Some words about powder spaces
The P-Max simulator requires the capacity of the case behind the loaded bullet to be entered as the powder space. The best way to get this number is to measure it yourself, and you are strongly encouraged to do that. See a short YouTube video which demonstrates a simple way to measure powder space. A good site which lists the powder space for a large range of common cartridge with various bullet weight is the Nosler load data website.

However, the estimates to the right will give you something to start with and allow you to get some idea of the performance of that particular cartridge. The listed powder spaces are estimates of the capacity in grains of water up to the bottom of the case neck, where the base of the bullet might be expected to be in the loaded case.

Remember, cases from different manufacturers for any particular cartridge can differ in case capacity by surprising amounts and you should not assume that the powder space listed is the powder space for your particular cases.

Remember too that for any particular calibre, heavy bullets will be longer than light bullets. If a given cartridge is loaded for the same cartridge overall length for heavy and light bullets, (to fit in the magazine, for example), heavy bullets will sit further back in the case and so the powder space with heavy bullets will be less than the powder space with light bullets.

Rifle Cartridges

17 Remington	25.9
204 Ruger	29.1
22 Hornet	11.3
22 Hornet Imp.	13.3
218 Bee	15.5
22 Rem Jet	15.4
221 Rem	18.6
222 Remington	24.6
223 Remington	28.4
222 Rem Mag.	29.2
5.6 x 50 Mag.	30.8
22 Nosler	31.5
219 Zipper	31.6
224 Valkyrie	31.8
22 Savage	32.7
22 BR	36.5
225 Winchester	39.3
22-250	41.9
220 Swift	46.2
22-06	62.3
6 x 47	29.6
6mm ARC	29.6
6mm PPC	29.9
6mm BR Norma	34.1
6 x 70R	36.1
243 Winchester	50.8
243 WSSM	50.6
6mm Remington	51.7
240 Wby Mag.	62.1
6 x 62R	63.5
240 Fl. N.E.	54.0
256 Win Mag.	18.1
25-35 Winchester	33.0
25 Rem	37.9
250 Savage	42.2
257 Roberts	52.6
25-06 Remington	61.9
257 Wea. Mag.	79.8
6.5 Grendel	32.0
6.5 x 70R	34.6
6.5 Jap	43.2
6.5 x 47 Lapua	43.5
6.5 x 52 Carcano	44.4
6.5 x 53R	44.5
6.5 Creedmoor	48.0
260 Remington	48.7
6.5 x 55 Swedish	52.8
6.5 x 57R	53.6
6.5 - 284 Norma	56.0
6.5 Rem Mag.	61.5
6.5 PRC	62.0
264 Win Mag.	78.8
270 Winchester	62.9
270 WSM	74.4
7mm-08 Remington	50.2
7 x 57R	53.7
7 x 57 Mauser	56.8
7 x 64 Brenneke	60.3
284 Winchester	60.3
280 Remington	61.5
7mm WSM	75.5
7mm Rem Mag.	78.5
7mm Wby Mag.	80.8
30 Carbine	14.0
300 AAC Blackout	21.0
7.62 x 39	31.4
30-30 Winchester	37.8
30 Remington	38.4
300 Savage	46.1
307 Winchester	47.2
308 Winchester	49.4
30 Fl. N.E.	51.1
30-40 Krag	51.2
7.62 x 54R	56.0
30-06 Springfield	62.4
300 WSM	75.0
300 H&H Mag.	79.6
308 Norma Mag.	80.0
30 Newton	81.1
300 Win Mag.	82.4
30 Fl. H&H	83.2
300 PRC	91.0
300 Wby Mag.	92.8
303 Savage	40.4
303 British	49.9
32-20 Win	14.8
7.65 Mauser	50.9
32 Remington	38.1
8 x 57 IS Mauser	54.3
8mm-06	62.4
8mm Rem Mag.	90.9
338 Win Mag.	76.2
340 Wby Mag.	88.0
338 Lapua Mag.	100.1
348 Winchester	63.7
9 x 57R Mauser	50.5
35 Remington	41.0
356 Winchester	44.9
358 Winchester	46.4
35 Whelen	59.5
350 Rem Mag	61.7
358 Norma Mag.	76.5
9.3 x 57 Mauser	52.6
9.3 x 72R	55.7
9.3 x 62	65.2
9.3 x 74R	70.9
360 No.2 N.E.	99.5
375 Winchester	37.3
357 2½ N.E.	54.7
375 H&H Mag.	82.5
375 Fl. Mag.	84.3
375 Ruger	87.2
378 Wea. Mag.	123.5
400 Jeffrey	100.8
416 Rem Mag.	89.8
416 Rigby	112.4
404 Jeffrey	96.6
458 Win Mag	70.9
458 Lott	84.9
450 3¼ N.E.	92.4
460 Wea. Mag.	116.7
465 N.E.	120.0
470 N.E.	121.3
475 3¼ N.E.	111.5
50 BMG	263

Pistol and Revolver Cartridges

32 Auto	7.0
32 S&W	6.2
32 S&WL	12.1
32 H&R Mag	14.8
9mm Luger	11.4
38 Auto	15.5
9mm Win Mag	20.4
380 Auto	7.5
38 LC	14.8
357 Mag.	17.8
357 Rem Max	27.7
38 S&W	9.5
40 S&W	10.6
10mm Auto	14.6
44 S&W	25.9
44 Rem Mag.	25.2
45 Auto	17.6
45 Colt	29.8
45 Win Mag.	29.3
454 Casull	33.8
50 AE	35.4