Discussion in 'Big Stuff -- 6.5mm, 7mm, 30 Cal' started by rpierce, Sep 10, 2018.
Dang, is that sexy!!
I was assuming that since the bolt diameter was bigger that the mating action would also be bigger. In this instance maybe not. That's the only way a bigger bolt body makes any sense to me. On with your regular programming.
I believe the only lapua bolt rem clone that went bigger in diameter is the tac338. The others, bat, kelbly, defiance, are still 1.350". Id like to see a 1.4" myself.
Lugs and abutments are one thing, maybe a good topic when talking about flex in an action, but not something I concern myself with when it comes to strength and safety. It's a pretty insane amount of pressure you would have to create to shear lugs or heavily damage abutments. Something like leaving a cleaning rod in the barrel of the rifle and firing a round...seen pictures of that actually happening
My safety and strength concern with a .700" bolt is your face is a lot weaker. Not much left on something like a Rem 700 after opening it for a Lapua case. You pop a primer with a hot enough load in a Lapua size case and you might blow the bolt face apart with it. The .750" bolts give you that little bit of extra meat around that big fat Lapua case rim for extra security.
Hell, I've completely blown apart a remington bolt face with a 204 Ruger when I screwed up on a powder charge many years ago.
Dave Tooley and others have measured lug setback on Bolts chambered in 338 Lapua. If they move they can fail. One of the reasons many gunsmiths wont chamber a Lapua on a Remington. Then you have the thin area around the bolt head. Matt
I just had to turn down a barrel job on a rem action with .005" setback in the lower lug. It was caused by a case head separation on a 7 mag. The case was still stuck in the old chamber when in came in here. That lower lug is not as strong as a guy would think, in a factory 700. Most of the customs have left more material behind that lower lug. I wont build a lapua based build on a rem 700. Customs only for me.
I agree. Building on a factory 700 isn't worth it. Ive completely stopped using factory actions. By the time its fixed up you have more money in it than a custom. Theres a ton of actions out there now for the 900-1000 price range with a standard mag or 308 bf. For lapua bolt face actions Kelbly has theirs for 1100 which is the cheapest one I know of. I know they've already sold a ton of them. Otherwise a guy can snag a few others out their for a little more money. Im going to be building myself another 300 norma improved but this time it will be lightweight. I have a Lone Peak Fuzion Titanium that's full nitride treated, Proof carbon barrel, Manners Eh1 stock in a bdl setup. Ill put my 5 port on it to kill the recoil. Ill also be putting the new Kahles K525i on it. Should be about 9.5 lbs with optics and everything. I looked through the Kahles K525i last week with a NF ATACR next to it and the Kahles was slightly clearer/brighter. That rifle will be the ultimate long range hunting rifle in my opinion. Ill probably try and get the 215 berger around 3300 in this build just cause its a pure hunting rifle and won't get shot hardly at all. Shouldn't be a problem at all with VV N570. I had 3200 with h1000 before I saw any pressure signs and it wasn't much. Could barely tell the primer pockets were slightly looser than the 100 fps less load. Web hadn't expanded much more either.
I never tried RL-33 in my Norma Improved 30°, only H1000 & Retumbo. They both get a 215 up & over 3200 from a 28" Bartlein, with ease. I suspect '33 could pile another hundred+ FPS on top, as it seems to in on their cartridges, almost by default!
The 300Norma is a BADAZZ, and 'improving' it only makes more of a good thing. You're definitely on to something, with both the cartridge and the choice of bullet. The balance of speed & b.c. that the 215 Hybrid allows make the downrange performance tough to match with a heavier boolit. Best of luck!
P.S. built mine on a Deviant LA, w/ integral,rail & lug, .750" bolt & extended tenon. IMHO, match made in heaven for a (Norma Mag) cartridge designed to shine in a 'standard length' Long Action...
I would like to see a pic of that action. Matt
Stupid question time...............
Bat MB 1.55 round, would this action be sufficient, with the proper bolt face, for a 300 Norma Improved???
3" port on the action...
They dont do a lapua bolt for the B sized action. The M is the way to go.
That settles that.........LOL....
Guess I'll be that person but I have a 300AX (30-338 Lap Imp) that was built on a chromoly Rem 700. Bolt face was opened up and a M16 style extractor installed. Had it built a few years ago and have not had a single problem with it. All I've ever shot in it are the Berger 230's. My accuracy load is 106gr US869 and that load sends them out the end of the 28in tube at 3250. I've run it all the way up to 108gr and the speeds were crazy fast but it shoots extremely well with the 106gr load and I've yet to through a piece of brass away.
I think these things can be built on Rem 700's without any problems but like most things, discretion and common sense will be your friend.
I've seen major bolt set back in a couple Defiance actions with Lapua improved cartridges, set back far enough the bolt handle was acting as a lug as well.
Every Remington action I've taken apart was set back with a Lapua size case, while I haven't done a truck load of them the only actions I have not seen set back in is the Stiller Tac 338.
Between the Lapua brass and the improved case design they can take and mask a lot of pressure!!!!
In 2019 Jim Borden (Borden Actions) is supposed to come out with a “true” 338 Lapua sized action. (As per Greg Taylor the leading Borden Action distributor) - will be interesting to see as Jim produces some of the highest quality actions I’ve seen.
Otherwise I wouldn’t go with anything smaller than a BAT model M OR an action with a barrel tenon any smaller than 1.125 in dia. for anything on the “Lapua Magnum/Norma Magnum case head size.
Yep, tenon size is important. Can cause extraction issues if too small. Matt
I believe the Surgeon XL is a larger diameter. But it is a flat bottom...not a Rem 700 clone.
Yes it is. I have one. Its more like a steel panda. Its a chunk!
Ok, so is bolt set back seen mostly with the Lapua cartridges, or is it prevalent with the RUM cartridges also?
I plan on building a lightweight 300 NMI with my reamer as well. Probably just use the Defiance Deviant Hunter since I can get a good deal on them. Put it in a AG Composite stock with a Proof carbon barrel. Then throw on a NF one piece mount, a lightweight scope, and Javelin bipod. Should work out pretty well.
Are you planning on making your 5 port brakes in titanium? I know Beast brakes are becoming available in Ti, just wondering if you are planning on doing the same? Makes a big difference in keeping a rifle light, especially when they need a big 5 port to tame them. Thanks.
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