OAL Question for 9mm

[burkdog]

I have loaded several hundred rounds using Montana Gold 124 gr. fmj's over 4.7 grains of Winchester WSF, with a 1.169 OAL.

I got the recipe right off the Hodgdon website.

Bullet Weight - 124 GR FMJ

Manufacturer - Winchester

Powder - WSF

Bullet Diam. - .355"

C.O.L. - 1.169"

Grs. - 4.7

Here's my question: This load has run fine through my Glock 17, using my factory mags and some kci mags. I've run probably a dozen or more idpa matches and never had any problems until recently.

I recently purchased a couple of after-market magazines that I thought were kci, but I guess maybe they are not. In any case, that OAL seems to be a little bit too long for the new magazines. I can get them loaded, but then the spring won't push them up after the first round gets loaded into the gun.

Also, I ran a bug match with a little kel-tec pf-9, and while the bullets all fed and fired with no problems, on my "unload and show clear," the bullet in the gun was onto the lans or rifling, and would not let go. I had to pull so hard on the slide that it pulled the case away from the bullet, which stayed in the barrel. We had to knock it out with a push rod.

That happened twice, and then I got the RO to let me fire the last round out rather than wrenching the case off the bullet. Again, fired fine everytime, just wouldn't come off the rifling.

All that to say, I want to try decreasing the OAL to see if it will help with the feeding in the new mags, and with the kel-tec.

4.7 grains seems to be working fine. I have not chrono'd the load, but have to assume it is pretty close to what is listed on the Hodgdon site, which is 1015 ft/sec., and 27,700 PSI.

About how much can I safely decrease the OAL, leaving the powder at 4.7? And if the answer is "not enough," can I lower the powder charge, and the OAL, and still end up around the same pressure?

I'm not overly concerned about the performance of the load, beyond reliable feeding in the magazines, and the the other 9's I own.

Your comments are appreciated.

Thanks,

Greg

[chirpy]

As a general rule, the deeper the bullet in the case the higher the pressure! I would try to contact someone at Hodgdon to get an answer to your question. Look at their site for a "Contact Us" thread. That being said, the little WW "Reloaders Manual" lists 1.169 as max OAL and 4.7 WSF as a starting load for an unspecified 124 gr. FMJ bullet. I probably would drop at least .1 gr. of powder and seat slightly deaper (enough so that your rounds function in your new mags) and then chrono.

FWIW

Richard

[Sarge]

Most 9mm minor loaders are seating their loads from 1.10-1.15. I am currently not even loading 9MAJOR loads out to 1.169.

For a glock I was loading 1.13 even though 1.15 worked fine. But 1.13 was more accurate in my gun than any other length.

Do a search of the 9mm reloading forum here and you will find a butt load of loads using your bullet and powder combination.

[Sarge]

Also, I forgot to add. It is never a good idea to go ahead and shoot a round that has locked onto the rifling. The bullet could potentially be shoved deeper into the case resulting in extreme over pressure. And that equals trouble for your gun and potentially you as well.

[mizer67]

I've fired 5.0 grains pf WSF with a MG 124 CMJ at 1.140" OAL, and was only making about 1,070 fps out of a 4.5" barrel. I wouldn't be too concerned dropping your OAL from 1.169 to somewhere around 1.140" +/- .005, personally. 1.169" is very long, and WSF isn't spikey with pressure levels like faster powders.

[yoshidaex]

Get a chrono.

[CocoBolo]

The 124gr RN MTG runs in almost all guns I have tried it in at 1.145 OAL. The max SAMMI spec for an RN is 1.170. I do see a lot of 1.10 and wonder why they would go that short, and I've only been there with FN Flat Nose bullets. WSF is somewhat slow powder that some use in 9 major, when you shorten your OAL consider dropping .1gr for each .02 you shorten the OAL. I recommend the 1.145 OAL for the MTG FMJ and CMJ (RN) 124gr projectile. With WSF you have a ways to go before you run into trouble. Once you have shortened the load visit the crono. For minor I like to hit 135pf or better. It isn't like major when you just go minor, you go no score.

