Savage Axis Primary Extraction

[Donny1]

I'm looking for a little insight on this.

Savage Axis II .308

I was asking in the ammo forum about this but it went beyond the scope of the thread. Specifically I'm having issues with new in box PPU Match Line 168gn where the bolt lifts but can't be pulled back without extreme force after firing. It's a new gun and the first ammo I tried has no issues. Fiocchi 150gn has not had a problem after 3 boxes. The PPU only made it 2 rounds before I stopped using it due to the case/bolt being stuck.

I assumed it was overpressure but the chrono did not agree at around 2650, primers look like the others and cases measure almost exactly the same when compared. Now I'm reading how the "primary extraction" pulls the round slightly from the chamber when the bolt is lifted, and how that function can be weak on some Savage rifles.

My assumption now is that because the brass is harder/thicker it's not enough initial force to break it free. Anyone familiar with this issue? As I said, no signs of overpressure and slower that the Fiocchi.

[Donny1]

So I took a fired PPU case and loaded it in the chamber. Same issue, lifting the bolt normally I was still unable to pull it rearward. I closed it again and lifted the bolt more sharply with a harder jolt and the bolt released and I was able to pull it rearward easily. I was able to reproduce this repeatedly. I resized them and they now extract perfectly.

So there is something in this camming action that is not doing enough with these cases to release the cases from the chamber.

On the bolt there is a part called a baffle. My understanding is that older savage bolts had a front and rear baffles but newer designs only have a front baffle. Searching I found pictures of the older rear baffle that actually has a ramp on it. But nothing I see in the newer design has that and I'm not sure how it accomplishes the initial pull on the case when the bolt is lifted.

On older models with a rear baffle you can insert a shim or feeler gauge in between the rear baffle and if it solves this issue it's a diagnostic aid but I see no such trick for this newer design.

Since no one has responded I'm assuming this is not all that common but some savage owners (on the interwebs) definitely have the same issue. For my own curiosity I will be dissecting the bolt to see how it works and inspect for any worn or defective parts.

If I find nothing I will be calling savage. I like to try to find out what's going on before trying to get a warranty repair. I have sent guns in only to have them returned with the same issue on more than one occasion. Maybe because they don't pay attention when you tell them a certain ammo or condition is causing the problem and they think they know better and ignore what you tell them, or who knows why but it happens.

[Donny1]

Ok, so I disassembled the bolt and found zero issues. There is no ramp of any sort on the lugs of the bolt so the motion that moves the bolt reward when you lift the handle must be in the receiver/chamber area but that is not easily visible. The bolt does move back about 1/16" when you lift the bolt.

We'll see if I can get a tech on the phone tomorrow.

[ar15barrels]

I'm looking for a little insight on this.

Savage Axis II .308

I was asking in the ammo forum about this but it went beyond the scope of the thread. Specifically I'm having issues with new in box PPU Match Line 168gn where the bolt lifts but can't be pulled back without extreme force after firing. It's a new gun and the first ammo I tried has no issues. Fiocchi 150gn has not had a problem after 3 boxes. The PPU only made it 2 rounds before I stopped using it due to the case/bolt being stuck.

I assumed it was overpressure but the chrono did not agree at around 2650, primers look like the others and cases measure almost exactly the same when compared. Now I'm reading how the "primary extraction" pulls the round slightly from the chamber when the bolt is lifted, and how that function can be weak on some Savage rifles.

My assumption now is that because the brass is harder/thicker it's not enough initial force to break it free. Anyone familiar with this issue? As I said, no signs of overpressure and slower that the Fiocchi.

Primary extraction is the part of the extraction that happens while the BOLT is being rotated.
As you lift the bolt handle of a closed bolt action, the bolt rotates enough to free the lugs from the lug seats and THEN moves rearward until the bolt stops rotating.
At this point, the case should have been pulled free of the chamber enough that pulling the bolt handle to the rear if it's travel will cause the case to slide out of the chamber and be ejected through the ejection port.

Factors that limit primary extraction are the fit of the extractor to the thickness of the rim as well as the timing of the primary extraction cams on the bolt and the receiver.
The more clearance that you have between the case rim and extractor, the more of the extraction cam travel you lose as the bolt is rotated before the bolt starts to pull on the rim.
The more clearance the bolt has between the receiver and the bolt's cam surface, the more of the extraction cam travel you lose as the bolt handle travel ends.

A good action has 0.060"+ of fully engaged cam travel.
When I say fully engaged, I am talking about the travel of the spent cartridge case.
Any clearances that you have between parts have to be removed by the cam travel before cartridge case travel can occur.
As the fit gets sloppier, you get less than 0.040" and you will have extraction problems where the case is not free of the chamber at the end of the bolt's rotation.

There is no "drop-in" solution to fix extraction cam shortages.
It usually requires fitting new extractor or bolt parts as required to get rid of the excessive clearances.

[Donny1]

Thanks Randall, looks like you just reinforced everything I've learned in the last two days. If it only happens with one type ammo that's one thing so we'll see going forward. But I can't wait too long before sending in for repair.

[SandDiegoDuner]

[Donny1]

No, they are brass.

[Cheep]

See if the extractor groove on the PPU brass is different than the others. If it is larger, the bolt may move rearward before starting to pull the brass.

[Donny1]

I was able to get out with it again.

Before I took it out this time I completely disassembled the bolt and cleaned it meticulously and very lightly oiled it. The first two rounds ejected normally and I thought I had it fixed but then they started sticking again. Just the slightest bit of heat seamed to tighten things up. An extra motion of the bolt handle and a little jiggle and you can feel them all of a sudden release and come right out.

[ar15barrels]

I was able to get out with it again.

Before I took it out this time I completely disassembled the bolt and cleaned it meticulously and very lightly oiled it. The first two rounds ejected normally and I thought I had it fixed but then they started sticking again. Just the slightest bit of heat seamed to tighten things up. An extra motion of the bolt handle and a little jiggle and you can feel them all of a sudden release and come right out.

This is exactly what I have seen as the Savage extraction problem.
If you run it fast/hard and get it hot, extraction sucks.
Most of the people that preach about how their savage works fine are probably not running them fast/hard enough to get the problem.

[sigstroker]

I was able to get out with it again.

Before I took it out this time I completely disassembled the bolt and cleaned it meticulously and very lightly oiled it. The first two rounds ejected normally and I thought I had it fixed but then they started sticking again. Just the slightest bit of heat seamed to tighten things up. An extra motion of the bolt handle and a little jiggle and you can feel them all of a sudden release and come right out.

Try this upgrade. https://www.kinneysshootingsupply.co...-p/ss-2401.htm

Or send it back to Savage. It seems like people report improvement after send it back.

[Donny1]

From what I'm learning the Savage chambers run pretty tight in general. Even though most load data says to run these projectiles a 2.800, that won't fit the chamber on this. After carefully re-measuring to the lands averaging over 5 bullets I got 2.790. Not sure how this will end up with a heavier projectile profile.

The short term plan is to resize, trim, reload about 10 of these cases and see if they run smoothly and then decide if it's worth it to try the upgrade or send it in, or just avoid this ammo, but it shouldn't be that picky.

The good thing about this rifle is groups are very good with everything so far.