275 H&H
Friends, I am considering building a M70 in 275 H&H simply because I have 4 7mm mags in the safe. My issue with it so far is Midway shows bullets for it are .288 and Ammoguide shows the neck as .284. Elk Ridge chamber reamers lists it in the .284 group, and they donot have a .288 group. I most likely will do a barrel set-back however, I have a M70 DBM and if I decide to build on that one I will definitely re-barrel.
Any input will be greately appreciated
Thanx [?] Curtis
Any input will be greately appreciated
Thanx [?] Curtis
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My 4th Ed. COTW list the belted H&H as .284, .287 for a bunch of stuff, the only .288 is 280 Rimless Jeffery.
I'll just be happy with my regular 7mm Rem Mag., but I haven't given up on making a 280 Ackley Improved out of a shot out 256 Newton on a Newton Action.0 -
cwhuntsalot,
I checked 9 resources for this cartridge with 4 having different groove diameters and 5 agreeing on one in the same.
If you want a definitive answer call Pacific Tool and Gauge Monday morning to ask Dave Kiff for the drawing call out. He has original European drawings for European cartridges.
quote:I most likely will do a barrel set-back
What chamber is existing in this barrel? This will determine the amount of set-back or even if it's possible. Much of a 7mm Rem Mag chamber will have to be cut off to get a proper .275 H&H chamber.
If the barrel is already and existing modern 7mm chamber then what's the problem?
The real answer is that if you're using a standard American 7mm barrel you will need a reamer for a 0.284" groove diameter. Dave can make this reamer for you or he might have one on the shelf (doubtful). This will solve the problem of bullet diameter since you will resize the brass for the chamber which is cut to accommodate the 0.284 bullet diameter and neck. Be sure to check with the die maker for the neck diameter before spending your hard earned money. Type-S dies have interchangeable bushings to make this sizing easier if the standard dies have a larger neck diameter.
quote:I have a M70 DBM and if I decide to build on that one I will definitely re-barrel.
Using a new barrel and a reamer ground for the 0.284 bullets is the better choice. You don't have to cut off an old barrel so you have the advantage of a tenon with the proper length for threading and new chamber/throat.
You state that you have 7mm Magnums in your safe but you don't mention the chambers.
This .275 H&H is very similar to the 7mm Rem. Mag except for the case capacity which is 6 grains less. The case is still 2.5" in length but with more taper.
The 7x61 S&H Super is slightly different having an 'improved' shoulder angle and case body. Ammunition and components are available through Norma. There are even rifles still made with this chamber.
With all this written, I still understand the desire to have a different headstamp and chamber rather than just another standard.
Best.0
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