G34 springs and load development

[mwwilkew]

I’m working up some reloads for a new G34 gen3 and have a couple questions. This is the first time I’ve swapped out the trigger assembly, firing pin spring, and recoil springs on a Glock. My goal is a soft-shooting load for use in Steel Challenge (>750fps) and IDPA (>125PF) using VV N320 with 147gr bullets (trying this load based on lots of posts).

Here’s my current setup:

-New G34 gen 3 with a Vanek classic trigger

-Stock RSA, and, ISMI 13# spring on a Jager polymer guide rod

-147gr Berry’s FMJ / 3.4gr VV N320 / 1.155 OAL --> produces ~890fps for 132PF

I wasn’t surprised when I got FTF’s with the stock spring since I’ve read and also experienced that the stock RSA needs about 135PF to run reliably but I was surprised that I still got FTF’s with the 13# spring.

Should I expect the new ISMI spring to behave differently after a few hundred rounds (does it need to be “broken-in”) or should I switch to an 11# spring?

Also was wondering if there’s a post/sticky/website that explains how all of the Glock springs interact?

[sweetback]

3.4/3.5 grn. of N320 is a good load. O.A.L.should be 1.145 that is the length the GLOCK magazine will tolerate.ISMI springs come a little long. Use a 13# and cut 3 coils off with a Dremel.

[LPatterson]

This is the point where I need to ask for your meaning of FTF. Is it a failure to feed or a failure to fire? There are several posts about how the springs interact however my searchfoo is not awake yet. The recoil spring has a primary function of keeping the slide in battery when the trigger is pulled. Simple check [disclaimer]MAKE SURE THE MAGAZINE IS OUT AND THE GUN IS EMPTY[/disclaimer] pull and hold trigger, point the gun vertical, pull the slide back and SLOOOOWLY let it forward. it should go into battery, let trigger go so it resets, pull trigger again, slide should not drop out of battery. If it does then the recoil spring is too weak OR the trigger spring, striker spring combination are pulling the slide out of battery. EVERY GUN IS DIFFERENT.

MY G34 will shoot 120PF ammo using WSP primers; with an 11# IMSI spring, tungsten guide rod, 6# trigger spring, 4# striker spring & extended tip striker. However I need to change the recoil spring frequently.

[disclaimer]This is not a recommendation[/disclaimer]

[mwwilkew]

Thanks for the replies so far. By FTF, I meant failure to feed. The fired brass is thrown clear but the next round does not feed from the magazine. I assume this is because the slide does not go back far enough, or, does not stay back long enough to allow the magazine spring to push the next round up into position. I'll try the test you recommend.

[LPatterson]

Thanks for the replies so far. By FTF, I meant failure to feed. The fired brass is thrown clear but the next round does not feed from the magazine. I assume this is because the slide does not go back far enough, or, does not stay back long enough to allow the magazine spring to push the next round up into position. I'll try the test you recommend.

Now you have an other parameter as you say the brass is ejecting. If you were getting stovepipes (empty not clearing as new brass is fed in), then I might question the factory RSA. But it sounds as though you might have a weak mag spring. You didn't mention if it was just 1 mag or several. My recommendation to you is fully load them at home, use 1 as a barney mag [DISCLAIMER]I WILL NOT RECOMMEND LOADING ANY PISTOL OTHER THAN A BERETTA M9 SERIES DIRECTLY INTO THE CHAMBER [/DISCLAIMER]. Then top off the mag and start shooting, if you don't get any failures then shoot STRONG HAND ONLY. Without being there to watch thats all the advice I can think of.

I'm lazy at the range so I usually load my mags at home so I can just go and shoot. If it is trigger control/slow fire/accuracy then I load the full 17 otherwise they just get 16 so I can shoot pairs. They are numbered because there are 30 to play with.

[usmc0326]

I’m working up some reloads for a new G34 gen3 and have a couple questions. This is the first time I’ve swapped out the trigger assembly, firing pin spring, and recoil springs on a Glock. My goal is a soft-shooting load for use in Steel Challenge (>750fps) and IDPA (>125PF) using VV N320 with 147gr bullets (trying this load based on lots of posts).

Here’s my current setup:

-New G34 gen 3 with a Vanek classic trigger

-Stock RSA, and, ISMI 13# spring on a Jager polymer guide rod

-147gr Berry’s FMJ / 3.4gr VV N320 / 1.155 OAL --> produces ~890fps for 132PF

I wasn’t surprised when I got FTF’s with the stock spring since I’ve read and also experienced that the stock RSA needs about 135PF to run reliably but I was surprised that I still got FTF’s with the 13# spring.

Should I expect the new ISMI spring to behave differently after a few hundred rounds (does it need to be “broken-in”) or should I switch to an 11# spring?

Also was wondering if there’s a post/sticky/website that explains how all of the Glock springs interact?

I started accuracy testing this week with the ransom rest and I am starting to see a trend for rounds less than 1.145 are more accurate than longer loads. (started to flatten primers at 1.165 lol. ) Waiting for the rain to stop for more testing.