7-300 Norma Mag Improved
- Thread starter BCX
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I believe there are a couple members here running that round so they should be along shortly. I was going to go improved but the gunsmith had a regular 7-300 norma reamer so I just went that route. Not sure when my barrel will be here though. I'm thinking BJay has the improved version.
I just purchased a LA MAG .590 bolt face and i already have a Bartlein 5R 1-7.5 twist barrel. O what to do with it?
What type of information are you seeking? I don't own a 7-300 NM Improved, but I have shot one a bit (I do own both 300 and 338 NM Improved rifles). Sierra 197s at 3250 with RL33 and a 30" barrel. Pretty brisk recoil in a hunting weight rifle. In general I am a huge fan of the Norma mags. If you are wanting an extreme 7mm, the 7-300 NM would definitely be my choice. Barrel life will obviously be extremely short, but anyone building a 7-300 knows what they are getting into. I would go with a minimum of a 28" barrel to really bring it to life. 30" would be better.
I figure barrel life is 700-800 rounds? What is the preferred reamer? Is there a no turn neck reamer?
I have a 7mm-300 Norma imp 40 degree built on a Stiller tac 338 I had it built with 2 barrels . It shoots amazing will last a long time as a pure hunting rifle . It has a fluted 30" barrel 12lbs with March 3x24 scope . I do not think I would go 40 degree again but at the time the gunsmith had the reamer and dies . As with all overbore calibers shoot it cool and it will last. It sure is a flat shooting wind cheating cartridge. Shooting steel with it gives you confidence to take ethical shots on game at longer distances it truly has a ballistic advantage running 195 bergers at good speeds. I ran the numbers though JBM before building it and out to 1000 it smoked nearly everything while still being comfortable to shoot. Enjoy!!!
Fire forming brass or using a hydro die? My concern is killing half of the barrel life due to fire forming brass.
I would only fireform 50 or 100 depending on how much you will shoot that rifle. No point in doing a bunch if you are only going to shoot 25 or 30 when you take it to the range. 100 pieces should last the life of the barrel and fireform loads can still be a great load just a little slower. Hydroforming gets it close but you will still have rounded shoulders that need fireformed from the research I've done on it. I considered it for another ackley cartridge that I have.
I have a hydroforming die from Whidden for the 7mm-300 norma improved 30 degree. I have 100 lapua brass fireformed and ready to load. Have an extra 100 300 norma lapua brass ready to form.
Did load work up on mine yesterday and worked up to 96.5 gr of rl33 with 195 berger and it yielded 3384 FPS, I probably could have gone a little higher but on high temp Louisiana days this could get into pressure. Humidity was around 60% and temp was 70.
It’s a cartridge I wanted to play with. Ideal setup is running a 2 barrel system. One burner barrel for fire forming. Barrel life must be 600ish?
Holy Christ!
16ish mils to my 1930 yard target at common winter DA wit 195’s.
That kinda fun can’t be nice on barrels.
16ish mils to my 1930 yard target at common winter DA wit 195’s.
That kinda fun can’t be nice on barrels.
Hi I bought a rifle yesterday that sounds a lot like the one you described above you didn’t happen to sell it to a guy from Australia?
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Mine is a Texas built on a Stiller Tac338 receiver w/ 20 moa Rail, PTG .300 Recoil Lug, Lilja 29'' Fluted Sendero 1-8'' Twist with seamless JP Enterprises Coolie Brake installed. Cerakoted in graphite black and chambered in the Wildcat, 7mm/300Norma Improved 40-degree shoulder. The gun was built to fire both the Berger 180 and 195's. Stock is bedded manners T5A and is cerakoted brown over coyote tan with the Mandilorian emblem on each side comes with Lilia 1 in 8 twist fluted barrel with JP enterprise brake set up for 180 and 195 Berger bedded into a Manners T5A comes with a spare new Benchmark 1 in 8 twist cut with the same reamer with a Badger Ordnance thruster brake and came with custom Whidden dies and 91 formed cases and weighs 5kg on bathroom scales.
I know this is an older thread, but I just picked up Redding dies and Peterson Brass from West Texas Ordnance, I’m going to have them put together my parts for their 7mm Norma Improved in a couple weeks. Sloan was super quick on the multiple email replies.
The Redding dies say 7-300 NBR on the box…. I know what the N stands for… any idea on the “BR”?
They only had the non-bushing dies in stock (comes with a separate micrometer seating stem for vid’s) but that’s okay, I figure I can neck down using my 300Norma bushing dies, then ream out the inside neck with a Wilson reamer and finish off by using my Porter precision expander die and mandrels to get the cases ready for fire-forming.
I managed to snag a 500 count box of Berger 180gr hybrids from Bruno’s two weeks ago for the real load development, I have a couple boxes of Sierra 180s or 175s for fire forming.
The Redding dies say 7-300 NBR on the box…. I know what the N stands for… any idea on the “BR”?
They only had the non-bushing dies in stock (comes with a separate micrometer seating stem for vid’s) but that’s okay, I figure I can neck down using my 300Norma bushing dies, then ream out the inside neck with a Wilson reamer and finish off by using my Porter precision expander die and mandrels to get the cases ready for fire-forming.
I managed to snag a 500 count box of Berger 180gr hybrids from Bruno’s two weeks ago for the real load development, I have a couple boxes of Sierra 180s or 175s for fire forming.
