What chambering for mag fed .338 (ELR)?

[Dud]

I have an action that is not available with a 338 Lapua Magnum bolt face. That caliber is out.

It can take a CIP length AICS style magazine which means my mag fed ammo must be less than 3.770" COAL.

Initially I looked at 338 Edge but I'm not sure anything would fit in the magazine.

I looked at 338 RUM which is 0.090" shorter and might work in a magazine.

The problem with both is that magazine choices are limited due to the shoulder being further forward than 338 Lapua Magnum, making most if not all 338 Lapua Magnum magazines incompatible.

A wildcat that has been tried is the 338-26 Nosler. It looks like it has the shoulder in a place that will work in a 338 Lapua Magnum magazine but it is a smaller case capacity.

The 33 Nosler is weird, they bumped the shoulder back even more to fit in 26 Nosler length actions (3.4" COAL with 225 grain bullets). It seems quite arbitrary and that is why I'm looking at the wildcat.

One other thing I have been looking at is the 338 Edge +P. It has a stepped throat that reduces initial bullet engraving force to allow for more powder and velocity at lower pressure.

In terms of velocity, the 338 RUM and 338-26 Nosler run behind the 338 Lapua Magnum and 338 Edge and 338 Edge +P is probably the fastest.

I wonder, if I take the 338-26 Nosler and add a +P style throat, how close could it get to 338 Lapua Magnum performance? Same thing with 338 RUM if it works out magazine fed?

Ideally I would like to be able to load Berger 250 grain bullets or maybe something like a Hornady 285 ELD-M at magazine length without too much jump to the lands and single load serious ELR rounds like 300 grain Bergers and ~250 grain solids.

Brass is an issue. I think the 338-26 Nosler could be formed from a few flavors of RUM brass, 338 Edge brass, 28 Nosler and maybe 26 Nosler (but I don't like the idea of expanding the neck that much).

I will be using a 30"+ barrel length with a profile around heavy varmint size, maybe fluted if it looks like it is going to be over 20 lbs.

I would be happy if 338 RUM fits the bill because it avoids wildcat status but I'm slightly worried about magazines and native 338 RUM Brass availability looks very sketchy.

The 338-26 Nosler wildcat should fit in the more available 338 Lapua Magnum magazines and brass can be formed a few different ways but it might be leaving performance on the table. One more thing I might be able to do if I form it from longer brass is extend the case neck to try to decrease throat erosion. I would probably steal the neck length of the 338 Lapua Magnum. I could call it 338 Schnoz.

Mag fed, I'll shoot mostly 1,000 yards at the closer range. Single loading will be for ELR shooting and load development at 1,000 yards. I'm not sure if a 250 grain lead core bullet would do well past 1,500 yards unless it has as pretty high muzzle velocity but my range options seem to be 1,000 yards and 2,000+ with nothing in-between and both a long drive.

This is a long term project, I have the action already and the chassis coming but everything else is going to happen slow, probably a 2021 project if that.

I really don't want to have a useless magazine on my rifle and I really would like something that has a chance at hitting at 2,500+ yards, that would give me a chance to be a contender at an URSA match instead of just a qualifier with my cheapo 284.

 

[Orr89rocz]

33 nosler or 33-26 nosler is probably all you can do at 3.77” to maximize the capacity. RUM or Edge would have to be seated more like 3.8-4 to get the most out of it esp with the long vld 250-285’s.

Ofcourse you can seat the RUM to 3.77 since normal spec is 3.60 but the bigger bullets would be well into the case limiting its capability somewhat.

33 nosler alternative maybe a 338-300 prc or 338/375 ruger wildcat of some sort. Be a 2.58” case or so, like the prc, would probably work fine at 3.77”

 

[boltfluter]

No clue if it would work, but I would check out the .338 Norma Mag. May be just what you are looking for.

Paul

 

[Alex Wheeler]

First I'll say theres NO reason to mag feed a long range rifle. If you must have a mag, your best bet will be a 338 Norma improved. It with run with an edge for speed and will fit a mag with the correct throat. Pick up a Bat hr with .580 bolt and with cip mag cut. The edge/norma really starts running out of steam at about 2k. If your serious about 2500, and mag feeding I dont have any better ideas on a standard action. If you can give up the mag, the 338 lapua will run the 300s 3000fps and would be a much better choice at that distance. Look at the 33xc as well.

 

[284winner]

As Alex says, single feed a 338 LM improved. I have a mag fed platform but using the 4.0+ length cartridges, I simply single feed them for the best performance when needed.

 

[Dud]

Neither 338 Lapua or Norma have a case head that fits a bolt available for my action.

For better or worse, I'm not going to buy a new action or give up on being magazine fed.

They might be lemons but I like lemonade.

 

[Orr89rocz]

Look up threads on the 338/375 ruger demon or campfire. Long barrel and proper throat gets pretty impressive. Same with the nosler based one.

 

[Kurz]

Look up threads on the 338/375 ruger demon or campfire. Long barrel and proper throat gets pretty impressive. Same with the nosler based one.

