PDA

View Full Version : At the chamber, what is the minimum amount the shell should stick out of the barrel?



Pages : [1] 2

tammons
05-21-2020, 03:53 PM
At the chamber, what is the minimum amount the shell should stick out of the barrel?

I have a 300 BO barrel with a bad chamber and the seller (not here) is not responding.
It is a cheap barrel, but very accurate, so I was thinking about hand reaming the chamber.

But I am not sure if it will clean up without setting it back.

I dont have a lathe and dont want to wrap up too much $ in a cheap barrel.

Thanks

charlie b
05-21-2020, 04:25 PM
Savage bolt action? If you get lucky and it does not move the shoulder much then you could just readjust headspace with the barrel nut (after any reaming you want to check headspace regardless). Loosen nut, adjust headspace, tighten nut (easier said than done). If not lucky then you'd have to have someone turn the end of the barrel.

Ted_Feasel
05-21-2020, 05:26 PM
At the chamber, what is the minimum amount the shell should stick out of the barrel?

I have a 300 BO barrel with a bad chamber and the seller (not here) is not responding.
It is a cheap barrel, but very accurate, so I was thinking about hand reaming the chamber.

But I am not sure if it will clean up without setting it back.

I dont have a lathe and dont want to wrap up too much $ in a cheap barrel.

ThanksIf its "very" accurate, I would leave it alone.. jmo:)

Sent from my SM-N975U using Tapatalk

tammons
05-21-2020, 06:13 PM
Savage bolt action? If you get lucky and it does not move the shoulder much then you could just readjust headspace with the barrel nut (after any reaming you want to check headspace regardless). Loosen nut, adjust headspace, tighten nut (easier said than done). If not lucky then you'd have to have someone turn the end of the barrel.


Yes. Savage rifle.
The chamber has a defect. Looks like a bad reamer. This is a RAI barrel and probably made in Pakistan or whereever.

Anyway, I need to clean up the end of the chamber. It looks like the reamer wobbled and the chamber is wider at the end follewd by a very rough spot.

An empty cartridge wont eject without a rubber mallet.

tammons
05-21-2020, 06:13 PM
If its "very" accurate, I would leave it alone.. jmo:)

Sent from my SM-N975U using Tapatalk

An empty cartridge wont eject without a rubber mallet.

tammons
05-21-2020, 06:15 PM
So, does anybody know the minimum distance from barrel face to cartridge head?

sharpshooter
05-21-2020, 06:41 PM
.125" -.130" cartridge protrusion. Measure the depth of the bolt face, most are .115". Then you need clearance of at least .005".

Ted_Feasel
05-21-2020, 07:15 PM
An empty cartridge wont eject without a rubber mallet.Oh didn't catch that part lol

Sent from my SM-N975U using Tapatalk

tammons
05-21-2020, 08:07 PM
NT

tammons
05-21-2020, 08:07 PM
.125" -.130" cartridge protrusion. Measure the depth of the bolt face, most are .115". Then you need clearance of at least .005".

Thanks

Robinhood
05-21-2020, 08:47 PM
Beat me to it.........

Stumpkiller
05-21-2020, 09:07 PM
0.125" is the standard depth of a shell holder for reloading presses as well. By no coincidence.

bsekf
05-22-2020, 10:04 AM
After reading this thread and thinking a little (dangerous)! Is it necessary for the chamber end of the barrel to be perfectly square with the chamber. There is about 1/8 inch clearance between the bolt head and the end of the barrel, Savage bolt head floats, so is a perfectly square barrel face necessary?

I have a barrel that has the chamber cut a little deep and when I headspace I am hitting the end of the barrel. I see no reason I couldn't just use a file to remove a few thous.

Redneck engineering and gunsmithing! Setting a barrel back with offset grinder and file!;)

tobnpr
05-22-2020, 07:31 PM
You can't "clean up" an eccentric chamber by just running another reamer in.
Running another reamer into it- whether by hand, or under power- isn't going to change it. The reamer will follow the existing hole.

That problem can only be resolved on a lathe by indicating the bore with a range rod, and using a boring bar to true the chamber to the bore/lathe axis, setting back and re-cutting the chamber.

Ted_Feasel
05-22-2020, 08:58 PM
Sounds like criterion or shilen has a solution for you lol... just kidding... kinda :)

Sent from my SM-N975U using Tapatalk

Robinhood
05-23-2020, 12:42 AM
After reading this thread and thinking a little (dangerous)! Is it necessary for the chamber end of the barrel to be perfectly square with the chamber. There is about 1/8 inch clearance between the bolt head and the end of the barrel, Savage bolt head floats, so is a perfectly square barrel face necessary?

