I have a Rem XP-100 receiver I want to turn into a rifle and have been casting around for some cartridge cases that would work in the smaller calibers...something I don't already have at least two of, something that will work in the action without having to carve it up and something with some real hair for whacking sage rats and such.

I looked at the BR cases because this XP was originally a 7mmBR and that case would be an obvious good choice, but again I have a 6BR, don't want another 6.5mm or 7mm, thought about the 30 BR, went nutz thinking about calibers all the way up to 45 before I woke up and started research on the WSM and WSSM cases.

What I found was for the smaller calibers the WSM has some powder/pressure ratio issues that's why Win didn't bother with using it and went to the WSSM case instead...so I figured they have already done the leg work why do it again.

I started researching the 6mm, 25 and 6.5 cals and thought the 25 WSSM fit perfectly...UNTIL I compared it to my Rem 788 250 SavAI and the 257 Roberts AI.

I took the data generated by Load from a Disk, Hogdons 2006 load manual, the data generated by my 250 SavAI and found that the 25 WSSM, while being the BEST choice as far as case length, COAL...and looking TOTALLY NARLY on paper...the NET loaded case capacity with seated 75gr Sierra HP was nearly IDENTICAL TO MY LOADS...49.879 gr H2O in my Sav and 49.465 for the 25 WSSM!!!!! and by playing with the seating a few thou I ended up with a net of 49.881 in the WSSM.

Not only that but the load my 24" barreled rifle shoots most accurate and gives 3560fs with RL-17 and 1/2" groups, gives almost the same velocity and pressure as AA2700 which is very close to RL-17 on the burn rate tables, in the 25 WSSM...LD doesn't have any RL-17 data yet.

AND...by comparing the 250 SavAI LD predictions with the Hodgdon 2006 manual, the results were again almost identical...giving identical velocity and pressure numbers...

I've been at this game for a while and noticed that equal case capacities gave equal pressure/velocities generally, caliber size notwithstanding, but until today I hadn't compared two DIFFERENT sized cases with identical case volumes as closely.

If I actually do a 25 WSSM using the Rem XP-100 receiver I can expect to achieve slightly higher velocities simply because the receiver is stiffer and has front bolt lugs, while the rear lugged Rem 788 suffers from more case stretching which I've observed in several Rem 788's and other rear lugged actions.

As far as "efficiency" is concerned, identical powders with identical weight amounts, identical bullets, primers and case brands, gave identical velocities and pressures...it seems to end up not having anything to do with whether the case is short and fat or long and skinny at least in this case...just what the case volumes have to say.

This observation may or maynot hold, but it would be interesting to get all the apples and apples together with other cases and see what transpires.

Nothing is new under the sun seems to fit here as in many other areas. Any one of the shorter WSSM calibers would work much better for my application in the XP receiver, without have to do any mill work, as would the other iterations of the 22-250 case...But I can mill the receiver and bolt stop to handle a 2.8" max COAL if I wanted to use a 308 case...25 Souper or AI version...

This does point up a thought I've had in the back of my mind these many years...there are many roads leading to Valhalla...unless you keep your eyes open and keep moving something's liable to jump up and bite you in the po po.

Food for thought.

This wildcatting is ALWAYS a fun thing to do.

Any observations or actual experience or good links for the WSSM cartridges will be appreciated.

Thanks

Luck

Foobar, I have been visiting www.wssmzone.com thinking about a 25wssm ar upper for a m-4 lower I have sitting around, there is good information there that you should be able to compare to your real world data.

Good luck on your project and keep us posted on what path you choose

You will find your velocities are very similar. I use 260 Rem brass for the 257DGR because it is the least amount of change in neck dia. The cses is slightly improved with a 30 degree shoulder, a .286 neck dia., and a .300 neck length. Velocities with a 75 gr are aroun 3700 depending on the powder from a 24" barrel.On the average it is a little over 100fps faster than my 24" barrel on my 250AI. Brass quality is better and brass life is longer.

www.duanesguns.com

Thanks for the links.

