Old Mr. Ferguson did the 257 STW (Hot Tomale) a disservice when he was pushing it as a 4000-4100 fps chambering with a 100 gr XLC bullet in a 28" barrel. Simply put, this is simply a sales pitch. It worked in the beginning but it was not long before the bad reports started to come in on these performance levels.
When I got into the rifle building business, I was also very interested in this level of performance for a flat shooting 500 yard and under deer rifle chambering.
I built one for myself and then another for my wife. Both were using 1-10, 3 groove Lilja barrels. Simply put, the Winchester 7mm STW brass will loose its primer pocket at anything over 3950 fps with a 100 gr bullet(ANY 100 gr bullet) in a 30" barrel.
I tested pretty much all the bullet combos out there to see where the best performance was at. Also, best accuracy results were in the 3850-3900 fps range, a full 200-250 fps off what Ferguson was claiming and this was out of a 2" longer barrel.
In my testing I came to really like the chambering once I realized the true performance levels of the chambering. It was accurate and flat shooting and did not need the ultra high velocity claims to make it sell.
This chambering is very barrel length dependant, as are all of the larger 1/4 bore magnums. In my testing, I took my 30" Lilja and set the barrel back an inch at a time until I was at 26" of barrel length. My findings that with the same loads, the velocity dropped an average of 42" per inch from 30" to 26".
Basically in a 26" barrel length you will see around 3730-3750 fps out of a Lilja 3 groove, 1-10 twist barrel with a 100 gr bullet. That is with a load that will produce a case life of at least 4 firings.
Far cry from the 4000 fps velocity claims of Ferguson but if you look at things realistically. Most loading manuals list the 25-06 at 3250-3350 fps with a 100 gr bullet. Most will list a 257 Wby at 3450-3550 fps with a 100 gr bullet, why would we expect another 500 fps to come from the STW. Its 3650 fps to 3750 fps velocity with a 100 gr bullet is exactly where it should be for this case capacity.
I have built several dozen of these rifles and all have been extremely accurate and consistant when used in their proper pressure ranges. I have also had several customers that needed a reality check thanks to Fergusons claims which in my opinion are not realistically possible with anything that resembles good case life.
It got to the point that I actually contacted Ferguson to see how he was getting these levels of velocity with what he claimed was acceptable case life. At first he simply dismissed my inquiries. I persisted as I did not feel it was responsible to recommend such levels of velocity.
Finally he admitted that he had very little concern about case life and that he only wanted velocity. He also admitted that the Win cases would have dramatic case loosening on the first firing and that after the second firing the cases were spoiled........
My comment was why not just drop off 150 fps and get much longer case life with longer barrel life and in most cases better accuracy and consistancy. His reply was that he did not want to give up the ballistic performance which simply says that he has not done the research to really see what the difference between the two loads was. Yes, the milder load will drop a bit more and have a bit more winddrift but in most cases, out to 500 yards, a shooters ability and shooting position will effect bullet point of impact more then the difference of these two loads. He never replied to that comment.
So simply put, if you can live with 3700-3750 fps in a 26" barrel or 3800-3850 fps in a 28" barrel or 3900 fps in a 30" barrel, you will be very happy with the STW. If you expect 4000 fps, you will not be happy with your rifle.
I would also like to add, the heavier the bullets the better. Yes they have a bit more drop and the velocity is not as sexy but in every rifle I have tested in at 500 yards, accuracy with the heavier bullets was better then the 100 gr bullets. In my opinion and from my testing, this was mainly because of velocity spreads. The heavier the bullet, it seems these big cases run much more consistant as far as velocity spreads. Or should I say its easier to get very tight velocity spreads compared to the lighter bullets.
I am not saying the 100 gr bullets are not accurate, most I shot out of my rifles were grouping under my 1/2 moa accuracy requirements at 500 yards. That said, the 130 gr Wildcat BCHP would consistantly play with the 1/3 moa range and often less then this.
Look at the 257 STW realistically and you will be happy, expect 4K with good case life and you will be very happy.
