Breaking in a new caliber slide

L. Boscoe · May 8, 2025, 09:09 PM

I got a 38 super slide for my Tanfoglio large frame. It will
cycle just fine with factory loads, which are way too hot for my use, bullseye shooting. It is beginning to cycle with my hand loads, may need another recoil spring, but what puzzles me is that about every 3rd round of handholds requires a recock and refire.
This is a brand new from the factory conversion slide. The factory loads don't need this.
I am thinking the firing pin is either gummed up or the FP
spring is too weak.
My hand loads run perfectly in my Colt 38 super, with an
8# recoil spring. I am running the lightest Tanfo has to offer.
Factory loads 1300 fps, handholds 800.

**4V50 Gary** · May 8, 2025, 09:33 PM

You could try a weaker recoil spring.

I once worked on some proprietary double stack 45 to get the magazines to fit (the proprietary company relocated the mag-catch hole such that Para-Ordnance mags wouldn't work. Had to cut new holes in the Para-Ordnance magazines. Anyway, test firing followed and the slide was really slow. Turned out the owner had a heavy spring for a hotter ammo that what I was using. I talked to the owner and told him that the mags held and when I mentioned about how slow the slide moved, he then told me that it is for hotter ammo.

L. Boscoe · May 9, 2025, 10:06 PM

am looking for one as we speak

nuchie11 · May 10, 2025, 06:32 AM

You’re probably right about the recoil spring. The lighter one might be struggling with your hand loads. Try a heavier spring, and also check your primer seating

**4V50 Gary** · May 11, 2025, 06:19 PM

BTW, we were taught to put a coil spring onto a rod and do a quick pass on the grinder. Little at a time, reinstall and test. Rinse and repeat.

L. Boscoe · May 11, 2025, 10:26 PM

the slide is less than 200 rds thru it so far, it is showing signs of
improving. I shot two mags of full power thru it this weekend and
that improved the firing situation. I would have to go back to factory spring if I did much of that, and my wrist/hand would not like me for it, so I will up the powder a tad and see if that solves
my issue.
thanks for all the replies.

May 8, 2025, 09:09 PM	#1
L. Boscoe Senior Member Join Date: October 30, 2021 Posts: 326	Breaking in a new caliber slide I got a 38 super slide for my Tanfoglio large frame. It will cycle just fine with factory loads, which are way too hot for my use, bullseye shooting. It is beginning to cycle with my hand loads, may need another recoil spring, but what puzzles me is that about every 3rd round of handholds requires a recock and refire. This is a brand new from the factory conversion slide. The factory loads don't need this. I am thinking the firing pin is either gummed up or the FP spring is too weak. My hand loads run perfectly in my Colt 38 super, with an 8# recoil spring. I am running the lightest Tanfo has to offer. Factory loads 1300 fps, handholds 800.

May 8, 2025, 09:33 PM	#2
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 22,288	You could try a weaker recoil spring. I once worked on some proprietary double stack 45 to get the magazines to fit (the proprietary company relocated the mag-catch hole such that Para-Ordnance mags wouldn't work. Had to cut new holes in the Para-Ordnance magazines. Anyway, test firing followed and the slide was really slow. Turned out the owner had a heavy spring for a hotter ammo that what I was using. I talked to the owner and told him that the mags held and when I mentioned about how slow the slide moved, he then told me that it is for hotter ammo. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

May 11, 2025, 06:19 PM	#5
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 22,288	BTW, we were taught to put a coil spring onto a rod and do a quick pass on the grinder. Little at a time, reinstall and test. Rinse and repeat. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

May 9, 2025, 10:06 PM	#3
L. Boscoe Senior Member Join Date: October 30, 2021 Posts: 326	am looking for one as we speak

May 10, 2025, 06:32 AM	#4
nuchie11 Member Join Date: July 18, 2019 Posts: 17	You’re probably right about the recoil spring. The lighter one might be struggling with your hand loads. Try a heavier spring, and also check your primer seating

May 11, 2025, 10:26 PM	#6
L. Boscoe Senior Member Join Date: October 30, 2021 Posts: 326	the slide is less than 200 rds thru it so far, it is showing signs of improving. I shot two mags of full power thru it this weekend and that improved the firing situation. I would have to go back to factory spring if I did much of that, and my wrist/hand would not like me for it, so I will up the powder a tad and see if that solves my issue. thanks for all the replies.