I have looked at your 257DGR several times over several years, Duane and thought it was an excellent case design (I like the long neck and 30° shoulder angles) and your rifles are boss, just never had a reason to build another 25 cal until now. I also wanted to do a 257 RAI barrel for one of my Savage LA's to compensate for selling my Rem Sendero 25-06, that was totally dumb after all the work I put into it bedding and trigger work and the load workup(3 stiff, bughole loads - 75 Hor VMAX, 100 gr Nosler and 120 gr Hornady) ut the guy offered twice retail cash...money talks for sure...and I bought it for 10% over dealer price...but other projects kept getting in the way.

I think I might do the 25 WSSM in 22" and a very light weight skeletonized stock for a walkaround and a 28", 25 ca...something for a Savage switch barrel for longer ranges, but I keep waffling between 25 cal and 6.5 cal. The 0.007" difference in bullet diameter doesn't mean much, but an additional 20 gr bullet weight at high velo and the much better BC of the 6.5 keeps waking me up at night.

What is the case capacity for your 257 DGR anyway...and OAL for the 75 VMAX?

I've always been partial to 30° shoulder angles and minimum tapered cases...they just look right.

Thanks again

Luck

Foobar, You said "Anyone of the short wssm calibers would work much better for my application in the XP reciever, with out any will work."
Does opening the bolt face up from .473 to .535 not count as mill work?

Good observation...

Yes, bolt work is mill work...BUT...I was refering to mill work on the receiver in relation to the 25 WSSM loaded OAL...I can extract a loaded cartridge 2.50" OAL as is without doing any receiveror/bolt stop milling work, so my thoughts that the WSSM case is optimum as far as case capacity and length is concerned still holds...but as with all futzing around with ANY kind of rifle/pistol work you have to start with a premis and work through the factors as you encounter them.

I would probably be dollars ahead just to buy a factory rifle and be done with it, but I like to fiddle and a receiver lying around without a barrel hanging off it just looks wrong.

There is also the 284 case to consider... shortened to ~1.85"-1.90" it gives about the same case capacity as the shorter WSSM, not quite as good a volume to length ratio but very close, stays within the 2.50" existing OAL case length limit and doesn't require any receiver/bolt/bolt stop or rim reduction...just squashing down a bit.

I changed the bolt over to a Sako extractor many years ago and it measures 0.480" ID on the face now and I wasn't planning on doing any bolt mods, just case mods if I choose the WSSM case...the case extractor groove will require a bit of reducing, maybe ~0.050"...not a whole lot.

Recutting rims is a fairly simple tool grind and set up...chuck the case in a 35/64" 5C collet set the length and depth stops, run the tool in, pull the tool out...one finished case...should be able to turn out a hundred cases in a couple hours even for a slow metal man like me...silver in his hair, gold in his teeth and lead in his azz...nothing more than a home grown, slightly more "rebated" WSSM case.

I've done similar "massaging" to Rigby and Gibbs cases, 45-70 cases and Rem 6mm Bench Rest small primer cases(to use with a 378 bolt experiment way back) to get them to work without resorting to major bolt face mods. No big deal and as far as I have experienced, no problems in extracting or pressure.

Or have a correct sized bolt fitted.(probably won't)

I'm still fiddling with all the parameters. I like to work through the thought experiment visualizing as much as possible to see where the path of least resistance goes, do some mock-ups, run a cost and "hassle" analysis, then decide.

This project is still in the early thought stages and I can't get into my unheated shop for several months yet.

Luck

quote:

As far as "efficiency" is concerned, identical powders with identical weight amounts, identical bullets, primers and case brands, gave identical velocities and pressures...it seems to end up not having anything to do with whether the case is short and fat or long and skinny at least in this case...just what the case volumes have to say.

I'm not certain anyone has stated that you get higher velocities from the WSSM case over another case with the same capacity - other than what you'd get from their higher SAAMI chamber pressures. What most have said is that the ballistic consistancy is better with shorter cases. This translates into improved accuracy at longer ranges and has been proven on the target range for decades. Pesonally I'm glad we have so many choices in case design to play with.


.

That was the point of the comparison...

When the WSSM cartridges came out I read a whole lot of "stuff" coming from many directions...and for the 25 WSSM statements such as "it's equal to the 25-06", or words to that effect, was and still is used, and the published ballistics bear that out, somewhat, so it is "guilt by association".

