25 STW

lee e. jurras

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indiana
Fiftry driver: I've built both 25 STW and 257 Banshee's for customers. I personally feel the Banshee has the edge, course then you have the fire forming and additional cost of brass. Nothing for the didicated LR shooter...:). My guys are mostly speed freaks rather than the BC from the heavier bullets. Local customergot a Prarie Dog at 1080 yds this year so he doesn't want to here remaining velocity and BC from me. He's using a 90 grainer at 4200 from a 30" Lilja bbl. As long as he keeps it to small varmints guess I can't argue. He uses the 100 gr. BT for Deer @ 4100 fps. Told him he is trading on the high side pressure wise. Claims his Hertenberg brass Primer pockets last longer than the RWS. I've had no PP problems using the 100 gr.BT's at 3850-3900 and can keep 3 shots under an inch at 500 yds... Ever done any Banshee's ?
 
Lee E. Jurras,

From a strictly design aspect, I would agree that the Banshee is a better round. It is shorter and fatter then the STW but like you said, one can hardly complain about the STW performance with the cost of brass.

There are two very different schools of thought toward extreme range shooting that I have found over the years.

One is to use flat out Horse power to drive light bullets to hyper velocities and simply muscle them out to extreme range.

The other is to use high B.C., VLD bullets driven to good speeds(+3000 fps) and let the bullet do most of the work at extreme range.

While both views have their strong points and weak points, I will always fall onthe side of the high B.C. theory when ranges reach 1000 yards and certainly beyond.

I will admit that there are several rounds on the market and in the wildcat scene that will drive light bullet fast enough to reach out 1000 yards with reasonable consistancy.

Past that range, velocity hyper velocity means squat in my mind.

Most shooters that think velocity is the way to go really like the super flat trajectories they get by driving a 90 gr bullet to 4200 fps.

Personally, I care little about bullet drop, they all do it and after 600 yards, they all drop fast!!!

This is also extremely easy to predict and correct for so I do not feel bullet drop is a major concern as far as hitting a target at extreme range.

What is a problem is wind drift, which is always variable and never consistant to figure. Even form one point in flight compared to another.

This is why I use the high B.C. bullets. Even these get blown around by the wind but they are dramatically better then the light bullets even when driven several hundred fps faster then the heavies.

Give me a .6 to 1.05 B.C. bullet at 2700 to 3500 fps any day over a .3 to .5 B.C. bullet driven from 4300 to 3500 fps any day when shooting beyond 1000 yards.

The consistancy in the changing wind conditions will show the weaknesses of the light fast bullets.

As fat as the Banshee goes, no I have not built any yet. Before I got my STW reamer I designed a round using the RUM case shortened to 2.5" and blown out with a 35 degree shoulder.

This case would at least equal the case capacity of the STW and would allow this round to be chambered in any action that would handle an '06 length round, especially in single shot mode.

I may still make one of these but form dies would be pretty spendy. If i used a case like the 300 Dakota and just necked it down and improved it basically, it would be relatively simple except for the trouble of getting brass and the cost of full custom dies which is always a given with these rounds anyway.

Good SHooting!!!

Kirby Allen(50)
 
Dwm,

The 25 SAUM is no doubt a good round as is the 25 WSM but these are best suited for short action rifles.

While both can get impressive results with VLD style bullets, neither will come even close to the brute horsepower of the STW or Banshee.

That said, for high volume shooting the short action rounds are better choices.

The huge cased 25 calibers are specialty rounds designed for reaching out to well over 1/2 mile and while the short actions can be made to do this relatively well, the STW and Banshee, along with perhaps teh Lazzeroni full length magnum are the standouts in power in the 25 caliber family.

Throat and barrel life are much shorter then the smaller rounds but there is a price to pay for extreme performance.

So to answer your question, there is nothing at all wrong with the 25 SAUM. We are just discussing the biggest and baddest of you will of the 1/4 bore family and the short action rounds do not make the short list.

