20 Myra extruder

[lawsie]

Thought you blokes might be interested in this one.
It's a 69 Brno mod 2 with a stainless 20 cal barrel that fire's standard 22lr.
Here is a link with some info for those that have never heard about it: http://shootingwithhobie.blogspot.com.a ... e.html?m=1

Unfortunately my old phone shit itself so I lost all my photo's of testing etc.
I haven't done a huge amount of testing but was getting some clover leaf groups with the SK standard velocity and cci stinger ammo at 50m.
This rifle has 3 action screws instead of the original 1. The back one is used to finely tune the gun to the ammo.
It definitely works as I had some CCI standards that shot poorly and then they shot acceptable with some adjustment.
I plan to shoot a bunch of the high velocity ammo and see what happens.

Speeds increased anywhere from 40-100fps depending on the ammo. I shot them side by side with another mod 2 for reference. Some of the stingers were hitting 1750fps so they were definitely scooting along.

Cheers

[MISSED]

Wow more info please

With pics

[Camel]

I always like the ideas that came out of Arthur Langford, smart old bugger, pity he is gone now. Rang him one day after reading about his extruder tests, wanted him to do a 17 for me, but he didn't have any barrels finished. Never did get back to him on it.

[Branxhunter]

Thought you blokes might be interested in this one.
It's a 69 Brno mod 2 with a stainless 20 cal barrel that fire's standard 22lr.
Here is a link with some info for those that have never heard about it: http://shootingwithhobie.blogspot.com.a ... e.html?m=1

Unfortunately my old phone shit itself so I lost all my photo's of testing etc.
I haven't done a huge amount of testing but was getting some clover leaf groups with the SK standard velocity and cci stinger ammo at 50m.
This rifle has 3 action screws instead of the original 1. The back one is used to finely tune the gun to the ammo.
It definitely works as I had some CCI standards that shot poorly and then they shot acceptable with some adjustment.
I plan to shoot a bunch of the high velocity ammo and see what happens.

Speeds increased anywhere from 40-100fps depending on the ammo. I shot them side by side with another mod 2 for reference. Some of the stingers were hitting 1750fps so they were definitely scooting along.

Cheers

Nice Lawsie. I have a Guns & Game magazine with an article on the Myra extruder here somewhere, will have to dig it out.

My Mod 2 has two screws; one either end of the trigger guard, with the rear one threaded into the rear of the action. Will have to try adjusting the tension on it to see if it will tune to the ammo. What sort of torque are you using on the front and rear screws? What constitutes the third screw on your Brno?

While my rifle still has the factory barrel the front and rear open sights, including the rear sight band and the stock screw that went into it, have been removed.

Marcus

[lawsie]

Here's the setup.on the screw's.

[Seddo]

thats not something you see every day!

[kickinback]

I did that with my cz452 except I welded a stud on. Made a huge difference.


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[trevort]

nice rifle. Interesting to see someone actually has and uses something I've only ever read about in a magazine

[lawsie]

Finally got out to shoot a few groups with some different ammo. Unfortunately is was dark when I started shooting so i was using a torch for lighting.



SK standards




It didn't like the bush rangers. This was the best I could get them after adjusting screw tension.




The mini mags went well. I think they could still be improved on but good enough for now.

[Branxhunter]

Found it:

image.jpeg (169.34 KiB) Viewed 1173 times

From the first edition (1994).

Marcus

[DSD]

Found it:

image.jpeg

From the first edition (1994).

Marcus

After reading Sean's posts a couple of weeks ago the second paragraph is interesting

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[curan]

Found it:

image.jpeg

From the first edition (1994).

Marcus

Thanks for the read. I reckon my neck will recover!

[Branxhunter]

Let me know if you want to read the other 5-6 pages.

Marcus

[lawsie]

Went to the range today to try the 20 extruder at 50m again.
I played around with the screw tension for the mini mags and will probably leave it as is for now. I then fired a 20 shot group with the SK ammo just to see how it went after adjusting to suit the mini mags.
Don't pay attention to the numbers. I was going to shoot 3 groups at the same screw tension but didn't bother as it shot well enough. You can see the larger groups were from too much tension on the rear screw. I then backed it right off and shot the group with 5 above it.

[Camel]

Cant really complain about those results, looks good.