124gr OAL data help

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LeftyTSGC

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I am looking for information.

I am attempting to load 9mm:

I tried 124gr MG CMJ using 4.3gr W231 at OAL of 1.125 - this fired weak but did cycle my Star 30m 9mm. very inaccurate

I then tried 124gr MG CMJ using 4.5gr W231 at OAL 1.125 - this fired well but felt like a hot load very snappy.

My manuals show 3.9 -4.4 load but no specific OAL just the standard 1.169 Max. Others suggested 4.3 -5.0 but no specific OAL.

Where can i find data on changing the OAL, I want to see if using 4.3gr W231 with a OAL of 1.090 -1.100 would produce a better load than 1.125? Any suggestions or advice.
 
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Seat to the shorter length you want to seat, then load the 3.9 starting load recommended.

Then work your way up, watching for excess ejection distance, etc.

That's what starting loads are for.

rc
 
OAL is gun specific.

Like RC said start low and work up. This is why it's always recommended to work up your loads. With some powder/cal combo a reduction in 0.010" can double the pressure.
 
Went to the range today with my test loads.

124gr MG CMJ 4.3gr W231 at 1.100 OAL

124gr MG CMJ 4.3gr W231 at 1.110 OAL

124gr MG CMJ 4.5grW231 at 1.125 OAL

124gr Berrys RN 4.3gr W231 at 1.125

I started at 4.3gr since that appeared to be the common average of all loads.
After about 100 rounds total, i think the best load for my STAR 30M 9mm will be:
124gr MG CMJ 4.3gr W231 at 1.110 OAL it gave the best shot group, best recoil and best overall feel. All of the 1.100 OAL loads felt Hot and sent brass flying. The 1.125 OAL loads even though they fired were very weak and felt soft. (do not have a chronograph to check velocity). I am still looking for any place that i can find the formulas to detrmine the power and CUP for each of my loads. Any one know where i can find info.
 
If you are changing more than one reloading variable at a time, it's hard to tell what variable is affecting the outcome (recoil, case ejection, accuracy, etc.).

As rcmodel and Blue68f100 suggested, I would first determine the OAL that works well for your pistol/barrel then conduct powder work up.

LeftyTSGC said:
I want to see if using 4.3gr W231 with a OAL of 1.090 -1.100 would produce a better load than 1.125? Any suggestions or advice.
Using shorter OAL/COL than what your pistol/barrel will support will result in more high pressure gas leakage around the bullet when the primer ignites the powder and may result in less consistent chamber pressures/muzzle velocities and decreased accuracy.

For many 9mm RN bullets, 1.125" will work in most pistols but will leak more high pressure gas than 1.135". What's the best OAL that will produce the most accurate loads? That's determined by using the barrel drop test to first identify the maximum OAL and then function testing by feeding/chambering from the magazine to determine the working OAL.

Once you determined the working OAL, then you should conduct the powder work up from start charge to identify the powder charges that will reliably cycle the slide and extract/eject the spent cases and produce accurate shot groups.

I am still looking for any place that i can find the formulas to detrmine the power and CUP for each of my loads. Any one know where i can find info.
To determine the power factor of your load, you'll need a chrono to measure the average muzzle velocities. Power factor is calculated by multiplying the weight of the bullet with muzzle velocity divided by 1000. Let's say your 125 gr 9mm load measures 1000 fps. Your power factor is (125 grain x 1000 fps) / 1000 = 125 PF.

Keep in mind that depending on variables like ambient temperature, muzzle velocities may vary so many match shooters develop loads that are slightly higher in PF to compensate for these variables that may lower muzzle velocities. So if you develop 130 PF loads, you will have some buffer to ensure your loads will meet the 125 PF requirement. If you don't have access to a chrono, you could use mid-range load data.

Hodgdon lists the following for the 125 gr FMJ bullet.
125 gr Sierra FMJ W231/HP-38 OAL 1.090" Start 4.4 gr (1009 fps) 24,600 CUP - Max 4.8 gr (1088 fps) 28,800 CUP
I use load data for 124 gr and 125 gr bullets interchangeably as most FMJ/JHP bullets vary by about 1 grain. Let's say your working OAL comes out at 1.135" but the load data was tested with shorter OAL of 1.090" which means the actual muzzle velocities will probably be slightly less than published. But even with the longer OAL, the mid range powder charge of 4.6 grain may produce greater than 125 PF. Let's say 4.6 gr charge produces 1030 fps. Then (124 gr x 1030 fps) / 1000 = 127 FP.

