Gunsmithing Primary Extraction issue with Savage 110 BA Stealth 338 Lapua Magnum

[Daherc]

Hello. The above stated issue is with a friend of mines rifle. He ordered the rifle new about 7-8 years ago. It was a rather expensive production rifle, and he topped it with a NF NSX scope with a NF 1-piece mount. He spent a pretty good amount on this shooting package, and had problems shortly thereafter.

He was telling me that he was having extraction issues with factory ammo. I told him we could try hand loading for it to see if maybe he just had too tight of a chamber for factory ammo.

Well, after trying Sierra 300gr SMk’s and Badlands 260gr SICBM’s, H1000, H4891, and Retumbo, we determined there was something wrong with the rifle, and not the ammunition. I tried a load ladder with each bullet and each powder. So lots of different loads were tried.

We were seeing stuck cases in 4 out of 5, or 5 out 6 shots. The bolt wasn’t “heavy” and there weren’t any real signs of pressure on the brass, but the bolt needed to be smacked with a block of wood or a mallet.

My friend sent it back to Savage for warranty work. Savage said they “rechambered and polished the barrel.” And then test fired it. It functioned fine according to them.

Upon receiving the rifle back, I tried five rounds of ammo loaded with 86.0gr of H1000 and 300gr SMK’s. All but one of them stuck in the chamber. So much for Savage’s repair work and test firing.

I looked online for what could be the culprit, and there was nothing really out there for a “sticky bolt.” Well, when I looked up primary extraction issues with Savage rifles, there came the info.

Apparently the larger caliber Savage rifles are somewhat prone to having primary extraction issues. There was talk about drilling, tapping, and installing set screws in the rear baffle, machining down the back of the bolt, and a few other things.

I needed to test for this as being the issue.

I loaded a load ladder with 300gr Berger OTM’s (because we ran out of SMK’s) and 81.0 - 85.0gr of H1000. I used a set of feeler gauges to see what the gap was between the back of the receiver and the rear baffle. I was able to fit 0.034” of feeler gauges in the gap. Essentially the bolt body is about 0.030-0.035” too long. This gap was prohibiting effective primary extraction.

I used the feeler gauge at the range as a makeshift shim to force the bolt handle against the rear baffle, and every round extracted flawlessly at all charge weights.

Another friend of mine is a very good machinist. He made me a 0.035” shim with the footprint of the rear baffle. I wanted to try something a little better than a feeler gauge to make sure I had it all figured out.

I did I another load ladder with the shim, and the rifle functioned great.

My machinist friend is going to machine the bolt body down about 0.030” at first to make sure we do not overdo it.

This extraction issue has been a pain for many months now. It feels great to have finally figured it out. (Hopefully)

 

[memilanuk]

Wow. Great post on finding the problem, and handling it

Sometimes just buying a few extra rear bolt baffles and finding one that mates up better with the cam on the bolt handle will work well enough, but it sounds like you're on the right track to a 'better' solution.

 

[Drvred]

My 110 Tactical in 6.5 Creedmoor had similar issues, I took it to a gunsmith who honed out the chamber and took care of the problem.

 

[Daherc]

My 110 Tactical in 6.5 Creedmoor had similar issues, I took it to a gunsmith who honed out the chamber and took care of the problem.

I did take the rifle to a smith who put a reamer to it to make sure the chamber was to spec before sending it back to Savage. That did not make any difference.

I had never heard of primary extraction before this Summer. This was definitely an eye opener.

 

[Daherc]

Wow. Great post on finding the problem, and handling it

Sometimes just buying a few extra rear bolt baffles and finding one that mates up better with the cam on the bolt handle will work well enough, but it sounds like you're on the right track to a 'better' solution.

Hadn't thought of trying a different baffle. Do you think a new baffle would have been 0.030" larger?

Haha. That would be easier than machining the bolt.

 

[memilanuk]

Hadn't thought of trying a different baffle. Do you think a new baffle would have been 0.030" larger?

Maybe not 30 thou, but perhaps enough that it wouldn't have been a major problem.

