Bluemooncricket

Sure thing! That's a theory I had never considered. I suppose the best way to measure would be with a feeler gauge between the barrel hood and breech face and then from the cases base to the end of the barrel hood. I've inspected my spent cases but I haven't really noticed anything peculiar on the primer end.

When I started working up the loads I had a few cases that were "sooty" at the mouth. The charge weight I've settled on burns much cleaner, especially with jacketed bullets.

I had a 9mm shell plate on my 550 cause about .010 variation. I swapped the plate for another and variance was reduced to .005 with mixed range brass. If you have a .40 s&w shell plate you could try that, they are the same.

Is there any visual clue I might detect in my fired casings that would indicate a loose pocket?

One thing that helped mitigate my oal issues was to operate the press handle consistently and pause on the downstroke for a second. Also make sure the shell plate isn't loose....

I'm loading WST with 124 gr MG fmj and BBI with mixed range brass and Winchester spp to minor power factor and noticed some pitting on the left side of my m&p 9's breech face. In the brief research I've done, this problem seems to be related to the use of magnum/rifle primers or major power factor loads, neither of which is applicable in my case. Could loose primer pockets be my problem? I load on a 550 and don't really notice any one head stamp being more or less difficult to seat primers. Is there a visual cue to a loose primer pocket? And lastly, is it common to have the pitting on only one side, or could this just be a defective slide? Sorry for the long post and lack of pics. Thanks in advance!

Awesome, I'll give him a call!

Does anyone know if Bayou Bullets are taking orders again? Their website still has the message up that says "Due to extremely high order volume......" but I haven't called to confirm.

I realize the M&P will never match the accuracy potential of the 1911/2011 platform, but after trying to get a Para 18.9 to run reliably I quickly fell in love with my 5" Pro. Not to mention the cost involved....

So the .380 and .223 she'll plates are the same as well? Glad to hear Dillon is taking care of you.

So, generally speaking, every gun/barrel combo could yield a different result with regards to accuracy from varying cartridge lengths and experimentation is the only way to maximize the accuracy potential of a given powder/projectile combination. Dang, I was hoping there might be a short cut..... Thanks for the speedy responses guys! Much appreciated!

If the chamber and mags of my M&P will take a MG 124 gr. fmj out to 1.170 is there any benefit to loading them shorter for minor power factor loads? I'm using WST currently because its readily available in my area. I'm using 4.7 grains and an oal of 1.160 - 1.165 with mixed brass. Functions fine but accuracy is nothing to write home about. I haven't had a chance to experiment a lot with the oal and thought I would seek some conventional wisdom from those with more experience before I waste too much time or effort. Sorry for the long post and thanks in advance for your help..

Sorry, I forgot to mention I purchased the press used. I have no idea how many rounds it produced before I acquired it. Perhaps the shell plate was bent slightly by the previous owner somehow?? I had a chance to load some MG 124 FMJ this afternoon and my oal variance dropped back down to about .005 with mixed range brass utilizing the ".40 S&W" plate. I'm pretty satisfied with that. Being a noob at this I just wanted to get a second opinion before I blamed the problem on a warped shell plate.

I've reloaded about 1500 rounds of 9mm with my 550B and started noticing almost .010 variance in OAL. I checked the shell plate for looseness and tried to tighten it up. Even when the plate is almost too tight to turn I measured .008 of movement between it and the ram. I had a .40 conversion kit on hand and swapped out the plate after I discovered they were the same (#5). Voila, down to .001. So, my question is do shell plates eventually wear and cause variance or have I done something incorrectly? Thanks in advance for any responses!

I just started working up a load for the BBI 125 TC for my M&P 9L and am a little bit puzzled. I loaded some dummy rounds out to 1.155" (mimicking my FMJ load) and while some drop right in and out, others won't. I've shortened some up to 1.13 and still experience some resistance just before seating. Could this be due to the coating? Up to this point I've only had experience loading FMJ and all of my rounds plunked in and fell right out. All the crimps are uniform at .377" and to my eye nothing stands out. Any help would be greatly appreciated!!