Good Shooting!!!

Kirby Allen(50)
 
Fiftydriver, I agee with you 100 % on BC vs Vel....
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Lee E. Jurras,

Another plus to using VLd bullets with high B.C. values is that one can use much smaller case volume to get the job done.

As an example, look at the 6.5mm family of rounds.

Sure there are some light weight bullets such as the 100 gr Ballsitic Tip that could be driven to extremely high velocities and probably perform at 800 yards pretty well.

Problem is that to get enough velocity to do this we are looking at burning 85-90 gr of powder. Very hard on the throat and bore.

Take a round like the 6.5-284 and use a 142 gr Sierra or some of the other custom bullets with even higher B.C.'s then the matchking and they are very useful out to basically as far as they stay super-sonic in flight, well past 1500 yards.

And all this is done with 55 to 60 gr of powder which will allow a throat to last a very long time.

Do not get me wrong, I tend to walk on a line that likes as much velocity as I can get combined with the ultra efficent VLD bullets.

I feel this is the ultimate for extreme range performance.

Here is an example of some real world data taken from my 338 Kahn I just finished building a few weeks ago. This rifle is designed strictly for shooting at ranges from 1500 to 2000 yards.

I listened to those that preferred ultra high speeds say how impressive the 200 gr Ballistic Tip would be in this rifle with its huge case capacity and 34.5" barrel.

When I told them I would be using the 300 gr Mk and the 300 and 350 gr Wildcat Rebated Boattail ULD bullets they almost laughed at me wondering why I would waste my time with these slow movers.

These folks were serious varmint hunters but 500 yards would be a long shot for them.

I decided to develope loads in both bullet weights and see where the rifle topped out and compare them.

I was hoping to get 3150 out of the Sierra and I was not able to do that. They are a bit to fat for my throat so when the Wildcat bullets get here the velocity will increase a bit.

THe 200 gr Ballistic Tip topped out at 3605 fps which is pretty impressive.

The 300 gr Matchking leveled out at 3050 fps which is 100 fps under what I was hoping for so I was a little nervous for the comparision.

At 500 yards, the farthest I have tested so far, busy in the shop, hunting season you know, Both loads were grouping in honest 1/4 moa three shot groups.

Well I got on my ballistics program and plugged all the numbers in and here are the results that are important.

I only compared out to 1000 yards and you will see why:

This is for both groups zeroed at 1000 yards:

200 gr Ballsitic Tip
3600 fps
B.C. .414
10 mph crosswind

Highest point in trajectory
550 yards @ +74.2"

velocity and energy @ 550 yards
2407 fps / 2573 ft/lbs / 18" wind drift

1000 yard velocity and energy
1639 fps / 1193.0 ft/lbs / 72.3" WD


300 gr Mk
3050 fps
B.C. .780
10 mph crosswind

Highest point in trajectory
550 yards @ +69"

Velocity and energy at 550 yards
2465 fps / 4047 ft/lbs / 10.8" WD

Velocity and energy at 1000 yards
2039 fps / 2771 ft/lbs / 39" WD

When zeroed at 1000 yards the only comparison that is relatively close is mid range trajectory and the slower bullet still shoots 5" flatter then that fast one.

To take this little comparision to a full 2000 yards with the same 1000 yard zero, things get real distinct.

200 gr BT @ 3600 fps

1250 yards
velocity Energy Drop WD
1306 fps 757 ft/lbs -145" 126"

1500 yards
1080 fps 518 ft/lbs -419" 201"

1750 yards
952 fps 403 ft/lbs -879" 296"

2000 yards
870 fps 336 ft/lbs -1579" 405"


Compared to"

300 gr Mk @ 3050 fps

1250 yards
1796 fps 2149 ft/lbs -110" 66"

1500 yards
1593 fps 1691 ft/lbs -287" 101"

1750 yards
1411 fps 1326 ft/lbs -551" 146"

2000 yards
1256 fps 1051 ft/lbs -925" 202"

Again the numbers show a clear and dramatic advantage for the heavy slow bullet.

