an Ackley. If you don't have the experience, find a real gunsmith that does. Thousands upon thousands of Ackley Improved chambers have been set-up this way. Only in the recent past have A.I. gauges been available, they are for the "newbies" that chamber. A.I. gauges won't work for your RCBS as they (AI) has 40* shoulder and your RCBS has a 35*. Go to https://mansonreamers.com/faqs/ for maybe a better explanation than I am prepared to give. The RCBS is gauged the same way Ackley Improved is. as they both can fire form from their 'parent' (.280 Rem.). Regardless of what the interdnet says, brass is NOT a headspace gauge.

 

[CjC73]

I called manson reamers, $140 for a set of gages and a couple months lead time.

 

[tobnpr]

Personally, I would have no problem using the fired/sized brass as a quick and dirty way to check the headspace.

More care is needed as brass will easily distort where a ground/hardened gauge will not. Completely stripped bolt so there's no resistance from spring, extractor or ejector. Bolt handle should fall with no resistance or VERY light finger pressure on fired case. Add a layer of cellophane packing tape (usually about .003- but mike it to know what you have) trimmed with a razor to fit the casehead. If bolt handle still falls with no resistance, add another layer of tape.

This will get you to something around +.006 depending on the thickness of the tape you're using. Bolt handle should not fall with reasonably "tight" headspace clearance.

 

[shortgrass]

As confused as the OP seems to be about checking head space on Improved cartridges (and that is all the 280 RCBS is, except it has a 35* shoulder instead of 40*) he should spend the $140 and wait on the gauges from Manson.

 

[CjC73]

I may have to. Was hoping someone had some I could rent.

 

[shortgrass]

It's an odd-ball. Gauges for it aren't to be found just anywhere. What will you do if the head space is short and the chamber needs to be deepened (that'd require a finish reamer) ?

 

[tobnpr]

It's an odd-ball. Gauges for it aren't to be found just anywhere. What will you do if the head space is short and the chamber needs to be deepened (that'd require a finish reamer) ?

One can "tweak" headspace in either direction via the recoil lug.
Get a thicker lug, have it ground to thickness that will get the headspace clearance desired.
Same concept for too much headspace, just take the lug on the rifle and have it ground down as needed.

 

[shortgrass]

One can "tweak" headspace in either direction via the recoil lug.
Get a thicker lug, have it ground to thickness that will get the headspace clearance desired.
Same concept for too much headspace, just take the lug on the rifle and have it ground down as needed.

That is not much more than internet hearsay. In theory that could be done, but it's only theory. I know of no one who has gone that route. It's just something that gets repeated on the interdnet. He won't take it to a knowledgeable gunsmith now to have the barrel installed properly. Just how many gunsmiths have a surface grinder in their shop? Not many! He can't figure out what he has now! How will he figure out how thick the lug should be ? He has no gauges, no depth micrometer.. If he did, he'd know which way to go. Machine shops charge by the hour. Those around here charge more than most gunsmiths, and even if the job only took a half hour, they'd charge the full hour. many won't touch anything firearms related. Ok, say you get that thinner recoil lug that brings head space into spec, but now the end of the bolt contacts the barrel. Go the other way and install a thicker lug and then you'll have more case unsupported by the chamber. How much? You don't know until you make the measurements. Bottom line, installing a shouldered barrel, or any barrel for that matter, when you don't have the understanding of "why" isn't the smartest thing to do. They ain't "drop-in"!

 

[RAGGED EDGE]

Have a barrel chambered in 280 RCBS, shouldered and not a Remage set up. Can't find head space gages to check it though. Loosely screwed onto the action, the lettering engraved is just above the stock line (see picture). If torqued down, I'm sure it would line up but not going off that to tell me it is headspaced correctly. I do have some fired brass from this barrel.

Can someone either lead me to some gages or a smith for some advice. I asked a couple local smiths and they don't have gages either.

I thought I could use 280 Rem gages since I was told you could shoot factory 280 Rem from this barrel, but want to be sure.

Any advice would be appreciated. Thanks!
View attachment 213098

I recall there were two versions of the RCBS, one (original) with a 28-degree shoulder and later one with a 30-degree shoulder. Do you know which one you have?