John
Member
Why does my S&W 360 have this warning imprinted on the barrel: NO LESS THAN 120 GR BULLET?
Smith & Wesson 360: No Less Than 120 Gr Bullet
- Thread starter John
- Start date
- Status
Pistol Toter
Member
- Joined
- Jan 10, 2005
- Messages
- 657
"Bullet Pull" In light weight revolvers the inertia of discharge with the accompaning heavy recoil makes the projectile start creeping from the casing. This can eventually have the bullet projecting from the face of the cylinder and locking up the gun.
John
Member
Pistol Toter said:
Thanks.
John
Member
coach22 said:
Thank you for answering the next question that was in my mind.
Master Blaster
Member
The other reason for no light bullets in .357 magnum is that it causes a high degree of erosion and possibly damage to the forcing cone. When you fire the bullet it has to make the jump from the cylinder throat to the forcing cone of the barrel, It jumps the barrel cylinder gap when it does this.
A larger heavier bullet doesnt have as far to jump and isnt going as fast, so it is easier on the forcing cone, it doesnt have the same level of impact, or high velocity of errosive gasses when it jumps the gap.
If find that I get better accuracy out of all my .357 revolvers with the heavier bullets, and I am a believer in the heavier slower school so I never shoot the lighter faster bullets.
A larger heavier bullet doesnt have as far to jump and isnt going as fast, so it is easier on the forcing cone, it doesnt have the same level of impact, or high velocity of errosive gasses when it jumps the gap.
If find that I get better accuracy out of all my .357 revolvers with the heavier bullets, and I am a believer in the heavier slower school so I never shoot the lighter faster bullets.
John
Member
Master Blaster said:
With that in mind, what do you think of firing Winchester WinClean .38 Special 125 GR JSPs from the S&W 360 and the S&W 60 (J-Frame .357 Magnums), because its purportedly "lead free and heavy metal free primer" "eliminate
Must I choose between (a) minimizing possible damage to the shooter and (b) minimizing possible damage to the revolver? If so, which is the greater or more likely risk.
John, I have fired a box of that ammo at the range and would not be concerned about damaging the revolver. You also should not be concerned about the possible effects of damaging your health with that ammunition being used in self defense scenario. Your exposure to any heavy metals will be insignificant during a self defense incident regardless of the ammunition used, unless those heavy metals are fired from a gun and headed in your direction. The Winclean could be beneficial if you use that particular ammo for a lot of practice at a range with poor ventilation.
Winchester gives that ammunition 775fps and 167 ft. lbs. I wouldn't expect any expansion from the soft point at that velocity but it should be very easy to shoot from your revolvers, although I feel that there are better choices in self defense ammo for your short barreled .38's.
Winchester gives that ammunition 775fps and 167 ft. lbs. I wouldn't expect any expansion from the soft point at that velocity but it should be very easy to shoot from your revolvers, although I feel that there are better choices in self defense ammo for your short barreled .38's.
telomerase
Member
Right. But that happens with heavier bullets more than light bullets, because heavier bullets have more recoil AND more inertia.
Pumpkinheaver
Member
Clean your chambers well before firing .357 ammo. Sometimes the fouling from the shorter .38 cases will cause the longer .357 cases to stick.
Master Blaster
Member
As far as bullet pull goes, it happens in light weight revolvers with high velocity light bullet loads. I have seen it in my 642 when I fired some of the Corbon 110gr +p loads. When I called corbon about it they said it was normal for the 110s
the problem would disappear if I used their heavier bullets.
Speer Gold Dot 135 grain short barrel loads are what you want.
They provide a good balance of power and and recoil, and are designed for reliable expansion out of a short barreled revolver. They make them in .38 spl +p and in .357 magnum.
Natchez Shooter supply carries them.
www.natchezss.com
http://www.natchezss.com/product.cfm?contentID=productDetail&prodID=CC23921
the problem would disappear if I used their heavier bullets.Speer Gold Dot 135 grain short barrel loads are what you want.
They provide a good balance of power and and recoil, and are designed for reliable expansion out of a short barreled revolver. They make them in .38 spl +p and in .357 magnum.
Natchez Shooter supply carries them.
www.natchezss.com
http://www.natchezss.com/product.cfm?contentID=productDetail&prodID=CC23921
Given that there is an upper limit on OAL, the heavier bullet will tend to have more bullet inside the case, increasing the area of the surfaces in contact. This will increase the force of static friction resisting the recoil force. Assuming that we're comparing like to like, of course. The differences in friction coefficient between lead and jacketed bullets also matter, and lead bullets are more likely to move under recoil than jacketed, assuming equal weights.
Since the recoil from the fired cartridge and the inertia of the remaining 4 or 5 will increase linearly as bullet weight is increased, (both are momentum effects), I wonder if the increase in bullet/case contact area is primarily responsible for the observation that heavier bullets are less likely to jump crimp than lighter ones? Basic Newtonian mechanics seems to indicate that, but interior ballistics is deep voodoo, and I'm not willing to go out on that limb. Yes, ultimately everything reduces to F=MA, but the devil is in the details. It's easy to simplify away important information and render your answer worthless. Plus, I'm an electrical engineer, not a physicist or ballistician. I'm just thinking out loud here.
Tim Sundles of Buffalo Bore posts here, and I know that his company has studied bullet pulling extensively. Hopefully, he'll chime in on this thread and add his experience to the discussion.
--Shannon
PotatoJudge
Member
The force of friction is independent of the surface area of contact.
Likely an increased area of contact allows the crimp to exert more force on the bullet, and vice versa. The force with which the bullet and case are pressed together will effect the friction.
Likely an increased area of contact allows the crimp to exert more force on the bullet, and vice versa. The force with which the bullet and case are pressed together will effect the friction.
- Status
