Anyone bedded a Sako 85?

Improving and repairing firearms. Rifle bedding, barrel work, stock replacement and other ways to improve your firearms.

Re: Anyone bedded a Sako 85?

Post by Flyer » 14 Jan 2017, 4:27 pm

This is where things get interesting . . . After pulling the rifle apart again, I discovered safety screw had left an imprint on the stock where it was hitting. It is the dent in the middle of the half-moon shape in this pic. This cannot be good for accuracy and I can't believe it took me this long to see it.
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There are possibly three reasons why the safety screw is hitting the stock

1) not enough clearance;
2) the rear action is moving around;
3) the safety screw itself is defective and sticking out too much.

I discovered it was probably a combination of all three. Have a look at the screw - there is a shank between the thread and the step where the screw seats against the trigger. You can see when properly screwed in, only a few threads hold the screw in place. On my rife, the screw was sticking out. It seems like a defective screw.

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I will either need to find another screw, or use a dab of Devcon around the shank to create more threads to ensure the screw stays in place once tightened into position.
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Re: Anyone bedded a Sako 85?

Post by Flyer » 14 Jan 2017, 4:40 pm

With the rear action sorted (at least, with most issues discovered), it was time to look at the front action. A friend of mine let me pull his new (12 months old) Sako 85 Bavarian apart and I discovered it had a different recoil plate to mine.

This is what mine looks like:
Recoilplate.jpg
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And this is the other design - which is much stronger and more stable (not my friend's rifle, but the same type of recoil plate):
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It is difficult to see in the photo below, but my recoil plate is see-sawing and moving around on the stock - you can see faint impressions of where it has been moving around. Clearly I need to get a new-design recoil plate and bed it properly in the stock.
Sakorecoilmovement.jpg
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Re: Anyone bedded a Sako 85?

Post by Flyer » 14 Jan 2017, 8:44 pm

First mod: deepening the safety screw hole/recess so it doesn't bottom out anymore. Shiny stuff is new wood sealant. I also put a little dab of Devcon on the safety screw thread and snugged it into place. I'll put the rifle back together without the rear pillar, initially, to see if clearancing the safety screw makes any difference. Always best to eliminate one possible bedding issue at a time until the problem is narrowed down.
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Re: Anyone bedded a Sako 85?

Post by Gwion » 15 Jan 2017, 8:05 am

Good to see some progress. Watching with interest in case I came one day afford one of these for a hunting rifle.
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Re: Anyone bedded a Sako 85?

Post by Flyer » 16 Jan 2017, 1:04 am

Hit the range today. Shot without the rear pillar in place and the rifle double grouped again. I put a little extra torque on the rear screw, too (40inlb), which didn't seem to make much difference:
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I also noticed the barrel had moved in the stock, from the centre of the barrel channel to the left, after shooting a few rounds through it:
Sakobarrel.jpg
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As soon as I replaced the pillar, the rifle started shooting a lot more consistently. All groups were at 100m:
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No doubt, the rifle needs to be bedded to stop it moving around. That will be my next project, but I will need to wait until I have the new recoil plate first. At least I seem to have nailed the problem.
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Re: Anyone bedded a Sako 85?

Post by Flyer » 13 Mar 2017, 6:43 pm

The rear pillar on mine is 29.5mm - but exact pillar lengths will vary (slightly) with each stock. I machined it from stainless tubing, as that's what was easiest to find ($9 on eBay), and the 8mm OD capillary tubing I used was the exact size for the 8mm screw hole to fit. I determined the length by removing the trigger guard, and pushing a length of 8mm tubing into the action screw hole until it hit the action, then cutting it slightly oversize (31mm), and rubbing the ends back with 320-400 wet and dry until I got the correct length.

I have not pillared the front, but I have bought a new recoil plate which I have now bedded. I'm also in the process - after lots of trial and error - of fully bedding the rifle (over the recoil plate).

Bedding the front recoil plate made almost no difference, but stabilising the rear with the pillar did remove the fliers, and got some of my 4-shot groups down to about .750" at 100m. Bedding the front should improve consistency. I'll post everything up soon.

