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Does anyone shoot ELR with a 284?

CIP is the colloquial name for the original 3.850" outside length 338 Lapua AICS magazine. It'll take rounds with a nominal COAL of 3.75".
Wait a sec...I thought it stood for "Commission Internationale Permanente", I thought it was similar like SAAMI...I could be wrong.

I don't see that 300 WSM on SAAMI, just looked again, nothing comes up for WSM when I search on there. No worries. I think that Lapua LM is the same as the 375 CheyTac in regards to COAL. I have a 2nd blank I could do that long, but only have the one I plan to use for 375CT and one other. Both will be tactical style. I have 2 x tube style Rem 700 blanks. I do plan to mount at least one of them in an AICS chassis. Seems the 300 PRC or 300 Norma would be possible in that same length. I have shot the 338 LM, it is a powerful cartridge, but I think I can get a better cartridge that uses the same or less powder.
 
Damn, there's always some downside...to every cartridge...Do you use Norma brass? I see there's no Lapua or Peterson brass for it...but Shaun mentioned the 33XC, Peterson sells brass for that, but an entirely different cartridge which won't fit in a short action.

I don't think the 300 WSM is SAAMI spec'd, is it?
You can get good brass for 7 saum and 300WSM
That’s why 7/300WSM is more popular than 7WSM

I avoid Norma brass, it’s decent but soft.
Lapua, ADG, and Peterson make good brass.
 
Wait a sec...I thought it stood for "Commission Internationale Permanente", I thought it was similar like SAAMI...I could be wrong.

I don't see that 300 WSM on SAAMI, just looked again, nothing comes up for WSM when I search on there. No worries. I think that Lapua LM is the same as the 375 CheyTac in regards to COAL. I have a 2nd blank I could do that long, but only have the one I plan to use for 375CT and one other. Both will be tactical style. I have 2 x tube style Rem 700 blanks. I do plan to mount at least one of them in an AICS chassis. Seems the 300 PRC or 300 Norma would be possible in that same length. I have shot the 338 LM, it is a powerful cartridge, but I think I can get a better cartridge that uses the same or less powder.
375 cheytac is substantially longer than 338 lapua
My 338 edge runs 4.2-4.25 depending on what bullets I run and it’s closers to cheytac than lapua.

300 rum outdoes 300 Norma and PRC with good and available brass.

The common 300WSM f class reamers would be excellent for ELR as they are single load with appropriate freebore.
 
Wait a sec...I thought it stood for "Commission Internationale Permanente", I thought it was similar like SAAMI...I could be wrong.

I don't see that 300 WSM on SAAMI, just looked again, nothing comes up for WSM when I search on there. No worries. I think that Lapua LM is the same as the 375 CheyTac in regards to COAL. I have a 2nd blank I could do that long, but only have the one I plan to use for 375CT and one other. Both will be tactical style. I have 2 x tube style Rem 700 blanks. I do plan to mount at least one of them in an AICS chassis. Seems the 300 PRC or 300 Norma would be possible in that same length. I have shot the 338 LM, it is a powerful cartridge, but I think I can get a better cartridge that uses the same or less powder.

CIP is an acronym for a real organization and they are the euro version of SAAMI.

Where it became slang was when we started using it to describe the length of a magazine. It's also a bit of a whine because that magazine is too short to load 300 grain bullets to their optimal length in 338 Lapua. The standard was set when 250 grain bullets were the norm. 300 grain bullets can be loaded to magazine length, but some of the luster is lost because of the reduced powder capacity.

The original AICS magazines had just 2 different lengths. One each for the 300WM and 338 Lapua. The chassis were not interchangeable. The US military came up with an intermediate length AICS pattern magazine to fit longer 300WM rounds under a R700 in a more traditional stock.

Beyond length, there are different feed lip configurations. The most popular 300PRC AICS magazine is the 338 length with the 300WM feed lips.

Beyond the feed lips, the ribs on the side of the magazine act as case guides. Their depth isn't random. The 300PRC will feed from either a CIP length 300WM or 338 Lapua magazine. A 300RUM or 30 Nosler will feed reliably from just the Lapua mag because the case is another 0.020" in diameter. If you get the itch for improved cases and want to magazine feed, checking here early in the process can save some problems later.

I have a 26 Nosler in a R700 that uses the military length magazine. I had to mill the stiffening rib out of one side to get the rounds to feed without sticking in the magazine. I'd learned my lesson when I did a 7/300wsm throated for 190 grain bullets in a 300wm Ruger American. That rifle uses 300wm length magazines that have the 338 Lapua feed lips and stiffening ribs. Some AICS magazine manufacturers are like Burger King these days, you can have it your way.

The 300wsm is on page 108 of the SAAMI Velocity and Pressure Data.

The 375CT is heading on an inch longer than a 338 Lapua when both are loaded with the most popular contemporary ELR bullets into the neck.

Given similar barrel lengths, pressures, and levels of bullet technology, a 300PRC approximates and slightly exceeds the 338 Lapua. Not enough to matter. There is a significant contingent out there that is fascinated by the 338 Lapua. If that's what it takes to get them involved, great. For years, it was a simple and reliable entry level path to ELR.