Once again you are limiting your use to the Hornady brass so maybe 3 times fired unless you run sub-powered loads. Yes, I've read all the claims by those folks who chose this cartridge including Ric but there are some modifications to the truth and the loads when you actually shoot one of these on your own.

 

[Orr89rocz]

Once again you are limiting your use to the Hornady brass so maybe 3 times fired unless you run sub-powered loads. Yes, I've read all the claims by those folks who chose this cartridge including Ric but there are some modifications to the truth and the loads when you actually shoot one of these on your own.

The guy who did the 30 sherman mag which is the 300 prc improved said the brass on the prc is better than the 375 ruger. Maybe you could use that instead?
If it still a concern use the nosler stuff then. Adg is making 28 and 30 nosler brass

 

[LA50SHOOTER]

ADG manufactured 28 Nosler brass necked up to .338 cal. - Shoot either 250 or 300 gr. Berger OTM Hybrids using one of the slower powders.

That's my recommendation to the OP in light of what he's said.

- Ron -

 

[284winner]

Neither 338 Lapua or Norma have a case head that fits a bolt available for my action.

For better or worse, I'm not going to buy a new action or give up on being magazine fed.

They might be lemons but I like lemonade.

Sorry, mis read your first paragraph. I read that you had a 338 LM boltface. I read it wrong.

 

[Kurz]

The guy who did the 30 sherman mag which is the 300 prc improved said the brass on the prc is better than the 375 ruger. Maybe you could use that instead?
If it still a concern use the nosler stuff then. Adg is making 28 and 30 nosler brass

Thank you for the suggestion.

I (we) have been shooting over 1,000 pieces of 300 PRC brass for last couple of months. None have made it past the 3rd reload with reasonable loads, not overloads. It's not the case design or the cartridge, it's the manufacturing. No offense meant but we shoot all day every day and we understand the parameters for testing.

 

[Orr89rocz]

Thank you for the suggestion.

I (we) have been shooting over 1,000 pieces of 300 PRC brass for last couple of months. None have made it past the 3rd reload with reasonable loads, not overloads. It's not the case design or the cartridge, it's the manufacturing. No offense meant but we shoot all day every day and we understand the parameters for testing.

Well that is disappointing for hornady brass. I guess that would rule out a 338 on those case designs until someone else makes brass.

 

[Kurz]

I think a lot of the opinions are based on using the loads which are either mid-range or slightly lower where case life should improve. But you sacrifice the number of loads as the pressure increases even though you're not over pressure. That's why brass from Lapua, ADG, Peterson and Alpha are represented as being better quality, the brass used and the design of the case is improved for the upper levels of pressure. Hornady is building brass for the much larger, middle of road group of users.

 

[moondog]

I did a 300 PRC knowing the brass would probably suck. I kept 50 pieces back for load development and to see how many cycles I would get. I'm on my 5th cycle on it and so far, so good. I have 200 pieces 1x fired I will use for matches. Until somebody starts making good brass, I'm ok with it for now.
On the plus side, it's cheap.

 

[Dud]

I think you are giving Hornady some weird type of credit. The number of loads it can handle at the primer pocket is determined by how thick the case head is and how strong the brass is.

The strength of brass is determined by the alloy, the heat treat and the work hardening.

Saying that Hornady makes brass that can't survive nodes that don't show pressure with swipe marks, sticky bolts or flattened primers and does it intentionally is bizarre.

Hornady should be big enough to precisely spec the brass alloy they use. Tuning the heat treat should be fairly straightforward. Unless they are screwing up the case head dimensions or have a forming process that doesn't work harden the case head properly, they have no excuse.

I'm going to look in to that ADG necked up 28 Nosler brass.

 

[DaveTooley]

338 PRC I have reamers and dies. ADG is currently working on 300 PRC brass. ETA 1st quarter 2020.

 

[Dud]

I took a look at 300 PRC compared to the 30-28 Nosler wildcat. The PRC is shorter to the shoulder and not a rebated rim so narrower too. Despite those two dimensions, the claimed/measured capacity in grains of water is only off by a couple grains.

That doesn't seem right to me.

Also, I have seen a few reviews of ADG brass that say the primer pockets get too loose after three reloads. I'm not sure if I should believe that but at $2+ per case, I would like better life than that.

One thing about the Nosler wildcats is that it looks like they could be formed from RUM or 338 Edge brass which would let you choose as long of a case neck as you would want. That might improve barrel life.

 

[Alex Wheeler]

The problem is you said 2500+ yards. Even for informal plinking a 338 edge with 300 hybrid starts to get unpredictable past 2000. If mag feeding and a repeater with standard bolt are needed then Id look at a 30-28 Nosler. Its about 3.7 with a 215 where it should be. I started doing the 30-28s to help case life with the nosler brass, no one else was making it at the time. But its not a 2500 yd round. More like a mile.

 

[Dgd6mm]

Maybe I'm wrong, but I don't see 2000+ to 2500 yards happening with the action you want to use. Hopefully you can prove me wrong.