Speer 147gr GDHP bullet length?

[johnandersonoutdoors]

I have load data in my Speer manual for their 147gr Gold Dot HP. I want to use the load data to begin my workup for my 147gr Hornady XTP bullets.

I have measured the my XTP bullet length and it is .660".

I am curious if anyone can haul out a 147 GDHP and measure the length.

I know I don't need it but just want to compare the two bullets lengths and resulting case volumes.

Thanks a lot.

 

[rcmodel]

I have a pretty old box of them that measure .652" - .653".

Don't know if that is current length or not?

rc

 

[johnandersonoutdoors]

Thank you.

I am using the 13th edition of the Speer manual.

As always, I plan to start low and work up.

I am working on plunk testing now. It seems my max overall length to get proper plunk in two different M&P 9s that I have is about 1.125". The max overall for my M&P Shield required me to go down to 1.110 - 1.112"

I am hoping I can get accurate results using the same oal and powder recipe in all 3 guns.

 

[gamestalker]

They have a good long bearing surface, so you shouldn't have a problem at the longer or shorter oal. I run most of mine at around 1.125", but I've run them shorter and accuracy has been as close to identical to the shorter oal as I can discern, I consider myself to shot well, but I'm no marksmen.

I don't really feel like digging through my inventory right now, but I'll measure a few in the morning and get back to ya.

GS

 

[rg1]

Just to add, Hornady's 9th manual lists the overall length as tested for the 147 XTP at 1.100".

 

[gamestalker]

And just to add to that, Speer tested them at 1.130".

This is why we should always work up from a reasonable start charge. BTW .030" can create a serious increase in pressures, especially when it concerns 9mm.

So seat them to the oal that fits and functions for the firearm you're loading them for. Just don't shorten the initial oal on an already developed load without taking the charge back down, and then working it back up at the new shorter oal. This is where one can get into excessive pressure trouble, and especially with 9mm.

GS

 

[johnandersonoutdoors]

Thanks for the replies guys.

Due to the M&P Shield's shorter throat? The OAL that I am going with is 1.110" which is 0.02" shorter than the 147gr GDHP data in my Speer manual. My plan is to load with WSF or Unique. For WSF, recommended is 3.6 to 4.1gr. For Unique, it is 3.8 to 4.3gr.

Being that my overall length is 0.02" shorter, should I go below the minimum when I start my workup?

 

[Mad Chemist]

Something is amiss here. I've run XTPs much longer through my S&W Shield. My std length used to run 1.140-1.145. I have recently shortened them a bit. This model of pistol absolutely does not have shorter than usual chamber lead.

You may want to make sure that your test rounds have all the case bell removed. You should be able to run very long OALs with this gun. Honestly, it's almost as generous as my G19.

Short chambers are more typical in CZ/Tanfolio, some of the newer Walther designs, and Springfield XDs.

 

[Toprudder]

Short chambers are more typical in CZ/Tanfolio, some of the newer Walther designs, and Springfield XDs.

Funny you mention that. I did plunk tests for all the 9mm projectiles I have, in my Witness PS, Witness Match, and CZ P-09. The Match, for some projectiles, plunks about 0.025" shorter than the PS, and the P-09 is about halfway between. Since I'm not shooting matches, I load all my 9mm for the shortest.