No diss or flame intended and as I said, I think the WSSM cartridges fill a niche and are excellent propositions.

I read a lot of VS this and that, but not all that much actual apples to apples comparisons...and the threads many times turn into grown men going back to the sandbox and throwing sand, sad to say.

I totally agree with you about choice. I see "efficiency" and "ballistic consistency" as being the pretty much the same thing, but that is more semantics or depends on your/my interpretation...or not...all those factors concerning case size, shape, shoulder angle and so forth have been chewed on and chewed up for as long as I can remember...well before the net was even a glimmer in the mind of it's maker.

We shooters have certainly learned a few things over the past umpteen years, components, reamers, dies, barrels and all the rest are totally cheap today as compared to yesteryear in relation to paychecks.

I'm just glad I have a computer with software where I can design a case while I eat breakfast, run some pressure/velocity/component predictions until noon and actually order a reamer and dies before afternoon break...and have the reamer/dies/barrel within a couple weeks and a rifle built from beginning to end and taking game in about a month.

Doing it in the old days meant breaking out the drawing board and doing it all by hand and it taking months and months for the hardware to come in...THEN having to work up the loads the old fashioned way...by guess and by golly sometimes with a very small selection of powder, primers, brass and bullets.

The last reamer PT&G did for me cost $135 plus shipping...that's less than 3 hours pay when I was worth something and last working for a living, and most standard dies run 30 bucks or so and even custom run less than $100...I mean, what's NOT to like...or whine about.

People that carp about "there is absolutely no use for a..." have NO idea just how GREAT it is to have choices nowadays.

All I did was compare two cases as closely as I could using the same components...apples to apples, then make an observation that seemed to fit my experience and thoughts...so it might light up a dark corner.

I know what ACTUAL velocities I could attain with the 250 SavAI and the 25-06 Sendero with 75gr VMax, 100gr Noslers and 120gr Hornady SP's, but I can't compare directly, those components in the 25 WSSM. I know what the published data indicates.

If you compare the 25-06 and 25 WSSM pressures/velocities/powders and bullets in the 2006 Hornday I think you will be surprised. The Devil is in the details and the fine print.

If you use the smaller case with a powder that is has a burn rate design that works better for that size case it will appear much more efficient, yet if you use a powder designed for the larger case you will gain a percentage, of the percentage of the difference, in case volumes, in higher velocity, for the larger case...and be just as efficient...for all appearances...Madison avenue just LOVES confusion, just as a good? lawyer does.

The 25-06 still has ~18% larger case capacity so it will always use more powder and handle the heavier bullets at a higher velocity...and that isn't saying anything other than case capacity and cubic inches make for a faster bullet or lower E.T...as it always has.

And that's the rub when you start comparing apples and Whopper Jr.s...the only thing they have in common is you can eat them.

Luck

quote:

I see "efficiency" and "ballistic consistency" as being the pretty much the same thing, but that is more semantics or depends on your/my interpretation...or not...

Actually I meant two different things - in my mind anyway. Efficiency is usually defined as velocity per grain of powder. Smaller cases are always more "efficient" - all else equal. But when I said "consistency" I meant that the velocity spread of x number of shots is lower with the shorter cases. This has been proven ad nauseum and is probably the biggest real world advantage for the shorter cases....but only at longer ranges where the short case accuracy is better.



.

FOOBAR,
You can shorten the bolt stop on your XP to eject 2.8" ctgs. OR get a bolt stop for the 600s.....If you don't want to change to an aftermarket one that is more user friendly.

Bob

Thanks, Bob...I hadn't thought of that yet...I will check out the parts people for a 600 bolt stop...the XP, 600, 660 are basically the same receiver, so there might be some difference in the angle/hinge point for the 308 size/length cases and the 7BR. I will start digging for data.

I would have had to reshape the OEM stop or make a new one, to gain more than about 0.100" from milling it without your suggestion

If this winter keeps up it will be May before I can get in to do any lathe/mill work anyway.

Hurry up and wait...story of my life.

I've been tearing the net apart finding pieces and parts...reduced the choices and decided to do the 257 Roberts AI...which saves mucking about with case and bolt mods.