A 230 ATip will have about 0.050" jump in a standard 300PRC chamber when loaded to CIP magazine length. The 300 Norma approximates the performance of a 338 Lapua Improved. Historically, the 30 caliber was at a disadvantage to 338 on BC. The velocity for BC tradeoff didn't work for the 30s. The introduction of the ATips changed that.

I'm well stocked on powder. Sometimes wait for bullets. Have product arrival notices and backorders that haven't popped in over a year for brass. I don't remember the last time I saw 215M primers for sale. I do remember that they were $60/1000, thinking the price is steep and I still have over 5000 on hand when I ordered another 5000. I'm shooting those primers now and $60/1000 looks pretty good today. My point is powder isn't the biggest problem.

The R700 has some limitations that may apply to what you're intending to do with it. Many aftermarket actions get past some of them, so there is hope.

For decades, it's magazine length limitations meant death in the marketplace for new rounds that exceeded 2.8" or 3.38" lengths. They can be overcome to some degree, but I'd have the chassis and magazine in hand when I started making changes to the feed port. Conceding the point on using a magazine will also remove the need for feed lips but you want some sort of stop to prevent overfeeding the magazine. I'd start with removing the ADL taint, but that won't always help because of where some chassis place the magazine.

The lug size and tenon diameter are disconcerting to some when they're used with the larger diameter contemporary rounds. I think they're OK if you pay attention but understand that further steps into stupid might hurt. The 0.175" section of brass that projects out of the barrel is the traditional fuse for the system. It's a misconception that the bolt supplies any support to that area. Some of the newer cases don't have external belts anymore, but that area is filled with brass so the fuse might have a higher amperage rating than what it's protecting. With both the barrel and action, use form tools for threading and not a piece of tool steel ground to a point. Stop the treads on the action well ahead of the action screw. Leave reasonable clearance for the bolt on the diameter just ahead of the lugs and don't leave a sharp corner at the lugs at the thread diameter. If I was making my own for the uses you're contemplating, I'd switch to 1.120x20 threads. Maybe 24 tpi. I think Winchester went to 28 tpi on 1" tenon actions for the WSM.
 
Hi, I have a couple 6.5 Creedmoor rifles which have been great out to 1,000 yards but my ballistics charts are telling me that trying for 1,500 is a stretch and hitting at a mile is probably more luck than accuracy.

The thing I love about them is I can shoot all day with pretty much zero fatigue.

Shooting bigger stuff like .338 LM or .50 BMG is a lot harder on the ears, the shoulder and the wallet.

I want to find something I can shoot without a brake that won't beat me up too bad and won't be ridiculously expensive to build or shoot.

It seems like 284 Winchester is the efficient cartridge that will stay supersonic out past 1,600 yards with just slightly more expensive brass (about 15%), about 20% more powder and 180-ish grain bullets that seem to cost about the same as 140-ish grain 6.5mm bullets. Barrel life should be a little less but negligible with the infrequent times I can actually shoot more than 200 yards. I think reloads work out about $0.05 more expensive per round than 6.5 Creedmoor or .308.

I'm planning to build two rifles over time.

The first is based on a Savage Axis long action in an MDT LSS chassis using a 3.560" magazine, and an Indian Creek Design P-Body 2 stock with an STFU folder.

What I learn from that rifle I'm going to apply to an ARC Archimedes long action in an ARC Xylo chassis.

Both actions use a Savage small shank barrel thread and will take a Savage Pre-fit barrel.

Getting down to the big question, I'm looking at buying an X-Caliber .284 Savage Pre-fit barrel that I can try out in both. It will be 31", the longest offered, in a "light varmint" contour, 416 Stainless and cut with a PTG reamer.

I'm having a hard time figuring out exactly what the chamber specs are supposed to be but I'm also wondering if PTG can actually grind a reamer right. I had a bad experience the last time I dealt with PTG.

Should I trust X-Caliber to make a barrel that will push good velocity without excessive pressure?

If it was a common chambering and I could get a review of a barrel cut with the same reamer, I wouldn't be worried but I can't find a matching review.

I have a few rifling options. There is a 5R option but 1 in 8" twist. There is a 1 in 8.5" twist 3 groove option and a 6 groove 1 in 9" twist. The two I think I can rule out are 6 groove 1 in 8" and 1 in 10" twist.

I think I should probably go for the 3 groove 1 in 8.5" even though I would like the 5R.

The good part about this barrel is that X-Caliber has a 30% off in August promotion which will bring the price down to $343 with 5/8-24 threads, a thread protector and the contour should allow it to be set back at least once.

I'll eventually get a shouldered barrel for the Archimedes but am I making the right choice to start with the X-Caliber barrel?

I'm going to order 6.5-284 Lapua brass, a couple boxes of Hornady 180 grain ELD-M bullets and some Berger 184 grain bullets tonight.

It sounds like H4831sc is the powder of choice for decent MV without a ton of wear.