BTW, Hodgdon load data used 4" test barrel. Star 30M 9mm pistol has 119 mm barrel which is 4.68 inches. That means your pistol may produce higher muzzle velocities than the Hodgdon load data. So you may be able to use 4.4 - 4.5 gr powder charges and still produce greater than 125 PF.

Most of us do not have access to chamber pressure measuring devices so we approximate chamber pressures (CUP/PSI) with muzzle velocities we obtain from chrono.
 
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I am still looking for any place that i can find the formulas to detrmine the power and CUP for each of my loads. Any one know where i can find info.
There is no such info anywhere.

Your Star pistol barrel is unique among all other Star barrels, and all other 9mm pistol barrels.

Pressure testing is done with SAAMI spec test barrels and a gazillion dollars worth of lab equipment.

Nobody has done all that with your exact barrel.

rc
 
bds rcmodel, you are correct, I will start over and make sure i start with the chamber drop test, I was not thinking about the affects of seating the bullets too short, only worried about too long. I dropped a empty shell in the barrell and noticed that all of my current OAL loads are the same as for the shell seating, so if i understand correctly i need to see at what OAL i actuall start to see a difference in the seat of the round chambered, is that correct? Also you are correct my STAR 30M barrel is longer, this specific model was in competition with the Baretta during the 90's new pistol search for the US Army, even though i do not have any spec data, i do have mil spec ammo guides that show what max pressures were made, so i know that i am good at least to those specs. I hope to be able to get out next weekend and start the testing. Thanks for the advice. LeftyTSGC.
 
TSGT:

Seat a bullet to "max" OAL for the cartridge (for 9mm Luger it's 1.169") in a case with no powder, point the muzzle (barrel out of the pistol) at the floor and drop the round into the chamber. It'll make a "plunk" sound. The ogive (the "rounded" part that sticks out the case mouth) of most bullets seated this long will hit the rifling before the round fully chambers. That's what you want to avoid. If you now turn the barrel muzzle up to let gravity pull the round out, you'll find that it won't fall out--it's stuck because the ogive has impacted the rifling. But you can easily pull it out with your fingernails.

Now gradually seat that bullet deeper a few 1000ths at a time, each time repeating this "plunk" test. As soon as you reach a try in which the round will fall out from gravity alone, that's the right depth for that bullet and that barrel. Verify this with a few more bullets to be sure; bullets vary even within the same lot.

Use that setting of your seating die, for that bullet in that barrel. In another barrel with a different bullet, the OAL will be different, so you have to do this all over again if you change bullets or barrels.

You could do this with primed and charged cases, but I don't recommend it until you have a pretty good idea what you're doing.
 
LeftyTSGC, beatledog7 expanded on how to determine the maximum OAL or COL. The proper Max OAL for the barrel will allow the round to freely fall into the chamber and spin without hitting the start of rifling.

But once you determined the Max OAL, you'll need to next identify the proper "working OAL" that will reliably feed from the magazine by function testing.

This is done by:

- Lock the slide back
- Insert the dummy round in the magazine
- Load the magazine in the pistol and release the slide without riding the slide

Sometimes Max OAL will be the working OAL but often the working OAL will be shorter than the Max OAL.
 
All,

Thank you for all of the information and advice. One realizes that "you dont know what you dont know". After i figure out my OAL to use, i will them restart the powder load process and work up from there. I will post results when i complete this, but may be a week or so before i can get to it. I guess the previous 500 rounds I loaded were all for not. I should of done this in the beginning when i started loading earlier this year.

Just an update, i got home and wanted to check the OAL. I took six 9mm shells made sure they were all the same length within specs. I took 3 each MG CMJ 124Gr and 3 each MG FMJ 124gr. (out of Berrys but have 3700 MG). I started at 1.169 on three, performed the chamber drop test. To my surprise all three dropped easy in and easy out, no ogive hit on rifling. The seating of the shell in the STAR 30M is a little different than most 9mm. There is no flush line. But all seated the same and i checked shells with my
case guage to verify and all seemed good. I then set all six at 1.169, all the same. I tested one at around 1.175 and finally hit rifling.