Barrel from ER Shaw overstock or Midway $65-$90, Richards Micro stocks close outs $50-$80, Lee dies $31, $50 reamer charge, $65 Jard trigger replacement parts, and make a receiver bedding block or pillars. I have plenty of 25 cal bullets and 7x57, 8x57 brass...all in all not too bad for this cheapo old, bald, snaggled toothed fat boy...a nice shootable rifle for a trip C note...can't get much cheaper than that.

I LIKE IT

The Roberts case is ~60 gr H2O so 75 gr Hornady VMax at 3800-3850 fs plus will keep the sage rats begging for mercy and 115 Nosler Part at almost 3200 fs will do for the rest, but I doubt I will use it for anything other than sage rats...basically ~75-100 fs more than the 25 WSSM, the same less than a 25-06 but it will fit the XP and all the comnponents are cheap and plentiful.

My eyes are falling out working through all the data crunching.

I'm HAPPY...HAHAHAHAHAH

Luck

3200 fps with a 115 grain Nosler Partition from a 257 Roberts seems on the high side to me, but I am a conservative reloader. I load to 3200 fps with a 100 grain bullets, but more like 3K fps with 115/117/120 grain bullets.

My chart shows the 257 Roberts with 55 grains of case capacity and the 25-06 with 66 grains of case capacity. Since the 25 WSSM has more case capacity than the 257 or 257AI, measured at 63 grains in my once fire Federal brass, I think that when loaded to equal pressures the 25 WSSM has about a 4% potential velocity advantage. 4% at 3K fps is 120 fps, probably less in a shorter barreled XP-100.

Jeff

My numbers for the 257RAI is ~60 gr H20 and ~52 gr for the 25 WSSM and ~68 gr for the 25-06...basically putting the 257 RAI right in the middle. But it's the NET case volume that will tell the tail...what's left over after the bullet is seated.

This XP will have a 24-26" barrel, not certain which...the ER Shaw is 24" and may or maynot be available and the A&B is 26".

My data for the 243 and 25 WSSM is 50 and 52 gr...that's interesting that your Federals run 10 gr more. I have some Win 25 WSSM's I ordered before going bipolar, coming from Midway, so I will get a new unfired weight fairly soon for comparison.

I had the same problem of different actual case volume weights with my 510 Makatak with Hornady and Norma 416 Rigby brass and 45-120 Norma brass...Load from a disk data had lower weight volumes than actual weighed samples.

You know the old story...never believe what you read and only half what you see.

I don't know for certain what the 257 RAI or 25 WSSM(I'm still waffling every day) will chrono until I get it built and actually test some loads, I was just crunching numbers in Load from a Disk, Hodgdons online data, Nosler, Lyman and Barnes manuals...and what data I have left from my 25-06 actual chono data.

I've hardly ever found two reloading manuals giving the same velocity for the same cartridge, but todays data, at least from Hodgdons pretty much is within statistical parameters...never off by more than one standard deviation.

Number crunching is just prediction making anyway, I don't go by published data except for use as a safe starting point as I found way back when I got my first Chrono the published numbers are usually not what you actually get. I let the rifle tell the story...each rifle is an individual and the barrel/components decide.

I think I made a typo and got cross eyed looking at the Hodgdon data again tho', APPROX 3100fs would be closer...25 WSSM, 3081 at 60.3K psi with Superformance...again, just guessing until I getrdone. 52 grs for the WSSM and 60 gr for the RAI equal a ~15% difference which may or maynot be actual.

A I said in the original comparison, both the 250 SavAI and the 25 WSSM were identical in velocity...etc...an additional 15% case capacity and 2 extra inches, if I go with the 26" bbl and the RAI, MIGHT give me some additional velocity or might just use more powder to get equal velocities...that's happened to me before...bigger case, more powder, but not much more velocity...and you never know for sure until you do it.


Bob...I tore the net apart looking for a bolt stop for a 600 and couldn't find one but I haven't checked with Remington yet...I did find a Mod 7 bolt stop at Midway.

