Author Topic: 124 RNFP, anyone else have issues with OAL in a 75b?  (Read 25869 times)

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Offline outdoor_guy

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #15 on: July 23, 2012, 10:38:55 PM »
I have some RN bullets loaded out at 1.135, these chamber just fine, either with the drop-test, or from the clip.

My XTreme FP (conical shaped to the FP), are the only bullets I've had a problem with in my 75b, Zero 124s (RN), Winchester 124s (HP), all have worked fine, loaded in the 1.25-1.35 OAL range (this is my regular OAL load range).

If I dummy load my Xtreme FP bullets at 1.00, they chamber just fine, again either using the drop test or the clip (I made 3 of this length).
Somewhere around 1.04-1.05 seems to be workable, I'm just not very comfortable loading this short.

Mostly I wish I hadn't bought the FP/conical-shaped 124gr Montana XTreme bullets.  Even though they were cheap, they're turning out to be more of a headache than the value has even come close to offsetting. 
They do shoot fine (loaded at 1.125-1.135) in my 9mm carbine, and worked fine in the Taurus I sold recently as well.

-pete

Offline Wobbly

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #16 on: July 23, 2012, 11:01:47 PM »
Pete -

My friend, I'd truly like to help you, but to do so we need you to take a chamber measurement using your bullet in your barrel.

Anything less is guessing. And you sir, are guessing.

And yes it's true, not every bullet was meant to be reloaded in every barrel. The measurements you make may tell us you have bought such a bullet. But the purchase is now a "done deal". The money is gone. Putting off the measurement will not make the bullet fit better or get you your money back. At this point you have nothing else to loose and yet everything to gain.

So why, my friend, are you procrastinating?

In God we trust; On 'Starting Load' we rely.

Offline outdoor_guy

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #17 on: July 23, 2012, 11:11:36 PM »
I have some RN bullets loaded out at 1.135, these chamber just fine, either with the drop-test, or from the clip.  I believe Wobbly's excellent graphic (above) showed my situation pretty well.

My XTreme FP (conical shaped to the FP), are the only bullets I've had a problem with in my 75b, Zero 124s (RN), Winchester 124s (HP), all have worked fine, loaded in the 1.25-1.35 OAL range (this is my regular OAL load range).

If I dummy load my Xtreme FP bullets at 1.00, they chamber just fine, again either using the drop test or the clip (I made 3 of this length).
Somewhere around 1.04-1.05 seems to be workable, I'm just not very comfortable loading this short.

Mostly I wish I hadn't bought the FP/conical-shaped 124gr Montana XTreme bullets.  Even though they were cheap, they're turning out to be more of a headache than the value has even come close to offsetting. 
They do shoot fine (loaded at 1.125-1.135) in my 9mm carbine, and worked fine in the Taurus I sold recently as well.

-pete

Offline outdoor_guy

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #18 on: July 23, 2012, 11:33:52 PM »
And yes it's true, not every bullet was meant to be reloaded in every barrel. The measurements you make may tell us you have bought such a bullet. But the purchase is now a "done deal". The money is gone. Putting off the measurement will not make the bullet fit better or get you your money back. At this point you have nothing else to loose and yet everything to gain.

So why, my friend, are you procrastinating?

I'm not procrastinating, I guess I don't understand what measurement you want then?  I posted that 1.04-1.05 will reliably pass the measurement test you mentioned originally.
I created a number of different sized dummy loads, to test what will feed with my FP ammo, and now know those are <=1.05.

From your first post then, if I subtract .015, that puts me down at 1.025-1.035 for a load that will reliably chamber with the FP bullets in question.

This is the part that concerns me, loading at 1.025, well below any published data I can find.

Would you please clarify how I'm guessing, if this doesn't qualify for the correct measurement? 

Thanks for all your help, even if I seem confused,  :o

-pete

Offline painter

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #19 on: July 24, 2012, 07:04:21 PM »
And yes it's true, not every bullet was meant to be reloaded in every barrel. The measurements you make may tell us you have bought such a bullet. But the purchase is now a "done deal". The money is gone. Putting off the measurement will not make the bullet fit better or get you your money back. At this point you have nothing else to loose and yet everything to gain.

