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The2aguy

Beyond short OAL

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ACME 115gr 9mm RN bullets

 

Length .530x .356

 

I ran a plunk test and determined I had to run a max of 1.058 to spin

 

Doing a ladder work up I decided 4.2 grains was ideal for me @ 1115 avg from a Glock 17

 

Firing up the progressive I find 10-20 out of 100 don’t plunk until 1.040

 

Does anyone load THAT short? 1.030-1.040

 

 

 

 

 

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28 minutes ago, The2aguy said:

 

Does anyone load THAT short? 1.030-1.040

 

If you have to, you have to ....    ;)

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OP, what gun?  I had a similar experience with Acme 124 gr round nose and my Walther P99 (for loading purposes, basically identical to a 4" PPQ).  They wouldn't plunk/spin consistently above 1.04" OAL, so I probably will have had to load them at 1.035" to account for variations in length with a progressive press.  I think Acme's round nose profile isn't very friendly to guns with short/tight chambers.  I've still got a stock of other bullets that I can load much longer with a known recipe, so I haven't done anything beyond determining OAL with the Acmes yet.  I'll be curious to know how the 115s work out for you, as I'm a bit leery of loading that short, too.  I'm worried that pressure will get too high before I can get them to make minor, especially given that my preferred powder is on the fast end of the spectrum (VV N320).  I've also got about 1/3 or 1/2 pound of Unique hanging around, and almost a full pound of CFE Pistol.  Those are both slower, so probably safer, but I've been hesitant to mess around with loading that short anyway.

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Er, nevermind on the gun.  Dunno how I missed that it was a G17.  I guess I'm used to people reporting on being able to load fairly long in Glocks, so that detail just flew right past without sticking in my mind.

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The gen 5 throats are ridiculously short

My minds saying the 115gr bullets shorter so seating deeper will just have the same effect as seating 124gr a bit longer

Ran up to 4.6gr @ 1.055 and didn’t see pressure signs but I set that as a bit hot for me as it avg 1204 from the 17


Cfe pistol I found a requirement to run near max..never tried unique

Will going from 1.055 to 1.030 be a major jump in pressure?

Quickload showed 28,000 to 29,500 psi jump


1.030 depth puts 0.25” of the bullet in the case..I also wonder if with a shorter bullet seating deeper may be ideal


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33 minutes ago, The2aguy said:

The gen 5 throats are ridiculously short

 

In that case, welcome to the CZ/Walther world. I've never been able to load Montana Gold 124 gr JHPs any longer than 1.08", and one of my guns is happier with them at 1.075".

 

I can't say whether Quickload is giving you accurate pressure information there, but the relationship between OAL and pressure is not always linear, so be careful; at some point it may spike quickly.  29,500 is well under SAAMI max for 9mm, though, so if Quickload can be trusted, you're probably ok.

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I used to run Bear Creek RN at 1.060" Glocks cannot be loaded to more than 1.180" because they will not feed thru the magazine. 

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Posted (edited)
12 hours ago, The2aguy said:

ACME 115gr 9mm RN

 

Quote

Does anyone load THAT short? 1.030-1.040

 

If you’re this displeased - and disconcerted - by loading this short?

 

Grab a 100rd sample pack of a 125gr truncated cone from blue bullets or black bullets international, and see what kind of length you can get.

 

An M&P that needed Acme’s 124 RN to be about 1.110” would feed a bullet with a TC profile flawlessly at 1.150”

 

Bullet shape really, really matters. Far more than weight.

Edited by MemphisMechanic

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OAL is just for feeding, bullet shape and length affects pressure (ie same weight bullet, TC and RN, will have not only have different OALs, but case volumes as well)

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On 1/6/2018 at 11:06 AM, MemphisMechanic said:

 

Bullet shape really, really matters. Far more than weight.

 

 

^^^This^^^

Sit back and picture what's happening.  Just a hair forward of the shoulder of the bullet, on the ogive/cone, there is the place on the bullet that makes first contact with the rifling, and loading to an OAL that keeps that spot just short of rifling contact is your max OAL where the cartidge will plunk and spin freely.  Right?  So your actual max OAL is all about how much bullet there is FORWARD from that point.  Or in other words, how much bullet there is that never makes contact with the gun and isn't sunk into the case.  ;)   If your max OAL is short, it's because the front of the bullet is stubby.  That's it. 

 

It DOES mean it's going to seat a LITTLE bit deeper, but not by the same amount as OAL varies.  If one bullet's max OAL is 1.160, and a different bullet's OAL is 1.060, that doesn't mean the bullet is seated .100 deeper into the case.  It might only be .05 deeper, or .04, or whatever.  It's not as big a deal as it seems.  ;) 

 

As someone already said, if it feed, it feeds.  ;) 

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Also, though, clean out your chamber with a brass brush and some solvent.  Make sure you don't have something in there making contact early.  ;) 

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ACME 115gr 9mm RN bullets
 
Length .530x .356
 
I ran a plunk test and determined I had to run a max of 1.058 to spin
 
Doing a ladder work up I decided 4.2 grains was ideal for me @ 1115 avg from a Glock 17
 
Firing up the progressive I find 10-20 out of 100 don’t plunk until 1.040
 
Does anyone load THAT short? 1.030-1.040
 
 
 
 
 
Sent from my iPhone using Tapatalk

With ACME 9mm 122 g FP I load to 1.04 in my CZ SP-01. Just make sure you start low and work up to where u are looking to go. Freaked out at first but they shoot good for me once I found the ideal charge weight.

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4.2 hp38 @ 1.050 was ideal for me

Going to try 4.0 @ 1.035 next run and see if they still make PF


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