340c and changing barrels

[Kmrere42]

Hi,

I have a 340c in nice condition and was thinking of getting a couple of barrels to extend its capability.  I even found a 222/223 bolt and barrel at numrich arms for about $55 - $65 ea although I was thinking of staying with the 30-30 case and going to a 22 and 35 cal bore.



Has anyone done this..



Paul

[Flash]

Gotta get em' head-spaced and fitted properly. You might be able to do it safely but why? T/C makes the perfect set-up for this with NEF being a close second.

[Kmrere42]

Hi


    I have several reasons.  First is that the 340 is a bolt action that has the same barrel nut setup that the more common series 10/110 rifles.  By using the same parent case I can use the same magazine and while there is room only for 3 rounds, that is 3 more rounds than the NEF.  Headspace gauges for rimmed cartridges are easy to make and while it may take longer to change barrels than the NEF, it will never have the lockup problems that the NEF is famous for.  Yes I have had several including the target model.  Just think, a bolt action 38-55 that actually has proper land and grove dimensions.   30-30 brass is also easy to get and form into many different calibers with a generous neck length that keeps the lube under the brass.


Just a few reasons



Paul

[Flash]

Hi


    I have several reasons.  First is that the 340 is a bolt action that has the same barrel nut setup that the more common series 10/110 rifles.  By using the same parent case I can use the same magazine and while there is room only for 3 rounds, that is 3 more rounds than the NEF.  Headspace gauges for rimmed cartridges are easy to make and while it may take longer to change barrels than the NEF, it will never have the lockup problems that the NEF is famous for.  Yes I have had several including the target model.  Just think, a bolt action 38-55 that actually has proper land and grove dimensions.   30-30 brass is also easy to get and form into many different calibers with a generous neck length that keeps the lube under the brass.


Just a few reasons

Well, you mentioned a 22 in your last post and the 22 round that's based on the 30/30 case is the Hi Power. The 340 is chambered for the Hornet with it being a totally different animal than the Hi Power. The rifling twist in the 340 barrels would be much faster for the light Hornet loads as opposed to the slower twist needed for the Hi Power and sure, you could load the necked down 30/30 case to equal 22 Hornet loads but then, all you'd have is a more expensive 22 Hornet in a different case. The 35 caliber barrel would have to be cut and threaded or, bored and rifled if you're starting from a 30/30 barrel and if this is the case, you'll have as much wrapped up in your project as a brand new Thompson Center Encore in 357 JDJ and a 220 Swift barrel. I'm not trying to complicate things, just giving you something to think about.



Paul

[Kmrere42]

Hi Flash,





The chamberings that I am considering are


.22 cal     22/30-30 Ackley improved     45gr @ 3900fps... oh yea, .224 bullets not .228
.25 cal     25/35 winchester
.284 cal    7/30 waters
.35 cal     35/30   similar to 35 rem but can use up to 275gr cast @ 1700fps
.375 cal    38-55   bore .366 groove .376




Just a short list but it covers a nice spread.  I have the tools at work to do all the barrel work.
Just need the barrels.


I do have a hornet,  Savage model 40.


Paul

[Flash]

You should be able to get some "take off's" from an auction site. It's a shame ebay changed it's policy since there were several barrels on there at one time. I personally tried to break the 4,000 fps mark in my 22/250 with several 45 grain bullets and couldn't keep them together. Yes, cutting two holes in the target with one shot. The bullets were coming apart in flight. The one bullet I didn't try before quitting the attempts was Berger. All the big name commercial manufacturers didn't have a bullet that would stay together. I never gave any thought to the Ackley cartridges. I asumed that you were doing this on a whim but we both know what assuming does. Sounds like you have a challenging project and the resources to make it happen. You'll like the 25/35. It can be a smokin' round. Good Luck

[trotterlg]

I am kind of thinking the barrel nut and barrel threads are not the same as on the 10 and 110 series.  You may need to make up a barrel nut wrench.  I was looking at a couple of them in 30-30, but decided they just would be too much trouble.  They are cheap, I found two in the same place for $169.00 each.  Larry

[woodchukhntr]

I have an early 1950's (before they drilled the receiver for a scope mount) 340 in .30-30.  I had never thought of a .38-55 or .375 Winchester barrel before.  I just got rid of a H&R .38-55 Target model because of the tight chamber/big bore problem, but would like a .375 that would be accurate.  Maybe I'll keep the dies and components around for a while and look into this.