Marlin barrel on m10 savage

**joeb33050** · 10-20-2018, 02:35 PM

To put a Marlin XS7 barrel, 223, on a Savage M10 action, I ground ~.2" off the FRONT of a Savage barrel nut. Everything fit, headspaced fine.

This after hours of assembling, measuring. disassembling, measuring... The Savage barrel nut front end goes over the unthreaded part of the Savage barrel---it does NOT fit over the too-big unthreaded part of the Marlin barrel.

NOTE: A FL sized 223 case protrudes from the/a Savage barrel ~.130"/.140"; and from a Marlin barrel ~.150"-.160" .

**Robinhood** · 10-20-2018, 08:50 PM

Use the Marlin Nut?

Interesting about protrusion. Is this being measured using sized brass?

**mnbogboy2** · 10-20-2018, 09:23 PM

.130 sounds about correct for a Savage. .240 protrusion sounds unsafe to me this would leave un-supported brass well beyond the case web!
I definitely would not shoot it that way. Research the problem maybe the case is hanging up in the chamber. Use a 223 go gauge. .120-.130 is in the ball park. Another measurement check would be bolt head counter bore + .005-.010.
No room for a goof up here!!
Randy

**mnbogboy2** · 10-20-2018, 09:46 PM

After a little research I found where the Marlin bolt head may be .008-.015 deeper than the Savage bolt head. This might push case head protrusion to about .140 or so on the Marlin. So the .240 number is way out of wack.

Check it again with a go gauge. .135-.140 could be correct but not .230-.240.
Even if it was more than .130 I would run a reamer in and bring it down to leave .005-.008 between the bolt head and breech face.

**RustyShackle** · 10-20-2018, 11:05 PM

Sounds like it might be a 221 fireball barrel. That’s a plethora of case hanging out the back!

**joeb33050** · 10-21-2018, 09:49 AM

My mistake, s/b ~ .150"-.160". Had to take everything apart, use new brass.

**Robinhood** · 10-21-2018, 10:16 AM

I thought so. Were you were using brass that had an oversized shoulder from being fired in a larger chamber.

**joeb33050** · 10-21-2018, 02:40 PM

Don't know. Shooting tomorrow, will report back.

**joeb33050** · 10-22-2018, 10:31 AM

The delightful Marlin barrel won't keep shots on 2' X 2' paper at 100 yards. The Marlin barrel has been an expensive and time-consuming mistake.

**J.Baker** · 10-22-2018, 12:29 PM

That's what you get for trying to bastardize a Savage with Marlin parts. LOL

**mnbogboy2** · 10-22-2018, 12:37 PM

Joe,
Re-check everything, sounds like scope mounting or scope itself. Action screws? Extensive crown damage? Torque on the barrelnut?
Something obviously wrong. Could be the barrel but I would hardly think any barrel would shoot 2 foot groups at 100 yards.
Is the twist in the marlin barrel adequate for your ammo?
Don't give up just yet.

**joeb33050** · 10-22-2018, 03:48 PM

Since so wild, I thought maybe 9" twist wasn't 9". Apart at home, it IS 9" twist. 68 gr bullets. Will try with 40 gr bullets Thursday. Never had a Savage barrel that wouldn't shoot < 1" 5-shot five group avg, 100 yards.

**RustyShackle** · 10-22-2018, 05:14 PM

Put an unprimed piece of brass in the chamber and shine a light from the breech end. Look from the muzzle for nice circles. If they converge or look distorted you might have a barrel problem.

**joeb33050** · 10-25-2018, 10:52 AM

10/25/18 68 GR BULLETS WON'T STAY ON THE PAPER AT 100 YARDS.40 GR BULLETS, 3 IN .5", 5 IN 1.225", 5 IN .9".It's the twist, my other 9" twist barrels stabilize the 68 gr, and shoot well < 1" 100 yd 5 shot 5 group avg.