Extruder/Squeeze Bore barrels - ATTN Yance

[Hobie]

Hey there Yance. Do you remember our discussion(s) on the old TC-List about the extruder or squeeze bore barrels for the Contender. Having long ago lost the posts I can't remember who it was that had one of those .22 LR to .17 barrels made up nor by whom it was made. Internet searches have turned up nothing. I am hoping you can help.

[AJMD429]

For those of us who are "lurkers" on this thread, please enlighten us...

What is a 'squeeze bore' barrel...?

Is it sort of like Pope rifling, only accellerating the bore snugness, instead of the rifling twist?

[Hobie]

http://shootingwithhobie.blogspot.com/2 ... -bore.html

[Yance]

Hobie;

I remember the thread on the squeeze bore barrels, but can't remember who owned it (them), but I'm thinking they were DVH barrels. I'll try a shot to the list. If anyone knows the info it'd be Doc Sharps.

[AJMD429]

Thanks for the link, Hobie!

...The question is whether or not one could use a relatively easily obtained .17 HM2 barrel or if one needs a more expensive custom rifled barrel with a faster twist...

Hmmm... If you used one of the new really light-weight .22 LR loadings, perhaps the really fast twist wouldn't be needed, as you'd not have the unusually-long-for-bore bullet after 'swaging'. Of course then you might have nothing more exciting than a sort of .17 HMR Short.

Pretty interesting concept though.

Maybe the ideal would be to combine it with Pope rifling, where the bore gradually shrunk (vs. a forcing cone) and the rate of spin increased as well.

Too bad it's so hard to make and rifle a barrel - not something 'hobby gunsmiths' can do very well...

[JimT]

In the 1980's I had John Linebaugh rebuild my old Ruger Blackhawk 45 .. we used an 8" barrel that was hand-rifled and hand-lapped. It went from .454" at the breech to .450" at the muzzle. Combined with a Taylor Throat it is still one of the most accurate guns I own.

I did this to a Italian-made copy of the 1858 Remington 44 cap and ball sixshooter also. I opened the cylinders to take a .460" ball ... reamed a long lead into the rifling and shrunk the ball to .445". It made a much more accurate and much harder shooting sixgun out of it.

[Yance]

According to Mike Scott from the TCBunch list;

"Dave Van Horn made at least one contender barrel 10-12 years ago. It is somewhat unique but the short version of the story is that you should get a 17 HMR. Mike"

Anyone want to sacrifice a .17HMR or MkIV barrel to have a LOOOONG throat reamed for experimental purposes?<G>

[Hobie]

Yance,

Do you know the twist on those barrels? My twist rate chart doesn't include the .17s.

PS - I see that EABCO's twist rate is 1:9.

[Yance]

Hobie;

My list must be only a little more up to date than yours. It shows both 1-9" and 1-10" for the HMR, and slight difference in bore diameter for the different twists. Hmmmmmm.

Can't attach the chart here.

[Hobie]

Can you e-mail it to me?

Mr. Langsford apparently thought the 1:8 was ideal but had and used the 1:7. I wonder if 1:9 would be enough.

[Hobie]

Yance,

Got it, thank you!

[Borregos]

Interesting thread
I am continually learning new stuff here, today I learned a lot

[awp101]

I never thought about the civilian applications of the squeeze bore! After reading Hobie's blog entry, I presume it would be more of a benefit to varminters than paper punchers?

I love really cool, really odd projects so I'll be following this thread.

[Hobie]

I don't know how much longer it will last, we're running a loop on the data.

[mikld]

I have that issue of Guns Magazine with the Squeeze-Bore rimfire article. Very interesting. If I had a .17 contender barrel and a bunch of money I'd have it reamed to 22 LR with a long tapered throat. Claims of improved velocity and penetration from Win. Super-X 40 grain HP, with no rise of pressure. At the end of the article though, it said the .17 HMR and .17 Mach 2 made further developement of "extruder barrels" unnecessary...

[Hobie]

Well, let's put it this way, what you get from the extruder barrels is DIFFERENT than what you get from a .17 HM2 or HMR barrel. With the later you get light fast bullets, with the former you get heavy LOOOOONG penetrating, maybe slightly faster than normal bullets. If they loaded the .17 HMR with a 40-45 gr. bullet I might be interested. Then again, I like oddball stuff.