THe fast 200 gr load goes under supersonic velcoity at around 1500 yards depending on teh altitude you are at. At this point the consistancy of the bullet is gone and there is no point even looking farther with this bullet/load but I did just to state a point.

As I said before, bullet drop means nothing to me as it is consistant and easy to figure and correct for but just for comparision at 1500 yards when both have the same 1000 yard zero, the 300 gr pill is flatter by +130"!!!

At a full 2000 yards the 300 gr pill is landing 650" higher then the 200 gr bullet!!!

Now I know this is of no concern if you dial in your elevation adjustment for each range until you figure how much harder it is to dial in to correct for 1579" of drop compared to 925".

Again, not a problem because bullet drop is easy to correct for as long as the bullet stays super-sonic.

What does make a huge difference is wind drift and this is where the big B.C. numbers shine.

At any range past 1000 yards teh 300 gr pill has less then half the wind drift of teh 200 gr bullet.

I am not saying the 300 gr pill does not get blown around because at 2000 yards it is blown of by +200". Still it is much easier to judge 200" of drift compared to 400".

Even more important, if I happen to mis read the wind, which I am humble to say does happen at times
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, my mistake in judgement will be cut in half by the 300 gr bullet compared to the same error with the 200 gr pill.

Other then that there is velocity and energy. The only real need in velocity is to stay super sonic. The 200 gr pill, dispite its 550 fps advantage at the muzzle will drop below super sonic speeds at right around 1500 yards.

The 300 gr MK will stay super sonic out to the 2350 yard range again depending on elevation. Thats an 850 yard advantage for the slower heavier bullet. Put another way, you have 1/2 mile longer range with the 300 gr pill.

Now energy is a tricky matter. In the target scene, it meanas nothing. Takes about 1/2 ft/lb of energy to put a hole in a paper target. Not so for long range hunting, even varmint hunting.

I do not believe kenetic energy has much to do with actually killing of a game animal.

What I do believe it that a certain bullet requires a certain amount of energy to perform well on game and allow it to destroy enough vital tissue to cause a quick and human harvest of that animal.

It is true that with the frontal area of a 338 bullet, this is of little concern until animal weight reaches the 500 lb range as any super sonic 338 bullet will easily fully penetrate any deer size target when impacted at an ethical angle(another story for another time).

For varmint hunting, such as rock chucks, I like 1000 ft/lbs when using the VLD type bullets simply because they do not transfer energy as well as a traditional hunting bullet.

Pound for pound a chuck is a very hardy critter. I have shot several chucks at ranges out to 1000 yards and a bit more with energies under 1000 ft/lbs and have been very disappointed with the results unless a head or chest shot is made.

Any bullet VLD bullet with 1000 ft/lbs or more seem to work dramatically better on chucks providing instant kills with no wounded chucks to crawl back to their dens.

With a tipped bullet I like the rule of thumb to be 1500 fps to allow the bullets to open. If a tipped bullet has at leaat 1500 fps the bullet will expand and deliver its energy payload on target.

For this reason, a tipped bullet does not nessesarily need 1000 ft/lbs of energy because it is better able to transfer more enegy to the target.

500 ft/lbs in a tipped bullet that will expand fully is plenty.

So if we look back at the numbers, the big 300 gr Sierra Mk packs 1000 ft/lbs well over 2000 yards to satisfy my requirements.

A look at the tipped 200 gr B. Tip reveals that it drops below my 1500 fps rule at around 1150 yards where it is packing around 900 ft/lbs of energy which is plenty with this bullet and it would perform well here but we are still nearly 850 yards behind the 300 gr Mk in effective range.

The B. Tip carries +500 ft/lbs of energy out to 1500 yards but unfortunately the velocity is so low that the bullet will not expand and it will be a poor performer on came.

