10MM 200 gr XTP bullet deformation loaded with AA#9

[Lennyjoe]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

Seems like the 200 gr XTP doesn’t really like a compressed load of AA#9 above 13.2 grains. I’ve had a good load of 13.5 gr in the past out of my G20 and recall moving the OAL up from 1.260 advertised to 1.280 to help keeping the bullet from deforming the hollow point. The 1.280” plunks fine and still fits in the magazine without hanging up.

Here’s what happens when I seat the 13.5 gr load @1.280”


I’ve added the banner at the start of this thread to meet forum rules since the Hornady 10th edition manual lists 13.2 gr of AA#9 as max (below).


For reference, the Speer manual shows a 200 gr bullet at 14.0 max (Speer #13 manual) but I highly doubt you could get the XTP bullet that high without deforming the bullet more just to test the load that high with the bullet. In the past, I used this manual to work up to 13.5 gr using the XTP but had to stop there because of the bullet deformation shown above.


So there’s no way to know if the 13.5 grain load with the deformed hollow point would expand as expected absent gelatin test (which I don’t have). In the past, this load grouped well in my G20 with KKM barrel with no signs of over pressure. Think I’ll just use up the few remaining XTP’s I have and move to a different 200 gr JHP bullet/powder. Have some Nosler 200 gr JHP inbound and will slowly work up an AA#9 load shortly.

 

[Cheesemaker]

I’ve had a good load of 13.5 gr in the past out of my G20 and recall moving the OAL up from 1.260 advertised to 1.280 to help keeping the bullet from deforming the hollow point.

So the "good load" you reference deforms the bullet - or not? Different cases?

Edit Add: You are using a round nose seater plug - or FP?

 

[GeoDudeFlorida]

So the "good load" you reference deforms the bullet - or not? Different cases?

Edit Add: You are using a round nose seater plug - or FP?

Seater was my first thought, too.

 

[gwpercle]

Your bullet seating stem doesn't properly fit your bullet . Buy a spare stem or two and "custom fit" the stem to the bullet with J-B Weld epoxy putty or glue , fill the hollow point with parrafin wax so the epoxy doesn't flow into it . Grease the bullet and clean the stem ... you don't want to epoxy the bullet into the stem .
Once you have a custom fitted stem you will be hard pressed to derform bullet nose / profile .

Any bullet with a flat spot om the nose , Round Flat , Truncated Cone , Wadcutter , Semi-wadcutter (SWC) can be seated with a flat nose punch ... fill the stem nose with J-B Weld , let harden and sand nose dead flat ... Wah-Lah ...Flat seating stem that can seat many different profiles and not deform the bullet .
I use a small ball of J-B Weld epoxy putty because it doesn't drip and run into places you don't want it to get into .
Tip ...use the 8 hour cure putty or glue ... the quick setting epoxies are not as strong and they don't give you enough working time to get everything in place , set up and lined up straight ... everything has to be in-line and straight to work correctly .
Gary

 

[WrongHanded]

I doubt it's the seating stem. It's far more likely to be a heavily compressed load, and you're using too much pressure to seat the bullet.

I've had it happen myself. Put your powder charge in a case, tamp it down with a pencil, and then measure from case mouth to the charge. I bet it's less than the depth you're trying to seat the bullet.

 

[sparkyv]

Lennyjoe, I use the same Speer data (#12, actually) for AA#9 10mm load data, a tad hotter, even. However, I haven't loaded heavies with #9, so I haven't run into your seating issue...but this has been noted!

 

[Skgreen]

What equipment are you using to seat these with?

 

[Lennyjoe]

What equipment are you using to seat these with?

Lee .40/10MM dies.

I doubt it's the seating stem. It's far more likely to be a heavily compressed load, and you're using too much pressure to seat the bullet.

I've had it happen myself. Put your powder charge in a case, tamp it down with a pencil, and then measure from case mouth to the charge. I bet it's less than the depth you're trying to seat the bullet.

