Hi 788Ham, although this thread was in appreciation of Corbon, I am also a CCI/Speer Gold dot fan.
I do like the short barrel .38 + p gold dots as a niche round that serves a very specific purpose for me. The firearms that this round really shines in are generally highly concealable and most suitable for pocket carry, ankle carry, light IWB carry, or similar use.
Speer's data indicates that the 135 grain .38 special + p gold dot (short barrel) has the following characteristics:
Weight: 135 grains
Velocity at muzzle (ft/s): 860 out of 2" barrel
Energy at muzzle (foot pounds): 222
This may be compared to the traditional gold dot in .38 special + p
Weight: 125 grains
Velocity at muzzle (ft/s): 945 out of a 4" barrel
Energy at muzzle (foot pounds): 248
One interesting difference to note is that the 125 grain round was tested with a 4" barrel yet the 135 grain round was tested with a 2" barrel. If the barrel length is taken into account, it appears the rounds have very similar ballistic properties. Anecdotal evidence corroborates this claim and some interested citizens have used a chronograph on the short barrel round from longer barrels and had it pushing 950+ ft/s with a 6" barrel. Yet, it should be noted that Speer themselves indicate that the short barrel round is ideal in the 2 - 4" barrel range.
Tnoutdoors did an informative review of the Speer 135 gr short barrel round which you can find here:
http://www.youtube.com/watch?v=k890Rio2oBY&feature=player_profilepage
In the video, he notes that although the round is published at 860 ft/s velocity, his 5 round average in the S&W 438 (a little less than 2" barrel) was 835 ft/s velocity with a high of 845 ft/s velocity. I carry it in a S&W 442. Despite these differences , Speer claims to have engineered the round to expand well in the lower velocity ranges, and that claim is supported in the Tnoutdoors video portion on expansion. In your Sp101 with a 3" barrel, the round would likely marginally exceed the published velocity.
There have been heated debates on the adequacy of a .38 special round in general self defense situations. My take on it is that it's better than a sharp stick, but if I could carry something more powerful, I would. Therefore, 80% of the time I'll have a .44 special or a .357 magnum round on me and the .38 special will be acting as a secondary backup, or as a primary in such situations where concealment is of the utmost importance - when my clothing does not permit a belt holster.
If the Sp101 can only fire .38 special, if it is carried by someone with high recoil sensitivity, or if it is carried in very tight situations where loud noises may be overly amplified, then I would choose to carry the 135 grain gold dot short barrel over any other .38 special round. It is one of the only rounds in that caliber that is in widespread use in law enforcement agencies around the country, and its proven performance even at low velocities is to be commended. It is an easy choice over the other 125 grain gold dot due to its heavier weight and easy expansion. As mentioned, a great benefit of all "special" rounds is less ear-cracking boom to worry about - although some posit that ear cracking booms are the last thing to worry about in true self defense situations.
If, however, your Sp101 is of the variety that can handle .357 rounds, and if it is carried by someone not adverse to some recoil and in situations where ear-cracking booms may be tolerated, I would strongly advise you to check out some of the offerings in that caliber.
First, lets look at the other Gold dot offering for short barrels, the Speer 135 grain .357 magnum short barrel(some have taken to calling this .357 medium)
Weight: 135 grains
Velocity at muzzle (ft/s): 990 from a 2" barrel
Energy at muzzle (foot pounds): 294
This round seems promising, but is actually more in the ".38 special" league for performance rather than approaching magnum capabilities.
Two other "medium" power magnum loads in .357 are the Remington golden sabre, and the Corbon DPX mentioned in my original post. The golden sabre is old technology, but does have a positive history by some accounts (others have noted its tendency of core-jacket separation).
The Corbon DPX .357 round is intriguing:
Weight: 125 grains
Velocity at muzzle (ft/s): 1300
Energy at muzzle (foot pounds): 469
Although Stephen Camp (R.I.P) tested this round and found it to be approximately 100 - 150 ft/s less than the published velocity, other reports using chronographs have tracked it up to speed. Even at slightly lower velocity than published, this round offers approximately 1.5 to 2 times the energy as the .38 special rounds discussed previously.
This discussion has been limited in its review of certain ammo types and brands, it goes without saying a number of other top notch manufacturers make products that might suit your individual needs. The .357 125 grain gold dot full power (not short barrel) moves at approximately 1450 ft/s and has just under 600 foot pounds of energy, which is the traditional .357 loading. However, I believe that one might be a bit much for the Sp101 - additionally it is quite loud and can be a handful even in larger framed revolvers. And yet, it has very impressive ballistic performance in gel as shown by brass fetchers testing
http://www.youtube.com/watch?v=Q7w4M-LNXuQ Others prefer a 158 grain round in .357, and I have some hardcast Corbon "hunter" rounds at 200 grains (no hollowpoint) in storage for woods carry.
One last point to consider is cost - short barrel gold dots in .38 special + p can be had from G&R tactical right now for $30 each box of 50. The DPX corbon rounds are more expensive, but the trade off you get is an all copper x bullet and the beautiful expansion of a DPX round.
In summary, if you are intent on carrying .38 special +P in your Sp101, I don't think you can go wrong with the 135 grain gold dot. However, I would encourage you to try out the .357 Corbon DPX round and see how it shoots. Everything with handguns is a tradeoff between concealability, noise, power, penetration, expansion, weight retention, accuracy, recoil, amount of lead, and a number of other factors. The target you shoot and the aggressor in a self-defense situation ultimately may not be able to tell the difference when faced with getting shot by your premium ammunition choice out of your premium firearm. Therefore, I advise you to shoot both and see which you can hit point of aim with. As mentioned, I personally carry both, but given your choice I would likely be putting the .357 DPX rounds in an Sp101 with a 3" barrel if it was not a .38 special only firearm. Jeff Quinn from gunblast also spoke positively of the "thunder ranch" branded Corbon rounds, although he spoke generally of a variety of calibers under the brand name. That review can be found here:
http://www.gunblast.com/RKCampbell-CorBonTR.htm
Best,
-T