Sometimes it's not entirely the rear baffle that's at fault... the cut in the bolt body where the handle sits can vary in depth, IIRC, which can change the relationship in a similar manner. I've heard of people having that notch re-cut to achieve similar / permanent results... but my understanding is that the bolt body is hardened and needs some specific tools / skills to machine. Hence the 'DIY' approaches you've came across, with people putting jacking screws in the front of the baffle facing the receiver, or gluing shims to it, or just swapping them out til it works right. *Most* of the time it works well enough from the factory... but sometimes you get that one, where the tolerances stacking across multiple parts bites you in the a$$.

As @Drvred mentioned, sometimes polishing the chamber a bit can help as well by cutting down the amount of work the baffle / cam has to do in the first place.

The other fun part is when you get a bolt handle (usually aftermarket) where the ramp on the handle is at a different angle than the ramp on the baffle, and you only get a tiny strip of contact or band of contact. All the work is being done over a much smaller area, which makes the lift feel quite a bit heavier.

 

[Steel head]

Somewhat common issue with a few fixes.

 

[SIDS01]

I loaded a load ladder with 300gr Berger OTM’s (because we ran out of SMK’s) and 81.0 - 85.0gr of H1000. I used a set of feeler gauges to see what the gap was between the back of the receiver and the rear baffle. I was able to fit 0.034” of feeler gauges in the gap. Essentially the bolt body is about 0.030-0.035” too long. This gap was prohibiting effective primary extraction.

I used the feeler gauge at the range as a makeshift shim to force the bolt handle against the rear baffle, and every round extracted flawlessly at all charge weights.

Another friend of mine is a very good machinist. He made me a 0.035” shim with the footprint of the rear baffle. I wanted to try something a little better than a feeler gauge to make sure I had it all figured out.

I did I another load ladder with the shim, and the rifle functioned great.

My machinist friend is going to machine the bolt body down about 0.030” at first to make sure we do not overdo it.

This extraction issue has been a pain for many months now. It feels great to have finally figured it out. (Hopefully)

Usually you can't run the gap down to zero without interfering with the closing cam. You'll feel that as a click or hitch when closing the bolt on an empty chamber. If you go too far and that happens, use a sharpie on the leading corner of the bolt head that contacts the closing ramp and file it back a couple strokes at a time until the click clears. I usually leave just over 0.015" to avoid the closing cam, but have had to remove up to 0.040". You may also have to grind clearance for the bolt handle in the stock.

It's not just big Savages, it's a common problem with a variety of manufacturers. The R700 requires removing the bolt handle and silver soldering a fresh one back on after moving it.

It's also a good idea to remove a similar amount from the big assembly bolt.

This prevents adding preload to the firing pin spring with the extraction modification. Instead of just facing the bolt, I turn a shoulder to hold the cocking piece in alignment.

Good job working through this.

 

[Daherc]

Maybe not 30 thou, but perhaps enough that it wouldn't have been a major problem.

Sometimes it's not entirely the rear baffle that's at fault... the cut in the bolt body where the handle sits can vary in depth, IIRC, which can change the relationship in a similar manner. I've heard of people having that notch re-cut to achieve similar / permanent results... but my understanding is that the bolt body is hardened and needs some specific tools / skills to machine. Hence the 'DIY' approaches you've came across, with people putting jacking screws in the front of the baffle facing the receiver, or gluing shims to it, or just swapping them out til it works right. *Most* of the time it works well enough from the factory... but sometimes you get that one, where the tolerances stacking across multiple parts bites you in the a$$.

As @Drvred mentioned, sometimes polishing the chamber a bit can help as well by cutting down the amount of work the baffle / cam has to do in the first place.

The other fun part is when you get a bolt handle (usually aftermarket) where the ramp on the handle is at a different angle than the ramp on the baffle, and you only get a tiny strip of contact or band of contact. All the work is being done over a much smaller area, which makes the lift feel quite a bit heavier.

Savage claimed to have polished the chamber. I did not verify that work, but that will be next after the bolt work if there is still an issue.

The bolt closed fine with the shim, so I am hopeful the 0.030" will still work just fine.

As far as the screw goes, I will talk to my friend about cutting that down as well. Thank you.