25/06

Curious about reloading with lead cast projectiles in a 25/06 but unsure of loads or powders? The following is a blog of my load testing and the results I achieved, warts and all! It’s an ongoing project and one that I will add to over time with various updates, be it powder or alloy mix.

I’ve owned my Ruger  MK77 Model II in 25/06 for near on 20 years, it was my first hunting rifle. I’ve successfully hunted fallow deer, pig, goats and wallabies with the trusty old girl. She is in very good condition and has been well looked after. It is fitted with a Leupold VXI 3-9 and has recently been threaded for a Gunworks suppressor.

The suppressor incorporates an internal muzzle break and has made a massive difference to the rifle.

The suppressor is now an integral part of my reloading, hunting and paper punching.

I had been giving some thought to how well the 25cal would take to lead cast projectiles ever since I began casting for my 308 and 303′s. So when the opportunity for a group buy on the “Cast Boolit Forum” came up I jumped at the chance and got a mold.

I purchased a NOE mold, a 4 cavity mold with the ability to make a flat nose 87gr, a hollow point 116gr and 2 flat nose 120gr projectiles at a time. The quality of the mold was superb.

After a bit of further research,  I found that many cast projectile reloaders made reference to M dies by Lyman as a means to increase their accuracy. The dies are neck expanding dies that flare the neck of the case, it allows the projectile to easily enter the mouth of the case without shaving any of the projectile. A quick call to the guys at reloaders supplies and one was on its way.

Recently I had been on a road trip with Jeff in which we picked up about 300 kg of lead. So from this lot I cooked up a test batch of lead, a mix of wheel weight, Linotype and tin.

I made up a batch of the projectiles,  sized them and Jeff and I  tested them in respects to their hardness.  Now the test showed that the lead I had produced a lead projectile that had a hardness of 10 brinell.

The next step was to set up the dies and work out the load data. The powder that I  am going to first test will be Alliant 2400.

A search on the web initially didn’t give me a lot to work from in the way of reloading data. And let’s be honest here the 25/06 may not be the ideal round to tinker with as it’s designed as a flat shooting fast projectile driven at good sturdy velocities, but its all a learning curve.

So I went back to the basics and checked what was safe and the pressures that I could expect to work to and with. being mindful that the lead alloy mix wasnt super hard.

SAAMI gave the 25/06 a max pressure of 63,000 PSI, roughly 53,000 CUP.

Now the load data that I had for a similar projectile of 112gr gave a range of 23.5 gr – 32 gr with a pressure CUP range of between 31,300 through to 49,000.  So well under max as indicated by SAAMI. But to be honest that wasnt my real concern, that was how much pressure the lead could take. It was going to be what the lead could take that would in the end dictate how this was going to pan out

But my main aim ultimately is to achieve a balance of velocity coupled with uniformed mushrooming effect (due to the lead alloy make up) as well as accuracy.

My test loads would start at 24gr and run at .5 grain increments, my first batch would consist of 3 rounds at 24gr, 24.5gr, 25gr, 25.5gr, 26gr and 26.5gr and be fired at 50 meters.

The round had a coal of 79.66mm or 3.136 inch, the projectile measured 1.004inch and weighed 116. The lube used was Beavergrease Lube and copper gas checks from Blammer from the Cast Boolit forum. The brass was federal brass that was tumbled, sized, trimmed to length, primer pocket squared up and cleaned, the flash whole debured, case neck deburred. I use RCBS full length sizer as well the Lyman M die. The primer is a CCI large rifle primer No 200.

I will post results as I go, but hopefully this will be of use to other 25cal owners.

Warts and all results promised!

Well for this to be of any use to other reloaders I need to show all the results, warts and all!So in order to help people who share the same interest and goals, I will post images and results of all tests, from this you can take what you want and hopefully learn from my trials.

Well today was not the result one would have liked however it was a blessing as it has been a very good lesson in pressure and what the lead could handle.

Have a look at the photos, they show the results of the loads that I made up. They are as I described earlier.

 

It’s not often that my range book reads “Test group 1 24gr, SHOCKING – felt hard on bolt turn, very poor group – no sign of pressure – case extracted fine”  “Test Group 2 24.5gr shocking group again same as above” the rest merely reiterated the general gist of the whole days shooting. BUT when you think about it its possibly the best (alternative) result I could have hoped for!

Whilst I didn’t have the benefit of using a chrono, the loads that I made were travelling in the region of and in excess of 2200fps. The loads that I were shooting were not handling the pressure. A bit of further research indicates that for loads that are traveling around 1800fps an alloy with a hardness of around 12-14 is needed. What I made was just not up to the job….so now we look at the other end of the spectrum 18 – 21 grains.  However the whole exercise was a good graphical way of showing the limits of lead.

One other aspect I could look into later will be the actual depth of the hollow point and how that affects the round, but that’s jumping the gun so to speak, right now im off to the garage to turn off the tumbler, tidy up some primer pockets and set up the bench to carry on tomorrow. The load will be the same as last time but with the following loads 18gr, 18.5gr,  19gr,  19.5gr,  20gr,  20.5gr, and 21gr.

Update

It appears that less is more! the 18gr gave a 1.6 in group the 18.5gr gave  two round side by side then the third round went out to lunch, as with the rest of the loads. But reassuringly they all grew in spread with the increase in powder load. So now I will make 17gr and 17.5gr and test those two loads.  After that, if things are not improving I will play with seating depth and after that then look at another powder! but just for laughs I will run the best group over a chrono just to see what was going on. But at this stage, ADI 2206H looks like the next powder to test!

07/02/12 : Wow have I been slack…. I’m off to the garage later this afternoon and dust of the 25 cal dies. After some further research, readings and playing with Alliant 2400 in other cal’s im going to make up some test loads in and around 14grs and see whats happening there. I think ive been pushing the projectile way too hard.  I’m not giving up on the 2400 just yet. It has had some extremely promising results in my .303, not saying that it will automatically work in my 25 cal, but its worth exploring!

I will also have to see how many projectiles I have, I am not exactly sure how many 116gr hp projectiles are left. I may have to use my 120′s?  That will be no real major problem as It will still give me some data and results to work from any way.

Well, as fortune would have it, I had enough to do 13, 14, 15 and 16gr with one spare. That went soon as I didn’t check my seating die which was seriously out. After re-reading this blog im going to be interested in the velocity and expansion of the projectile that this range of powder is going to produce. It will also be interesting what can be achieved with heat treating the lead to make it harder and if I can push it a bit harder?