Berrys 124 FN and a new CZ 75D - I need an OAL lesson

[amada8]

(mods...maybe move to the Berrys section???)

I have one day experience with 9mm on my 650XL.  Have loaded .40S&W and 10mm since September.

I just received my first 9mm...a Cajunized P75D Compact.

I ran two sample 124g Berrys FN with Bullseye loads into once-fired FC case with CCI SPP.  (3.7g and 4.3g).  The 3.7g ran fine and chrono'd an average 920 FPS with a SD 20.  The 4.3 had feeding issues.  Not all....maybe half.  Once in chamber, they average chrono'd 1027 with a SD 30.  Accuracy off a bench rest was MUCH better with the 3.7g cartridges.  (anyone wanna hazard a guess about why a vast difference?)

My question revolves around OAL

As we know, Berrys says: "We recommend using hard cast load data or start with mid-range jacketed data".   So I web looked up Bullseye loading data and found they only list for a 124g GDHP showing a 1.12 minimum OAL.  Not much help with a FN.  In my Lyman 49th page 342, the cast data chart of value:
120g. #356242 1.065 (min) OAL  looks more like a RN...but closer match to the Berrys FN than the 120g. #356402.

My test cartridges had OAL for the 4.3g @ 1.070 and the 3.7g @ 1.065.  I really like the FN in the Dillon 650 because the OAL doesn't vary more than .001 with the Berrys in 165g and 180g.  The feeding problem looks like the FN was on a 45? angle stuck between the magazine and the top of the barrel opening.  I am thinking that a shorter OAL may help with the feed issue but wouldn't that get me into unknown territory since the 1.065" listed above is a minimum?  Some of the 115g bullets show shorter OAL possibilities but.....well, I'm a noob that wants to keep the 75D    My plan of action is to run another series at 1.065 and then go shorter in .005 increments until the feeding issue disappears.  Sound sound  ?  Otherwise, eat the FN and go with HP or RN profiles.

One last piece of the puzzle.  I took the barrel out of the CZ and dropped in an empty case to visualize where the head sits at rest.  Then as I was building my cartridge I dropped a seated and crimped dummy to find maximum OAL and "think" I am at 1.075" with the FN. (I "think" because I want to retest this.  I wrote it down as 1.075" in my reloading notebook....but now want to recheck that number since I am have this problem.)  To answer your question, I DID put a caliper to all my test pieces and the 4.3g was consistent at 1.069" ?.001

Thanks for helping out a noob.
 

[vwpieces]

Search threads on "Push Test" & read the Sticky
http://www.czfirearms.us/index.php?topic=34225.0

You are close when you inserted an empty case into the barrel to see the protrusion. But pick a LONG case & spin the case with your fingers & remember what it feels like. Now keep seating the bullet back until you feel the same "no drag" while spinning the seated bullet in the chamber. That is your MAX OAL, for Yoiur gun. Don't compare Other bullets from books. I have a CZ 75B & a P-01. I determine the MAX OAL for the 75B & know they will work in my P-01.

With Bullseye you may find accuracy in the 3.9-4.1gr range. But work up your own loads for your gun. I run lots of Bullseye in my range loads because I have lots of it & was cheaper than anything, if you can find it, today.

I have run a bunch of the X-Treme 124gr FP in my CZ's with no issues. I think once you get your MAX OAL sorted, feeding will be better. Sorry but I do not feel that giving measurements to OAL will help but may short cut you to just using my numbers from my guns.

Nick

[amada8]

Thank you for the quick reply.

Once I have established my barrel OAL maximum.... how much shorter is a good cartridge OAL?  Given the 650 ability to hold ?.001 with the FN....would a .010" shorter OAL be a "good" length?

I know that is a loaded question as the cartridge needs to obtain near-perfect feeding ability.  Also, are there velocity watermarks that would red flag a too deeply seated bullet?  I do understand case inspection bullet points.  Additionally, I have read where you want to keep the distance between a "good" cartridge OAL and length where a bind occurs to .010"-ish.  Is that correct?

Thanks again

[painter]

.010" shorter will work fine as long as your deviation from your desired OAL doesn't exceed that number.

If you see wide swings in OAL you should decrease the OAL to account for those swings.

I'd also suggest if you see close to .010" swings your process, or press, needs examining.

Have fun.

[Wobbly]

Amada -

First things first...

Welcome aboard !!

Some thoughts....

