.357 Mag Pressure Signs: How Sticky is Too Sticky?

[PzShrekt]

Everything is accurate at ten yards and we are all expert shooters at that distance. As a suggestion, try the same at 25 yards. You'll get much more useful information.

I've done shooting with a barricade at ~24 yards before using the same gun and Accurate #9 loads before in the past, typically my most accurate was actually 12.6 grains, then 12.8, and then group sizes would increase at 13+ grains at least out of my gun.

I got a ragged 3 inch fist sized hole that distance at 12.6 grains, a non ragged 4.5 inch group with 12.8 grains, and a 4.5-6 inch grouping with 13-13.5 grains (higher recoil, got like 1240-1260 fps out of those loads).

I typically consider a load "accurate" if I can hold a 5"-6" group in rapid double action fire at 10 yards (basically the longest distance in my house), my current home defense load is a 8.5 grain load of Accu #5 loaded under a 110 grain XTP, shot 1100 fps out of my Model 15-3, pretty sure it's a +p+ load considering Hodgdon's calls for a max of 7.6 grains, I was going by Sierra's 6th edition. Managed to get a 3" group at 10 yards in rapid double action.

The .357's just a backup, hate shooting that thing without ear protection, for the hell of it I shot one round in doors without hearing protection on a quiet range day, a bit of poo came out, and I was ringing for a solid minute. The plus p load I had wasn't too bad, so I figure if I had to shoot my piece in the dark of the night half naked it'd definitely be a better alternative to me blowing out my eardrums with magnum loads.

At 1100 that is JUST shy of the speed of sound at around at 1125 at sea level, some of the highs were around 1150, lowest was 1090 I believe.

 

[Keith C.]

Wouldn't "the best I can put together" include using new brass or at least brass you know?

Of course; I figured that was assumed.

Using mixed brass that's been fired an unknown number of times (you never know if the brass you find on the ground is really once-fired) puts you at an immediate disadvantage. Mixed mystery brass often works well, but will never work better than new or once-fired brass of the same batch or at least the same headstamp. It's difficult if not impossible for you to analyze the situation without having adequate control factors and brass is one of them.

rockquarry, I didn't need to assume. You explained the situation quite clearly in post #8.
On another topic, sticky cases can be caused by many different variables. If you have sticky cases and flattened primers, you should stop right there and evaluate your situation.

 

[rockquarry]

rockquarry, I didn't need to assume. You explained the situation quite clearly in post #8.
On another topic, sticky cases can be caused by many different variables. If you have sticky cases and flattened primers, you should stop right there and evaluate your situation.

Okay. Post #8 has been a while ago and sometimes I get confused.

 

[Lance Boyle]

Looking at primers is a poor indication of pressure.

Yep take any good average pistol load then swap in a Federal pistol primer. They almost always will appear flattened a bit. I am currently using old stock Winchester and Federal and there is a big difference in a post firing appearance.

 

[rockquarry]

Yep take any good average pistol load then swap in a Federal pistol primer. They almost always will appear flattened a bit. I am currently using old stock Winchester and Federal and there is a big difference in a post firing appearance.

Not just Federal. I've seen the same with CCI. It often depends on the gun and not the load. Another reason not to read too much into primer appearance. Use a chronograph and compare velocities with book figures, but use several books.

If you want to depend on primer appearance to crudely indicate excessive pressure, this is what I would do: use the same brass from the same batch, same bullets from the same batch, and same primers from the same batch. Increase powder charge until you see flattening and fire at least ten rounds so you have a standard to go by. Don't go above book figures for the load and compare velocities, again, using several books against your velocity readings. If you're getting velocities appreciably higher than what you extrapolate from several books (not Internet), you've likely exceeded safe pressures, but none of this is foolproof.