Have a customer wanting to achieve switch-barrel on a Marlin XS7. Wanting to make things simple...the question is...are the threads on a Savage aftermarket barrel the same as the Marlin threads? Inquiring minds want to know!

Ol' John

Yes.

Threads are the same,

BUT

Chamber depth MAY be different due to the difference in bolt face recess depth. This COULD cause a false indication of proper headspace when installing the barrel.

Read this:
http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/3707557/9


Bruce

When I put an A&B barrel on an XL7, I set headspace and tightened the barrel, then I rechecked headspace by placing 0.001" shim stock under the gauge, one shim and bolt closing was possible but had to force, 2 shims no close . since it was spacing out the gauge, I knew it wasn't hitting the bolt head.
I recognize though, it may be different with the short action XS7.

It is also possible that my A&B barrel had the chamber cut a few 1/1000" deeper than your barrel.

Jeff

Yes, all should be considered for safety sake.

I use FL sized brass from my dies/shellholder to set up all

my Savage project....no gauges for my odd ball wildcats...

I don't know about installing a Savage bolt head on a Marlin bolt.

Sometimes I wish that I hadn't brought this issue up, but, OTOH, if somebody got hurt and I knew that there was the potential for a problem lurking out there, but didn't say anything, I'd feel pretty bad. That is why anytime anyone brings up the Mossberg 800s, I tell them about the plastic trigger housings.

Jeff

I don't want to hijack John's thread, But it IS pertinent. Jeff brings up another interesting question... Will the Savage bolt head fit the Marlin?

I haven't compared any bolt heads yet, but remember that the Savage stem is long enough to pass through the gas baffle before reaching the bolt body. The Marlin doesn't have a gas baffle.

Bruce

The barrels will screw in. Don't know about the bolt set up. The stocks are will not interchange.

Measured some:

Marlin XS7 and XL7 bolt heads appear identical.
Savage 10 and 110 bolt heads are different. I don't have a 10 available.

The question is, "How critical is a 20/1000" difference in bolt face depth?"

Jeff

Jeff,
20/1000" in headspace is quite critical. Typical diff. between go/no go is .004".
That much stretch on a case MIGHT not be a big deal, IF you have your dies set correctly. But, there are a lot of reloaders out there that aren't that sophisticated. They are assembling ammo, not custom reloading!
In this instance, all you have to do, is face .010" off the barrel face, and you're golden.

You think that 20/1000" is worth considering and I think that 20/1000" is worth considering, but a lot of people are screwing Savage and Savage-specs barrels onto XL/XS-7 actions and going on their merry way when they feel friction against the bolt.

I've been trying to point out to folks that different in the depth of the bolt face recess MIGHT be a problem, because the friction that they are feeling MIGHT be the back of the barrel against the front of the bolt, not the rear of the headspace gauge against the bolt face. With 20/1000" you are going to get case stretch, but how much stretch is there before the case separates? When I realized that the difference in bolt face recess might cause a false "proper" headspace feel, I trimmed my barrel back and recut the chamber.

Jeff

First, an apology. A corrected photo has been posted.

Using a Starrett depth micrometer, I got new measurements.

To the nearest 0.001, my two Marlins are 0.130 deep. My Savage is 0.115 deep.

I need to retire my old dial caliper. When the depth micrometer is set at 0.130, the caliper measures it at 0.140.

Safety on these barrel swaps is easy to check.

Before interchanging barrels, people need to measure cartridge protrusion from the chamber. That measurement must be greater than the bolt face depth.

Bruce

Thank you gentlemen for your detailed posts. Great thread for someone making a .308 Marlin XS7 into a switch barrel rifle. .358 Win and 6mm-.22-.250 barrels are in the queue.

My measurements of the bolt face depth of my XS7, done with a Frankford Arsenal digital caliper, came out 0.130 +/- 0.0005.

Now the question is "how critical is 15/1000" when setting the headspace?".

Jeff

Gentlemen,

Thank you one and all for your replys and concerns on the headspace issues. .015 would be critical IMO. The difference between go & no-go gauges for the .308 family of cartridges is .006 if memory serves me correctly and .010 for the military 'field' gauge. If a bolt closes on the 'field' gauge that particular rifle is destined for the armorers "post-haste". Brass will only stretch so far before case separation.

Again..many thanks for your replys!

Ol' John

I received a new Adams & Bennett Savage barrel finish chambered for 250 Savage.

Five new Remington 250 Savage cases protrude from the barrel 0.120(2), 0.121(2), and 0.122, measured with a depth micrometer. Savage bolt faces measure about 0.115 depth, which would allow several thousandths clearance between this barrel breech and a Savage bolt nose, when this barrel is screwed in until it is tight on a case or gauge. A GO gauge should be slightly longer than a case.

Headspace measurements I have for the 250 Savage are:

(GO 1.5792)
(NO GO 1.5852) = GO + 0.006
(FIELD 1.5892) = GO + 0.010

If this barrel is screwed in until it barely touches a Marlin XS7 bolt nose, there will be about 0.008 to 0.010 free space between the case and the XS7 bolt face, which is 0.130 deep. This makes the chamber between NO GO and FIELD size, not dangerous but not good for a new barrel installation.

Note that the barrel CANNOT be screwed in until it is tight on the new case, or tight on a GO gauge. The barrel will tighten against the bolt nose first.

Bruce

PS Five new Winchester 243 cases protrude from the Marlin XS7 barrel 0.138(2), 0.139(1), 0.140(2).

Interesting thread.

Nice to see some people doing actual measurements instead of just "argyin".

The "fixes" are simple, but probably noteworthy. Were it me putting an A&B "Savage" barrel on a Marlin action, before installing the barrel, I'd opt for dropping a gauge (or case from my reloading dies), in the chamber, measure the protrusion, compare to depth of bolt face, and either 1) turn the excess off the breech, 2) ream the chamber deeper, or 3) leave alone if within specs. However, 1 and 2 are not available to the "regular Joe" just looking to "drop" an aftermarket "Savage" barrel on a Marlin action.

I'm not one to 'worry' about headspace too much. However, one of the great "things" about "building" one's own rifle is the ability to put into it all the precision you can. While I don't "worry" much about headspace, I AM a nazi when it comes to setting the headspace on a rifle I build. To be sloppy with headspace is to be, well... SLOPPY. To me, that seems contrary to the concept of "do it yourself".

Paul

ok guys i have a question i have a model 111 savage with a 26 inch bull barrel in .223 , now then i want to swap my barrel out to a .270 marlin barrel , any advice ?? (its either .270 or spend the nearly $400 for the .338 lapua barrel and deal with my wife!!! )

The Lapua is too big in diameter for the 110 action.

I believe that a few have tried it but a responsible gunsmith will not chamber that round in that action.

IIRC the techs at Savage have said much the same.

Ya think they deburred the Savage BH enough?