.222 keyhole

[jambrdly]

I recently picked up a mid 50s Sako Riihimaki in .222. I took it to the range yesterday and the bullets were keyholing. The bore is bright and shining with good rifling. I used a medium load. No signs of excess pressure or backed-out primers. What could be the problem?

 

[littlebuddybr]

What bullet did you use?

 

[LHSmith]

That older Sako twist should be a 1/14" and it should shoot any standard jacketed lead tipped bullets up to 55 gr. well.

 

[ebb]

Those rifles were of a slow twist and bullets of today have gotten heavier that in the past. Most likely the bullet you choose is too long. If it is very much over 50 grains I would be looking for something lighter and shorter. Mr Little buddy is right on track I am sure.

 

[LHSmith]

Inspect the crown for any damage.

 

[Hal]

Some of the very early Sako had a 1-16" twist.
Try some 40 gr bullets.

Hal

 

[kyotekiller25]

40g vmax/nbt with imr4198 shot the best in my 1970 700 ADL. Many groups in the .2s and killed a lot of dogs with it too.

 

[Zero333]

Try Flat Base 40 gr bullets.

Sierra 40 gr HP Varminter ( # 1385 ) would be a great start because it's a very short bullet and should stabilize even in a 16" twist barrel

 

[whatsupdoc]

40 or 45 sierras work in my 16" twist more like 15.5 twist Riihimaki. I did shoot some
53gr Flat base Sierras in it and it seemed to shoot them fine but I tried some other
low 50gr bullets and they tumbled bad. Dont even think of using a boat tail bullet.

 

[DumpHollow]

Inspect the crown for any damage.

Considering the vintage and sophistication of the shooters in that era, I would rule out the crown before chasing my tail on theory.

 

[Gary in MD]

Yea, almost surely using a bullet that is too long to stabilize. Try some 50 -52 grain flat base bullets.

 

[L.Sherm]

Do the ole cleaning rod trick to get an idea what twist barrel you have

 

[K22]

Do the ole cleaning rod trick to get an idea what twist barrel you have

This should answer your question.

 

[LHSmith]

This should answer your question.

According to the Sako Collectors Club forum that the very early L-46 .222's (early '50's) were first supplied with 16 twist barrels since those were the barrels supplied in the .22 Hornet and .218 Bee which preceded the .222 chambering. Later Sako standardized the .222 twist rate to the more common 14 twist. So, the only sure way to know is to simply measure it.

 

[sw282]

Do the ole cleaning rod trick to get an idea what twist barrel you have

l did the cleaning rod dance on my 0ld 700BDL Varmint in 222Rem THREE times.
Each pass l came up with 1 in 15''

 

[jambrdly]

What bullet did you use?

45 grain "varmint"

 

[K22]

l did the cleaning rod dance on my 0ld 700BDL Varmint in 222Rem THREE times.
Each pass l came up with 1 in 15''

You need to use a snug fitting patch to ensure the rod rotates with each movement. It not exact but close enough to distinguish between a 14" twist from a 12" or 16".

 

[sw282]

You need to use a snug fitting patch to ensure the rod rotates with each movement. It not exact but close enough to distinguish between a 14" twist from a 12" or 16".

l couldn't believe it at first. To try and eliminate any error l took a sized without primer case. Seated a bullet in the case BACKWARDS and then chambered it. l also made sure the tip w/patch was tight on the Deweys rod. l still came up with 1 in 15'' twist. Really not a problem for me. l rarely ever shoot anything over 50gr in gun. lts an old ''B'' serial 700 Varmint. l bought it 'used' many years ago off gunjoker. The gun came to me with a broken ejector button. l just left it that way. Saves me from having to chase brass.
The barrel has a ton of inspection and proof marks on it. 0bviously passed. 15'' twist twas just a SURPRISE. l appreciate the 'Pre China' era of manufacturing. l have later guns with ZERO proof and inspection marks.
Sad a gun company like Remington in llion NY closed after 200 plus years last month

 

[Knotwild]

Was told by a barrel maker that buttons can slip a little during rifling. That is why Harold Broughton's first button machine had a guide incorporated into the rod that pulled the button to insure the twist came out as specified. I'm not smart enough to know if it made a difference or not.

 

[LHSmith]

Was told by a barrel maker that buttons can slip a little during rifling. That is why Harold Broughton's first button machine had a guide incorporated into the rod that pulled the button to insure the twist came out as specified. I'm not smart enough to know if it made a difference or not.

The OP's barrel was most likely hammer forged ( I am assuming here) and due to the nature of the process the twist rate should vary very little from one lot of barrels to another.