I have a barrel that has the chamber cut a little deep and when I headspace I am hitting the end of the barrel. I see no reason I couldn't just use a file to remove a few thous.

Redneck engineering and gunsmithing! Setting a barrel back with offset grinder and file!;)

There is only .005"-.015" between the bolt head and the barrel breech face.

Use a Gage to measure the protrusion. (the problem could be your sizing process)

Like Fred said, measure the depth of the bolt face and measure protrusion. The protrusion number must be greater than .005" than the bolt face depth.

mnbogboy2
05-23-2020, 01:27 AM
After reading this thread and thinking a little (dangerous)! Is it necessary for the chamber end of the barrel to be perfectly square with the chamber. There is about 1/8 inch clearance between the bolt head and the end of the barrel, Savage bolt head floats, so is a perfectly square barrel face necessary?

I have a barrel that has the chamber cut a little deep and when I headspace I am hitting the end of the barrel. I see no reason I couldn't just use a file to remove a few thous.

Redneck engineering and gunsmithing! Setting a barrel back with offset grinder and file!;)

This will work with no problems providing the original chamber isn't "egged" as tobnpr mentioned. I've shortened the breech with a hacksaw on numerous occasions and squared it up with a big bastard. Any craftsman can get within a thousandth or two and that will pose no problem. Just make sure the go-gauge protrusion matches the bolt head recess + your desired bolt head to breech face clearance. It usually falls in that .125 to .130 number. Some aftermarket heads like PTG may require a little bit more.
Make sure the reamer pilot matches the bore just ahead of the throat. Do all the hand reaming vertically with the barrel mounted below your work station. I have a barrel vise mounted specially for hand reaming and stand above it on a stool to provide constant equal down force on the reamer. The reamer will follow the "old" hole, as long as you don't induce side pressure. I do not recommend trying a full chamber with this method. Withdraw the reamer every .010 - .025 and clean it and the chamber & barrel. Re-lube each flutter with cutting oil each pass. Use a reamer stop for the last passes. I've only done this 10 or 12 times to create Ackleys , wildcats or simple cartridge swapping. Not for complete chambering.
Yes it works fine if you have the time. There is a learning curve.

Robinhood
05-23-2020, 08:47 AM
This will work with no problems providing the original chamber isn't "egged" as tobnpr mentioned. I've shortened the breech with a hacksaw on numerous occasions and squared it up with a big bastard. Any craftsman can get within a thousandth or two and that will pose no problem. Just make sure the go-gauge protrusion matches the bolt head recess + your desired bolt head to breech face clearance. It usually falls in that .125 to .130 number. Some aftermarket heads like PTG may require a little bit more.
Make sure the reamer pilot matches the bore just ahead of the throat. Do all the hand reaming vertically with the barrel mounted below your work station. I have a barrel vise mounted specially for hand reaming and stand above it on a stool to provide constant equal down force on the reamer. The reamer will follow the "old" hole, as long as you don't induce side pressure. I do not recommend trying a full chamber with this method. Withdraw the reamer every .010 - .025 and clean it and the chamber & barrel. Re-lube each flutter with cutting oil each pass. Use a reamer stop for the last passes. I've only done this 10 or 12 times to create Ackleys , wildcats or simple cartridge swapping. Not for complete chambering.
Yes it works fine if you have the time. There is a learning curve.

And in other news..... LOL

mnbogboy2
05-23-2020, 11:24 AM
7182

Here is an example of a "hacksaw" rechamber quicky. Was a .260 Rem, hacksawed .250 off breech, filed square, ran 6.5 creedmoor reamer in .075 deeper than creed depth. Used 260 brass in creedmoor die to bump length...trim to 2.003. 2-1/2 grains more capacity than CM and shoots ok. Barrel did have over 1000 rounds so no break in was required.

Edit: this was 5 shots at only 100 yards with Berger 130 vlds pushed with h4350.
Also .010 off with no other load developement. Velocity was 2984 ave over 5 with sd 9.1 over mag speed.

Robinhood
05-23-2020, 03:26 PM
Can't argue with results. There was a big name gsmith over in Webster Texas. He did a hand reamer job for a friend. Don't know why he didn't set it up in the lathe, it was a long fluted 308 barrel with 10 rds being reamed to a win mag. It came out like a 5 sided cam. Worst thing i have ever seen.