Now these are my pesonal guidelines and requirements from what I have seen and tested in teh field. I do not expact others to use these as they should test their own theories but it has brought me to my stand that for shooting past 1000 yards.

Velocity means very little!

Others will say that they are dealing with rounds that deliever velocities in teh 4200 fps range.

I say yes you are but you are also dealing with bullets that have a B.C. of under .4 and to be honest, a 200 gr Ballistic Tip perform almost identically as a 100 gr Ballistic Tip loaded to 4200 fps.

They both drop to 1500 fps at around the 1100-1200 yards range. The hyper speed 25 is flatter shooting and bucks the wind better by around 18"(126" vs 108) but the little 100 gr .257" bullet is only packing 500 ft/lbs of energy at 1250 yards.

Again, these light, hyper velocity bullets are usable out to 1000 yards but for 1500 yard shooting they are practiaclly useless and for 2000 yards shooting, they are totally useless.

Sorry for the novel, jsut like to compare such things and see what others feel about solid numbers and facts.

Feel free to drop your opinions on the subject. It is always interesting to read others points of view.

Good Shooting!!!

Kirby Allen(50)
 
Hi Fiftydriver,

A lot of good info here. You mentioned the 6.5x284, what are your feelings on the 6.5 WSM, taking the 270WSM and necking it down?

Thanks
Andrew
 
Agunner012,

Funny you mention the 6.5mm WSM as I received notice from my reamer maker that my design for my version of the 6.5 WSM has been approved and should have been shipped on the 30th of August.

I designed this reamer for use in single shot firearms but in standard '06 actions it would work very well also.

What I did was take the SAAMI reamer print and tightened up the case body dimensions to min spec. Not tight, just min.

I then redesigned the neck area to what I call a semi-Match neck as it is should allow the use of 270 WSM brass to be necked down and used with no further neck turning needed but there will only be 0.0015" cleanance on firing.

Because of this I will instruct my customers to double check this critical dimension on their loaded ammo and turn their necks if needed to allow this 0.0015" clearance.

The throat is full blow match with a decently long throat to allow the long VLD bullets to be seated plenty far out of the case volume but not so far that hunting style bullets still could not be used accurately.

The throat diameter is 0.2642" so it is only 0.0002" over bullet diameter.

I call this my hunting/match hybrid neck/throat design and it has owrked very well providing match quality accuracy and consistancy without the need for major neck prepping.

I will be chambering an XP-100 handgun using a 1-8" Lilja 15" stainless blank with this new reamer and will use of for my deer hunting handgun this fall.

As far as what I think of this round, well I will let you know here in a couple weeks after I fully test the rig but from what I know of the 6.5-284, the WSM will be just more of the same thing but not so much to prevent decent volume shooting.

It will produce around 3200 fps out of a +26" rifle barrel with any of the 140 gr class VLD bullets which is a couple hundred over the 284 version.

I think it will be a hell of a big game handgun round as well as a long range rifle round.

I would say that 1500to 1 mile may be its effective limit at extreme range but thats a hell of a long way.

Compared to teh 25 WSM and the 270 WSM, I think its head and shoulders above those two. Its got the very high velocity with the lighter bullets liek the 25 WSM but it actually has higher S.D. big game bullets and much higher B.C. VLD bullets then the 270 and has the ability to drive them to very respectible velocities which allow it to outperform the 270 WSM at long range.

Like I said, my reamer will be here soon so I will giev a full report when I get to the range.

Good Shooting!!!

Kirby Allen(50)
 
Thanks Fifty,

I would be interested in reading your range report. There was a lot of talk about 6.5WSM, and it seems to be quieting down a little. Good luck with it, and let us know how things turn out.