On a side note, my 85 is an older rifle that had been in someone's safe for a long time with very little use (hence looked new, but was 6-7 years old). Whether, over time, that had affected the stock so that mine didn't sit right is a distinct possibility, as I have seen a couple of new 85s that shot great straight out of the box - including a 243 varmint laminate using factory ammo (Winchester Ballistic Silver Tip 55gr and 95gr both seem to work nicely, as well as Federal 80g Power Shok).

If I were you, I'd go out and shoot it and see what it's like - it could well surprise you. And, being a new rifle under warranty (and five-shot 1 MOA guarantee), if it doesn't shoot great out of the box, I'd return it. The only reason I am going through all this is because mine was second-hand, quite a few years old, and I wasn't in a position to return it to the factory.
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Re: Anyone bedded a Sako 85?

Post by Apollo » 13 Mar 2017, 8:10 pm

Boy, I really hope you solve this drama. I hope in some way what we have discussed will have helped.

I have not shot a calibre rifle Sako or not of what you have so I don't know but in saying that any Sako I have shot say .243W and below has always produced sub 1//2 MOA results.

I feel for you.
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Re: Anyone bedded a Sako 85?

Post by Flyer » 14 Mar 2017, 12:15 am

We'll find out soon enough. I've just finished bedding it tonight and will pull it apart tomorrow to see how it looks. I left the recoil plate in, and plasticined the redundant recoil lug hole (the one they used with a floating recoil lug system in the Sako 75s and Tikka T3s), so that it doesn't create another recoil point like your .243 laminate (the one bedded by the gunsmith that uses an epoxy/Devcon recoil lug). I've also only bedded under the tang - not both levels of the rear (around the rear action screw) like your .243. I can always bed the bottom part later if I feel the need.

Apart from that, I used your .243 as a guide - so that's been very helpful. I decided to pull the trigger (so to speak) and properly bed it because I figured the way it sits in the stock now is obviously the problem, and the pillar I machined is really only a temporary measure. The action really needs to be bedded front and back so that it can't move around in the stock.

In my favour at least is that the rifle shoots pretty consistently with the rear stabilised. Below are a couple of groups I shot yesterday, and they both measure under .900". Nothing outstanding (there was a bit of wind about), but OK for a sporter barrel and at least no more fliers.

I also take heart in the fact that, whoever had your .243 before you bought it obviously felt the need to have it bedded, and that after bedding it seems to shoot really well. Which is to say, Sako's own bedding system clearly isn't perfect.

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Re: Anyone bedded a Sako 85?

Post by Apollo » 14 Mar 2017, 1:02 am

I wish I had kept my last target from what was going to be a test day for load development.

1st fouling loads produced 4 in one hole and the 5th shot just touching at 100m so, just as we moved targets to 300m the wind plus mirage turned up. End of testing as it would not have been worth wasting barrel wear. I actually think the one out of the single hole may have been the first cold shot.

It was a busy day as I had 100 220Russian cases to fireform into 6mmPPC so I was swapping rifles every few minutes.

BTW, I was really impressed with the 6mmPPC even though this was just 100m Fireforming. A number of sub 1/4 MOA groups so I'm keen to see how it goes at competition which will be 100 & 200 Yards. Fireforming was from just a very old hand me down worn out 18" barrel that was a gift.
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Re: Anyone bedded a Sako 85?

Post by Apollo » 14 Mar 2017, 1:06 am

Opps, I forgot you have a .243W... but it's a Barvarian with a light profile barrel.

Sorry, I keep thinking it's a higher calibre....

I'm getting too, too old.....
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Re: Anyone bedded a Sako 85?

Post by Flyer » 21 Mar 2017, 7:46 pm

Well I hope this helps someone, because this whole episode has been doing my head in!

However, there is light at the end of the tunnel, and it turns out all my problems could be down to one loose screw . . .

First thing's first: I replaced the front recoil plate with the new/old design. I say "new/old" because I have seen this recoil plate on both new and old original Sako 85s, but somewhere in the middle they changed the design and then went back. The dimensions that count (thickness, width, screw hole placement etc) are exactly the same. They are also the same (interchangeable) throughout the Sako 85 range, from XS to S, SM, M and L actions.

Recoil.jpg
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Original recoil plate left, and the new one I bought from Beretta right.

