With only magnum primers

[Greenwood10mm]

So zero large pistol primers available.
All I have are winchester WLP and Federal 155.   How much difference?
Using PB, Unique, Bluedot, HS-6, h110

[blaster]

yesterday I loaded up some .45 Super brass with magnum primers because I was getting primer swipes with standard lg. pistol primers. using the same 10 grs. of Long Shot and a 230 gr. bullet, the magnum primers jumped the velocity up around 50 fps. be careful!

[CtYankee]

10mm out of a Ruger GP100 using 165 gr lead with 5.2 gr of Power Pistol, with Fed 155 magnum primers increased velocity 30 fps (757 fps to 788 fps). Not a problem with light loads but at the high end you will probably get higher velocity (and pressure) than predicted. Winchester Large Pistol primers are sold as standard/magnum primers, enough power to ignite magnum loads, but (reputedly) less pressure increase than other magnum primers; Hornady and Hodgdon both use Winchester in their loading data. Using the same gun with 200 gr GDHP with 8.9 gr Blue Dot I measured 1106 fps, which is .1 gr less powder than the Hornady data showed for that data. This increase may be caused by the fact that pistol caliber revolvers tend to have higher velocity than semi-autos due to longer travel before engaging with the rifling, or it may be slightly higher pressures. If you want to, or have to (like I have) use magnum primers use Hornady or Hodgdon data and maybe use Winchester primers.

[sparkyv]

WLP were my typical 10mm primer before the current shortage.  Now I've been readjusting my loads for Rem standard LPP so save the WLP for my 44 Mag.  I haven't done a head-to-head chrony study, but so far I haven't seen that much of a difference.  Going back the other way, I'd start the load a bit lower and work my way up.  Should be just fine.