9mm sorta problem

BCboy

Moderator
Moderator
Rating - 100%
166   0   0
Location
Duncan BC
Hey I am loading for my sr-9 useing w231@ 4.1gr(max load) with a 147gr bullet 1.125oal (win SP). it has always shot well befor with this load and if I load any lighter it would hold open on the last round (never jams). So now I am useing a new can of w231 @4.1gr and now the last shot will only hold the slide open about 70% of the time ,the gun still functions fine and am geting around 930-950FPS . what would you do ? bump up a point or 2? ,it left me scratching me head .
DSC05220.jpg

DSC05222.jpg

DSC05224.jpg
 
what firearm is this? Interesting drag on the pin indentation on the primer; I am no expert but this looks like violent/premature extraction?:confused:

ETA: sorry just saw SR-9 when I re-read your post
 
If there is no signs of pressure, then why not bump up the load?

Different batches of powder will vary slightly, and as long as you take is slow, and keep an eye out for pressure signs I can't see any issue.

You say this load is max, but you might find that max load varies depending on the manual.
 
Looks kind of hot to me. From the images, it appears that the primer is flowing back into the hole around the firing pin.

I've had a hot load that would not lock back the action on an AR because the bolt speed was apparently faster than mag spring could lift the bolt stop. Could that be happening on your pistol?

Did you work this load up from a published starting load?
Did the velocity plateau or become erratic on the chronograph at some point during this workup?
 
I've had a hot load that would not lock back the action on an AR because the bolt speed was apparently faster than mag spring could lift the bolt stop. Could that be happening on your pistol?

?

I thought about that , but I think I would see FTF's if that was the case , also the recoil spring in theory should define the speed that slide moves forward ?

I really don't know , the load data is almost bang on with the croney speed , Lyman is the only book I could find with 231 and 147s

I really has me baffled
 
Might be a magazine problem? You probably already know this, but number or otherwise uniquely mark your mags so that you can determine if one or two give you more problems than others. At that fps, you're still under 140 PF, so I wouldn't worry about too much or not enough powder. I'd now put my attention on your gun and/or mags rather than the ammo.
 
Lyman is the only book I could find with 231 and 147s

That is what I found for 231 and Bullseye, 5 manuals and only it mentioned it. I did a bunch more digging and found many mention to those two being to fast for the 147 bullet in 9MM. If I like shooting 147s I think maybe try another one, doesn't hurt to have more powder around :)
 
At the risk of stating the obvious, have you zeroed your scale before dispensing powder? Just wondering in case you are assuming it is 4.1 but maybe it isn't. Just a thought. :)
 
I might be a little latein my reply, but I was able to get the SR9 trigger assembly reassembled incorrectly and it caused problems with it locking back.

I had the spring on the lock back installed wrong. It still functioned properly but put less pressure on the lever and occasionally it would fail to lock back.

Once I got it together correctly all was well. Might be something to look at if you have had it apart.
 
Back
Top Bottom