9mm - exceeding "Never Exceed"
- Thread starter harbl_the_cat
- Start date
Thansk for all the great posts all.
I had PRK (Laser eye surgery) 4 days go, and can't see 2 feet in front of my face, and have had alot of time to meditate on this subject.
Some points - I have about 2000 copper plated 124 gn 9mm projectiles and about 4 lbs of AC#2 and 2000 CCI small pistol primers. I was running them on my glock 17 and decided to stock up a while back. Running those same loads through the Sub 2000 was causing me all kind of grief with FTE/stovepipe.
Thinking about the design of the Sub2000, I think there's a couple logical possibilities - one, the bolt is gigantic and the recoil spring, I am assuming (being new) is probably quite stiff) - meaning I could (as suggested) consider a ligher recoil spring - or I was thinking I could cycle the action a few thousand times and keep the slide locked back for a few weeks to try to lighten it up myself.
A chrony definately is in order though - that will have to be my next procurement.
Any suggestions?
Looks like I'm out of action for at least a week or two - so those 30 rounds of otentially hot 9mm sitting in my garage will just linger in the back of my mind to no end.
Well - I can't keep my eyeso pen any more - good takling, all.
I had PRK (Laser eye surgery) 4 days go, and can't see 2 feet in front of my face, and have had alot of time to meditate on this subject.
Some points - I have about 2000 copper plated 124 gn 9mm projectiles and about 4 lbs of AC#2 and 2000 CCI small pistol primers. I was running them on my glock 17 and decided to stock up a while back. Running those same loads through the Sub 2000 was causing me all kind of grief with FTE/stovepipe.
Thinking about the design of the Sub2000, I think there's a couple logical possibilities - one, the bolt is gigantic and the recoil spring, I am assuming (being new) is probably quite stiff) - meaning I could (as suggested) consider a ligher recoil spring - or I was thinking I could cycle the action a few thousand times and keep the slide locked back for a few weeks to try to lighten it up myself.
A chrony definately is in order though - that will have to be my next procurement.
Any suggestions?
Looks like I'm out of action for at least a week or two - so those 30 rounds of otentially hot 9mm sitting in my garage will just linger in the back of my mind to no end.
Well - I can't keep my eyeso pen any more - good takling, all.
harble,
I will speak from experience. Many years ago when trying to develop subsonic loads for my sten I massively overloaded some rounds by accident.
In a subgun, as long as you keep your face away from the ejection port, it really doesn't matter what you do. I blew a number of cases to pieces and the bits were simply thrown out of the ejection port with no issues. I never even hurt an ejector nor did the gun stop working.
You are not going to hurt a blowback SMG no matter how hot you load it. The case will simply bulge or even split as it pushes the bolt backwards and then everything will be pushed out of the ejection port by the expanding gases. Just make sure no parts of your body are in the path of any shrapnel exiting the ejection port.
Says who? Where exactly did you get this from? Sounds like one of those typical "well everyone knows" kind of pronouncements that has no basis in fact.
I will speak from experience. Many years ago when trying to develop subsonic loads for my sten I massively overloaded some rounds by accident.
In a subgun, as long as you keep your face away from the ejection port, it really doesn't matter what you do. I blew a number of cases to pieces and the bits were simply thrown out of the ejection port with no issues. I never even hurt an ejector nor did the gun stop working.
You are not going to hurt a blowback SMG no matter how hot you load it. The case will simply bulge or even split as it pushes the bolt backwards and then everything will be pushed out of the ejection port by the expanding gases. Just make sure no parts of your body are in the path of any shrapnel exiting the ejection port.
Says who? Where exactly did you get this from? Sounds like one of those typical "well everyone knows" kind of pronouncements that has no basis in fact.
Rocket Surgery
CGN Ultra frequent flyer
I'll second this. My auto-disk cavities throw different charges based on how much powder is in the hopper. You basically have to keep the thing full, and it still never throws as much as the cards say it will.
mudgunner49
CGN Ultra frequent flyer
So I guess the US Navy was really breaking ground with the gajillions of rounds of Winchester 147 gr OSM they put through their MP5 SD's back in the day?? I fired one 4 or 5 years ago that had a documented 400K + through it - most of it 147 gr. Granted it was a little raggedy...
Necro-thread time!
Some developments since.
I've ran about 5-6 different loads through my sub 2000, and my current running theory is it's a combination of ammo and the follower in the 10 round mags glock mags we have up here in Canada.
I picked up a chrono and will be trying out a few more different loads (including some hot ones). I'll make sure I run them through my sub gun first before I try them in my glock.
On the subject of the auto-disk loaders, when I start a load, I measure the first 10 charges with a digital scale, then do a spot check every 100-200 to make sure it's still loading a consistent charge.
