165 FMJ FP loads - huge disparity between Lee, Lynam load data

[Teninator]

So I'm looking for loads for some 165 FMJ FP's I got that were police/military pulldowns. I was shocked at the disparity between the Lyman 50th and the Lee Second Ed's. Lyman is way more conservative.

For example,

Lyman 165 TMJ
Powder          Start  Max
Power Pistol   7.8    8.7    (29K PSI)
Blue Dot         9.1    10.2  (27.4K PSI)
Unique           6.5     7.3    (27.3K PSI)

Lee 165 XTP
Powder          Start  Max
Power Pistol   8.8    10.0     
Blue Dot         10.1  11.5c
Unique            7.3    8.3

WTH? That's like a totally different caliber (e.g., 40 vs 10mm)

Weirdly, both list 13.5/15 for Accurate #9 (but I don't have that powder).

All the Lyman loads are under 30K psi, while the Lee's are mid-30K, all the way up to 37.5K! Are Lyman just afraid of Glock chambers or what (they have a Glock warning for 40 S&W but not 10mm).

Ironically, Lyman's intro for the 10mm says, "The advertised muzzle velocity for a 200 grain bullet was 1200 FPS." 

So which manual should I believe? BTW this is for a Glock 20SF and a S&W 1006.

[Ten2six]

Alliant shows 10gr. Max for 165 gr bullet on their website.   9.6 to 10 range and 165's are my favorite loads.

[The_Shadow]

Teninator, welcome to the forum...Have you strolled through the data listed here on the forum?
http://10mm-firearms.com/reloading-10mm-ammo/10mm-load-data-collection/
Glock 20 using 4.6" factory barrel  Sierra 165gr HP's bullets
Blue Dot -12.0gr = 1215
Blue Dot -12.5gr = 1288
Blue Dot -13.0gr = 1315

Glock20/6" 165gr. Golden Saber 10.2gr. PP MV:1508fps ES-35 ME:830ft/lbs.

Glock20/6"
Bullet - 180g Speer Gold Dot JHP
Case -  DT (NEW)
Primer - CCI #350 LPM
Powder - PP 9.6 g.
# of Rounds Loaded & Fired - 5
VELOCITY :
1) 1408     2) 1419     3)1399     4) 1407     5) 1410
Average Velocity : 1409 FPS
Average Muzzle Energy : 820 FT LBS
Extreme Spread : 20 FPS

Glock 29
165 Grain Montana Gold HP
OAL 1.255
New Starline Brass
Temp 62F Cloudy

9.7 Gr Power Pistol CCI300 LPP
Glock Barrel No pressure Signs
1267
1267
1222
1250
1273
1284
1279
1267
1278
1309
SD 21.4
Avg 1270 F/PS
Energy 590 Ft/Lbs

[The_Shadow]

Also you may want to look at this commercial offering from the pull down documentations http://10mm-firearms.com/factory-10mm-ammo-pull-downs/parabellum-research-pbr-165gr-fmj-pull-down/msg11470/#msg11470

[Teninator]

Thanks guys - yeah no duh, should've looked at Alliant's website.

I've seen the pulldowns section, very impressive, and why I first started following this forum; but since I'll be gifting some of these for Christmas, I don't want to emulate Underwood's fire and brimstone loads. 

Sierra 165gr HP's bullets
Blue Dot -12.0gr = 1215
Blue Dot -12.5gr = 1288
Blue Dot -13.0gr = 1315

Cheers all!