I know this came up in a different thread and in that thread a video made by the Yankee Marshal came up where he addressed it. In his video, I wasnt a huge fan of his testing as he not only used hotter rounds, but he’d cycle the same round through again and again until the crimp jump got really bad. I didn’t feel this was very realistic as few people will cycle the same round in cylinder after cylinder without shooting it.

I did a quick test of my own, taking a measurement of a round, cycling 4 rounds, removing the control round and taking a measurement. For today, I had CCI Blazer brass 124gr FMJ, Fiocchi 115gr FMJ, and Winchester white box NATO rounds, 124gr FMJ. I ran three sets of each:

CCI Blazer Brass:
Ave factory length: 1.154”, average crimp jump: 1.204”

Fiocchi:
Ave factory length: 1.152”, ave crimp jump: 1.162”

Win NATO:
Ave factory length: 1.154”, ave crimp jump: 1.162”

Just for fun, I popped in one of the Blazer rounds with 4 harder kicking NATO rounds...the bulled jumped so much, I didn’t want to fire it! It measured 1.257”, +.103” over the factory measurement!

So...what did this tell me? Well, for starters there is obviously crimp jump...but in one cylinder 5 round set, I found the .010” to be more than acceptable, especially with the NATO which didn’t jump much at all despite having more “umph” than the other two. The Blazer jumped too much for my taste, I won’t be running it again in that revolver.

I also learned that little revolver loves those NATO rounds, it was very accurate with them and handeled the recoil perfectly fine.

I guess I’ll say this, it really depends on the rounds. I was going to order more of that Blazer Brass as it is typically accurate and clean shooting, but I won’t be now because I cannot run it in the Pitbull.

Thanks for taking the time to do some testing. I did some very limited testing on this too. I used a S&W 940, and left one cartridge in the moon clip until I'd fired 8 rounds. The Winchester and IMI 124 NATO only moved about .002", the Federal 124+P HST, about .050" IIRC. That being said, I've never actually had a 9mm round cause an issue due to bullet pull in any of the several 9mm revolvers I've owned. Always glad to see other's results with this stuff.

__________________
NRA Life, COTEP 640

What your results show is the reason I sold my Ruger LCR 9mm. I ran the same results you did.....I brought my calipers to the range with me and took masurements as I fired. Never found any love for that gun and glad I sold it.

Thank you for the informative post! I have been thinking about adding a 9mm revolver, hadn't considered this angle.

Personally, it doesn’t bother me much, I was just curious to see how things would come out. From time to time I’ll measure a round to see if they are doing this, but jumping .010” isn’t anything I’d consider dangerous.

Personally, I love that Pitbull. It’s taking some time to master, but I find it to be a fun handgun to shoot. The best part is that figuring that I don’t reload at the moment, I was shooting myself out of house and home burning through .38 like there was no tomorrow. 9mm isn’t free by any means, but it is far cheaper than .38.