300 Norma Mag on a ‘stock’ Remington 700 Long Action?

[91Eunozs]

So I have a hankering to step up to longer range shooting, and have a nice custom short action already in progress (300 WSM on a Defiance action), but also have a Woox chassis and matching Hawkins bottom metal for 338 LM on hand.

However, the only long action receiver I currently own is a like-new stock Remington 700. It’s a couple years old, but has literally never even been built up except to install a decent Timney trigger.

My brain tells me to just finish building that 30-06 that the receiver was intended to be used on, and get a nice custom long action with a larger bolt, like a Surgeon XL or similar. However, with the year-plus lead times we’re currently seeing I’m seriously considering just getting a PTG one-piece long action bolt made with a Lapua (.590“) face, getting my stock action trued, and simply mount up a new barrel chambered in 300NM….along with the thickest recoil lug I can fit! LOL

Bad idea? I would have a local custom gun builder (Hill Country Rifles) do the truing and chamber/mount/headspace the barrel. I could probably do it myself, but my machinist skills aren’t quite to that level.

I’m a pretty experienced shooter, but a novice to bolt action rifles. What am I missing?

Thanks in advance for any advice/tips.

 

[Mike Casselton]

Sell the Remington and put that money towards one of these. You'll be much, much happier.

VPR SST .338 Lapua Magnum Action RH

We specialize in custom firearms.

shop.kaugerarms.com

 

[phlegethon]

This used to be on the Lilja web page but I can’t find it any longer:

You are being redirected...

“____________________________________________________________

I feel this way for several reasons. First the Remington uses a 1-1/16" diameter thread shank with 16 threads per inch. In my opinion this leaves a marginal wall thickness between the root of the barrel thread and the chamber wall. The .378 Weatherby belt diameter is .610" and the largest diameter of the big Rigby case is about .590". With a thread root diameter of about .992" or so (normal for 83% contact) that leaves a wall thickness of .191" over the Weatherby belt. With the Rigby case the thickness is a little better at .201" but still marginal in my opinion.

I think all of the custom actions designed for the big cases have a 1-1/8" diameter thread shank. Much better from my viewpoint. But someone wanting to use a Remington could argue that the Weatherby MK 5 action has the same barrel thread size as the Remington. That's true but it doesn't change the fact that it is still marginal.

The Remington's thread size isn't its only shortcoming though. To make case extraction work well a Sako extractor should be installed. Opening the bolt face diameter to .600" or bigger inside a .700" diameter bolt leaves just .050" wall thickness per side. Again, marginal in my opinion. But to make the Sako extractor work the outside needs to be machined away near the business end or it won't snap over the case rim. The problem is that the extractor pivots too far beyond the .700" diameter of the bolt nose and contacts the inside of the counterbore in the Remington-type barrel. Without removing some of the end of the extractor or opening the inside diameter of the counterbore, it won't work. Marginal again.

Several years ago I wrote an article for Precision Shooting that determined bolt lug strength for a given bolt size and material strength. There was included in the article a computer code that also calculated bolt thrust developed from various cartridges. If we run the numbers through the program for our example here, the 378 Weatherby case and a standard Remington 700 action, we find that the bolt thrust value is about 12,760 pounds for a stiff handload (and whose aren't?) of 65,000 PSI. The lug strength value is greater (thankfully) at about 37,770. But that isn't near as great a margin as some lesser cartridges have in the Remington action. And with the standard repeater model the lug abuttments in the receiver are probably weaker, at least on the bottom side, than the bolt lug. The reason for this is because of the substaintial machining required for the feed ramp.

The program I used to calculate these numbers also crunches a value for lug flex at peak chamber pressure. For this example it was .0026". This means that the cases are going to stretch this much each time they're fired and explains why it becomes necessary to full-length rezise cases. This stretching isn't as much of a problem with new cases because the brass retains some elasticity and returns close to its original size for a few firings.

Oh yes, one other problem with these cases in a Remington. It is a single shot only proposition. While this won't matter to many users it might to some. My advice, when asked, is to leave the Remington 700 for smaller cases.

Best regards,

Dan Lilja”

 

[Frank Green]

read post #4 I just did on this the other day....

8mm rm to 338 lm conversion

I'm thinking of converting a 8mm rm to a 338 lm. There case dimensions are very close. What does everyone think? Is it doable? Safely.

www.snipershide.com

 

[91Eunozs]

Thanks everyone!

Greatly appreciate the input and advice based on experience.

I made the mistake of test fitting that receiver to the chassis yesterday, and it looked so good the lizard brain/excitement of maybe getting there ~ a year faster just took over! I‘m glad I wrote that last night as I was about to crash; my brain was trying to cut through the noise and tell me something.

Patience grasshopper…patience.

 

[Shoots 700's]

No

 

[91Eunozs]

As a follow up, I took the action in to be trued and fitted with a 24” barrel chambered in 280 Ackley Improved today. Gonna be right at $1K for the work and a 24” stainless barrel from Benchmark; threaded 5/8-24” for my cans. Guess I’m getting into the 7mm game now too… LoL

Now the ~7 month wait begins for them to get to my build. Have to decide on a stock/chassis too. Tempted to just go with a Magpul hunter and keep this a low budget build, but will decide soon. They sell their version of a McMillan stock (made for them by McMillan) at that shop…higher comb and a few other tweaks.

Grabbed one box of Norma 280AI ammo while I was there to measure and set up my dies (crap, gotta buy those, brass, and 7mm booleets now too), and to test mags in whatever platform I go with.

 

[91Eunozs]

No

Laconic post of the day award!

 

[45-90]

Of coarse you can...Remington built rifles on the 338 Lapua case, so the 300 NM will work.
Put the trued barreled action in an aluminum chassis made for detachable mags with long COAL of 3.715 " or 3.85" depending on Chassis. Easy, simple and works...strong enough for sane loads...but big magnum actions do offer an extra margin of safety...if you're really gonna push the pressures.

 

[BJames]

Yeah, no. Can the action handle it? Sure, but there’s not enough meat there to handle any appreciable round count, for a class, ELR match, or whatever. I was at a class with a certain person here that had that kind of build, I remember watching as he literally kicked the bolt open because everything heated up and bound up the action. It was actually pretty impressive, I thought the bolt handle was going to let go, never did. Moral of the story, it didn’t run.

 

[45-90]

So here is a 300 NM in Remington 700 bolt with m16 extractor, which allows the counterbore clearence, with the case in place,... its below the bolt diameter, as pictured.
It works...but it's not for the average guy, as the parts need fitted. So a lathe and milling machine are handy to own. Other than that it aint hard to do. True the action, increase the thread dia, then increase the barrel thread dia to match, the trued action. Chamber and thread for muzzle brake, drop in aluminum chassis, MDT mag for longer COAL and you're good to go...a cheap 300 NM that will shoot accurately.
A factory 300 WM bolt for comparison.