[burkdog]

Awesome information guys! Thanks. I'm going to make some runs in quantities of 10 tonight, and chrono them tomorrow.

Thanks.

[Sarge]

Awesome information guys! Thanks. I'm going to make some runs in quantities of 10 tonight, and chrono them tomorrow.

Thanks.

Do yourself a favor and do more than lots of 10. I would do maybe 30 each and put a target out beyond the chrono. This way you can see how each group groups. Often times the best feeling loads don't group so well or the POI is not on the POA. This is what makes reloading so fun.

[leemoe83]

Shooting a round with bullet touching the lands causes high pressure as well. As long as your not compressing the powder when you shorten your OAL you will probably get a pressure drop untill the bullet is seated to deep and the pressure starts to rise again. If your using minimum charge with max length you should be able to start loading rounds shorter with the same charge. I reload 9 mm for a Glock 34 with 3.9 gr Titegroup at 1.118"-1.120" with a 124 gr. MG JHP.

[CocoBolo]

Awesome information guys! Thanks. I'm going to make some runs in quantities of 10 tonight, and chrono them tomorrow.

Thanks.

Do yourself a favor and do more than lots of 10. I would do maybe 30 each and put a target out beyond the chrono. This way you can see how each group groups. Often times the best feeling loads don't group so well or the POI is not on the POA. This is what makes reloading so fun.

Sarge lets just tell it like it is! You got an open gun you know this, changing the load can move the poi 4 inches in any direction at 15 yards or more than one direction, yep every time I change my load I re-zero the gun. No load is cherrie till it passes the 50 yard group test. Once you find a load that works for you, its comfortable to shoot, it is accurate, and you got the oal down so it feeds, stick with it! Shoot the snot out of it. Changing loads is like changing guns doesn't help you get better, you just get older.

I put a target behind the crono at 15 yards and shoot off a rest, get the fps, the poi, and the group all in one operation. At least 10 over the crono, then a couple runs on plate racks to check the dot movement, plate racks rock.

[Dr. Phil]

+1 on the plate rack! I use the same formula: chrono, groups, log all the info, then I shoot the 8" plates at 10 yd. against 2 controls. 1. the .22, and 2. my old standard load that I'm testing against. I log 1st shot, average split, low split and, of course, E.T. I also, if testing more than 1 load, shoot without knowing which load I am shooting at that rack. I put the loaded mags in my pocket and load without looking, only logging the numbered mag after the run. That way, all runs are unbiased. After awhile, the notebook begins to speak very loudly as to what each gun likes...

Edited January 8, 2012 by Dr. Phil

[Sarge]

Awesome information guys! Thanks. I'm going to make some runs in quantities of 10 tonight, and chrono them tomorrow.

Thanks.

Do yourself a favor and do more than lots of 10. I would do maybe 30 each and put a target out beyond the chrono. This way you can see how each group groups. Often times the best feeling loads don't group so well or the POI is not on the POA. This is what makes reloading so fun.

Sarge lets just tell it like it is! You got an open gun you know this, changing the load can move the poi 4 inches in any direction at 15 yards or more than one direction, yep every time I change my load I re-zero the gun. No load is cherrie till it passes the 50 yard group test. Once you find a load that works for you, its comfortable to shoot, it is accurate, and you got the oal down so it feeds, stick with it! Shoot the snot out of it. Changing loads is like changing guns doesn't help you get better, you just get older.

I put a target behind the crono at 15 yards and shoot off a rest, get the fps, the poi, and the group all in one operation. At least 10 over the crono, then a couple runs on plate racks to check the dot movement, plate racks rock.

Yes this often escapes the new reloader/ load developer. I know because it happened to me a few years back when I was working up loads for my G34. The gun shot nice groups but depending on powder, oal, etc the groups center of mass would move from 1 oclock to 6 oclock to 10 oclock on the target. I remember telling myself,"That's not possible" but it sure is very possible. Just like changing oal and powder drop can effect group size. The general opinion is that loading a round long will produce the best groups but I found that to not be the case with MY GUN. It was remarkable how much better it shot at 1.13 than any other length in the general ballpark.

[burkdog]

Well, I went to the range with the chrony today. My results seemed to be all over the board.

