Sounds like a plan, I know that round will surprise most folks when i comes out of a good barrel..Mine is a nos star Barrel..
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Sounds like a plan, I know that round will surprise most folks when i comes out of a good barrel..Mine is a nos star Barrel..
So who's reamer did you use for the 7mm? Did it come out good as far as reaming and then showing headspace was met with gauges?
Tim,Quote:
Originally Posted by timshufflin
I used a PTG Finish Reamer as you know the reamer companies don't make a pull through reamer in 7mm Mauser.
Here is how I did it for your own knowledge but I'm sure its not economically feasible for you to offer it as a regular basis unless the customer knows it will cost the time and effort.
I received my barrel back from you last week and put a call out to www.reamerrentals for the reamer. It arrived 2 days ago and I proceeded to work on the chamber.
I placed the barreled receiver vertically in my bench vise with the front receiver ring protected by a piece of old leather (boot tongue in my case.)
The adapters needed to hand-chamber a Garand with a barrel mounted is to use a set of 3/8 socket extensions, (2" and 4"), a 3/8" universal swivel socket, a 3/8" 8-point socket and a socket wrench.
I slipped the reamer into the short chamber after I dipped the reamer into a cup of metal cutting oil, then added the 2" extension then the universal swivel and then the 4" extension. With the extensions added, the socket wrench with the 8-point socket is fitted to the square end of the 4" extension.
The angle of the extension is about 20-30 degrees off center from the reamer due to the requirement to clear the closed back of the receiver. It also clears the back of the receiver with enough room for you to operate the wrench without wrapping your knuckles. With the universal swivel, the concern about the offset angle of the force used to turn the reamer is negated and the reamer stays true to the chamber (With the understanding that it would never be as true as a lathe-cut chamber). The reamer was plenty sharp enough to cut the chamber with the hand pressure applied as it was turned.
Here is the time factor. I started with twenty 1/4 turns of the wrench with additional oil added at the halfway mark to prevent any issues with chips in the chamber than took the reamer out and cleaned both it and chamber out.
I would then slip the stripped bolt into the receiver and then measure with the headspace gauges. I would then repeat this process of cutting, cleaning and gauging for about 3 hours. I lowered the number of twists of the reamer with each successive time I would do the cycle until as the bolt slowly moved further forward and finally seated into the receiver's lug points and met the headspace gauge requirements.
I then reassembled the rifle and bolt and did several function checks for loading and ejection of the new cartridge with a couple of dummy cartridges I made up. Everything did as it was supposed to do so I took it to the gun club last night for a test fire.
I fired 14 shots total at 100 yards. 6 single fire and one full clip of 8 to verify the ability to rifle to load and eject a full clip.
Here is the current issue with the rifle. The stock gas port was cut for standard .079" 30-06 port size. It doesn't cycle with a 40gr IMR 4895 and 140gr bullet.
I'm going to take it apart tonight and run a drill into the port to move out to the 7.62 NATO (.106") port size and try again later this weekend (hopefully tonight).
Now for the good part. Before the rebarrel, this old girl would be lucky to pull 5MOA at 100 with quality 30-06 loads. Now. 14 shots fired - 2MOA. And this with having to break firing position after every shot to eject the empty and cock the hammer. It shoots a little low for the original sight settings but it will be easy to build a data book with repeated firings at the various ranges.
Another good thing is that the rifle isn't bedded or even match prepped yet so there still remains a lot more potential to coax out of it.
Bruce
I actually don't know that reamer companies don't make pull throughs for 7mm mauser, I've never checked. It seems like the difference between 7mm and 7.62mm wouldn't be so drastic as to make a smaller rod for pull through available. 7mm = .275" and there is a pull through reamer for .270. Can anyone educate me on if the math is the problem or if it's just that nobody has a 7mm pull through.
Bruce,,,,Appreciate the update! Please follow-up with gas port size and ongoing range reports. This info is very much appreciated!
Greg
Tim,
I think they just haven't built one as the demand isn't there to stock one on a regular basis. I can see 270 having a pull through reamer as I've seen 270 Garands before. I've even seen a 243 Garand before but I've never seen a barrel in 7mm Mauser.
Greg, I may be able to get to the range this weekend but my gas cylinder is a very tight fit on the new barrel so it takes a bit of tapping with a rubber mallet to seat and unseat right now. That's a plus right? ;)
Bruce
Not a gunsmith, but as others have said....tight is good. Block of wood and a mallet usually gets it seated.
I went and cleared the gas port of brass shavings from the singleshot operation on Thursday (it seems like the port must have been rough enough to shave enough lead off the bullets as they went by to close off the port completely) and reamed the port out to .095 and now The Heretic is working and functional.
I'm going to have to relook 40gr as the primers are flattened more than I would like. I may drop down a grain or two o see if the rifle functions without flattening the primers. The bullets definitely go where they are supposed to go but the brass ejection goes from 11 to 3 o'clock during firing and the clip does eject when empty.
On 3 of the 4 clips of ammo I fired this evening, the bolt would ride over the 8th round causing me to have to manually pull the bolt back for that last cartridge. More studying and more review of Kuhnhausen's book on that little issue I am sure.
Drake, thanks for you follow-up,, you Might have to chamfer the gas port if it still is shaving enough bullets to stop up the port? But you did open up the port..Flattened primers...
The port was blocked from the original gas port hole size. The old hole was .072" and yes I opened up and chamfered the port and after firing 4 clips last night there was no evidence of shaving bullet jacket material after I opened the port.
Yes I have flattened primers with the new port size. When it was firing in single shot mode last week, I had less primer flattening but this is more for my personal choice on the cartridge cases as the primers were not cratered or pierced.
Now I wonder if Tim could pull these replies from this thread and place it in another thread so that we could continue this conversation but without blocking the original intent of the thread which was about Tim's turn-around time on his work.
Bruce