Load Development 25-06 berger 115, 26"barrel

[Cal1980]

Hello guys, I am new to LRH and have been checking out the threads for a long time and it inspired me to rebuild an 1972 savaged passed down from my uncle. After 3 years of saving, reading LRH threads I am finally done, purchased a reloader and trying to develope a load for my rifle. I am shooting a 1972 savage 25-06, 26" krieger eavy sporter 1/10 twist barrel, vias muzzel break. I started with seating just far enough off the lands I couldn't see marks on a smoked bullet. @ 100 yards Using retumbo in .5 grain increments I started with 57.5 grains and stopped with 60.5 grains (no pressure signs). After shooting the test loads I am having trouble determining what load I should focus on because they look similar in group size. This is my 1st time doing any of this and looking for advice from some of you pros on dialing this rifle in.

Thanks,
Caleb

 

[MudRunner2005]

Welcome to LRH. I have found Retumbo to be a very temperamental powder in several of my rifles. I also think Retumbo is a bit too slow for the '06 sized cases (personal opinion). I use 7828 SSC in my .25-06 AI pushing the 115 Bergers. It seems to be a better suited powder for the '06 based cartridges, from my experiences.

Also, I seat almost all my Berger at .015" off the lands. I get my distance to the lands using a comparator and a cartridge length tool that uses modified case gauges.

 

[Plinker147]

Looks like your two top groups have same point of impact with no verticals stringing. I can't read the powered charges but looks like a node to work with. The 60 gr load has some verticals but 60.5 looks like it come together as has some of the same point of impact on vertical as 60. Might be something to work with. I would work with the two top loads and see if you can fine tune. Good problem to have when all groups are looking good

 

[Dosh]

1980, three groups look good, but the 60.5 is very nice. My son and a couple of my friends have 25-06 and all have improved their accuracy with Retumbo using the Berger 115. There are some threads on this forum on the use of Retumbo in 25-06 and on other forums also. As a bonus Retumbo is insensitive to temps and is on the shelf at most stores. Perhaps if you go .2 - .3gr increments you may squeeze a bit more out of it. Welcome and good luck.

 

[dsculley]

If I am reading the charges correctly (top 2 at 57.5 & 58) there is a wide node there to work with. I would bet that the flier to the left on 57.5 and the high flier on 58 are shooter induced (not questioning your ability, just my guess - the other shots grouped too closely for me to believe otherwise). After the 58 gr charge, point of impact starts changing, By 59 gr it appears you are into a scatter node which points to another good node near 60 Gr. If you look at your target, as was stated earlier the 60 & 60.5 have very similar points of impact.

With all that said, if it were me I would test the 60 - 60.5 gr area and see what I have. Hodgdon shows 60.5 as max but you said you showed no pressure signs at 60.5. I would probably shoot 60, 60.3, 60.5/60.6. I will check my Berger manual tonight and see what it shows as max. Of course, I would watch closely for signs of pressure. It would also help if you could shoot these over a chronograph, primarily to use MV as a sign of pressure. Of course, the other data from the chronograph would help to, especially SD of each charge.

FWIW

 

[Cal1980]

Welcome to LRH. I have found Retumbo to be a very temperamental powder in several of my rifles. I also think Retumbo is a bit too slow for the '06 sized cases (personal opinion). I use 7828 SSC in my .25-06 AI pushing the 115 Bergers. It seems to be a better suited powder for the '06 based cartridges, from my experiences.

Also, I seat almost all my Berger at .015" off the lands. I get my distance to the lands using a comparator and a cartridge length tool that uses modified case gauges.

Mudrunner, Have you noticed any temperature sensitivity with the 7828 SSC? Reason I ask is this rifle is my one and only at the time and I plan to to hunt deer and yotes with it here in the midwest and also use it for the mules-proghorn-and elk in colorado. My concern is accuracy consistancy in the different temperature / elevation enviroments.

 

[Cal1980]

If I am reading the charges correctly (top 2 at 57.5 & 58) there is a wide node there to work with. I would bet that the flier to the left on 57.5 and the high flier on 58 are shooter induced (not questioning your ability, just my guess - the other shots grouped too closely for me to believe otherwise). After the 58 gr charge, point of impact starts changing, By 59 gr it appears you are into a scatter node which points to another good node near 60 Gr. If you look at your target, as was stated earlier the 60 & 60.5 have very similar points of impact.

With all that said, if it were me I would test the 60 - 60.5 gr area and see what I have. Hodgdon shows 60.5 as max but you said you showed no pressure signs at 60.5. I would probably shoot 60, 60.3, 60.5/60.6. I will check my Berger manual tonight and see what it shows as max. Of course, I would watch closely for signs of pressure. It would also help if you could shoot these over a chronograph, primarily to use MV as a sign of pressure. Of course, the other data from the chronograph would help to, especially SD of each charge.

FWIW

Man all of you guys are awesome! Thank you for all of your input!

DSculley, You are correct.

Top target: L 57.5gr, R 58gr, M 58.5gr
Middle Target L 59gr, R 59.5gr
bottom target L 60gr, R 60.5gr

I will do as you suggest. I purchased a pro chrono still in the box. As stated all of this is my 1st go at any of it. Up until now the rifle was a stock 30/06 youth model and shooting amo off the shelf getting 3" groups @ 100yards. I am by no means a seasoned "crack shot" marksman so I am sure there could be some error on my part. However, I have been trying my best to learn from you guys reading all the threads. What velocity threshold should I be aware of when i start going over max load suggested? SAMMI is calling out 63,000 CUP but I have no idea how to translate that from velocity.

 

[MudRunner2005]

Mudrunner, Have you noticed any temperature sensitivity with the 7828 SSC? Reason I ask is this rifle is my one and only at the time and I plan to to hunt deer and yotes with it here in the midwest and also use it for the mules-proghorn-and elk in colorado. My concern is accuracy consistancy in the different temperature / elevation enviroments.