I will be throwing my charges with an Auto-trickler, resizing with a Hornady Match bushing style full length sizing die and seating bullets with a Hornady micrometer seater.

I may upgrade my dies later if necessary.

Small questions: what is the best die to use for necking up to .284 and what primers should I try for this combo?
No way a .284 win is going to be supersonic at 1 mile. With Berger 180 gr hybrids, you’d have to have a muzzle velocity over 3300fps to even have a remote chance at being supersonic at 1 mile, and that ain’t happening with a .284 win. Better look elsewhere.
Dave
 
No way a .284 win is going to be supersonic at 1 mile. With Berger 180 gr hybrids, you’d have to have a muzzle velocity over 3300fps to even have a remote chance at being supersonic at 1 mile, and that ain’t happening with a .284 win. Better look elsewhere.
Dave
I am working out to a mile here and should be ready next month. I shoot between 4500 and 5000'. JBM says my .284 at 2834 FPS will still be running at 1222 FPS.
 
It doesn't need to be supersonic for good results on ELR targets in the 1.5-2 moa size range.

The ELR end game is deep transonic and below Mach 1.

This is old news.
Yes sir, BUT.

On all my rifles, up to transonic, it is usually quite easy for elevation at a given distance. Transonic and subsonic make things complicated ( and fun indeed)

But staying in .284 cal, a 7 SAUM with 190 Atip @ 2850 ft.s-1 should stay supersonic up to 1 Mile.

I'm attending a multi caliber LR comp at the end of the months ( Lords Of Steel in France), I'll let you know how the theorie works in practice :-):

  • 22LR (RWS R100) from 200m up to 500m
  • medium cal - 6.5 Creedmoor (153 Atip @2710) from 442m up to 1174m
  • Magnum cal - 7 SAUM (190 Atip @2850) 549m up to 1582m
 
Welcome to the rabbit hole and I hope you enjoy that competition.

With the exception of the 22LR, those distances make staying supersonic practical. They're generally considered Long Range and not Extreme Long Range.

My comment on the availability of bullets that'll perform well through the transonic range being old news is based on the US military's program in the mid 90's to extend the range of its 7.62 sniper ammo. The 175 Sierra Match King was the result of that program. The 5.56 77smk was another result. Their updated boat tail configuration spread through the industry after that. That program was more application than raw research. I have a paper from the mid 60s that investigated the impact of boat tail geometry on bullet stability. That research likely wasn't available to Sierra when they designed the 168smk in the late 50s.

10 years ago, you'd be shouted down for suggesting you'd hit anything at significant distance with a subsonic bullet. It was the internet consensus but hadn't been true for a long time.

There are still bullets that won't transition, but transitioning is also often blamed for other problems.

10-15 years ago, as solid bullets became more popular for ELR, there were a few manufacturers that were capable of manufacturing bullets but not very good at designing them. Untested claims for very high BCs sold them. When they tumbled by 1000 yards, it was blamed on transitioning being impossible. The real problem is they were never gyroscopically stable to start with. Some of them needed more twist than was in common use. Several of them wouldn't settle down regardless of the twist.

Currently, the transitioning thing is often blamed for what are actually the accumulated effects of velocity and BC variations. If you give up on longer distances or search for other bullets that will transition better, the real issues won't be addressed. This is an easy misconception to form if you only shoot at one distance.

Once cartridges with case capacity to bore area ratios larger than about the 28 Nosler, 300 Norma, 33XC, 375CT, and 416 Barrett are required to maintain supersonic velocities, the overheads of what more case capacity does to the barrel throat makes them more trouble than they're worth if strings of much more than 5 are needed for the COF. The 28 Nosler is probably just over that line. The 300 Norma and 375 CT are just under it. The 33XC and 416 Barrett are standing with their toes over the ledge and it's easy to push them over. It's not just how long the barrel will last, it won't be long. It's what happens to the velocities during that short life and how well it treats the bullets. The consistency and predictability of velocities deteriorates, as does the BC consistency. By the time a barrel on that line stops shooting decent 100 yard groups, it's been past its prime for targets beyond a mile for quite some time. The combined effects of erosion, chemical attack, and differential temperatures compound so the "barrel life" deteriorates far faster with each step up in case capacity. At the same time, the overbore effect is reducing the velocity increase from each step.

The same general comments apply to chasing velocity with extremely high pressure or double base powders. Combining large case capacities with double base powders and high pressures is a common mistake. The rounds impress the chrono and shoot decent 100 yard groups for a short while but have so much dispersion at 2000 yards they paint a vertical stripe 4 targets high in calm conditions.

Similar comments apply to bullets that over emphasize BC and under emphasize BC consistency.

Testing the gun for these effects at 100 yards is another common mistake. Nothing will be found. The testing must be done at a mile or more. The opportunities to shoot those distances into a target with a steep backstop in still conditions tend to be limited, so this one is taking a while to soak in. It's discussed in the latest Litz book and if you're at an event where AB is doing CDM testing, it'll show up there as well.

So, there are practical limits to how far staying supersonic will work. After that, the game becomes BC and velocity consistency. No, it's not easy. That's the point of chasing it.
 

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