That said, I them tried to cycle all rounds and 1.169 is too long. So i tried 1.65, some worked some did not. When i got to 1.160 all cycled fine and fed thru magazine and extracted. When i looked up the M882 (Milspec 9mm)it is set at 1.165 OAL. so the 1.160 should be good. It is a little longer than i expected, but again i have the STAR 30M (Military Nato spec 9mm).

1.160 will be my starting OAL, relooking at my manuals, i see 124gr FMJ starting at 4.2grs.

125 GR. SIE FMJ Winchester 231 .355" 1.090" 4.4 1009 24,600 CUP 4.8 1088 28,800 CUP (Hodgden on line)
124 gr. FMJ 231 4.2 1005 28,800psi 4.5 1060 32,700psi (NO OAL, only SAAMI 1.169)

I will work up from there this weekend. Did i do anything crazy on determing the OAL? Will provide results when complete.

LeftyTSGC
 
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124gr Test data

I went out this weekend and tested my new loads.

Attached is the data. I had two handguns, STAR 30M and a STAR 30MI, basically the same thing but listed them seperate.

Even though you see the 4.5 with 1.125 OAL have a higher PF (velocity) the accuracy with this load is not there.

The 1.160 will be my OAL, all i have to do now is shoot different Powder loads for accuracy testing. I will most likely use 4.4gr, 4.5gr, and maybe test a 4.6gr with W231 powder. I will try to get out this week or next weekend and see which loads give the best shotgroups at 10yds and 25yds.
 

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4.6 looking for 1040/1045 should be pretty good, and not real sooty.
1030'/sec will run, but is also pretty weak. With Win 231 it'll burn "sooty/dirty" as will be seen on the inside of your pistols.

Just my findings but YMMV.
 
Seat a bullet to "max" OAL for the cartridge (for 9mm Luger it's 1.169") in a case with no powder, point the muzzle (barrel out of the pistol) at the floor and drop the round into the chamber. It'll make a "plunk" sound. The ogive (the "rounded" part that sticks out the case mouth) of most bullets seated this long will hit the rifling before the round fully chambers. That's what you want to avoid. If you now turn the barrel muzzle up to let gravity pull the round out, you'll find that it won't fall out--it's stuck because the ogive has impacted the rifling. But you can easily pull it out with your fingernails.

Now gradually seat that bullet deeper a few 1000ths at a time, each time repeating this "plunk" test. As soon as you reach a try in which the round will fall out from gravity alone, that's the right depth for that bullet and that barrel. Verify this with a few more bullets to be sure; bullets vary even within the same lot.

Use that setting of your seating die, for that bullet in that barrel. In another barrel with a different bullet, the OAL will be different, so you have to do this all over again if you change bullets or barrels.

I have been working on some of the same issues as the OP. I have been using 4.0 grains of Titegroup behind a Berry's 124 gr HBRN DS bullet and seating them at 1.150 with no problems and they shoot very accurately in my CZ SP 01 Phantom. Then I picked up some Berry's HBFP bullets in 124 grain and have had a hard time finding the sweet spot on the OAL. Using your procedure I end up with an OAL of 1.065 which seems pretty short but it does the drop test perfectly. My Lyman book shows a HP OAL at 1.075 which I thought was a close bullet profile to the HP. Does going that short make good sense with this bullet profile? There really is a huge difference between bullet profiles.

Am I on the right track? Thanks
 
There was an article in Handloader 282 that tested with OAL of 1.05 with different bullets. Nothing unusual was found. As always, start at the bottom load and work up.
 
Huskerguy , I load that same 124 HBFP bullet in a 75B and a new 75 Shadow at 1.065"; and it shoots very well with 3.9grs VV n320 at 129PF.

This is well-short of my CZs' chambers max. oal. I started building the load at a longer oal and it didn't impress. 1.065" was suggested by "Wobbly" as a good oal 'for that bullet' and it is better in my guns.
YMMV
 
Has anybody seen a 9mm service-type pistol feed a 1.169" OAL round reliably? I sure haven't. With MG 124s it looks like the bullet is barely seated. I make mine shorter, closer to a length you'd find on a factory round.
 
Huskerguy , I load that same 124 HBFP bullet in a 75B and a new 75 Shadow at 1.065"; and it shoots very well with 3.9grs VV n320 at 129PF.

This is well-short of my CZs' chambers max. oal. I started building the load at a longer oal and it didn't impress. 1.065" was suggested by "Wobbly" as a good oal 'for that bullet' and it is better in my guns.
YMMV

Doing the test did open my eyes a bit to the big differences in bullet profiles. I knew it but never could really put a number on it until I did this with my CZ.