So why, my friend, are you procrastinating?

I'm not procrastinating, I guess I don't understand what measurement you want then?  I posted that 1.04-1.05 will reliably pass the measurement test you mentioned originally.
I created a number of different sized dummy loads, to test what will feed with my FP ammo, and now know those are <=1.05.

From your first post then, if I subtract .015, that puts me down at 1.025-1.035 for a load that will reliably chamber with the FP bullets in question.

This is the part that concerns me, loading at 1.025, well below any published data I can find.

Would you please clarify how I'm guessing, if this doesn't qualify for the correct measurement? 

Thanks for all your help, even if I seem confused,  :o

-pete

Take a spent case from your gun...don't size it.

Put the bullet in question in the case just barely starting it.

Remove the barrel from your pistol and push this dummy round into the chamber as far as it will go.

Take it out and measure it.

Repeat this process until you start getting repeatable numbers.

Subtract .010-.015 from that number and now you have the max oal for that bullet brand and type in your barrel.

You can't just assume that because 1.04 or 1.05 work that that's the number you work from.
I had the right to remain silent...

but not the ability.

Offline Wobbly

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #20 on: July 24, 2012, 08:33:48 PM »
I'm not procrastinating, I guess I don't understand what measurement you want then? 
Pete -

Welcome back. It's in post #9 of this thread.


I posted that 1.04-1.05 will reliably pass the measurement test you mentioned originally.
With all due respect, if you had asked me about my weight so that you could accurately mix medicine to cure me, and my response was "between 180 and 240 pounds", then you might start to understand our predicament here. In post #15 you said "Somewhere around 1.04-1.05 seems to be workable...." The method I outlined, returns an exact number, precise to 3 decimal places. An exact method that will work EVERY time. Not a mushy dimensional range.

And that's my point. In order to help you we need a number. An exact number. If you'll do the "push test" trial with 10 different bullets, then one number will start to appear over and over. That's the number we need. Then we can start to help you.


From your first post then, if I subtract .015, that puts me down at 1.025-1.035 for a load that will reliably chamber with the FP bullets in question. This is the part that concerns me, loading at 1.025, well below any published data I can find.
? I will not try to deny how you feel about a certain OAL. I have strong feelings and preferences myself. But THAT is not part of this discussion. The focus, first and foremost, has to remain on measuring the max OAL your chamber will allow with that particular bullet.

? To get a safe load for a short OAL is the easiest part of this ordeal. All you have to do is call the powder manufacturer and ask. They have tons of data they do not publish, but will gladly fax or email to you. There are also ways to calculate it. But first, we need a max OAL measurement.

The ONLY way to get the exact load is to KNOW the exact OAL. Follow?
 

So please, focus like a laser on the maximum OAL your chamber will allow.   ;)
« Last Edit: July 24, 2012, 08:37:40 PM by Wobbly »
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Offline outdoor_guy

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #21 on: July 24, 2012, 11:34:53 PM »
Ok, I didn't do a full ten, but I did test 5-6, and they all came out at about 1.040-1.045.
Using your "subtract .015" method, I loaded a small batch at 1.030 (at 5% less than minimum published charge), and they all pass the plunk test.  Almost all rotate after the test too, so this seems to be about where I'm at with this bullet combo.

I tried calling XTreme awhile ago about some 7.62x39 plated bullets and velocity data, and it was very difficult to get anything from them.  They finally gave me a number of 1500fps, and maybe I could get away with faster velocities, they had heard of others doing so.
I didn't exactly hang up with a warm-fuzzy feeling, or any great data either.
Hopefully it was the person I called, and not indicative of the whole customer-service experience there.

To be honest, I'm not really that particular about how I "feel" about a given OAL, other than some heresay I've read about the shorter OAL.  I am however very wary of loading outside of published data, in this case 0.05 outside of the data, which is where I start to feel nervous about the whole deal.

