25×47 Mystery Solved: Precision Load Development

John and I took my new 25×47 build and turned it into a tack driver! Our initial sight-in results were disappointing, but after unlocking its potential, this may be possibly our best PRS build to date. In this video we walk through how we did it. Follow along as we work up some loads, gather some data, and test until we land on the winner.

Disclaimer

Ultimate Reloader LLC / Making with Metal Disclaimer: (by reading this article and/or watching video content you accept these terms). The content on this website (including videos, articles, ammunition reloading data, technical articles, gunsmithing and other information) is for demonstration purposes only. Do not attempt any of the processes or procedures shown or described on this website. All gunsmithing procedures should be carried out by a qualified and licensed gunsmith at their own risk. Do not attempt to repair or modify any firearms based on information on this website. Ultimate Reloader, LLC and Making With Metal can not be held liable for property or personal damage due to viewers/readers of this website performing activities, procedures, techniques, or practices described in whole or part on this website. By accepting these terms, you agree that you alone are solely responsible for your own safety and property as it pertains to activities, procedures, techniques, or practices described in whole or part on this website.

About the Build

My recent 25×47 Lapua build centers around a BAT Hammerhead short-action and a Custom Rifle Barrels (CRB) 28” 1:7.5” .25 caliber blank I chambered on my PM-1440GT-VS with an Alpha Legacy reamer.

This combination rests in a Foundation Samson with new natural, soft-touch finish, complete with Hawkins Precision M5 DBM, a TriggerTech Diamond Trigger and an Element Theos in the new Hawkins TM one-piece mount.

More and more precision rifle competitors are turning to the 25 caliber, as evidenced by Cal Zant’s “What the Pros Use” on the Precision Rifle Blog.

Load Development and 100-Yard Results

As a wildcat, there isn’t as much data available for this cartridge as there is for others. There are, however, dedicated die sets including the Redding premium set we used.

(Do NOT use our load data, always work up from safe, minimum loads and seek multiple sources of legitimate reference data.)

I started with headstamped 25×47 Lapua brass from Alpha Munitions, eliminating the need to neck cases down, and opted for a bullet that had performed well in my previous 25-caliber builds: the Blackjack 131-Grain ACE.

Five-shot groups at 100 yards with this bullet and H4350 measured approximately ¾ inch.

Discouraged by these results and tired of trial and error, I was grateful to welcome F-Class John to the case. He and I inventoried all possible bullets we could use that we had on hand and John reached out to his friend Jonathan Thronton, a high-level PRS competitor, for advice. We set aside the Blackjack bullets and the hunting bullets we found to focus on Berger .25 Caliber 135-Grain Long Range Hybrid Target Bullets and Hornady 138-Grain A-Tip’s.

Jonathan has significant experience loading for and shooting the 25×47 Lapua and was able to fast-track us, recommending 38.0 grains of H4350 and the Berger 135-Grain Long Range Hybrid Target bullet. He had no personal experience with the 138-Grain A-Tips. John and Jonathan looked up a min and max load for the A-Tips and decided to proceed with a big bracket. John loaded and tested in one-grain increments, not finding anything that was up to his standards. The goal is to have all bullets touching at 100 yards under ½ minute. The Berger 135’s shot well with the suggested load, but there was still room for improvement with my rifle.

John reached back out to Jonathan with the Berger results and chronograph data, who immediately recommended upping the charge 0.5 grains to 38.5 grains. He was absolutely right and we were grateful for the assistance!

I fired a 0.331” five-shot group with Berger 135’s, just edging out John’s 0.333” group with the same load. The SD for this second load was a very small 4.6 fps with an average velocity of 2775 fps.

One of my personal tricks when looking for good groups is to change the tune of the rifle by swapping out muzzle devices.

We also tried this, but documented much better results with the ACE Max brake than a suppressor.

I asked John how he would approach the A-Tip 25×47 Lapua loading dilemma from an F-Class perspective with the goal of wasting as few components as possible. He shared that the sizes and shapes of the previous groups indicated that we needed to slow the bullet down. (In his experience, heavier bullets tend to stabilize at lower speeds.) We tried 40.0 and 40.5 grains of H4350, and saw some improvement. The 40.0-grain load three-shot group measured 0.581” at 100 yards while the 40.5-grain load shrunk to a very round 0.286” with an SD of 0.7 fps!

John wasn’t fully content with the very wide 40.0-grain group and didn’t fully trust the stability of a cloverleaf group.

With the goal of stacking bullets in mind, John moved the bracket to try 40.1-grains and 40.4-grains. At this point, John explained he wanted to see if either side of the bracket showed a larger improvement. 40.1-grains returned a vertical group with more stacking than the 40.4-grain load.

He decided to come up to 40.2 grains and test the other side of the cloverleaf. F-Class John, Serena Juchnowski (Serena Shoots), and I all headed up to the 100-yard range to take advantage of the last remaining light. Though Serena has worked for Ultimate Reloader for four years and visited several times, she had never had the opportunity to shoot a rifle I had built.

Sitting down with the 25×47 Lapua she had watched come together the day before, she stacked five shots into an impressive 0.231” group with John’s 40.2-grain load. Average velocity was 2855 fps with an SD of 8.1 fps.

As John expected, the group blew open on the other side of the cloverleaf with 40.6 grains of H4350.

This test perfectly demonstrates just how much a small powder increment change can affect precision. If we had chosen larger brackets, we would have missed the amazing 40.2-grain load!

Ridgeline Shooting

From here we braved snow and cold to shoot on the ridgeline, starting with a nearly-impossible-to-see IPSC at 660 yards.

We used a bipod and the Creedmoor Sports Soup Can bag, which made for a very stable platform.

John and I both hammered the target before moving on to Harold at 1390 yards.

I managed three subsequent impacts on the white-spottled Harold in a near-whiteout. We all cheered when we saw the Caldwell Flash Bangs flash green through the snow!

F-Class John and Serena also had successful hits, but it was difficult to keep up with wind changes as we couldn’t see our misses.

The ACE Max brake and Micarta Samson nearly eliminated recoil, so it would have been easy to see hits and misses through the scope if it weren’t for the blizzard.

John and I also did some positional shooting off a stump using the Creedmoor Sports freezer bag.

Conclusion

We spent approximately half a day working on load development for this rifle, but were very happy with the end results. Part of the reason I chose the wildcat 25×47 Lapua was because Alpha Munitions produces consistent, headstamped brass for it. (Be sure to check out our high-pressure experiments with Alpha brass, but do not try them at home!)

It was wonderful to be able to collaborate on this project with F-Class John and to be able to share the experience of shooting a newly-built rifle with my team.