AusVarmint

Wondering if anyone can explain the cause & effects of tumbling. I recently received a 17 rem in Sako from Magnum Sports , sight unseen & upon trying out various loads I found a number had "tumbled" ( read gone in sideways on the target) & pressure signs were evident via pierced primers. Not clearly evident from the attached photo but can be seen below the arrow on the LHS target where I was experimenting with various loads. Any enlightenment will be appreciated. Crown appears OK & loads are not hot. Barrel has been given a good going over with Iosso & also Hoppes No 9.

Highly likely the barrel has a build up of carbon in it from prevous owner/s.

I picked up one cheap with a canjar trigger on it and had a similar experience. After I got the carbon out it would group the 20 gn vmav at around .5 inch. But it needs to be cleaned after about 20 rounds max. Then a couple of fowling shots to settle again.

They are 1 in 10 twist so 25 gn vmax is generally to long. 25gn hollow points are ok.

Thanks Mudgegonga - any trick to getting rid of the carbon build up , I've given it a really good go over with Iosso & Hoppes several times.
Barry

Any details on projectile weight and barrel twist

Bill

Bill , projectiles are 20 grain , 2207 is the powder at 17.2 grains but can't tell you re the barrel twist , can't even find out the maker of the barrel , it's SS. There may be some Sako tragic who can chime is about twist but ATM I'm in a jaundiced Sako mood I guess I've gotta wait for the Council Clear up time before sending it to the dump !!
But , do appreciate all suggestions.
Barry

I'll take it to the tip for you for $200

Marcus

I have a late 70's Sako .17 Rem that sends the 25g vmax sideways and prints a perfect side on profile of the pill on target, still doesn't group half bad Went back to the old fashioned 25g HP and it shoots like a trooper

Branxhunter - the offer is appreciated but my blood pressure has now receded & I may persevere a bit more.!
Waldo - yep , it's strange how some projectiles work & other create the tumble effect. I'm now starting to blame the hot (around 36/38 ) weather when I've been experimenting but then again ADI powder is not supposed to be affected so much

barryb wrote:Branxhunter - the offer is appreciated but my blood pressure has now receded & I may persevere a bit more.!
Waldo - yep , it's strange how some projectiles work & other create the tumble effect. I'm now starting to blame the hot (around 36/38 ) weather when I've been experimenting but then again ADI powder is not supposed to be affected so much

Going too fast due to high pressure won’t induce tumbling. And your barrel twist should be right for a 20 vm.

I have had a dirty 22 start spreading pills all over the place so I am going to agree with the dirty or worse, worn out barrel. Someone with a borescope will tell you


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Scrub the beejesus out if it, better yet a chemical foaming solvent... and start the process of looking for a new barrel.

Many 17Rem rifles I think are just not cleaned properly. Once done, their life returns.
Cheers...
Con

Con wrote: ↑Fri Dec 29, 2017 7:20 pm Many 17Rem rifles I think are just not cleaned properly. Once done, their life returns.
Cheers...
Con

Shits of things to clean they are too

Waldo wrote: ↑Fri Dec 29, 2017 7:25 pm

Con wrote: ↑Fri Dec 29, 2017 7:20 pm Many 17Rem rifles I think are just not cleaned properly. Once done, their life returns.
Cheers...
Con

Shits of things to clean they are too

Q-tips/cotton ear wax cleaners ... I cut them with a bit of the stalk left and push them through with a $15 cheap 17cal rod. The cotton tip can be soaked in Sweets or WipeOut (non-foaming) and they create a ripper and firm patch. Good patches too!

I DETEST scrubbing with a nylon brush etc as your right, they're a shit!
Cheers...
Con

If you have already scrubbed with iosso and no improvement, sounds like your best bet is to unscrew that tube and start a tomato garden. Get a new barrel and be done with it.

Thanks everyone for your suggestions/input. I'll do a bit more brushing this time using the Sweets & Wipeout process & see what happens. If everything fails where would you point me directionally to find a reasonably priced 17 Mach1V barrel for a replacement.

barryb wrote: ↑Sat Dec 30, 2017 7:01 am If everything fails where would you point me directionally to find a reasonably priced 17 Mach1V barrel for a replacement.

I'm due for two barrels in 2018. One will be a Swann stainless to see what the quality is like. Love to do a 17/222, believe he has both reamers.

Cheers...
Con