Hopefully my 1.030 loads will yield clean cycling, plus give me some indication that the pressure is still fine.  I can work up from there, slowly I guess, unless I can get data from the manufacturer as you mention (I prefer this, at least as a starting point).

I think it's the fact I've only been reloading for a couple of years; if I'd been doing this for 20 I probably would have a much better "feel" for the whole margin-of-error factor.  Right now I mostly have what I can read, in reloading manuals and online, and most of it tells me there is very little margin in 9mm, given the case size (which makes perfect sense, from a physics angle).

Thanks again for all your help, hopefully this gives more to go on,

-pete

Offline 1SOW

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #22 on: July 25, 2012, 12:39:11 AM »
Pete, sounds like you have what you need to 'develop' a load for these bullets.

As you said, I recommend you start low and work up slowly with your  load data.  Load 5-10 at the low end, 5-10 a short step (.1 gr with titegroup) up in the load data, etc..    Make sure those low end loads punch holes in the paper, before you you pull the trigger again----watch for squibs---make sure the action cycles smoothly.

Load data is a "Guide" for loading safe ammunition.  .  It is just loaded "within" SAAMI/CIP size and pressure standards for 9mm.  Eastern European chambers (CZ-XD) are different than German (SIG) chambers.  German chambers may be different than US chambers.  Etc. Etc.  No two are identical.    A LOOONG slender jacketted round nose bullet (what Eastern Euro guns were designed around) will normally load out to SAAMI MAXimum with no problems.   Change from that standard ogive round nose design, and all bets are off.     Bullet NOSE-Shape is usually the biggy.

You may end up really liking that bullet-powder combo.   We're all waiting to hear about how they shoot. 

If you change to a different bullet, DO the Push Test again to check for the MAX oal that will run in that pistol.

 



« Last Edit: July 26, 2012, 01:17:01 AM by 1SOW »

Offline Wobbly

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #23 on: July 25, 2012, 01:01:38 PM »
Ok, I didn't do a full ten, but I did test 5-6, and they all came out at about 1.040-1.045.
Pete -
Hooray!! Now that's a number we can work with!! Sorry if you feel like I've put you 'through the ringer', but in reloading I prefer exactness.

Using your "subtract .015" method, I loaded a small batch at 1.030 (at 5% less than minimum published charge), and they all pass the plunk test.  Almost all rotate after the test too, so this seems to be about where I'm at with this bullet combo.
? We usually work with novice reloaders, and so the .015" dimension is an allowance that accounts for inconsistent OALs over a group of 50 rounds. You said that you were a long-time reloader, and if you have no trouble holding OALs at very consistent lengths then you may, if you like, shorten up on that number.
? Generally in pistol reloading, the "starting load" is 10% less (or 90% of published). Best accuracy starts to appear around 95% of published. So you are missing your safety factor and your "control" shots to gauge your increase in accuracy by starting at 95%.

I tried calling XTreme awhile ago about some 7.62x39 plated bullets and velocity data, and it was very difficult to get anything from them.  They finally gave me a number of 1500fps, and maybe I could get away with faster velocities, they had heard of others doing so. I didn't exactly hang up with a warm-fuzzy feeling, or any great data either. Hopefully it was the person I called, and not indicative of the whole customer-service experience there.
? If you want to know how much the bullet drops over distance, then call the bullet manufacturer.
? If you want to know load data, then call the powder manufacturer.

You've simply consulted the wrong resource. If you'll call the powder manufacturer, then he'll fill your inbox with enough data to choke a cow.

To be honest, I'm not really that particular about how I "feel" about a given OAL, other than some heresay I've read about the shorter OAL.  I am however very wary of loading outside of published data, in this case 0.05 outside of the data, which is where I start to feel nervous about the whole deal.
That's very reasonable. I respect your caution in this area.