I have not noticed much, if any, but I primarily do load development during the wintertime, so the loads will perform the best during hunting season.

I have shot it during the spring and fall, and have not noticed any real difference.

I'm sure if it was during the middle of the summer, the loads might be a bit hot from the ones shot during the wintertime, but you can always load a summer and wintertime load and compare the 2 for differences for yourself.

If you are concerned about temp sensitivity, try IMR 7977. It is an Enduron powder, similar to Hodgdon's "eXtreme" powders that are supposed to be non temp sensitive. 7977 is slightly slower than 7828, and is right next to H1000 on the burn chart. So, that might be another viable option for you.

I have 7977, as well, but have not had the time to try it yet.

 

[cape cove]

In my 25/06 I've always had great accuracy with IMR 4831 and the Sierra 117gr SBT The 115 Berger has also been good with this powder. As for primers the CCI 250 has been good for me

 

[dsculley]

I looked up your load in the Berger Manual. They show 60.5 gr as the max as well, but in this manual I saw why. You are limited by case capacity. Since the higher loads are compressed, you may get better results if you have some way to vibrate the cases after you dump the charge in. My 6.5x47 load is compressed and I recently tested rounds that had been packed by placing them in my sonic cleaner for 5 minutes versus those that had received no treatment. There was a noticeable difference in the results. Those that were packed/settled in the sonic cleaner shot 3/4" at 200 yds and those that were not shot 1.5" at 200 yds. These two groups were shot before the wind picked up. After that, there was horizontal stringing due to wind (I made no correction for wind), but vertical stayed pretty much the same.

By the way, it may have been accidental but you chose a safe powder to start with. You pretty much can't pack enough powder in to produce an overcharge. Just don't try to compress too much powder. It has been said that nasty things can happen with compressed loads when you add just a little too much powder. Apparently the compression affects the burn rate and causes pressure spikes. I have never seen this, and don't want to.

Good Luck,

 

[Cal1980]

I have not noticed much, if any, but I primarily do load development during the wintertime, so the loads will perform the best during hunting season.

I have shot it during the spring and fall, and have not noticed any real difference.

I'm sure if it was during the middle of the summer, the loads might be a bit hot from the ones shot during the wintertime, but you can always load a summer and wintertime load and compare the 2 for differences for yourself.

If you are concerned about temp sensitivity, try IMR 7977. It is an Enduron powder, similar to Hodgdon's "eXtreme" powders that are supposed to be non temp sensitive. 7977 is slightly slower than 7828, and is right next to H1000 on the burn chart. So, that might be another viable option for you.

I have 7977, as well, but have not had the time to try it yet.

Mudrunner

Thanks for the insight! I have some H1000 that I had as a back up incase the retumbo didn't work out. By the sounds of it its pretty close to the same burn rate as what you are using. I will def check out the powders your suggesting! It sounds like you have tried them all and figured it out.

 

[Cal1980]

I looked up your load in the Berger Manual. They show 60.5 gr as the max as well, but in this manual I saw why. You are limited by case capacity. Since the higher loads are compressed, you may get better results if you have some way to vibrate the cases after you dump the charge in. My 6.5x47 load is compressed and I recently tested rounds that had been packed by placing them in my sonic cleaner for 5 minutes versus those that had received no treatment. There was a noticeable difference in the results. Those that were packed/settled in the sonic cleaner shot 3/4" at 200 yds and those that were not shot 1.5" at 200 yds. These two groups were shot before the wind picked up. After that, there was horizontal stringing due to wind (I made no correction for wind), but vertical stayed pretty much the same.

By the way, it may have been accidental but you chose a safe powder to start with. You pretty much can't pack enough powder in to produce an overcharge. Just don't try to compress too much powder. It has been said that nasty things can happen with compressed loads when you add just a little too much powder. Apparently the compression affects the burn rate and causes pressure spikes. I have never seen this, and don't want to.

Good Luck,

dsculley,

Very interesting. My manual said same as yours. I figured I would hear a slight crunch when seating my bullet with the max load but never did. Might be because of my seating depth. I will try the vibration trick and work up by 1/10th grain increments once over 60.5 and post my results. At this stage when I am shooting over the chrono is the main objective to identify velocity consistancy with the load? 6.5x47 leads me to believe you do some bench rest shooting? I have read a many good things about that caliber.

 

[dsculley]

I use the chronograph first to compare my velocity to published velocities. If my velocity starts exceeding published velocities I know that pressure is also higher. That is what I consider my max load. If my powder is a "hotter" lot, this could occur before I reach published max loads. It is just a "reasonableness/safety check" for the charges.

The statistical data from the chronograph is very useful as well. To get really good data, you need more than 3 shots per load, preferably 10 or more. But the data from 3 - 5 shots during load development is useful. Some guys really only look at Extreme Spread, unfortunately that number only applies to that population. If you take Standard Deviation and multiply that by 6, you get the extreme spread you can expect for that load with those components loaded with the same care that did those loads.

Your best data will come after you have selected a load and go to the range to prove that load. I will take 20 - 50 rounds to the range to prove a load. If you can chronograph that many rounds you can get good data. The data will include any affects as the temperature changes during the day, barrel heat, etc. You will then have a good set of data for the selected load and your loading procedures.

FWIW

 

[MudRunner2005]

Mudrunner

Thanks for the insight! I have some H1000 that I had as a back up incase the retumbo didn't work out. By the sounds of it its pretty close to the same burn rate as what you are using. I will def check out the powders your suggesting! It sounds like you have tried them all and figured it out.

Far from that man, I've nowhere near tried them all. Just a whole bunch of research, studying, and personal experience.