Some developments since.
I've ran about 5-6 different loads through my sub 2000, and my current running theory is it's a combination of ammo and the follower in the 10 round mags glock mags we have up here in Canada.
I picked up a chrono and will be trying out a few more different loads (including some hot ones). I'll make sure I run them through my sub gun first before I try them in my glock.
On the subject of the auto-disk loaders, when I start a load, I measure the first 10 charges with a digital scale, then do a spot check every 100-200 to make sure it's still loading a consistent charge.
So I took the advice given here and bought a chrono and tried to chrono a few different loads through my G17 and Sub2k.
I was bit noobish learning how to use they Chrony and shooting indoors.
I used 3 types of ammo (I couldn't get a readout using my glock with the BDX ammo).
124 gn FMJ, BDX reloads (Unknown load),
124 gn FMJ, 4.2 gn Accurate #2
124 gn CP, 4.0 gn Accurate #2
I'll have to measure the OAL's I forgot, but here's my findings. I think it explains what I was seeing with my Sub2k.
I only had frequent FTE's with the copper plated bullets (the low FPS seem logical).
Someone posted here it's possible gas from the round is escaping in front of the bullet as it travels down the barrel, possible explaining the low velocity. I could slug the barrel, but I think the point is clear - stick to jacketed bullets.
I'm also not sure about the velocity variance's I was seeing there. Don't know if it's the chrony or not. I measure my loads, and the charge comes in very consistent. I had a lot of miss reads (ones that were obviously too low - like 150-200 fps, or too high - like 5000 - 9000 fps). Any thoughts?
It's also strange that the velocities out of the Sub2k would read lower with my own jacketed loads. I'll have to do some more testing.
As an aside, I didn't shoot those hot loads - just added them to my pull pile.
Glock 17 9mm 124 gn copper plated (TSE) 4.0 gn Accurate #2
Shot Count 12
Maximum 964
Minimum 1136
Average 1060
Glock 17 9mm 124 gn FMJ (BDX) 4.2 gn Accurate #2
Shot Count 5
Maximum 1012
Minimum 1162
Average 1075
Sub 2000 9mm 124 gn copper plated (TSE) 4.0 gn Accurate #2
Shot Count 6
Maximum 549
Minimum 695
Average 627
Sub 2000 9mm 124 gn FMJ (BDX) -BDX Reload - charge unknown
Shot Count 6
Maximum 1158
Minimum 1395
Average 1249
Sub 2000 9mm 124 gn FMJ (BDX) 4.2 gn Accurate #2
Shot Count 12
Maximum 848
Minimum 1065
Average 999
I was bit noobish learning how to use they Chrony and shooting indoors.
I used 3 types of ammo (I couldn't get a readout using my glock with the BDX ammo).
124 gn FMJ, BDX reloads (Unknown load),
124 gn FMJ, 4.2 gn Accurate #2
124 gn CP, 4.0 gn Accurate #2
I'll have to measure the OAL's I forgot, but here's my findings. I think it explains what I was seeing with my Sub2k.
I only had frequent FTE's with the copper plated bullets (the low FPS seem logical).
Someone posted here it's possible gas from the round is escaping in front of the bullet as it travels down the barrel, possible explaining the low velocity. I could slug the barrel, but I think the point is clear - stick to jacketed bullets.
I'm also not sure about the velocity variance's I was seeing there. Don't know if it's the chrony or not. I measure my loads, and the charge comes in very consistent. I had a lot of miss reads (ones that were obviously too low - like 150-200 fps, or too high - like 5000 - 9000 fps). Any thoughts?
It's also strange that the velocities out of the Sub2k would read lower with my own jacketed loads. I'll have to do some more testing.
As an aside, I didn't shoot those hot loads - just added them to my pull pile.
Glock 17 9mm 124 gn copper plated (TSE) 4.0 gn Accurate #2
Shot Count 12
Maximum 964
Minimum 1136
Average 1060
Glock 17 9mm 124 gn FMJ (BDX) 4.2 gn Accurate #2
Shot Count 5
Maximum 1012
Minimum 1162
Average 1075
Sub 2000 9mm 124 gn copper plated (TSE) 4.0 gn Accurate #2
Shot Count 6
Maximum 549
Minimum 695
Average 627
Sub 2000 9mm 124 gn FMJ (BDX) -BDX Reload - charge unknown
Shot Count 6
Maximum 1158
Minimum 1395
Average 1249
Sub 2000 9mm 124 gn FMJ (BDX) 4.2 gn Accurate #2
Shot Count 12
Maximum 848
Minimum 1065
Average 999
The extreme spread does seem odd. If the chrony is too close, the gases will really give strange results.
Yeah - I was firing about 1 meter back from it. I thought that was pushing it.