Hopefully my 1.030 loads will yield clean cycling, plus give me some indication that the pressure is still fine.  I can work up from there, slowly I guess, unless I can get data from the manufacturer as you mention (I prefer this, at least as a starting point).
I don't think you're ready to load just yet. Can you please share the name of your powder with us again. Sorry, but I'm following 6 threads on 2 boards and don't want to mess up.

I think it's the fact I've only been reloading for a couple of years; if I'd been doing this for 20 I probably would have a much better "feel" for the whole margin-of-error factor.  Right now I mostly have what I can read, in reloading manuals and online, and most of it tells me there is very little margin in 9mm, given the case size (which makes perfect sense, from a physics angle).
That's correct, and that's the driver for my insistence on exact numbers and lots of details.

All the best.  ;)
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Offline outdoor_guy

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #24 on: July 25, 2012, 01:14:11 PM »
[color]

? We usually work with novice reloaders, and so the .015" dimension is an allowance that accounts for inconsistent OALs over a group of 50 rounds. You said that you were a long-time reloader, and if you have no trouble holding OALs at very consistent lengths then you may, if you like, shorten up on that number.
? Generally in pistol reloading, the "starting load" is 10% less (or 90% of published). Best accuracy starts to appear around 95% of published. So you are missing your safety factor and your "control" shots to gauge your increase in accuracy by starting at 95%.

? If you want to know how much the bullet drops over distance, then call the bullet manufacturer.
? If you want to know load data, then call the powder manufacturer.

You've simply consulted the wrong resource. If you'll call the powder manufacturer, then he'll fill your inbox with enough data to choke a cow.

To be honest, I'm not really that particular about how I "feel" about a given OAL, other than some heresay I've read about the shorter OAL.  I am however very wary of loading outside of published data, in this case 0.05 outside of the data, which is where I start to feel nervous about the whole deal.

I don't think you're ready to load just yet. Can you please share the name of your powder with us again. Sorry, but I'm following 6 threads on 2 boards and don't want to mess up.

[/color]

Tried to cut/past the most relevant parts here, to respond to.

To be clear, my 5% less loads are 5% less than the published minimum, for a 1.090 OAL.
I'm loading 3.9gr of TiteGroup, for reference.  Published load minimums are 4.1-4.7, depending on which source you're referencing.

Too late on the "not ready to load", I put together 50 rounds last night at this load, and 1.030.  They all pass the "plunk" test, and most turn in the barrel (a few are very close the rifling and "catch" a bit).  My plan is to test these later today.
Given that I'm under the low-end of the loads for my poweder, I feel pretty safe.

Previously, my 4.2-4.3gr loads were getting "default compressed" by my CZ, I just didn't know this was happening when I was tapping the slide to close it, until I ejected an unspent round. 
A spooky way to test, but the 4.2-4.3 loads didn't seem to show any signs of overpressure, the way I understand them, the cases still fit back into the chamber, and the primers weren't flattened.

One of these days I need to get a chrono (to get a better bead on pressure, etc), but they're not "offically" allowed at either of the ranges I shoot at, but one of them I could get away with it, particularly if I went during a weekday, there's often no one else shooting...

-pete

Offline outdoor_guy

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #25 on: July 26, 2012, 12:16:04 AM »
Update:
My 1.030 loads at 3.9 of TG work, at least in terms of feeding ok, and cycling the action.  75 rounds worked fine.
Accuracy suffered significantly though, I was surprised, since prior to this, the CZ was by FAR my most consistently accurate handgun.  It would shoot one ok, then 3-4 low by 2-4 inches (tried different distances, ranging from 7-15 yards), then a good one again, rinse, repeat.
Prior to fiddling with the whole FP bullet mess, I would get 8 or 9 VERY consistent shots at these distances, 1.5-2" groupings at worst, more often along the lines of 1-1.5".
Weird, I'm not sure I see how my accuracy took such a dive, but at least I know it cycles with this load (tossed the brass pretty good, 7-10ft consistently).  No pressure signs on the cases either, everything looked ok.  I'm hoping I was just have a really bad day, I probably should've tried shooting from the bench or something to verify.

