POI Same Gun 38 vs 357

[ken p]

Hi Everyone

If I use a Model 13 with 3 inch barrel (fixed sights) with the same weight bullet in 158 Grain should I have the same or very close POI?

Should the difference be because of velocity? What would you expect?

Proposed load will be factory ammo .38 (Buffalo Bore .38 +P LSWCHP 158 Gr) VS. .357 (Speer Gold Dot 158 Gr)

 

[reddog81]

In theory the .38 Special load should be in the barrel longer while the gun is recoiling and that should result in a higher impact. In practice it varies... what distance are you talking about? Anything under 15 yards and they should be close enough that it doesn't really matter.

With the specific rounds you're asking about the BB load is closer in velocity to .357 anyways so the difference will be even less noticeable.

 

[stoneke]

I tested both of these rounds today in a 3 inch model 65. At 7 yards they both printed within an inch of each other. Chronographed velocities were: Speer 135 .357 - 1098, 1115, 1091 fps. Buffalo Bore 158 38 +P - 1057, 1053, 1037 fps. The Buffalo Bore had a slightly harder recoil impulse.

 

[Nevada Ed]

The POI will vary with some people, due to their hand, wrist and arm strength
used to resist the acts of recoil with a weapon.

The design of the grip can also change the POI..........

Mastering POA can be very frustrating at times.
Have fun.

 

[rockquarry]

You'll need to shoot both of these ammos the way you normally shoot: rested on sandbags, unsupported two hands, unsupported one hand, etc. Point of impact will likely be different, sometimes very different, with different positions. Shooting up close is fine, but also do it at 15 yards and 25 yards just so you'll know where point of impact is at varying distances.