I checked my other XP a 7-08, 120 gr Noslers and Hornady bullets seated 2.83" OAL. That extra 0.030" causes the ruckus, but since I carry a tool just to depress the stop when shooting it and usually don't load until I'm ready to fire AND fire the round, the extra length never caused much concern...I will be shooting the 75 gr VMax's so the over length problem might be moot.

I also measured a Rem Mod 7 today and for all intents and purposes the XP seems to be almost identical except the Mod 7 has a larger and longer port opening...something very good to know and quick and easy to mill out

Thanks for the observation, Jeff...my mind is always running way ahead of my fingers. I might be well ahead to just do the bolt mods and do the 25 WSSM and forget the 257 RAI if I find the Win WSSM cases actually do run a higher weight of H20 than I use for calculating, that would make the "appearant" 15% case capacity advantage of the 257 RAI null and void...no matter what, they both require some sort of metal work and opening up the bolt won't cause any redazz if I decide to do a switch barrel to a standard 473 case head some day...a 375 or 416 WSM looks tempting... Just like the old days...one receiver, one stock, one scope, three bolts and 3 barrels and switch'um between matches. Hahahaha

Luck

If your going to make comparisons, you'd better look at neck wall thickness as well.
If I was building a custom WSSM, I'd definitely be turning the necks back to "normal" thickness, and the reamer made to smaller neck dimensions.

According to ammoguide the walls on the 25WSSM are the thinnest of the WSSM series at over 20 thou thickness per side this is pretty thick

I'd be turning it back to 12 - 12.5 at least, to get it back to the proven thickness of the benchrest cartridges.

I also wonder what this would do to pressure signs ?

22BR

Sorry for the slow answer- I load the 75 V-max to 2.70 and it works fine in 600, 700 and model 7 Rem. actions. Way back when I first designed the case I did some H2O capacities and if I remember correctly 52 grains. It duplicates or exceeds the 25wssm in many ways. The choice for brass is better, any 308 family brass works, I use 308 Lapua if I want a "tight neck" fit. Feeding is not an issue, no modifications need for bolt face or magazine when using a standard 700 SA.
The Roberts AI has a larger case, but when you keep the OAL to 2.8 with 100 gr bullets or bigger, the bullet has to be seated into the case and much of the availible space is used. I looked at many different paths before settling on the 257 DGR and in a Remington SA and the only way to beat the present design was to increase rhe case diam. and that limited the actions the case would fit or extensive modifications were needed to the "standard" short actions.
In your case a 257AI, remove the factory bolt stop, put an external spring loaded pin type stop, and enjoy.
Duane

www.duanesguns.com

The 22BR is a very good one, I just have way to many rifles in 17, 20, and 22 cal right now to do another one, but I did look hard at it and the BR case up to 30 cal. I also have a very nice shooting 16.5" 6BR NEF and only ONE 25 cal.

You're right about the neck thickness on the WSSM cases, but neck turning depends on the reamer specs which depend on SAAMI specs...I will be renting the reamer in this case, so have to take what I get. Turning that much just makes for a ton of neck wall stretching during the reloading/firing cycle.

Thanks Duane. It takes a ton of mucking about to finally decide and I really appreciate you information. I'll have to think about the external pin stop, I envisioned just adding/building up the backside of the OEM stop and moving the actual stopping point backward about 0.200"...might be quicker and just as effective, unless I can find a relatively cheap and easy one to install. A quick and painless milling of a small amount of metal at the front of the port will also solve the problem. But that comes much later if at all, as I plan on just using the 75 gr Vmax for the most part, but I will try several brands and use the most accurate one and I won't seat below the neck/shoulder juction in any case if I do go to a heavier bullet

I will also reiterate...published data is ALWAYS suspect, doesn't matter where or what. Each rifle is an individual and you have to treat the ammo as individual also. You develope your data by using individual pieces and parts of the components and NOT mixing...I buy at least 100 cases of the same brand, or in this case 50 because that's how Win ships the 25 WSSM cases...they may or may not match the measurements of another brand...again...I won't know just what the WSSM case measurements ar until I get a batch.

