No-Lathe Chamber 8x57 to 8mm-06

[Flouncer]

The Midway video shows a no lathe chamber method for "pre-fit" barrels. This would apply to unfinished in the throat or throat area type barrel products, as opposed to another method that is fully reamed but requires a lathe to remove about 0.050-inch from the barrel face. I assume one uses a 30-06 reamer and runs it down to end in the barreled 8x57 action, and then grinds away. Check with rented go/no gauges. Does anyone here have experience with simply renting a reamer and using in my potential application ? Just carefully slowly ream an 8x57 to a 8mm-06 type of work....... Both my manuals mention a "simple operation for the mil-surp 8x57".... Hunting -rifle that shoots 3/4-inch groups at 100 yards with 200g Nosler partitions. Any advice is appreciated.

Also, the 30-06 has a 17 +/- shoulder, the Mauser a 20.5 +/- shoulder. Another subject, I know. (can't get the Midway page/link to load)

https://videos.midwayusa.com/index....a_mauser_short_chambered_barrel?id=1_81qarlsy

Thanks for advice or info

 

[Dusty Stevens]

I think youll be best served letting somebody do it in a lathe. I figure running a sharp reamer by hand may leave chatter in there but to answer your question i think youre on the right track with your thoughts on what you plan on doing

 

[shortgrass]

You would have more than 1/8" to cut by hand with the reamer. That is a very long distance. I can see several stumbling blocks . #1 as Dusty says, chatter and lots of it, #2 hand reaming that distance is sure to invite a wallowed out, oversized chamber. That can happen with a lot less distance to ream than what you propose. and #3 what happens when you over shoot the headspace dimension and the bolt will close on the NO-GO gauge? What's wrong with the 8 x 57mm Mauser anyway? It is a formidable cartridge , every bit as powerful, when hand loaded for a modern rifle capable of modern pressures, as the .30/06. Factory loads are mild out of respect for the pre '98 Mausers that are still in circulation. What you have in mind is a re-chambering job best done by someone familiar with this type of work (meaning a decent gunsmith). Pre threaded & chambered barrels are not my forte. If all I can get out of a rifle is 3/4" I'm wondering what's wrong with it!

 

[Flouncer]

Thanks for your replies. The unsymmetrical bore or wallowed out chamber is not something I considered. I have full high power loads for my 8x57, the -06 simply adds 4 or 5 grains more powder, almost 10%. I am getting slightly flattened primers but no other signs of high pressure. These loads out of a 22-inch thin hunting barrel already exceed Speer and Sierra max loads by 55 fps with their 24 inch barrels. Side by side, all equal, 150 fps gain is what I am hoping for. I have a new, mil-step 24-inch barrel ordered. Cost was $95. That is seductive, or destructive in it's appeal. So with the reamer and gauge rent I can have a try at the great unknown for about $175. What could possibly go wrong ? Har Har. I'm fine with a 3/4-inch group off sand bags, my first cold bore shot is always right where I want it and it doesn't wander from week to month.

 

[shortgrass]

Then, have at it! "It's so easy a caveman could do it!". If it was me, I'd be looking for better groups than 3/4" instead of 150fps. But, its not me, and $95 barrels aren't worth fooling with, IMO.