Small Magnum pistol Primers as a substitute??

[Cannonman1]

I have a 1907 vintage 73 in 32/20, requiring small pistol primers.. Well, you know the rest of that story.. They just are not available..
I do, however have access to some magnum small pistol primers.
Question ?? Can I use them when loading, using Trail Boss smokeless and if so, do I need to adjust my powder charge down a speck or is it inconsequential?? 

[Abilene]

I'm going to say inconsequential, particularly with Trailboss.  With most loads, no problem if you aren't at the max loading.

[Professor Marvel]

I agree in principal with our good Abilene.

The '73 is a stoutish carbine, and the 32-20 is a lovely little cartridge, so any increase in pressures is likely to be minor.
Might change your POI tho.

yhs
prof marvel

[Snake Oil]

I am by no means an authority!!!
I have not tried it myself, yet...
However having the same question I have chased down many a thread on many a forum (seems this has been a recurring problem?!).  One thread even had some shooters who had actually chronographed their loads with magnum primers vs regular... they saw anywhere from 25 to 50 feet per second difference, with felt recoil feeling very similar...
I may be trying something similar, but I may reduce my load a pinch... my equipment has liked the hotter loads for performance sake...

Good luck, anxious to hear of your success!

[Coffinmaker]

  Oh goody goody   

My turn!!      I don't have ready reference to ALL the scientific gobbledygook, however I can break it down to something understandable.

The difference between "Magnum" and "Standard" small pistol primers, is relative "BRISANCE."  Brisance is the measurable difference in Flame Travel and Flame Dwell Time.  In some manufacturers priers, the relative Brisance of their "Magnum" primers is slightly greater than "Standard" primers.  Hotter if you will.  Other manufacturers don't bother with different "Magnum" or "Standard" primers and make "One Size Fits All."

THE BOTTOM LINE

The actual difference in performance is Academic.  There isn't enough difference to spit at.  You can in fact get 25 FPS deviation without any change in components.  SO:  SNAKE OIL . . . NO!! you do not have to reduce your loads a pinch.  There is not enough of a difference to alter POI enough to measure.  The difference is inconsequential.

[River City John]

Much like the thin pickings on brands on the shelves of toilet paper, any old port in a storm.

[Coffinmaker]

  Aw Crapola   

I forgot to include the "other" considerations of widely misunderstood trivia. SO:

Pay Attention Class . . . . there's gonna be a TEST.  In the world of "SMALL" primers, one may, at one's discretion, substitute small RIFLE primers is pistol cases that require small pistol.  Little to NO difference in performance.  One CAVEAT however.  The relative thicnkness/hardness of the primer CUP still holds true.  The use of CCI primers WILL result in less than Harmonious experiences if one is utilizing lighter, more "competitive" Main Springs.

Stay Safe.  Lots of Idiots out there

[Dirty Dick]

It was standard practice in IPSC many years ago to use small rifle primers in .38 Super loaded to make major power factor to eliminate the 'cratering' ' of the primer around the firing pin which would sometimes cause a malfunction. When large pistol primers were in short supply for loading .45 ACP it was quite common to use large rifle primers. Yes, they would protrude a bit from flush with the case but I never heard of or experienced a slamfire from the practice. 

Just my $.02

[Tater Pickens]

I have normally used Federal Large pistol primers in my black powder loads for 45-70 trapdoor, 73 and 92 winchester rifles and Colt SAA revolvers but none can be found. A friend has told me he has some CCI large pistol primers I can use. Are they good primers? I have always used federals but can't get any.

[Abilene]

Tater, CCI are excellent, but have a reputation for having harder cups and some folks with lightened springs in their guns have a problem setting them off reliably.