Thicker necks do have an effect on pressure somewhat as the thicker brass grips the bullet harder, but the pressure is controlled by the reloader to a greater or lesser extent. Thick necks usually mean a thick case wall all the way up and down. The WSSM case is reported to be very strong which means the case is carrying more of the pressure load and allows for higher pressures with less case problems...it could also mean it needs to be annealed more often to keep work hardening cracks from happening...
only those that shoot the WSSM can answer that.

I always measure necks and turn them to about 80% average after the first firing for ANY rifle I build/buy, just to keep things uniform. And the necks DO even out after a few firings. I do this as part and parcel of my rifle/ammo tuning. It is arguable as to what it does to accuracy and depends on a ton of factors, but accuracy level is a personal concept...accuracy to one might mean "that's garbage" to another or vice versa. A lot of what I do in tuning rifle and ammo is a waste of time for many who just want to enjoy their toys without too much futzing around.

FWIW...I, along with a few of my mentors way back, experimented and found that firing a full load will iron out many case irregularities like necks and unsquare bases, and that updated and re-examined information has been published on 6mmBR. (I think)

The jist was we were discussing accuracy and where it comes from. Everyone was looking at a number of cases, measuring everything possible and head scratching. Someone remarked that a batch of new cases were just "sh**". The arguments, needling and questions started, some had already been facing their case bases and most neck turned because at that time the buzz was a TIGHT, SAAMI MINIMUM chamber...keep it plumb, square, perpendicular and parallel...I was relatively new and dumb so they used me and my rifle as the dumby...wear out HIS rifle, he's the FNG. OK by me, the knowledge was worth 10 rifles and some upset people later on when I did get my rifle competitive.

We just, measured the hell out of ten cases, loaded my "normal" target load, fire for group and measured again...each case was numbered and the measurements recorded. The group I shot wouldn't have even gotten my name two feet BELOW the BOTTOM of the board, but it still was basically a nickle sized one-holer, my rifle was just a blueprinted, Shilen, cylinder barreled Remington 700, 308 glass bedded in a hunting style laminated stock and not benchrest competitive by any stretch of the imagination, but it WAS a varminting/game hunting phool.

The fired cases were measured again and the bases had magically squared and some of the neck thickness variation was removed..."ironed out". More head scratching and discussion.

The case necks were turned just a bit, weight sorted and the 6 best were again loaded with a little more finess and fired. This group would have at least put me on the board but near the bottom ...BUT...it wasn't me or my rifle that was the center of attention, it was what was going on with the brass).

We were testing how to reduce variation, WHERE part of that variation actually was showing up and WHAT could be done about it.

I haven't gotten this deep into a cartridge since my benchrest days...it does take the boredom out of just building a rifle and going shooting, tho'

Thanks again for the insights.(Bipolar waffling continues...hahahaha)

Luck

I had a 250AI, but it was a rechambered Ruger 77 RSI 18.5" and none of my 25 WSSM are shorter than 21", so it wouldn't be a fair/accurate comparison.

I'm getting 3700+/- fps from my 21" and 3750+/- fps from my 24" 25 WSSM varmint rifles with the 75 grain VMax in necked up Federal 223/243 WSSM brass. I'm getting 3250+/- from my 22" 25 WSSM deer rifles with the 100 grain Partition in the same necked up Federal 223/243 WSSM brass.

I'd put the 25 WSSM in the 257AI/25-284 neighborhood, a little faster than the 257R/250AI, and a little slower than the 25-06.

I'm a happy 25 WSSM shooter, maybe a little nutty too, as I currently have 15 Winchester/USRA 70s chambered in 25 WSSM. 11 that remain NIB and 4 that are shooters. I like getting near 25-06 performance from a shorter/handier vehicle.

FWIW, I have much better success with the modified Federal WSSM brass than I did with the Winchester/Olin. I have loaded some of my 75 grain VMax pdog loads 8x. I have 200 dedicated cases for each of my 2 varmint rifles and 100 dedicated cases for each of my 2 deer rifles. That is 600 cases that have been loaded a minimum of 3x and a maximum of 8x times. The Winchester/Olin brass is so heavy/thick that you have to push it at maximum pressure to get the brass to expand and seal the chamber. Even at that, you often get smoked necks from gas leaking back into the chamber. Or at least that has been my experience.

