Headspace question?

[mao0720]

Hey guys, I’ve got a headspace question for you all, more just making sure I’m thinking correctly. I picked up a used 243 barrel for a Remington 700. I am planning on putting it on one of my actions for hunting. I know the Remington standard thickness recoil lug is 0.187, bu that recoil life and headspace or Remington actions can carry quite a bit. I’m not concerned if headspace turns out short. But, if it’s long by a few thousandths, can I just fire-form brass to the chamber then bump shoulder .002 off of the actual chamber length and be safe? Isn’t this essentially the same thing as a wildcat like 6 dasher (minus the shoulder angle change), where the headspace of the wildcat is longer than the parent case and the shoulder is blown forward in fire-forming? Thanks for the help!
Mason

 

[madmixerman]

I have a 30br that has a little long headspace. I just bump it .002 and never had any problems.

 

[AJC]

How you accomplish that stretch may matter. Using a false shoulder or seating into the lands make save you some case life.

 

[linebaugh]

If the definition of a few thousandths is less than .010. If it's more you might want to question why its off so much as that is a fair amount but it still will not kill you if done properly. I would make a false shoulder at the neck and run it. The key will be keeping the case head on the bolt face. I'm sure the safety police will post that this is gonna blow up and all sorts of bad things like global warming will happen. In reality, just as you said, you will be blowing the shoulder forward as in any wildcat cartridge.

 

[mao0720]

I don’t have the barrel yet, but I would highly doubt that it would be off by more than 0.010. If that’s the case, I’ll get a different recoil lug to adjust.

 

[jepp2]

But, if it’s long by a few thousandths, can I just fire-form brass to the chamber then bump shoulder .002 off of the actual chamber length and be safe?

If you measure new factory brass vs your headspace, you will find the new brass is normally shorter. Sometimes much shorter. I encountered some loaded Fiocchi 204 Ruger brass that was over 0.010" shorter than my fired brass. After firing, the primers were extended out of the case head (brass datum to case head still considerably shorter) and none of the brass exhibited any signs of the excessive stretching (visible or picked up on the bent paperclip check).

That said, always good to check before firing. If you don't have a headspace gauge for your new .243 barrel you can use .243 brass cases. Sounds like you have a way to measure datum to case head. You can add either brass shims or tape to the case head to increase the case length until you find bolt contact. So you know what you are dealing with before firing anything.

 

[6MMsteve]

only thing is when you try to gain case length the dies will not match and you will have some extraction issues...ask me how I know this...I tried it and it didn't work..but I went way overboard but I was fireforming with cornmeal and cotton balls..it was a savage so after the fact I just head spaced normal.... but just a few thou maybe .004 would be ok that's about it...the experts may chime in... I'm sure someone has done similar

 

[6MMsteve]

the barrels and actions at remmington have a nominal so they should be within tolerence..if your on the low end it's good.... high end iffy

 

[Twicepop]

I read a while back that all unmodified Remington 700 rifles will accept the barrel from any other Remington 700 rifle, and the head space will be within SAAMI tolerances.

 

[carlsbad]

I read a while back that all unmodified Remington 700 rifles will accept the barrel from any other Remington 700 rifle, and the head space will be within SAAMI tolerances.

Did you read that on the internet? If so, it must be true.

Sarcasm off.

That is absolutely not true.

 

[mao0720]

Did you read that on the internet? If so, it must be true.

Sarcasm off.

That is absolutely not true.

It would be nice though. Every Remington would be switch barrel ready.

 

[carlsbad]

Hey guys, I’ve got a headspace question for you all, more just making sure I’m thinking correctly. I picked up a used 243 barrel for a Remington 700. I am planning on putting it on one of my actions for hunting. I know the Remington standard thickness recoil lug is 0.187, bu that recoil life and headspace or Remington actions can carry quite a bit. I’m not concerned if headspace turns out short. But, if it’s long by a few thousandths, can I just fire-form brass to the chamber then bump shoulder .002 off of the actual chamber length and be safe? Isn’t this essentially the same thing as a wildcat like 6 dasher (minus the shoulder angle change), where the headspace of the wildcat is longer than the parent case and the shoulder is blown forward in fire-forming? Thanks for the help!
Mason

If it is long then your bolt nose will be short into your tenon by that much, your lug clearance to the tenon will be loose, and most importantly, the distance from the boltface to the back of the chamber will be long which will mean you have MORE UNSUPPORTED CASE than your should. I like to shorten the bolt nose a few thousandths when I install a sako or M-16 extractor to give you MORE support around the case. You're proposing the opposite.

I have declined to bush a bolt that has face damage more than .010" deep because that results in too much unsupported case.

--Jerry

 

[carlsbad]

It would be nice though. Every Remington would be switch barrel ready.

This is part of what you get for the extra $700 to $1200 you pay for when you buy a "custom" action. Most customs have the same headspace with others of the same brand and model although they can change with "generations".

 

[mao0720]

If it is long then your bolt nose will be short into your tenon by that much, your lug clearance to the tenon will be loose, and most importantly, the distance from the boltface to the back of the chamber will be long which will mean you have MORE UNSUPPORTED CASE than your should. I like to shorten the bolt nose a few thousandths when I install a sako or M-16 extractor to give you MORE support around the case. You're proposing the opposite.

I have declined to bush a bolt that has face damage more than .010" deep because that results in too much unsupported case.

--Jerry

Good point. I hadn’t thought of that part.

This is part of what you get for the extra $700 to $1200 you pay for when you buy a "custom" action. Most customs have the same headspace with others of the same brand and model although they can change with "generations".

I know: I’ve got a bighorn tl3 and a nesika. The bighorn is the best action I’ve ever used and I love that I can just order a shouldered barrel cut for it. No need to send in my action.

 

[swd]

I read a while back that all unmodified Remington 700 rifles will accept the barrel from any other Remington 700 rifle, and the head space will be within SAAMI tolerances.

No offense but that’s the funniest thing I’ve heard for a long time. Don’t go spreading that around any more.

 

[Twicepop]

It was a goodly number of years ago, and I don't remember if I read it on-line or in a publication. Seems to me it was in some gun-mag.

 

[Ackman]

Several times I've played musical barrels with Remingtons. They always headspaced just fine. The last one, probably most extreme, was a new stainless .223 varmint takeoff screwed onto an old 722 action. Headspace is perfect. Even custom barrels from one action to another. Those actions are surprisingly uniform in that regard.