Protected Primer Reload


Picked from a bargain bin for the primer type. On closer look, was a bit surprised to read the headstamp.

I assume these Winchester primers were available to reloaders?



Are you sure its a reload? Winchester began loading US Cartridge Co ammunition in 1926, so perhaps it is a factory load.


I think Guy’s right that this was produced in the period when WRA was handling the USC production. In .33 WCF caliber the protected primer was, I believe, larger than the standard .210 in. so required a special oversize primer pocket to be employed. Neat! Jack


These primers were available to the reloader. Although not 100% sure the ones without the impressed “W” were.


Pete: My understanding is that there were two sizes of these protected primers, a smaller one which would fit in a standard .210 pocket, and a larger one that required an oversize pocket. I think the .33 (as made by WRA) used the larger version, so (if I’m recalling correctly) a cartridge in that caliber likely has the big pocket, which was specific to WRA. Another possibility is that a standard USC case with a .210 pocket has one of the smaller protected primers seated in it, but that doesn’t seem to be what I see and also seems less likely. Jack


Thanks to all for the comments. A Forum post by Gourd from about four years ago describes the 5W primer at .210" dia. as Jack indicates and the 5-1/2W primer at .237" dia. as used on Winchester .33 WCF, etc. Later I’ll get a measurement of this one’s diameter and take a closer look at it for signs of reloading. My first impression (biased by the primer type!) was that it is a reload. The case mouth seems a bit rough for a factory crimp and the bullet seems to look a wee bit deeply seated. I’ll post a side view for any interested to weigh in on.

They don’t let me out much so I have to ask this question of the pros…Does anyone have a “known to be factory loaded” USCCo. cartridge with a Winchester Protected Primer?



I thought the initial reason for the initial on the primer was to give the shooter the idea if it was a factory load or a reload. The initial primer was never sold to re-loaders? The protected primer was a new one to me I guess we learn something new every day. Thanks for the post. Vic


Hi Jack
I have both 5 W and 5 1/2 W type primers packaged to be sold to re-loaders. 100 each in a sleeve/tray package just like today.

The “W” on the package or next to the name (5 W) meant they were stamped “W” that is what I was talking about when I said I was unsure if the plain were marketed.

Hi Dave
I don’t have a .33 by U.S.C.Co. but I do have W.R.A.Co. headstamped rounds showing the protected primers all have the inner bit, the cup, of copper, but some have an impressed W and some are plain.
Yours looks tinned & not stamped.

edited once for further clarification on my earlier post


Thanks Pete!

The inner primer cup does appear to be tinned. The OD of the outer cup/ ID of the primer pocket measures at .236". OAL is 2.560".

Shows some signs of loading and/or chambering. Projectile may be deep from having some time in the magazine while on the hunt…?