Strange Swiss Bullet

It looks like you have a police lineup going on there.
I’m guessing you didn’t have a 175gr SMK, Hornady 175 ELD-X, or a 178 BTHP to compare it to?

https://ravenrocksprecision.com/swissp-30-cal-308-168gr-hpbt-match-bullet-250-ct/ Not the GP-11 bullet, but pretty cool at a very attractive price. Close to the radical boat tail angle and the same Tombac jacket material and skinny ogive. Should be a great bullet in the K-31 at a pretty reasonable price. $.28/100, I just ordered 500, so we'll see how they do, but probably in my M1 and Springfield first!

I've been loading the K-31 and G-11 for over 20 years now, and I've long ago switched to the 155 grain match bullets over a lighter charge of IMR 4064. They hold up well to 300m, and the recoil is much more pleasant with fine accuracy. They tend to zero to my sights at 200 yards CMP distance which is perfect for my application.

You will not find a proper lookalike to the GP-11 bullet. The only similar design with that radical BT I've seen was a Czech 8mm bullet from WWII. The closest is probably the 173 grain used for loading match 30-06 and 7.62 ammo back in the day. I believe PRVI has an FMJ in a similar weight but the ogive is fatter requiring deep seating if loading for a K-31. Specifically the Barnes and Sierra 175 match bullets may be loaded effectively in the K-31 if you wish to shoot this weight. The Nosler is too fat.

That extreme bowtail makes the bullet much longer for its weight class and requires a higher twist rate to properly stabilize. Bullet makers want as broad of market as possible, meaning your highly unlikely to find it....

The quest to duplicate GP-11 ammunition is a world wide endeavor. When I got my first K-31 I spent a lot of time researching on the Swiss Rifles board:


Great site BTW. There is a "ammunition" forum that has load data and discussion from people all over the world. It would take literally days to pore over all of the posts and recipes that are given. If I recall, some of the most diligent investigators determined that RL17 was the GP-11 powder. The natural inclination is to get heavy 170 class bullets because that is what they use in GP-11, but posters have tried every 30 cal bullet and suitable powder ever invented.

My personal thoughts are that GP-11 was loaded pretty hot and didn't live up to the accuracy hype that I expected when shot from my rifle. In fact, I didn't see much difference accuracy wise from PPU 174 FMJ ammo which I shot to get brass to reload. I finally settled on a 168 HPBT load with PPU brass and IMR4350 that was a little more accurate that GP-11. I bought a Swiss Products clamp on mount (great product!) and scoped my K-31 in my load development phase.

As an aside, GP-11 is a very effective long range machine gun cartridge and influenced the US to create the 173 gr. M72 bullet and M1 ball ammunition to extend our machine gun range after WWI. In that regard, the M72 bullet was our attempt to duplicate the GP-11 bullet. Of course, I had to try those and bought 500. As is typical of FMJ's, they weren't as accurate as 168 match bullets or GP-`11.

You forgot to include a picture of your K 38.

I bought a K31 when the flood hit a few years ago and they were selling for about $100.00. It shot so well I bought two more. Over the years I've given two away, trying to reduce my amount of stuff.