razorfish Posted April 5, 2015 Share Posted April 5, 2015 I'm not sure I follow that logic...what you're using the gun for doesn't change the pressure or wether or not the load is safe. A load that is going to blow up in a IDPA gun is going to blow up in a open gun too. With that said, I do intend to use this gun for open. You'll want a FULLY supported chamber to shoot 9mm major power factor. Many stock barrels aren't fully supported to allow the pistol operate more consistently using a variety of ammo. Also, you'll want to setup your recoil system for 9mm major to avoid damaging the pistol. The term "open gun" in USPSA terms "generally" refers to a pistol with a fully supported barrel and a compensator to mitigate the added recoil. 9mm major power factory ammo is likely to catastrophically fail in your factory barrel if the chamber is only partially supported (Glock, M&P, etc). The 9 Major ammo will likely fail right at the top of ramp and cause all sorts of nastiness as the base of the case becomes shrapnel flowing into your magazine. Fully supported barrels for basic production guns are available from a variety of vendors (Storm Lake, KKM, etc.) Also, unless you increase the recoil spring weight and/or compensate your barrel or you'll likely "break" your gun or worse. Link to comment Share on other sites More sharing options...
yellowfin Posted April 6, 2015 Share Posted April 6, 2015 Basically unless you're REALLY getting it all 100% right, you're better off with .40 and most people would be best to do a 40 to avoid the potential mess. Link to comment Share on other sites More sharing options...
BoyGlock Posted April 6, 2015 Share Posted April 6, 2015 I'm not sure I follow that logic...what you're using the gun for doesn't change the pressure or wether or not the load is safe. A load that is going to blow up in a IDPA gun is going to blow up in a open gun too. With that said, I do intend to use this gun for open. You'll want a FULLY supported chamber to shoot 9mm major power factor. Many stock barrels aren't fully supported to allow the pistol operate more consistently using a variety of ammo. Also, you'll want to setup your recoil system for 9mm major to avoid damaging the pistol. The term "open gun" in USPSA terms "generally" refers to a pistol with a fully supported barrel and a compensator to mitigate the added recoil. 9mm major power factory ammo is likely to catastrophically fail in your factory barrel if the chamber is only partially supported (Glock, M&P, etc). The 9 Major ammo will likely fail right at the top of ramp and cause all sorts of nastiness as the base of the case becomes shrapnel flowing into your magazine. Fully supported barrels for basic production guns are available from a variety of vendors (Storm Lake, KKM, etc.) Also, unless you increase the recoil spring weight and/or compensate your barrel or you'll likely "break" your gun or worse. Until now I thought most pistol oem barrels have fully supported chambers except .40 Glocks'?Years ago my major 9 loads were shot in a Glock 17 and Bereta 92f without any problem of over pressure. Ymmv. Link to comment Share on other sites More sharing options...
Patruck825 Posted April 6, 2015 Share Posted April 6, 2015 Thanks for the info guys, I thought my M&P performance center would have a fully supported chamber, and I've read a couple places that it did. I'll have to look into it more. Link to comment Share on other sites More sharing options...
truborshooter Posted April 6, 2015 Share Posted April 6, 2015 Just check my 5" CORE 9mm barrel, a KKM Match and a Wilson Match barrels and they are all fully supported barrels Only difference in barrels is finish Cartridge case extension out of barrels are within thousands, only the extractor groove shows. Link to comment Share on other sites More sharing options...
cnote Posted April 6, 2015 Share Posted April 6, 2015 Just check my 5" CORE 9mm barrel, a KKM Match and a Wilson Match barrels and they are all fully supported barrels Only difference in barrels is finish Cartridge case extension out of barrels are within thousands, only the extractor groove shows. The aftermarket upgraded barrels usually are Link to comment Share on other sites More sharing options...
truborshooter Posted April 6, 2015 Share Posted April 6, 2015 Sorry I wasn't clear the 5" CORE barrel is S&W factory one dot. The other two are upgraded All a fully supported barrels. Link to comment Share on other sites More sharing options...
Patruck825 Posted April 10, 2015 Share Posted April 10, 2015 (edited) ive got some test loads worked up with some Eggleston munitions 115gr coated bullets, ive got 4.5, 4.8 and 5.1gr of autocomp under them. One thing I notice is that my lee die is producing a variance in my seating depth from 1.13x to 1.15, this is probably likely due to variances in the bullet(I am taper crimping with a separate die) but does anyone foresee it causing a problem? they all pass a plunk test in my 5" M&P PC Note: Hodgdon's load data calls for 4.4gr to 5.1gr max at a COL of 1.100 Edited April 10, 2015 by Patruck825 Link to comment Share on other sites More sharing options...
razorfish Posted April 10, 2015 Share Posted April 10, 2015 ive got some test loads worked up with some Eggleston munitions 115gr coated bullets, ive got 4.5, 4.8 and 5.1gr of autocomp under them. One thing I notice is that my lee die is producing a variance in my seating depth from 1.13x to 1.15, this is probably likely due to variances in the bullet(I am taper crimping with a separate die) but does anyone foresee it causing a problem? they all pass a plunk test in my 5" M&P PC Note: Hodgdon's load data calls for 4.4gr to 5.1gr max at a COL of 1.100 What kind of brass? If you're using mixed brass this is completely normal and not that alarming with matched brass. As long as you're M&P has no issue with your longest rounds, you're good to go. (Note... take your 1.15 loads drop them in your barrel and then spin them with your fingers... If the bullet is touching the lands you'll feel it.) Time to go the range and test them! Link to comment Share on other sites More sharing options...
Patruck825 Posted April 10, 2015 Share Posted April 10, 2015 yeah its mixed brass, good to know, thanks! I loaded up some Dummy rounds when I was doing my plunk test and even with a round loaded to 1.165, I didn't feel anything. im used to loading .308 where your jump to the lands is important, is this the same case in pistols, or is it less of a factor? Link to comment Share on other sites More sharing options...
razorfish Posted April 10, 2015 Share Posted April 10, 2015 yeah its mixed brass, good to know, thanks! I loaded up some Dummy rounds when I was doing my plunk test and even with a round loaded to 1.165, I didn't feel anything. im used to loading .308 where your jump to the lands is important, is this the same case in pistols, or is it less of a factor? The bullet jump depends on the pistol... My CZ's are more accurate with a shorter load... I could load longer for my CZ's but I get better accuracy when I load shorter. Of course there's more factors in play than just the OAL (bullet type/brand/weight, powder type/brand, power factor loaded, etc.) My son's M&P Pro is more accurate with a longer load that's pretty close to the lands. The main thing is to not put a bullet "into" the lands. Bad things can happen here... A couple of thousandths into the lands will often allow the pistol to light off the round just slightly out of battery. Probably won't maim or kill you (as long as you've got eye protection) but you'll only do it once Link to comment Share on other sites More sharing options...
Patruck825 Posted April 10, 2015 Share Posted April 10, 2015 Thanks for the info, im headed out to the range today to see what she likes best! Link to comment Share on other sites More sharing options...
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