The Accurate Reloading Forums
25-300WSM
17 January 2011, 22:11
BISCUT25-300WSM
Wondering thoughts on turning a Savage 300WSM into a 25-300WSM??? 100 - 120gr bullets. Redding makes the dies, Savage barrel cheap, neck up 270WSM brass in one shot (pun intended), and velocities should be near 257 Weatherby.
Besides a barrel burner.....what can you think of as negatives?
18 January 2011, 03:07
333_OKHI think Winchester tried this in the beginning and it was deamed overbore capacity. There was a big boom, and inefficient use of powder without hte expected velovity gains.
It would be necking down the brass from .277 of the 270 WSM to .257 and would not be fire forming brass until after the necking proceedure in a die set on the bench.
I would either stick with an already made WSM like the 270 or go to the 25 WSSM...The Super Short Mag.
Personally I would use the 250 Sav AI....
18 January 2011, 23:53
rcamugliaA friend of mine at Browning made one quite some time ago. I'm not sure which WSM brass he used but he calls it a 25 WSM
He says it shoots .3" at 3700 fps with the 100 grain TSX
19 January 2011, 10:02
Cliff LyleThere was an article in Rifle Shooter magazine regarding this wildcat. The author called it the 25 pronghorn. I have the pdf of the article and if you would like to see it I can email it to you.
pm me your email address and I'll send it.
19 January 2011, 18:58
bluedotMade one when the 270 wsm 1st came out. Was an ok caliber but finicky. Shot the 7x7 bull in my avatar with 115 partitions using it. Dropped him where he stood. Barrel life is short, velocity was ok but not alot more than my 25-06. Was a pac-nor polygonal rifled barrel. Was very accurate. Pushed 100 gr bullets as fast as 3600 and 115's up to 3400.
Forming brass was very easy.
3-7-77
19 January 2011, 21:43
FOOBARIt has a HUGE case capacity comparitively speaking for a 25 cal bore...almost equal to the 257 Weatherby and slightly more than a 25 Ackley, 25-06 Ackly Imp or 25-350RM, but great for a SA.
You do get fantastic velocity figures, as already posted and it WILL do a good job on anything it touches using the right bullet for the velocity, but it likes to eat barrels 10 times a day...but for all intents and purposes, if used as a hunting rifle shooting <25 rounds a year or so it will last a lifetime or longer.
The problems come from burning a large amount of powder which takes more time relative to a smaller case, and all that heat over a longer period of time(we're talking micro-seconds here) ablates the barrel metal at the throat and a ways down the barrel...just like ANY other large capacity case...plus it takes more time for all that pressure and heat to funnel down that small hole.
But Hey...if you want speed you have to pay for it some way.
I think it's cool.

Luck
20 January 2011, 02:12
BISCUTThank's boys. I thought it pretty cool as well. I lucked into a few 300WSM Savage lefty rifles from an estate sale. Was thinking of messing with one of em....Truth be told the 338-300wsm was waht got my fancy but OAL with many of the 338 offerings just wouldnt work with the magazine.
Of course my noodle is strained

as I write this I'm wondering what about a 6.5-300wsm??????? The head is a flutter....and confused.....
21 January 2011, 18:26
bluedotIf i was to do it all over again i would do the 6.5 wsm, better bore life, better bullets...........the 25 WSM actually turned me off of the barrel burners, its the pits to build a nice rifle and have the barrel give up the ghost at 1500 rds. I have gone over to more efficient cartridges since then, 6.5x55=reasonably flat shooting, great ballistics, fun to shoot and much bettter barrel life.
3-7-77
21 January 2011, 19:54
MileHighShooterI think you'd be much better off basing a .257 or 6.5mm short mag cat off the SAUM case. A bit less capacity and a bit longer neck. If used in the same magazine box as the WSM's (which should be a hair longer then standard short actions) you would also have a bit of seating room to play with.
Biscuit - that there is the reason the 338wsm never came to be. It was originally slated as the next WSM but with those long standard bullets, they just couldn't get within range of the 338 Win Mag, as they could with the 300wsm/win mag. It was scrapped and the 325 was the result. Should've been a 358 IMO, thats a great, effective, powerful wildcat
If you think every possible niche has been filled already, thank a wildcatter!
21 January 2011, 21:35
FOOBARTrue, true, MileHigh...the SAUM is also an excellent case and about the reason for the "lost" 338WSM in factory. But what happened then...along came the 338 Federal.
If you look at the SAUM, WSM and WSSM cases as a basis for an excellent SHORT ACTION cartridges and NOT in competition with a similar capacity LA case, then there is no reason NOT to develop your own wildcat, and the WSM has been wildcatted up to 50 cal already so take your pick.
All the wildcatted WSM cartridges have pros and cons just like any other case, but every one of them will kill just as effectively as something "slightly" larger in standard length or belted mag cases...and THAT's the reason we wildcatters play our games.
I've been looking at the Jeffery case since I first opened P.O. Ackley's books 50 odd years ago. I liked it then and I like it AND it's "wee bayrrr'n's" today.
I hope to score a used Savage WSM action/rifle so I can do a few iterations...just for kicks. I mean reamers are cheap, dies are cheap and in some cases you can use Redding Bushing dies for several different calibers using the same case.
All this hair splitting and comparison krap just makes for closed minds and many people miss out on some very good shooters just because someone else convinced them
it isn't as "good" as something else.
The more things change the more they stay the same.

