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View Full Version : Headspacing after recoil lug changed?



Dantheman
03-24-2017, 10:48 AM
I have a 11vt in 308 that is not grouping very well. I am debating on switching the stock for an Accustock. I believe I can complete this swap if I change the recoil lug. The barrel removals and install seem straight forward, but will the headspacing need to be checked after replacing the lug(same bolt and barrel)? Thanks in advance.

joeb33050
03-24-2017, 11:20 AM
You can't change the lug without setting the headspace.

olddav
03-24-2017, 11:22 AM
I would say "Yes", it is the safest way to go.
You may be able to index the barrel before you remove it but I have no experience along those lines.

olddav
03-24-2017, 11:25 AM
Joeb33050 is headspacing without a go or nogo gauge. It is a valid option (as if he needs my approval) but does require more of a feel.

hereinaz
03-24-2017, 12:26 PM
Deleted stupid brain fart answer...

I can't remember how to tie my shoes sometimes...

You will have to pull barrel completely, because the barrel nut won't thread off barrel towards muzzle... so, only way off for lug is chamber side of barrel... DOH

Dantheman
03-24-2017, 12:59 PM
Thanks for the info. Exactly what I needed to know.

hereinaz
03-24-2017, 02:14 PM
You are welcome.

short round
03-24-2017, 04:34 PM
Your going to have to remove the barrel & set head space, no other way to change lug.

hereinaz
03-24-2017, 06:02 PM
Your going to have to remove the barrel & set head space, no other way to change lug.
Brain fart on my part. Total screw up. Ignore my stupidity. Yes, you will have to remove barrel, because the barrel nut threads on and off from the chamber side...

DOH, complete idiot brain spasm... edited my post above accordingly.

bsekf
03-25-2017, 09:27 AM
You could carefully index the barrel and action with witness marks.... but I still would check the HS with a gauge. If you change the recoil lug, you will want to re-bed the lug at least.

Bill

LoneWolf
03-25-2017, 10:10 AM
If you remove/loosen the barrel from the action you will have to check and reset headspace regardless of changing the recoil lug. Trying to use witness marks with no gauge will only be "close" at best.

Always remember this is a charge of powder and a lot of pressure occurring 4" from your face! It's best to do it right or not at all! Never set yourself up to be a statistic!


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RC20
03-25-2017, 05:05 PM
You could carefully index the barrel and action with witness marks.... but I still would check the HS with a gauge. If you change the recoil lug, you will want to re-bed the lug at least. Bill

Anytime you disturb the relationship, you need to check the headspace, even if you index it.

I played with that, I thought you should be able to put the barrel back to where it was by the barrel markings, not even close.

Any method you are comfortable with from the gauges to using re-sized or non fired brass for the No go end and fired or tape on the back of a non fired or resized case to the gauge again for the No go /field reject.

On the 7.5 Swiss build I am going with new brass for the No Go and a combination of tapped brass and fired brass for the no go. Will see how it goes, Also a cross check to see if fired in a K31 and if I can set the chamber on the LW barrel can be made to work.

Normally I am a gauge guy but I have gotten comfortable enough with the operation to venture into the wilderness.

Robinhood
03-25-2017, 06:46 PM
If you remove/loosen the barrel from the action you will have to check and reset headspace regardless of changing the recoil lug. Trying to use witness marks with no gauge will only be "close" at best.

Always remember this is a charge of powder and a lot of pressure occurring 4" from your face! It's best to do it right or not at all! Never set yourself up to be a statistic!

Yep



If you are using the same barrel with the original action you can get close by index marking. I would not shoot without some method of verification however it will get you very close.

You need to understand the dimensional relationship of the bolt head with the case and its protrusion from the chamber as well as the linear movement of the barrel in one rotation @ 20 TPI. If you measure the depth of the bolt face and measure the depth of the case protrusion out of the breach then you will understand that once the barrel is screwed in till contact with the bolthead is made, you will have less than a half of a turn back to your index mark (on 99.99% of Savage Model 10-110's). Savage-Smith 101.


Edited: Remember, 36 degrees of rotation is .005" linear movement.

Zero333
03-27-2017, 10:23 PM
You can use a once fired case from that chamber and use it as a go-no-go gauge if you know what you're doing. I don't recommend it to anyone who's never set headspace before, but it's possible.