I flew to Colorado last Friday and spent the weekend with a buddy dialing in a load for my Heym 577NE in preparation for an upcoming buffalo hunt in Australia. Following are a few photos from the effort along with a brief explanation.

Knowing that we had a short window of opportunity to figure out a decent load, I sent my 577 barrels to Denver to make sure that the Jamison brass we ordered would not present a problem.


Similar to pre-baiting for a leopard hunt with limited time, my good friend had ordered a number of bullet types (softs & solids) in various weights along with various powders. He then made up 42 rounds using different load plans as a starting point for when I arrived. This was a huge time saver for us.


We wasted no time in getting from the airport to the rifle range where we bore sighted the rifle to get a Docter sight on paper at 35 yards. The plan was to use the Docter sight to baseline initial grouping behavior for the various loads. Once we landed on a load combination we liked, the plan was to move to express sights and migrate the point of impact to point of aim.

Bore sighting the Docter sight


Making adjustment to the Docter sight


As a baseline for grouping, we began with factory Kynoch ammo, which is what the rifle was regulated with at Heym. As anticipated, the grouping with the Kynoch ammo were decent but unfortunately I have not been able to locate a reliable source for Kynoch ammo in the USA. Hence the project to develop a custom load for the rifle.

Kynoch factory ammo


Baseline grouping with Kynoch factory ammo at 35 yards


We added a chronograph to the mix for additional baseline data and began testing the various loads that had been cooked up prior to my arrival.


View of the spotter/scribe’s bench where shots and velocities were recorded.


We moved to 50 yards and as you can see, some loads performed better than others as we shot our way to a couple of loads that showed enough promise to take to the next level of tweaking.









Now this one looks promising.


Even the Range Officer thought it looked promising so he had to snap a few photos himself.


A few more loads were tested and then we landed on this one! Everyone thought that this load was THE ONE to look at as a primary load and the other load that we all liked, including the Range Officer, would be used as the secondary focus.


Discussing the load and next steps.


Same load, three different shooters. Interesting results.


After 26 shots and two loads that significantly outperformed the rest, we were ready to call it a day for the range portion and head back to the loading bench.


We began day two with a plan to migrate away from the Docter sight and begin focusing on shooting the “chosen” loads with express sights. This picture should be interpreted starting with the first bullet hole on the far right as it depicts a point of impact to the right of the point of aim (bulls eye, center mass). We then drifted the rear sight a slight bit and fired another round. You can see the impact move left with each subsequent shot/adjustment. The two shots on the far left (vertical string) represent a little too much drifting of the rear sight.


We covered up the shot in the orange, adjusted the rear sight ever so slightly back to the right and shot one more round for good measure. Perfect! Just a tad to the right of center mass.


After a lot of work at the loading bench and on the range, the end result…. Two well placed 577NE rounds in the 3” bulls eye at 100 yards with express sights. I’d say I’m ready for buffalo in Australia!


A few rounds loaded in preparation for Australia.

Awesome. Good load workup and nice easy to see targets!

Will you hunt with the Dr optic or just open sights?

Good luck on the hunt.

Cheers, Chris

I will hunt with open sights. I used the Docter optic at 50 yards to see which loads grouped the best. Once we had a solid load and adjusted the express sights at 50 yes I removed the optic and shot express sights at 100yds. The optic is amazing and IMHO a great advantage, I'd rather shoot my double old school as long as I can. I'm sure there will be a day when the eyes give way and I put the optic on.

Safari James,

Good choice to use express sights. I had a Doctor on my 577 to do load development also but after about 8 to 10 shot it went nutts. I know others have had good luck with them on big bores but it didn't last long on my gun. I have the same set up you have so maybe it was just a bad optic. Kinda glad it didn't work because I was starting to like it. Sin to put an optic on a double. I use a peep sight now because my eyes just can't see the express sights without glasses. You really should try the CEB 600 gr Raptor and 650 gr solid in your 577. You can have much higher velocities and same penetration as the 750s with a lot less recoil. My Heym shoots them into one hole at 50 yds if I do my part.

Sam

Now that's what I call good work. Fine job and good luck on your hunt.

Srose: my rifle did not like banded bullets for whatever reason.

What velocity did you get banded bullets to?

That's good shooting at 50-yards... much less 100!

Good report James. Now for the Buff report. With that doctor sight I thought you may have quit drinking your coffee black as well! LOL

Also, this caliber can be loaded with birdshot for
driven birds - English Gentleman style!!!


{I'm a HUGE FAN of the 577 NE and I hope you
enjoy it with your friends and family decade
after decade! }