The Titegroup 4.0 grain loads at 1.150 were dead on and worked in every measurable way. Now that I switched, albeit for only a few hundred of the HBFP bullets, all bets are off. I will need to go back and test some of the FP loads with 4.0 grains and the new OAL of 1.065 for pressure signs OR just empty every one and start working back up from the suggested starting load of 3.8. That is one of the downfalls of TG powder, the narrow range from min to max.

Thanks for all of the help, God Bless.
 
After conducting my tests and reading all of the replys and analogies from others, I believe that i may need to find out what type powder is being used in the Mil SPEC 9mm ammo, as in fast burn vs slow burn. That may answer how a 1.165 OAL ball round still gets 1000+fps. I am having to use 4.5grs W231 to reach 1000fps, unless i use a different powder.

What would i need a faster powder for a 1.160 OAL or a slower powder to build more pressure at 1.160? anyone know?

thanks
 
If you consult any reloading manual, it will be apparent that the highest velocities are achieved with slower burning powders.

OAL has nothing to do with it.

Just a glance at Lyman #49 shows a MAX load of:
Clays giving 960 FPS at 31,700 CUP.
W231 giving 1,043 at 32,000.
Power Pistol giving 1,107 at 31,300.

As you can see the slower powder gives higher velocity at lower pressure as you move down the burn rate chart.

Think of it as trying to move a bowling ball with your hand.

Would you want to?
Double up your fist and hit it as hard as you can. (fast powder)
Or push it as hard as you can with your palm. (slower powder)

The second method will get it going faster, further without breaking your hand. (gun)

rc
 
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rcmodel - i do not wholly agree with OAL has nothing to do with it. I do agree with your powder analogy. what i need to do is combine the two thoughts.

my rationale: if you look at the data, 1.125OAL with 4.5gr started at 1025fps. the 1.160OAL with 4.5 started at 995. So OAL does affect velocity at a point. So instead of just putting more powder in the load (may not have room at some point) I need to determine the best powder for the given OAL that provides the best PF (velocity). I guess i need to figure out the PF limits of W231 against different OAL as compared to Unique or Bullseye given the amount of powder and OAL.

FWIW
 
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Unique will push slower and get higher velocity safely with less pressure then Bullseye or W231.
Because it's slightly slower burning.

I think you are over-thinking this!

rc
 
Since your probably loading on a progressive go with WSF, ball powder. Very close to the same burn rate as Unique. Will yield up to +P velocities if you want. Being a ball it meters dead on unlike the corn flakes.
 
I worked up my loads and had great results.

All rounds has this as the standard:
4.0 grains Titegroup
Berry's 124 grain HBFP bullet
mixed brass, CCI primers

The only thing I changed:
1.075 OAL
1.070 "
1.065 "

The 1.075 is at the long end for my CZ but it works. It starts to get free at 1.070 and 1.065 gives some room for work. I shot 10 rounds of each at 30 feet and checked each piece of brass for pressure signs. There were none. All were equally accurate with only 1 our of 30 outside the 2" black from a rest. I feel comfortable with this load between 1.065 and 1.070 and it is accurate. Now I need to do the same to my SR9 and see how big of a difference I have between my two 9's.

Note that I did not chrono these at this time. I will do that later when I have more time. I also only changed one thing at a time and that was OAL which I know should not make a huge difference with this small amount but I am always watching for signs of pressure. To think when I was first trying these bullets I was starting around 1.120 which was like a broom handle - way too long. Thanks for the help guys - really appreciate it. Blessings
 
LeftyTSGC said:
what type powder is being used in the Mil SPEC 9mm ammo, as in fast burn vs slow burn. That may answer how a 1.165 OAL ball round still gets 1000+fps.
While I like to use W231/HP-38/Bullseye/Titegroup for range/match loads, I have used WSF to load similar/duplicate factory JHP loads using Speer Gold Dot and Remington Golden Saber JHP bullets.

Hodgdon load data
lists 124 gr FMJ loaded with WSF at 1.169" OAL producing 1015 fps with start charge and 1115 fps with max charge out of a 4" barrel.
124 gr FMJ Winchester WSF OAL 1.169" Start 4.7 gr (1015 fps) 27,700 PSI - Max 5.3 gr (1115 fps) 32,700 PSI
 
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