? The OAL listed in your manuals is not a recommendation, merely a report. It is however, the shortest OAL you should use with that data without tweaking the load.

? When seating RN we generally tell people to back off the "push test" dimension by .015 to get Max OAL. But you're right, since you're able to hold better than most using the FP, you can drop that to .010 inches.

? I would not go lower than .010" because you're trying to keep the bullet out of the rifling. Remember that the 9mm head spaces on the case mouth, but you are doing your check by OAL which does not account for case length. Therefore two cartridges with the same OAL could have long and short bullet protrusions simply due to case length variations. And commonly available 9mm brass can easily vary by .006-.007".

? That being said, going to pains to hold a tight OAL is good practice, but may result to zero increase in accuracy or any other measurable metric.

? You got good numbers. I load the Berry 124gr FP at 1.065" for my SP-01.

How else can we help ?

 

[1SOW]

I also use 1.065" for the BRY 124 HBFN.
This doesn't mean your pistol will accept this same oal,  but it should be fairly close.  Every pistol chamber may be slightly different.

[himurax13]

Some people use barrel reamers in order to be able to load their bullets longer. If you decide to go this route, find someone who has experience doing this to prevent any permanent damage to your barrel.

[Wobbly]

Even if you DO decide to get your barrel reamed, you're still going to need to do the "push test" to find the Max OAL for every bullet you load.  The only difference is 1) you'll have spent money to make your barrel different from our barrels, and 2) therefore you may not be able to use any of the OALs or load data we share here.

IMHO, that's sort of like spending more money on your health care to cover people who still can't make the premium payments and therefore still aren't buying health insurance. 


Just my observations. 

[1SOW]

Even if you DO decide to get your barrel reamed, you're still going to need to do the "push test" to find the Max OAL for every bullet you load.  The only difference is 1) you'll have spent money to make your barrel different from our barrels, and 2) therefore you may not be able to use any of the OALs or load data we share here.

IMHO, that's sort of like spending more money on your health care to cover people who still can't make the premium payments and therefore still aren't buying health insurance. 


Just my observations. 

AND,  those long oal loads may not fit in other un-reamed 9mms--like CZs or XDs.

For an Open class pistol's really hot load it might be beneficial,  but for a minor class/range load,  it's your choice to make.

[amada8]

Bench and range update.

I push tested the 75D barrel and found 1.071" max OAL......so the 1.069"-1.070" OAL 4.7g cartridges (from initial post) were doomed to give me feeding issues.  I made twenty 3.7g that all calipered at 1.060" OAL as well as twenty 4.4g at 1.057" and hit the range this afternoon.  No feeding issues with either except......my initial racking in the first cartridge.  It made it into the chamber but wasn't a smooth transition.

I shot the 3.7g first
avg 956
ES 68
SD 18

The 4.4 was amazing (to me)
avg 1060
ES 27
SD 8

Groups were about the same size.

Thanks everyone, especially the link by vwpieces......that was a really helpful explanation of the OAL dynamic.  I think I have it now and will need to ...ahem....recheck my handiwork with my past .40S&W and 10mm reloads.

[Wobbly]

Great news !! Congrats !!

[himurax13]

Even if you DO decide to get your barrel reamed, you're still going to need to do the "push test" to find the Max OAL for every bullet you load.  The only difference is 1) you'll have spent money to make your barrel different from our barrels, and 2) therefore you may not be able to use any of the OALs or load data we share here.

IMHO, that's sort of like spending more money on your health care to cover people who still can't make the premium payments and therefore still aren't buying health insurance. 


Just my observations. 

I thought Obamacare was put into place so the middle class can pick up the tab for those who made less?


The Manson reamer was only $40 and I can increase my OAL to maximize the space in the magazines (3 to 5 turns).  The push test doesn't seem to work too well with the Bear Creek bullets and I don't see the point to try and make them longer than the magazines.

The difference in velocity and standard deviation, with my ammo made to my previous specs, was minimal and I should be able to run a larger variety of ammo now. I only have 600 rounds downrange so far but I have not had a single hiccup and accuracy has not been affected.

The longer ammo (Bear Creek 124g RN @ 1.155) fits perfectly in my Glock 17, Glock 34, and my springfield 1911. I did not have to use the reamer on any of them.

It was a tad too long for my Buddies M&P Pro but they still went into battery.

Using the reamer did not even occur to me until I tried making .40 major loads for a friends STI.  It appears that this is commonplace for USPSA and now I see why.