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View Full Version : WSMP vs Fed Sm Pistol Primers



10mmShooter
06-12-2010, 08:36 PM
Anyone ever compared Winchester small magnum primers vs Federal small pistol primers.

I have loaded .38 Special with 3.5 grain of Green Dot(I was hoping for 850 fps per manual), same brass and bullet, same crimp, same press ect., only difference is the primer.

Federal Small Pistol primers chrono'd at 769 fps average velocity.
Winchester small magnum primers chrono'd at 834 fps average velocity.

The Winchester primers yielded 60 fps increase?? Thats quiet a change in velocity, I know primers can change the pressure and velocity. but wow 60 fps is alot.

Bass Ackward
06-12-2010, 09:39 PM
Shot gun shells have a compressed charge of powder with a shot cup designed for seal holding a heavy shot charge sitting on top of that with a complete fold over the end to enclose it all and they still use a shotgun primer that is much hotter than the hottest rifle primer.

So shotgun powders can require some heat to burn well even in the fastest speeds. IT just depends on to many variables that can very simply be decided by a few shots.

felix
06-12-2010, 09:52 PM
Hard compressed powder is hard to ignite, John. ... felix

Bass Ackward
06-13-2010, 06:13 AM
Hard compressed powder is hard to ignite, John. ... felix



I know. But it does go the other way too. Unique can exhibit powder position sensitivity in larger cases. And most people wouldn't expect that.

Point was that it never hurts to test primer if it can keep you away from filler.

44man
06-13-2010, 09:31 AM
Shot gun shells have a compressed charge of powder with a shot cup designed for seal holding a heavy shot charge sitting on top of that with a complete fold over the end to enclose it all and they still use a shotgun primer that is much hotter than the hottest rifle primer.

So shotgun powders can require some heat to burn well even in the fastest speeds. IT just depends on to many variables that can very simply be decided by a few shots.
True, John but read all the warnings in a shotgun manual that state use ONLY the primer the load info was developed with. The wrong primer can exceed pressure limits. A shotgun also operates at very low pressures to start with.
Using a hotter primer will ignite powder better but hot is different then a high pressure primer that needs it's pressure added to chamber pressure. The high pressure primer can also move out the boolit before ignition, increase case capacity different from shot to shot and ruin accuracy.
So what causes the increase in velocity? Is it creating more air space? Is it close to an S.E.E. event?
The primer can also add to boolit damage. Thank God for cylinder gaps!
I would stay with the Fed primer myself. Velocity is not the end all, accuracy and safety is.

Bass Ackward
06-13-2010, 02:05 PM
A shotgun also operates at very low pressures to start with.

Velocity is not the end all, accuracy and safety is.



Read his post again and I will tell you my logic.

3.5 gr GD is fairly low pressure too and too much for a full wadcutter, so he has case volume there. The low velocity gives it away.

Depending on the bullet, that is 8k to 11k psi which is shotgun pressure ranges.

And since he only mentions velocity, my assumption was that there is no scope on this with no long range purpose in mind. My guess is was a snub 38 for defense in which case accuracy is not of paramount importance, velocity is.

The fact that he only achieved book velocity told me that he was only producing book pressure with the magnum primer regardless of the physics involved.

Did I win or what?

44man
06-13-2010, 02:53 PM
Read his post again and I will tell you my logic.

3.5 gr GD is fairly low pressure too and too much for a full wadcutter, so he has case volume there. The low velocity gives it away.

Depending on the bullet, that is 8k to 11k psi which is shotgun pressure ranges.

And since he only mentions velocity, my assumption was that there is no scope on this with no long range purpose in mind. My guess is was a snub 38 for defense in which case accuracy is not of paramount importance, velocity is.

The fact that he only achieved book velocity told me that he was only producing book pressure with the magnum primer regardless of the physics involved.

Did I win or what?
Nope, bet he can shoot the boolit quite far down the bore without powder, maybe all the way to the target. :holysheep