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New recoil plate

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Old recoil plate

I then set about bedding the rifle. First, I bedded the recoil plate into the stock so that it was level and would not move in the channel. I used masking tape on three sides of the receiver lug - front and sides - that fits into the square hole at the rear of the recoil plate so that the rifle action sat level, with the rear of the receiver lug making contact with the recoil plate. I used masking tape around the barrel to centre it in the channel, then tipped the rifle on its stock and tapped it on the ground to settle recoil plate, lug and receiver at their rear-most point to ensure proper battery. I then torqued the rifle down so the action screws were nipped up front and back.

After bedding the recoil plate, I then bedded the action and rear tang. I also redrilled the rear action screw hole and centred it in the stock using 8mm tube and bedding compound.

Bedding.jpg
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You can see where I have bedded over the recoil plate. My main concern with this is that the recoil plate is made of steel and the bedding compound is mostly aluminium (Devcon). If the steel expands when it heats up, there is the possibility it could rise and dislodge the bedding compound. However, after shooting the rifle and pulling the action out of the stock when hot, I've discovered the recoil plate does not heat up much and so far there are no signs of disturbance.

I also plugged the action with plasticine where the old floating recoil lug would have gone (same as the Sako 75s and Tikkas). You can see a couple of rough patches either side of the bedding compound where I have plugged the gap.

Yes, I have a plan "B". If the bedding compound is compromised in any way, I will simply remove it from the recoil plate and leave the remainder attached to the stock (the bits on either side) to keep the action centred. The recoil plate is where the action beds to the bottom of the rifle - the bedding compound along each side of the inner stock simply keeps it centred during assembly and battery.

Tang.jpg
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I only bedded under the rear tang, and not the lower level (I can always do this later). Like the recoil plate, I left some wood untouched as a guide, then removed some wood around it with the Dremel and bedded the bottom, sides and rear of the tang. After bedding, I clearanced a very small amount of bedding compound around the very rear of the tang to prevent the tang hitting it under battery and chipping the wooden stock. I needn't have bothered, as I discovered the action is now rock-solidly bedded in the stock and does not move at all when the action screws are tightened and loosened.

So, did this make any difference to the way my rifle shot?

No. And yes.

My first five shots were all over the place. The bedding had made absolutely no difference at all. I was dumbfounded! So I tried my old trick again, and put the stainless steel pillar back in the rear of the rifle and tightened both front and rear screws to 6nm.

Vmax.jpg
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I could not believe it. The first shot went 1/4" low at 100m. The next two shots went into the same hole, just above. I loaded a fourth round and it, too, went into the same hole. That's a .150" three-shot group opening to .400" with the first shot. This is the best group I have shot so far with the rifle, and the bedding does seem to have worked. It certainly hasn't hurt. This was with my 87gr V-max load of 44.5gr of 2209 chronoed at about 3300fps.

VmaxGroup.jpg
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So I pulled out another accuracy round, 100gr Game Kings with 39.5gr of 2209 at about 3000fps. The first shot was pulled after the guy next to me let off his 243 just as I pulled the trigger and jumped out of my seat. The next two shots went into the same place as the Vmax (almost the same hole). The third shot was a little lower. Everything seems OK . . .

GameKing.jpg
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The next group is when things started to fall apart. Two shots into the same hole 2" above the target - same as the others, then two very wayward shots low and left-right.

Just out of curiosity, I got my torque wrench out and put it on the rear action screw - it was loose.

I have noticed that each time I shoot the rifle without the steel pillar, it's all over the place. As soon as I put the pillar in and torque it down, the rifle shoots dead-straight. I was seeing a pattern developing . . .

When I first got the rifle, it shot really well. But then I noticed the action rattling around in the stock. When I pulled the action screws out, I found remnants of thread locker on the action screws and thought nothing of it. This oversight is what has probably cause me all my grief.

What I have learned in all this is that the stainless steel pillar not only helps stabilise the rear of the rifle, but it allows me to torque the rifle up tight without putting too much pressure on the wooden stock. Without the pillar, the rear action does not like to be too tight in the stock (the more you tighten it, the more groups spread). However, with the correct torque - and no locking compound on the threads - the screw simply works its way loose after a few shots and shoots like a pig. With the steel pillar in, you can tighten it with the correct tension on the stock, but it also stays in place longer (but eventually it, too, vibrates loose).