I’lol do that and see. Guessing this is the issue.

 

[murf]

use a fired 9mm case: insert the case into the powder-filled case (10mm), measure the length of the two, measure the length of the 9mm case, subtract the latter from the former to get the powder level in the 10mm case (distance from the base to the top of the powder).

murf

 

[WrongHanded]

use a fired 9mm case: insert the case into the powder-filled case (10mm), measure the length of the two, measure the length of the 9mm case, subtract the latter from the former to get the powder level in the 10mm case (distance from the base to the top of the powder).

murf

Smart!

 

[gwpercle]

Lee .40/10MM dies.




I’lol do that and see. Guessing this is the issue.

Lennyjoe ... a properly fitted seating stem will not close the hollow point smaller ... Trust Me on this one ... your seating stem doesn't fit your HP bullet's profile .
You can custom fit it easily ... see post # 4 .
50+ years reloading has taught me how important a properly fitted seating stem can be and how easy it is to do with a little J-B Weld .
Gary

 

[AJC1]

Lennyjoe ... a properly fitted seating stem will not close the hollow point smaller ... Trust Me on this one ... your seating stem doesn't fit your HP bullet's profile .
You can custom fit it easily ... see post # 4 .
50+ years reloading has taught me how important a properly fitted seating stem can be and how easy it is to do with a little J-B Weld .
Gary

Probably the best thing going for Hornaday dies despite me not owning a single set. Some day sooner than later I will learn the secret of machining my own. Once I am living at the same location as my lathe I'll make a ton of chips and scrap.

 

[murf]

use a fired 9mm case: insert the case into the powder-filled case (10mm), measure the length of the two, measure the length of the 9mm case, subtract the latter from the former to get the powder level in the 10mm case (distance from the base to the top of the powder).

murf

for other cartridges (357 mag, 9mm, 45 acp, etc), i use a pin gauge to stick down on top of the powder charge.

murf

 

[GooseGestapo]

What brand cases are you using?

Not all are created equal. I had Norma in the beginning. They held approximately 5% more volume.
A Winchester case wouldn’t hold a max load of Acc#7 and a 200gr XTP. PRESSURES were also higher!


The Lee seating stem is causing your squeezing issue. I fill mine with bullet lube as paraffin is more brittle. Also, seat and crimp in separate steps!

 

[WrongHanded]

How about you resize an empty case, and make a dummy using your current setup. If the HP still gets crushed, it's a seating die issue for sure. If not, it's a combination of too much force (from powder compression), and an improper fit into the seating stem.

 

[Walkalong]

Definitely need a better fitting seater stem, but even then you may deform the bullet with such a compacted load.

 

[Hartkopf]

I had this problem with Lee dies with 44 magnum and IMR4227. I made a flat faced seating stem for XTP bullets. This helped but the Lee dies resize the case down so small that it reduces case capacity. That or the Starline brass just had a small capacity to begin with?? I never could get anywhere near the max charge because powder would not compress enough or the bullet would push back out. But, the bullet never deformed with a flat faced seating stem.

 

[Lennyjoe]

What brand cases are you using?

Not all are created equal. I had Norma in the beginning. They held approximately 5% more volume.
A Winchester case wouldn’t hold a max load of Acc#7 and a 200gr XTP. PRESSURES were also higher!

The Lee seating stem is causing your squeezing issue. I fill mine with bullet lube as paraffin is more brittle. Also, seat and crimp in separate steps!

New Starline brass

 

[.38 Special]

Definitely need a better fitting seater stem, but even then you may deform the bullet with such a compacted load.

Quite some time ago I had troubles with a particular JHP in .45 ACP. No matter what I did the nose would deform much as the OP's does. Eventually I modified an RN stem by thoroughly coating a bullet with paste wax, filling the stem with bedding compound, and mating the two. It still took significant effort to remove the bullet from the stem, but I then had a perfectly fitted combo and the trouble was solved. And about six months later, the bullet was discontinued.