Felt Recoil
A few days ago I went to the range to compare the felt recoil from several different loads. I should note that I have the M&P340CT, which has the Crimson Trace LG-405 (with the recoil pad on the backstrap). I grip the gun as high as possible on the backstrap, with the web of my hand right at the top of the recoil pad.
Before I started shooting I tried to calculate the Free Recoil of each type based on the published (or chronographed) muzzle velocity, bullet weight and estimated powder charge (which I later verified by weight difference—with some surprising results). To determine the amount of powder in each round I weighed the starting round and then subtracted the mass of the spent brass and the mass of the bullet.
I considered the following ammunition (in order of calculated Free Recoil):
- 38 Special, Remington UMC, 130gr MC, 5.87gr powder, 675 fps muzzle velocity (estimated), 4.7 ft-lbf recoil (calculated)
- 38 Special, Fiocchi, 130gr FMJ, 6.67gr powder, 843 fps muzzle velocity (estimated), 7.08 ft-lbf recoil (calculated)
- 38 Spl +P, Buffalo Bore 20B, 125gr L.V. Gold Dot, 8.31gr powder, 1050 fps muzzle velocity (estimate based on BB data & jfh chrono), 10.32 ft-lbf recoil (calculated)
- 357 Magnum, Buffalo Bore 19E, 158gr JHP (Sierra), 8.58gr powder, 1015 fps muzzle velocity (chrono by Tim Sundles @ BB), 14.45 ft-lbf recoil (calculated)
- 357 Magnum, Buffalo Bore 19E, 158gr Gold Dot, 9.13gr powder, 1015 fps muzzle velocity (chrono by Tim Sundles @ BB), 14.78 ft-lbf recoil (calculated)
- 38 Spl +P, Buffalo Bore 20A, 158gr LSWCHP, 10.50gr powder, 1010 fps muzzle velocity (chrono by jfh), 15.49 ft-lbf recoil (calculated)
- 357 Magnum, Remington UMC, 125gr JSP, 19.58gr powder, 1000 fps muzzle velocity (estimated), 15.76 ft-lbf recoil (calculated)
Unfortunately, I do not have any Speer 135gr Gold Dot Short Barrel in 38 Special, but the calculated free recoil is about 8 ft-lbf (based on chrono by jfh and my guess about powder weight) suggesting that it is lighter than the Buffalo Bore 20B.
Also note for 19E with Gold Dot I only shot/weighed one round (I'm saving those for home defense in my 686-Plus), for 19E with JHP I weighed three rounds, for UMC 125gr JSP, I weighed 7 rounds. For all 38 Special I weighed 10 rounds. Numbers shown for powder weight are averages.
Based on Felt Recoil I rank the rounds as follows:
- 38 Special, Remington UMC, 130gr MC: as expected this was very light
- 38 Special, Fiocchi, 130gr FMJ: I’d say this was slightly more recoil than UMC 38 Special, but still very light
- 38 Spl +P, Buffalo Bore 20B, 125gr L.V. Gold Dot: This was significantly more than Fiocchi, but very controllable. Should be no problem for follow-up (i.e. the Quad-Five drill).
- 38 Spl +P, Buffalo Bore 20A, 158gr LSWCHP: More recoil than 20B, but less than UMC 357 Magnum. Really not too bad. With a little practice I should be able to do the Quad-Five drill with two hands…not so sure with one hand, or weak hand.
- 357 Magnum, Remington UMC, 125gr JSP: This was stout, noticeably greater recoil and report than Buffalo Bore 20A.
- 357 Magnum, Buffalo Bore 19E, 158gr JHP or Gold Dot: I’d say that this is a little more than UMC 357 magnum, but pretty close. It is likely more than I want for M&P340.
Based on the calculated Free Recoil, the greatest recoil should have been the Remington UMC 357 Magnum followed closely by the Buffalo Bore 20A 38 Spl +P LSWCHP, with the Buffalo Bore 19E 357 Magnum third in line. This was not the case. Both .357 Magnum rounds had felt recoil that was significantly more than the Buffalo Bore 20A. The recoil of the two 357 magnums was very close, with the BB 19E having a slight edge. The recoil of the 357 magnum was definitely uncomfortable (i.e. somewhat painful) but did not have any lasting effects (no tingling, no numbness, no bruising, etc.). My 15-year old son shot the same rounds and concurs with my assessment (also note that this was his first time shooting a J-frame). That said, I think that shooting 50 rounds of either 357 magnum might cause some lasting tenderness, but there should be no problem shooting the standard pressure 38 Special all day. Either Buffalo Bore 38 Special +P should be OK for extended practice (assuming you can afford it). The 20A has enough recoil that it may cause some fatigue, but I’m fairly confident that I could shoot a lot of the 20B with no ill effects. I don’t know how I would feel about shooting without the benefit of the recoil pad on the LG-405.
A few words about the mass of powder in the rounds: I was surprised to find that the Buffalo Bore 20A (38 Spl +P) had more powder than the 19E (357 Mag), but I was really surprised to find that the UMC 357 Mag had more than double the powder of the 19E. This mass of powder in the UMC really skewed the calculated free recoil—I’m guessing that the bullet exits the barrel before all that powder is burned, which may really decrease the estimated muzzle velocity, and could also decrease the “effective” mass of the powder (assuming that the calculation should only count that portion of powder that burns before the bullet exits the barrel).
Hope somebody finds the information useful.
If anybody has any chronograph data on these rounds from a 340, I’d be interested in seeing the numbers.