I did send Hodgdon's an email asking for load data for the shorter OAL, hopefully they'll have some more insight, and I can maybe load up a bit and see if that's the problem...

-pete

Offline 1SOW

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #26 on: July 26, 2012, 01:31:02 AM »
Titegroup is a very snappy high pressure powder with a very short load range.  Especially with the short oal, load increases should be in .1 gr increments.
Accuracy may change with load change. 
What "I" would do:  Drop 4.0 grs (weigh the load) into a case and measure from the case mouth to the powder using the depth gage on your mic.   Drop 4.1 grs and measure that.   Compare this to your "bullet seating depth" to make sure the bullet base will be safely ABOVE  the powder level.  Use one of the shortest cases for this check.

If it is, load 5-10 rds at 4.0 grs and 5-10 rds at 4.1.  Try the 4.0 load first,  and watch for signs of pressure including how far it throws the ejected cases compared to regular commercial range ammo.  Shoot slowly & check for accuracy.  If all is good, try the 4.1 gr loads.   
« Last Edit: July 26, 2012, 01:44:23 AM by 1SOW »

Offline Wobbly

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #27 on: July 26, 2012, 12:47:23 PM »
Congrats on finally having some success.

Since you are "very wary of loading outside of published data", may I ask where did you got your load recipe from?

I assure you that the pistol's accuracy did not change with the weather. Your CZ is still the same as it always was. So the variations in accuracy can only come from a limited number of variables...
? Variations in OAL
? Variations in the amount of powder
? Using mixed brass
? Inconsistent primers
? Wrong powder
? Simply a bad personal day at the range

Chase those down and it sounds like you'll have it.   ;)
« Last Edit: July 26, 2012, 12:49:02 PM by Wobbly »
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Offline outdoor_guy

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #28 on: July 26, 2012, 12:57:39 PM »
I get my load data from a combination of two manuals (Speer, Lee) and online data from the powder manufacturers.  I also have some data from bullet manufacturers, such as some of the older Rainier data.

I think my accuracy problems are most likely stemming from the powder quantity, but that's just a guess.  Other variables are addressed below:

I have the same primers (SP have always used CCI), the OAL that's right for my barrel/bullet combination, always used mixed brass, almost always load with TiteGroup for small pistol. 
It could've been simply a bad day at the range, no question. 
I think I'll load up some more FP's at the 1.030 and lower-end of the powder scale and some RN loads at my more regular OAL and previous powder quantity.
This way, I can shoot them side-by-side and if I get really consistent results with RN (regular OAL, standard powder quantity) and inconsistent results with the FP (short OAL, less powder to compensate).  RN loads at 4.2-4.3gr have always given me really accurate results with the CZ.
Hopefully this will yield some answers.

Not sure what I'll do with my zillion FPs if that's the culprit though, other than try carefully loading them up, as suggested, or maybe try and sell them off...

-pete

Offline Wobbly

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Re: 124 RNFP, anyone else have issues with OAL in a 75b?
« Reply #29 on: July 26, 2012, 01:33:30 PM »
I think I'll load up some more FP's at the 1.030 and lower-end of the powder scale and some RN loads at my more regular OAL and previous powder quantity. This way, I can shoot them side-by-side and if I get really consistent results with RN (regular OAL, standard powder quantity) and inconsistent results with the FP (short OAL, less powder to compensate).  RN loads at 4.2-4.3gr have always given me really accurate results with the CZ. Hopefully this will yield some answers.


You can certainly do that, and you will certainly get results. Unfortunately the results won't mean very much and IMHO would be a very bad basis to choose a bullet on. The problem is that by having mixed brass and no control (that I see) on your powder, you start the "race" with a severe handicap. Then you are going to load 2 different length bullets, which may be from different manufacturers, over different amounts of powder.... Right there are 5 major variables you're not controlling.

That's like me trying to compare my wife to a male pig. Different genus, different gender, different earning potential....  I've only changed 3 variables and yet the uselessness of the comparison should be plainly obvious.


Give us a hint. Exactly what is it you're trying to determine? 

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