Luck
22 January 2011, 00:31
BISCUTHey there....a 35cal off the 300WSM?????? Really? That one never came to my noodle. Any idea what ballistics with say a 225gr AB would be like????
And I would think barrel life would be a hell of a lot better than the 25 or 6.5.
Now that really has me thinking.

22 January 2011, 02:18
MileHighShooterWell I'm not sure, I have seen data for 250's up to 2700fps, and the 350 Rem Mag can push a 225 to around 2700 as well so....I'd venture to guess in the 2800-3000 range?
Just look up what a 358 Norma can do and subract like 3-5%
If you think every possible niche has been filled already, thank a wildcatter!
22 January 2011, 04:41
FOOBAR350 RM case capacity ~72 gr H2O...WSM cc ~80-82.
Might get 2800fs...Win claims 2840 fs with a 200 gr bullet and that ain't got no moss on it...BUT...the 225 Nosler AB is 1.375" long and you need to seat it out to 3.10-3.20" to ge full case volume...might not work so good in a SA...you will lose too much case volume with bullets seated so deep at 2.86" LOA.
A 338 WSM has an even bigger problem as the AB bullet is 1.43" long, but it has a higher BC.
I would forget the SA unless you could load to at least 3.25" to get max case volume with bullet seated flush with neck bottom...not many can.
This case is hamstrung just like the 284 W in the model 88...bullets seated way down into the case taking up powder room and not getting max value out of it...they never could match the 270 velocity so it went downhill like a snowball headed for ....
I think the WSM case was designed for the SA in 270/30 cal at <2.9" LOA and works well there.
If you want to take it up a notch or two you need a LA. Even the factory 325 WSM bullets are seated with the base well below the shoulder/sidewall junction.
Run an online search for 35 WSM and/or 35 Sambar...lots of good information on both.
You're thinking right on...

Luck
25 January 2011, 08:22
ColoradoMattquote:
Originally posted by bluedot:
the 25 WSM actually turned me off of the barrel burners, its the pits to build a nice rifle and have the barrel give up the ghost at 1500 rds.
I think I would use the 25 WSM as a long range deer and prairie goat round (I'm really not a long range guy though). 1500 round barrel life sounds perfectly acceptable to me. In fact, I'm sure I wouldn't shoot it out in 30 years. Barrel life certainly can't be any worse than the 257 Wby. Long live the BOB!
Matt
FISH!!
Heed the words of Winston Smith in Orwell's 1984:
"Every record has been destroyed or falsified, every book rewritten, every picture has been repainted, every statue and street building has been renamed, every date has been altered. And the process is continuing day by day and minute by minute. History has stopped. Nothing exists except an endless present in which the Party is always right."
25 January 2011, 09:53
MileHighShooterFUbar,
THe .358 225gr Accubond will be shorter then a .338 25 Accubond though, right? I know its still a long bullet, but it should be short enough to MAYBE make what, 3.00 on the dot possibly? If you were to use a Win M70 action, which has a longer box, this might JUUUST fit. Maybe. Maybe we should consult Michael458 on the OAL he gets with his B&M cartridges in the M70 action. I think some of them are running right on the 3.1" mark.
30 and above, I say go WSM case, under, IMO, stick to the RCM or SAUM case. Bit shorter OAL length.
If you think every possible niche has been filled already, thank a wildcatter!
26 January 2011, 02:32
briarlbrownI have a 25-300 wsm built on a 700 action.
I love the gun. It is devestating on whitetails.
I have 2 loads a 75 grain V-Max at 4278 F.p.s. on the chronograph, 1/2 MOA all day long.
also 100 grain tsx with same point of impact. 3882 on the chrono.
pentation not an issue, goes thru 3/4" plate @ 265 yards.
just an awesome caliber, not seeing any barrel erosion yet. my gun has had about 300 rounds thru with load development. must let barrel cool after 2 shots. 3 is alway 1" out if i do not.
26 January 2011, 07:52
rcamugliaSounds like a friggin' Laser!