Andrew
 
Fifty

With the STW already being in a mildly overbore condition in its 7mm config I would hate to imagin the barrel errosion when configured to a 25.
What could one expect with the mentioned velocities for barrel life?
I have a fella that wants just that, 3800 fps 6.5mm 140 plus grain bullets. I keep telling him that speed does not always equate to accuracy. I was a big follower of this thought process when I first started and have since come to the conclusion that most of the time your top velocity will not be the most accurate.
This is my own personal experience as to not take flak from folks on this site who may have reached their top velocity and top accuracy, I say well done to you and congrats I just havent managed it yet.
I drive my 7mm stw with 74.5 grains of H1000 and push the Berger 180 vld at 3100 fps out of a 34 inch Lilja barrel and that load gives great accuracy for me. I'm guessing here but if I rechambered it to a 7mm RUM the 20 or so grains more case capacity would probably net me maybe 300 fps more using the same Berger 180 grainers.
Thanks
Dave
 
Daveosok,

IF you are very consciencious of your shooting and keeping the barrel cool and clean, the 257 STW will provide at least 1000 rounds of quality accuracy life and some have reached 1500 rounds.

THis is a very short life for a varmint rifle but for a long range or big game rifle, it could be a lifetime of use.

Key is to take very good care of your barrel and use a quality barrel in stainless steel to begin with.

Your friend that wants 3800 fps with a 140 gr 6.5mm bullet is in my opinion dreaming a bit. Rounds like the 6.5 STW will deliever 3300 fps with long barrels with the 140 class bullets and any case much larger then this really does not offer alot more velocity in this caliber.

If by chance he could get the velocities this high, there is no match quality VLD on the market that would survive such a launch.

Well, the Wildcat bullets that Richard Graves builds may handle this as he can build bonded core long range designs but I have never heard of a 6.5 round that would drive this bullet weight this fast.

Other then that you would have to shoot either a Partition, X or some of the exotic solid alloy bullets and even these would be strained at 3800 fps.

Most match bullets will top out in the 3200-3500 fps range for peak accuracy and most calibers will be in the 3200-3300 fps range.

Again tight moa groups are far more important then hyper velocity.

I have seen accuracy come at low pressure/velocity levels and at pressures I would consider on the ragged edge of safety. It all depends on the rifle, the bullet and enough other factors to sink a ship.

If I were you I would keep your STW until you burn the barrel out. It is true the 7mm RUM is a larger case but not by the as much as you think. You may be able to get 20 more grains of ultra slow burning powder in the case but youwill get about 150-175 fps more velocity and not the 300 fps you are expecting.

In conventional rifles(26" barrels) the RUM will average 125 fps over the full length standard belted magnum rounds of same caliber.

Likewise, the 300 RUM will come within 125 fps of the huge 30-378 Wby with 180-200 gr bullets.

True with longer barrels the big Wby will gain more of a velocity edge but not more then 200 fps in my testing.

Still this is a major increase in performance but sometimes more then match bullets can handle.

IF you have guys wanting to use match VLD bullets in big cased rounds, remind them that these bullets have velocity limits and make sure they know this before they spend $3000 on a rifle that will drive a 140 gr bullet to 3600 fps but will only be accurate when driven to 3300 fps.

Been down that road early in my career and its no fun trying to explain things after the fact.

GOod Shooting!!!

Kirby Allen(50)
 
Tahnks for your reply, this will help me greatly in turning my buddy away from such an idea.
Hes dead set on it though and a few words of wisdom from guys like you can prevent such a mistake.
Thanks again.
Dave
 
Fiftydriver, A Man after my own heart. Thats why I built a 30/378, 338/378 way back in '95 on a Hall G action with 30" Lilja tubes. That was my LR Varmint set up for heavy bullets with good BC for those thse 1000 plus shots on Coyotes. You don't have to convince me when it comes to BC over velocity, not counting wind drift which I too have erred on on more than one occasion....
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Lee E. Jurras,

I know I do not have to convince you my friend. Just listed the comparison for those who do not realize what happens when those bullets get past the 1000 yard marker.

Good Shooting!!!

Kirby Allen(50)
 
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