30-30 rebore to 375

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roughcreek
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30-30 rebore to 375

Post by roughcreek »

I recently purchased a Glenfield 30A that has been rebored to 375 winchester.
my concern, is the Marlin able to handle the increase in pressure of the 375 win.
On another forum it was suggested that the round bolt was made stronger on the
factory Marlin 375 to make it able to handle the presssure. Thus this one should only
use lower pressure hand loads. Any suggestions appreciated.

Thanks, Roughcreek
Roughcreek
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Ray
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Re: 30-30 rebore to 375

Post by Ray »

.38-55 loads are the way to go.
m.A.g.a. !
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Griff
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Re: 30-30 rebore to 375

Post by Griff »

My Marlin 375 appears to be built with a std. 336 frame and parts, (well, except the barrel of course)... and that only in the stamping. I've heard that the thread pitch and style differs in the 375... but, I haven't ever checked that.
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fordwannabe
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Re: 30-30 rebore to 375

Post by fordwannabe »

My375 is a Marlin and I inspected it pretty well the reciever doesn’t seem any different or the bolt. I would call Jesse Occumbaugh(sp?) at JES reboring as he does this rebore and knows the whats and wherefores.
Great guy also.
a Pennsylvanian who has been accused of clinging to my religion and my guns......Good assessment skills.
wm
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Re: 30-30 rebore to 375

Post by wm »

My factory original 375 was built on the same frame, using the same bolt as the standard 336 in 30 wcf. If it was a well executed job on the barrel you should be fine.

Wm.
Last edited by wm on Sat Dec 22, 2018 9:49 am, edited 1 time in total.
Pete44ru
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Re: 30-30 rebore to 375

Post by Pete44ru »

roughcreek wrote: Fri Dec 21, 2018 11:18 pm I recently purchased a Glenfield 30A that has been rebored to 375 winchester.

my concern, is the Marlin able to handle the increase in pressure of the 375 win.

On another forum it was suggested that the round bolt was made stronger on the
factory Marlin 375 to make it able to handle the pressure.

Thus this one should only use lower pressure hand loads. Any suggestions appreciated.

Thanks, Roughcreek


Baloney.

The issue Marlin Model 375 I had was no different than any other of my Marlin 336/1895's, except for the bore size. (and the higher value, of course ;) )

.
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Old Savage
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Re: 30-30 rebore to 375

Post by Old Savage »

Pete, local gun shop owner here years ago pointed out that the part number on the receiver is the same.
In the High Desert of Southern Calif. ..."on the cutting edge of going back in time"...

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roughcreek
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Re: 30-30 rebore to 375

Post by roughcreek »

Thank you all for your replies. Appreciate it.
Does this mean I could load my 30-30 Marlins to much higher pressures and still be safe?
Roughcreek
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Griff
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Re: 30-30 rebore to 375

Post by Griff »

roughcreek wrote: Sat Dec 22, 2018 8:37 pmThank you all for your replies. Appreciate it.
Does this mean I could load my 30-30 Marlins to much higher pressures and still be safe?
I don't believe so. The .30-30 is a tapered case and has more bolt thrust than the .375... Also, IIRC, when the .375 was being developed, a Marlin & Winchester 94 were both being used as the test platform, the Marlin failed before the Winchester... Long before I found this out, I loaded my Marlin at full power, now... not so much.

'Sides, the .30-30 is simply a magical cartridge, certainly more than capable in it's factory form.
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earlmck
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Re: 30-30 rebore to 375

Post by earlmck »

roughcreek wrote: Sat Dec 22, 2018 8:37 pm Does this mean I could load my 30-30 Marlins to much higher pressures and still be safe?
Marlins are plenty strong for their intended purpose (30/30 level loads) but are not truly super-strong actions -- I always wondered if they weren't pushing the design envelope a bit when chambering for the .375. If it were mine I'd consider it to be a wonderful 38/55 and put lots of nice cast bullets through it.

And if you want more soup out of the 30/30 load it with a top load of Hodgdon's LVR powder. You can keep within SAAMI pressures and still get 100 to 150 fps more velocity than with any other powder.
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roughcreek
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Re: 30-30 rebore to 375

Post by roughcreek »

yup, all good advice, thanks.

Will use the Marlin for 38-55 and leave the 375 for the win XTR.
Thanks all.
Roughcreek
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