I am using a Dillon 650 with a standard powder charger. All the brass is scavenged range brass, assorted. The scale I'm using to measure the powder is the little Frankford Arsenal scale that only goes to 1 tenth of a grain. Using a 20 dollar digital caliper.

I only made 1 or 2 adjustments to yield the various OALs... with the same settings, I was getting variances of as much as 0.005 from one round to the next, from the press.

I measured each finished cartridge and sorted them by length.

I weighed each charge for probably the first 20 charges, to make sure it was holding at 4.8 grains, and it was. After that I weighed probably every 5th round.

I set the chrony up 6 feet in front of the bench. All the rounds were shot off-hand. Groups and point of aim was difficult to establish because of the set up at the range... not enough frequent opportunities to go down range to put up new targets, plus we were shooting off-hand anyway and neither of is is a sharp-shooter.

Using 4.8 grains of Winchester WSF over 124 grn. Montana Gold fmjs, CCI primers, shot from a factory Glock 17.

I have attached the results as a pdf, but here is the average for each length...

1.160 927

1.161 947

1.162 951

1.163 953

1.164 901

1.165 955

1.166 1032

1.169 893

Like I said... all over the place. Don't know what to make of it, if anything.

[burkdog]

Well, I went to the range with the chrony today. My results seemed to be all over the board.

I am using a Dillon 650 with a standard powder charger. All the brass is scavenged range brass, assorted. The scale I'm using to measure the powder is the little Frankford Arsenal scale that only goes to 1 tenth of a grain. Using a 20 dollar digital caliper.

I only made 1 or 2 adjustments to yield the various OALs... with the same settings, I was getting variances of as much as 0.005 from one round to the next, from the press.

I measured each finished cartridge and sorted them by length.

I weighed each charge for probably the first 20 charges, to make sure it was holding at 4.8 grains, and it was. After that I weighed probably every 5th round.

I set the chrony up 6 feet in front of the bench. All the rounds were shot off-hand. Groups and point of aim was difficult to establish because of the set up at the range... not enough frequent opportunities to go down range to put up new targets, plus we were shooting off-hand anyway and neither of is is a sharp-shooter.

Using 4.8 grains of Winchester WSF over 124 grn. Montana Gold fmjs, CCI primers, shot from a factory Glock 17.

I have attached the results as a pdf, but here is the average for each length...

1.160 927

1.161 947

1.162 951

1.163 953

1.164 901

1.165 955

1.166 1032

1.169 893

Like I said... all over the place. Don't know what to make of it, if anything.

WSF.pdf

[yoshidaex]

Different brands of cases have slight variations in case capacity.

Try to stick to one brand when you're doing load developement.

As for OAL, anything +/- 0.005" from the OAL you've decided on should be good.

The ammo I load can range anywhere from 1.155" to 1.165". My bullets aren't any where near the rifling, accuracy is decent (1" at 25 yards freestyle) and I've never failed to meet power factor at any of the big matches I've been to.

Edited January 8, 2012 by yoshidaex

[warpspeed]

I'd guess variation in the cases is causing a variation in the crimp.

That and the fact that the Chrony line of chronographs are not known for being ultra precise.

[Braxton1]

The load that you're using is very close to my old load for Production Division. I used 4.6 of WSF under the 124 Montana Gold JHP, but only loaded them at 1.115 OAL. That feeds thru all of my mags without a glitch, makes a 129PF in my G-34 and a 128 in my G-17 and a friend's XDm.

[CocoBolo]

Well, I went to the range with the chrony today. My results seemed to be all over the board.

I am using a Dillon 650 with a standard powder charger. All the brass is scavenged range brass, assorted. The scale I'm using to measure the powder is the little Frankford Arsenal scale that only goes to 1 tenth of a grain. Using a 20 dollar digital caliper.

I only made 1 or 2 adjustments to yield the various OALs... with the same settings, I was getting variances of as much as 0.005 from one round to the next, from the press.

I measured each finished cartridge and sorted them by length.

I weighed each charge for probably the first 20 charges, to make sure it was holding at 4.8 grains, and it was. After that I weighed probably every 5th round.

