1st 9mm reloads where do we go with the data

[roval]

I tested my first 9 mm reloads yesterday. chrono beta master

5.7 unique cci primer/ federal brass /speer 115 tmj
lo 1266 fps
hi 1324
av 1302
extreme spread 57.5
standard dev 18.78

6 unique cci primer/federal brass/ speer 115
lo 1330
hi1367
av 1343
es 37.12
sd 14

6 unique cci primer/federal brass/ Remington 115 fmj bulk
lo 1321
hi 1374
av 1348
es 53.15
sd 17.86

for comparison I chronoed 10 rounds of Winchester 115 fmj white box
lo 1154
hi 1281
av 1212.4
es 127
sd 40.93 (manually computed after looking up the formula in the internet but I double checked it -my chrono can only store 6 strings)

While I am very happy with the consistency and low spreads and sd's(especially compared to my 230 grain 45 acp reloads with bigger sd proportionally), in my speers manual the velocity with 5.6 unique was 1166 fps and 6.3 grains with 1244 fps. Do you stick with the load or go to lowest recommended(5.6 grains) or even lower than recommended.

Accuracy wise I think it's more me and the gun at 25 yards. I hit my 25 yard gong more consistenly with my 45 acp with the bigger spreads of velocitites than with my 9 mm but still good .

 

[witchhunter]

Don't go under the listed data. Your pistol might like another bullet or weight though. At close range the sd or ed won't matter much. I would load the most accurate and not worry about the chrono results if they are ballpark.

 

[greyling22]

bah, I go under listed data all the time without issue. As long as your gun cycles and you get the accuracy you want it's not an issue. Witchhunter is right about the rest through.

As for differences in what you get and what the manual says you should be getting in velocity, well a lot of times when they test they are not using an actual gun, just a barrel. Maybe a different length barrel than yours. maybe a barrel with different rifling depth, twist, and barrel length. Different humidity, powder lots, primers etc can all have an effect too. Don't sweat it.

 

[Walkalong]

What barrel length? A 1348 FPS Avg with a 115 Gr bullet is smoking from a handgun.

 

[mulyhuntr]

X2 on barrel length? Those 5.7 grain loads are over 130 fps faster than my 115rn 5.5gr loads.

 

[roval]

xdm 5.25 the Winchester was shot from the same gun.

 

[LeonCarr]

Wow...those are +P+ type velocities.

Keep in mind while those may be safe loads, prolonged use of those will result in premature wear and tear on the handgun.

Just my .02,
LeonCarr

 

[GaryL]

Best accuracy may not be at top velocities like those.

But I would also double check your scale. My older Hercules manual lists 6.1gr @ 1185fps as the top load for 115gr FMJ and Unique. A little variance from gun to gun is normal, except that the Win you shot is right in that top load range.

 

[roval]

elevation may be a factor, 5900 feet at the shooting range. but again the Winchester factory load is still about 1200 fps. do I reduce the load till I get to 1100-1200 fps?

 

[roval]

scale is brand new rcbs electronic scale and I do calibrate it everytime sometimes multiple times as i'm using it. as mentioned with my other post about unique and 115 fmj. my metering technique typically leads to +/- 0.1 grains from my target grains. I weigh every 10th case and charge only 50 cases at a time.

 

[verb0s]

I go under the listed load all the time. I started going under the listed loads I think on my 3rd batch of loads (#200?). Literally just a few weeks after I got my own press and started loading!

Never had problems with going under the published starting load. With the revolver calibers I learned you'd really have to go under to cause problems. With semi's there's a indicator of going too light when you gun doesn't cycle. you'd have to keep reducing charge quite a bit more before you have problems.

To go under you just reduce 0.1 or 0.2 grains every 5-10 rounds and you'd test them, see what you like, what's accurate and good velocity (depends on purpose).

For example my loads-
I have a 100 gr LFP with 3.2 titegroup, chrono about 880 fps out of my 3.5" bbl Hi Point C9
Lee lists has a similar- not same- 100 gr FMJ with 4.7 gr titegroup and 1234 fps.
I've made about 2500 of this specific load and shot 1900 of them without problem. they're very accurate and pleasant to shoot.

I don't recommend going 'off the book' until you know what you're doing and have a good "feel" for your caliber and how your gun likes your reloads. And also when you go under the listed load you end up with ammo customized for that specific gun, shooting them in another 9mm may result in less than satisfactory results, such as jamming, not cycling, inaccuracy, etc. reduced loads should not be shot in a carbine either, at least until you'd tried the same for the carbine and know there won't be any issues.

 

[GaryL]

By scale, I meant powder scale - sorry about any confusion.
As far as velocity goes, elevation isn't going to affect muzzle velocity. Downrange is a different story.

The chrono seems to be working fine, given the white box ammo check. So something makes me think pressures are up, so either powder charge or bullet setback.

You went up 0.3gr, and saw 40fps avg increase. So drop 0.3gr, and see if you see about 40fps drop in velocity. That will at least tell you if you are in a linear range. It's only 1 piece of data, and doesn't tell much about pressure, but if you see a 100fps drop, you'll know something isn't right. Looking at my Hornady manual, most powders in 9mm show a linear velocity to charge relationship. Also, the Hornady lists 5.1gr @ 1150fps as max for Unique with a 115gr FMJ/JHP.

 

[mulyhuntr]

What's the overall length of your cartridge? Something is definitely off here. I'll have to chrono some similar loads from my g34 to see what I come up with.

 

[Hondo 60]

Do you stick with the load or go to lowest recommended(5.6 grains) or even lower than recommended.

Never lower!

Did you find a combination that was more accurate than you?
That's what I'd stick with.

 

[eldon519]

Any chance your chrono was off?

 

[roval]

coal is 1.138 speer manual says not to load shorter than 1.135. the volume of 5.7 grains of unique in the 9 mm case is a lot more so with 6 grains and it looks like it was a compressed load as I asked about in my unique and 115 fmj post a day or 2 earlier. speer lists the range as 5.6-6.3 grains unique for that bullet.

 

[roval]

chrono likely wasn't off since the velocity for the Winchester factory rounds seemed appropriate and my 45 acp reloads measured during same time had averages of 789.3 and 790.6 for 6.2 grains of unique and seemed appropriate

 

[roval]

here's a pic I took of 5.7 grains unique left and 6.3 grains unique right in the federal 9 mm case. I only used the 6.3 grains max for illustration I loaded only 5.7 and 6 grains. with bullet seating for coal of 1.135 even at 1.138 I think it would have been compressed.

 

[eldon519]

How do the primers look? If you just want to try to knock the velocity down without dropping the charge too much, you could try going to a longer COL. I know that can decrease maximum pressure, I'm not entirely positive how much effect it would have on velocity. I usually load pistol rounds to about the maximum length that will fit in the magazine and still cycle reliably, usually about 1.160" or so for 9mm, but I shoot almost exclusively 147s. Not sure if 115s can seat out that far.