40 loads were close but need another 30 FPS. More powder or shorten COL?

[tysdad115]

I'm working up some 40 load for major PF. I'm real close at 162 with an average FPS of 902. I need roughly another 30-35 FPS to get to where they would exceed 165 PF enough. What are opinions on getting such a minor "adjustment" out of rounds. My current load I tested is 4.5gr N320 , at 1.135" (Glock G35), 180 gr Zero JHP with Federal GM100 primers.

I'm wondering if I should bump the powder charge up by .1 or .2 (there were no pressure signs in the 75 cases I fired of this load) or try shortening COL by .005" and .010" to see if that will do it.

Is anyone else using N320 for 40 major PF in a Glock G35?

I'll make a few more this week and test them this weekend once I replace the chrono rod I shot on my brand new pro chrono.

 

[EddieCoyle]

Don't shorten them up. What are you using for data? Are you below max?

Keep in mind that the first pressure sign you see might be the pistol in pieces.

There's not a lot of wiggle room with the .40

 

[tysdad115]

I haven't found published data on VV N320 and 180gr JHP, but supposedly it's a preferred powder among USPSA and IDPA shooters. VV doesn't show a true load with N320. They show N340 but thats a slower burning powder I believe.I came up with 4.3 and 4.5gr from reading a ton of other shooters recipes for this round but I'd rather not blow my gun up. I know 40 is "sketchy" which is why I asked if making those changes would be ok or not.
I don't know if making the COL changes would spike pressures and without a true max load to go by I don't want to just add more powder either.

 

[EddieCoyle]

Shortening the C.O.A.L. will add pressure but not necessarily increase the velocity.

There are plenty of powders that will safely get you north of 1000 FPS with a 180gr bullet.

Yet you're using this powder without data because everybody else is doing it?

Well Sir, I can tell you what my mother would say to that.

 

[tysdad115]

Mine too. I'll switch to titegroup for this and use the N320 for 9mm.

 

[Gammon]

Shortening the OAL can also lead to feeding problems.

 

[wiryone1]

Does this help?

http://www.vihtavuori.com/en/reloading-data/handgun-reloading/-40-s-w.html

I would wager a guess that with your COAL and powder you may be close to max load now. Based on the link above you may want a slower powder. They show 1.126 with 4.1 gr as a max load with N320.

 

[SJan]

N320 and other fast powders are very popular in loading soft recoiling 40 when loaded long, 1.17- 1.20

if your gun cant handle that length, staying with published data is safer and smarter.

 

[spt_1955]

Does this help?

http://www.vihtavuori.com/en/reloading-data/handgun-reloading/-40-s-w.html

I would wager a guess that with your COAL and powder you may be close to max load now. Based on the link above you may want a slower powder. They show 1.126 with 4.1 gr as a max load with N320.

I cannot understand how pushing a 180gr bullet at 968FPS could be pushing max load.

 

[SJan]

I cannot understand how pushing a 180gr bullet at 968FPS could be pushing max load.

With some of the fast burning powders we action shooters use to make light recoiling loads, we need to be at max or even over published max to make power factor.

 

[Rob Boudrie]

With some of the fast burning powders we action shooters use to make light recoiling loads, we need to be at max or even over published max to make power factor.

This is not a problem with the SVI, STI an clones thereof. One could even argue that the longer than SAAMI length cartridges these guns use actually result in a different cartridge than the regular 40 S&W.

I can certainly understand taking a more cautious approach when loading for a Glock. O wouldn't even bother trying to load 40 major in a Glock - SxI is better for Limited division, and 9x19 is the optimal caliber for Production division.

Another precaution would be to exercise extreme care to avoid using any bulged cases in a Glock, as you do not want a round firing slightly out of battery.

 

[tysdad115]

4.7 N320 at 1.135 gave me 169 PF . And they shoot beautiful. 800 rounds of it so far and the brass has zero pressure signs.

 

[tysdad115]

This is not a problem with the SVI, STI an clones thereof. One could even argue that the longer than SAAMI length cartridges these guns use actually result in a different cartridge than the regular 40 S&W.

I can certainly understand taking a more cautious approach when loading for a Glock. O wouldn't even bother trying to load 40 major in a Glock - SxI is better for Limited division, and 9x19 is the optimal caliber for Production division.

Another precaution would be to exercise extreme care to avoid using any bulged cases in a Glock, as you do not want a round firing slightly out of battery.

I case gauge every round I make, in .40 and 9mm. All the time.

 

[spt_1955]

With some of the fast burning powders we action shooters use to make light recoiling loads, we need to be at max or even over published max to make power factor.

Yes.. and I am one of those shooters. My comment was based on the referenced Vihtavuori load data calling for a max load of 4.1gr with an FPS of 968 while their published max load of their other powders produces 100FPS more. It makes no sense that 4.1 is max load for VV N320 with 180gr bullet..

 

[spt_1955]

I case gauge every round I make, in .40 and 9mm. All the time.

+1. I also have a Lee Sizing/Crimp die in my RCBS Rock Crusher to clean up anything that will not gauge coming out of the Hornady progressive press. (an old habit from shooting Glocks)

 

[tysdad115]

I also have a Lee Sizing/Crimp die in my RCBS Rock Crusher to clean up anything that will not gauge coming out of the Hornady progressive press. (an old habit from shooting Glocks)

Just to correct myself, I make Tyler case gauge all his own rounds after I'm done making them.

 

[Supermoto]

4.7 N320 at 1.135 gave me 169 PF . And they shoot beautiful. 800 rounds of it so far and the brass has zero pressure signs.

I would bump up to 172pf if you plan to shoot any majors, don't want to go minor if the chrono is slow

 

[tysdad115]

I would bump up to 172pf if you plan to shoot any majors, don't want to go minor if the chrono is slow

Thank you. I plan on rechecking them if the damn temperature ever starts to increase to see the effect once it gets warmer.

 

[SJan]

Yes.. and I am one of those shooters. My comment was based on the referenced Vihtavuori load data calling for a max load of 4.1gr with an FPS of 968 while their published max load of their other powders produces 100FPS more. It makes no sense that 4.1 is max load for VV N320 with 180gr bullet..

Are you saying that because the other powders produce a higher velocity, it is safe to reach that same velocity with any powder?