So what to do? I just bought some Loctite :lol: The next stage may be to bed the stainless steel pillar into the stock and simply leave it there and Loctite the action screws into place and be done with it.

If my rifle shoots consistently after all that, I will have reached a number of conclusions:

1) The Sako 85 bedding system works well - when it works
2) Bedding a Sako 85 does not seem to hurt it, and may even improve it marginally
3) So far, bedding over the recoil plate (as long as the recoil plate is bedded first) seems to be OK
4) Sako 85s do not like a lot of tension (screw torque) on the rear action!
5) For reason 4, pillar bedding is a good idea
6) Thread locker!

I may need to examine the threads on my action screws and the action itself to determine if they are flawed, but considering the whole thing is only held in by a few threads anyway, thread locker (Loctite) simply makes sense.

I hope others can learn from my mistakes and that this has all not been a terrible waste of time! I will report back with more results in due course.
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Re: Anyone bedded a Sako 85?

Post by Chronos » 22 Mar 2017, 7:11 pm

Have a mate with a 85 in .308, action screws often come loose as well. We do like to mock him with a little "rattle rattle" tease from time to time which started on a hunt when he shook the gun and the action rattled in the stock :lol:

Hope you finally have it sorted mate, Chronos
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Re: Anyone bedded a Sako 85?

Post by brett1868 » 22 Mar 2017, 9:51 pm

What a great write up, some excellent forensic work done with the results to back it up. I haven't worried about bedding my 85's cause they shoot better then I can at the moment but I'll definitely take the lessons you're learnt onboard for future reference.
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Re: Anyone bedded a Sako 85?

Post by Gwion » 23 Mar 2017, 6:18 am

Glad you got to the bottom of it but had to admit I have been wondering why you haven't bedded the pillar in the stock from the moment you mentioned putting a pillar in.....
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Re: Anyone bedded a Sako 85?

Post by Flyer » 23 Mar 2017, 10:21 am

I guess the answer to that is the quest for knowledge. I knew the pillar worked, but I didn't know exactly why. Was it stabilising lateral (side to side) movement in the stock, linear (up and down) or fore and aft movement? Was the rear the main problem or was movement in the front action contributing? Could a simple bedding job resolve the issue without a pillar? Would I need to do a proper pillar support job on the rifle (redrill the action screw holes and install proper 14mm rifle pillars) to permanently fix it?

Maybe I'm overcomplicating things here, but it's one thing to fix a problem and something else to understand how and why it worked so that you can apply that knowledge to the next job.

So I'm probably going to order a pillar bedding kit and do the job right at some point. The stainless steel pillar I made up from 8mm tubing was really only meant as a stop-gap anyway, and to experiment with stabilising the stock.

Turns out, my main problem may simply have been the screw working loose (as it was not sitting straight in the stock - the rear action screw hole was drilled off centre). Took a while to figure out, I admit, but bedding the rifle wasn't a big job and it doesn't seem to have hurt anything.

Now, I may have made a bit of a goose of myself, but at least the next person who comes along can save themselves some time and trouble!
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Re: Anyone bedded a Sako 85?

Post by orkhunter » 26 Dec 2017, 7:51 pm

g,day flyer , I read with great interest of your trials and tribulations with your sako 85 . l have a 85 hunter that did shoot well ,now it doesn't .the action is moving in the stock under recoil.in your last post you mentioned a pillar bedding kit .did you get one and where do you get them from. l have been looking for answers in overseas forums and an aussie came up with the cure .many thanks for your research.
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Re: Anyone bedded a Sako 85?

Post by Member-Deleted » 26 Dec 2017, 10:07 pm

G'day Flyer I've been watching and mate you've certainly been in the midst of it
Mate I have had 3 sakos and still have 2 my 85 I couldn't stop the barrel moving around in the stock
eventually I glass bedded it and Bingo end of problem my 2 roughteck's had same issues so I glass bedded my
last one before even firing a shot and have no issues '' But barrel had too much movement when it arrived''
My personal opinion is most sako rifles with the stock recoil system now need glass bedding unless like the larger calibers
above 300 have lock in type bits to stop movement
Anyway mate a little trivia for you may help may not
Cheers
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