I set the chrony up 6 feet in front of the bench. All the rounds were shot off-hand. Groups and point of aim was difficult to establish because of the set up at the range... not enough frequent opportunities to go down range to put up new targets, plus we were shooting off-hand anyway and neither of is is a sharp-shooter.

Using 4.8 grains of Winchester WSF over 124 grn. Montana Gold fmjs, CCI primers, shot from a factory Glock 17.

I have attached the results as a pdf, but here is the average for each length...

1.160 927

1.161 947

1.162 951

1.163 953

1.164 901

1.165 955

1.166 1032

1.169 893

Like I said... all over the place. Don't know what to make of it, if anything.

The OAL variance is good. I would move the crono out to at least 10 feet. Since the max is 5.3 you go a ways to go, bump it .3gr, then load some a 5.2 and 5.3. The only shot that looks out of place is the 1032. With range brass it is common to get a spread of 60 fps. I had one of those Frankfurt Aresnal scales $19.00, used it for a couple years. When it got cold I couldn't trust it. I load in my metal building (welding shop) no heat. When the batteries get weak again the trust factor goes way down. I added a dillon beam scale I bought used, it don't care how cold it gets. Calibrate often and pay attention to how much the plastic pail weighs, you know it doesn't change, but it will vary on the scale from time to time. I have a RCBS750 scale now and it is much more consistent and has never failed to match the beam scale. All of the scales are rated +-.1gr, just make sure there is no fan running, window open, or you are not exhaling over it when you weigh. On my Frankfurt you would weigh a drop and it would say 4.8 then look away a few seconds then look back it would say 4.9, after a while I decided that when it did this I went with the first reading. Reminds me of the 240SX I had with a HUD, it was impossible to run at a steady speed the number was always going up or down.

[thebridge]

I shoot a 1.150 in my 34, diff grain bullet and powder. Glock chambers are deep but the mag on a 9mm does hang for some people with anything over the 1.150. I loaded to 1.150 because it is the most accurate and consistant in my gun from my hands, my spread is way tight about 25fps with range brass. Try this one, 147gr rn / 3.0 vit320 @1.150. oh and you will need a 13lb recoil spring -3 coils or an 11lb ismi spring. (giving away my secrets)

Edited January 9, 2012 by thebridge

[Mbauer67]

If you are shooting a glock the sweet spot is 1.130-1.135, it is right around factory length rounds. Don't play the oal length game glocks, just load to this length and shoot your brains out.

[burkdog]

Do you have a powder and a measurement recommendation, or just recommending the 1.13 oal? I would be afraid to jump down to 1.13 from 1.16 using the same powder and measure.

[mike l m]

I use a 115 gr jhp from Monatana Gold with 3.9 gr of Clays, oal is 1.125-1.130.

In a G19 and G26. Nice, flat and accurate to shoot. Try it and let know.

Mike

[thebridge]

I would also like to add that when you can find some 135's, they are very nice also. they seem to be a touch sharper recoiling than do the 147's in front of vitavori 320. 135's are my second choice..

[Hi-Power Jack]

Well, I went to the range with the chrony today. My results seemed to be all over the board.

I set the chrony up at 6 feet. Like I said... all over the place.

Burkdog, there is a serious problem, as you suggested.

Your loads are "ALL OVER THE PLACE".

They shouldn't show the extreme variation that all of

your rounds are showing.

In each group of ten (10) shots, you vary from a low of 696 - 881,

and your highs range from 957 - 1181.

Your extreme range for 70 shots is 696 - 1181 fps, or 485 fps.

I've never seen that wide a dispersion ...

Hopefully, the problem was that your chrono was too close to the

gun and you're measuring blast, or lighting conditions ...

But if not, something is wrong with your powder dispenser, or you

used too much lube on your cases, or the crimp is not proper.

But, the FIRST thing you have to do is get your velocities to

be in a narrower range -

looks like they average about 850 fps - I would expect 20 - 30

shots to ALL be in the range of 780 - 920 fps; not 696 - 1181.

Solve that problem first, and then we can look at the effects

of OAL on velocity.

Good luck,

Jack