Jeff

Yeah, Jeff...no comparison there because of barrel length. Your gonna make a mint someday selling those extra shooters.

I took a ride today taking pictures of the river overflowing and flooded fields and took a reality check. Hair splitting just never appealed to me and that's just what I've been doing...I have rifles/pistols in 17 to 6mm covering the 221, 223, BR and 308 case sizes, so another 50 gr H2O or less case is just duplicating something I already have...I HATE it when I start on a project and loose what little mind I have and go bipolar at the same time.

You know what I'm gonna do?

I have a perfectly good set of high dollar Redding benchrest dies in 6mm-284. I've burned up two or three barrels over the years with that cartridge and enjoyed every minute of it...and at least one barrel lasted only one rat season. I won't sell those dies for the chump change I've been offered, so it's another 6mm-284 for me, 28" straight cylinder this time, ...I even have about 100 rounds of loaded ammo that's been haunting me for the last 7 years at least to start with..and at least 300 already prepped cases. I can only hope the reamer I rent matches the dies.

Yeah...and while I'm at it I'm gonna do a 15-18" switch barrel for the 375 JDJ I bought dies and brass for about 10 years ago and hang it off my other XP. Might have to do the bolt stop work for that one...or not...my super-duper bolt extractor tool is quick and easy or a thin bladed screw driver works just as good.

I might even do a switch barrel 220 Swift to get some use out of the Redding Benchrest dies, brass all the factory loaded ammo that keeps laughing at me.

TX Nimrod...that is a very good definition of efficiency. And your absolutely right about the consistency...I call that "precision". Again, nothing but semantics and the connotation words bring to a persons mind. One particular theorist posits that "relative things" equates what we humans "see" to a persons "inertial reference frame". What a person sees when standing on the train platform is different than what as person sees who is traveling IN the train. Samo-Samo with words...no one is right OR wrong...it just where we happen to be standing.

Feels good when the final decision is made.

Luck

FWIW...here are illustrations of why I continue to say that published data is suspect and only useful for predicting a starting load...Start low and work up slow...and...BE CAREFUL!!!.

Load from a Disk.

26" bbl, 65 VMax, 100% load density -63.3 gr H4831, MV 4154/51685 CUP using my previous 6mm-284 WW cases- 2.15" trim, 66.0 gr H2O, 2.75" cartridge OAL, 0.230" seat, base of bullet at bottom of neck, net case capacity from LD, 63.308 gr H20...notice the MV and CUP.

From Hogdons site...

26" bbl, 65 VMax, 2.735" cartridge OAL, WW cases, MAX load 57.5 gr H 831, MV 3678/51,300 CUP...same powder, lessor amount, not much more CUP but a HECK of a lower MV. This makes my eyes open wide.

The 243WSSM will do as well or better with most bullets with Superformance powder at about 23% less case capacity so here is a good example of higher efficiency at smaller case capacities as TX Nimrod pointed out so well, but maybe Superformance powder will also work good in the 6mm-284 case and produce even higher numbers...testing is the only way to know.

Take a look at the reloading data on this site also for another comparison.

I tossed all my previous 6mm-284 data so I don't have any figures, but I do remember the most accurate bullet in one barrel was the Sierra 70 gr HPBT MK and the velocity was WELL over 3850fs. It was also the most accurate bullet in my 6mm Rem around 3650-3700fs. Anyone interested in comparisons can get more data from Reloaders Nest and several other net locations...this goes for ALL cartridges.

Number crunching is like trying to get drunk from looking at whiskey bottles...you need a highly active imagination to get their... ...but it isn't at all like working over a good bottle of imported Scotch, or even domestic Chivas Regal or Glenlivet...two of my favorites once or twice a year when I'm feeling flush.

The real proof is in the chrono for THAT particular rifle at THAT particular time, and that can be off by 100fs or more easy enough.

Midnight Fire stock coming from Richards Micro, Tubbs Recoil lug and Mod 7 bolt stop from Midway and Shilen trigger when they arrive in stock...26" ER Shaw, 2 1/2 contour barrel when they get back from the Las Vegas shot show.

I'm REALLY HAPPY....

Luck