Hornady 115 XTP/Win 231 load question

[destmiker]

I scored a bunch of inexpensive 115 Hornady HP/XTP (and 115 HAP) bullets at a local estate sale.  I started loading these bullets using data from the 4th edition of Hornady's manual - which lists the max load of Win 231 as 5.5 grains at a COL of 1.050.  I tried about 100 and they worked great in my Glock 34 Gen 5 MOS - extremely accurate and 100% reliable.

 

I realized that my book was getting pretty old (okay, really old) so I bought their latest volume, the 10th edition.  The load data for the 115 HP/XTP with Win 231 is significantly different in the newer volume.  So, I tried it.  The max listed load for Win 231 is now 4.7 grains (versus 5.5) and the Hornady listed COL is longer -now 1.075 versus 1.050.  I did a 100 or so rounds and while they were still extremely accurate, functioning was terrible.  I got 2-3 failures to feed for every 25 rounds - each time the round was jammed bullet up into the chamber.

 

So I'm curious - why the huge change?  Is 231 that much hotter now?  Is Hornady just more cautious?

 

And more importantly, what's a better load and length for these bullets in my Glock 34?  I want to use Win 231 if possible since I have so much of it.  I do have quite a bit of TiteGroup too, so I can change if necessary.

[Sarge]

You sure you can rule out a magazine? That oal change is pretty minuscule and most of us run them longer than that anyway. And 4.7 231 should be plenty to cycle the gun properly. Do you have access to a chrono by chance? I guess it’s possible they are a little too weak but only a chrono can tell you that.

  4.7-5.5 are not exactly hot loads so turn them up a little to get them back to where they run 100%

[Hi-Power Jack]

15 hours ago, destmiker said:

 COL is longer -now 1.075 versus 1.050.  functioning was terrible. 

 

what's a better load and length for these bullets 

 

Every time you change a bullet (not just weight, but even brand),

you need to do The Plunk Test. 

 

That will tell you what is a good OAL for Your Gun and Your bullet.

 

Sounds like your gun likes the OAL to be shorter - if you were 100% at

1.050", with the identical bullet, that's what I'd run.     

[radny97]

Honestly, run them with the old data. The new manuals are sometimes appropriately cautious, and sometimes seem to be written by lily-livered pantywaists.

In this case it appears to be the latter. 

[destmiker]

I've always plunk tested bullets - even before it was named the "Plunk Test."  Both lengths plunk equally well in my G34 barrel.

 

I think the main difference is the decreased powder charge from the newer manual.  My G34 (which is the only gun I tried the load in) has the stock recoil spring assembly so it seems like the gun just doesn't want to function with the lighter load.  Even though I always tell people who ask me for reloading advice to buy a current manual and follow it, in this case I might just go back to the older data.  And yes, I should test the load over a chronograph, but just haven't had the time to do it yet.