6.5x55 SE Sanity Check

Hi, I just getting started loading for a 6.5x55 SE but I'm having doubts about some of the load data.

I will be using 129gr Interlock SP to start with and ADI AR2209 and AR2213SC powder.

The problem is determining a maximum load. Looking at ADI's data, it's significantly under pressure. ADI list maximum pressure as 46,000CUP (~51,000psi). CIP list the maximum pressure as 55,1100psi, an 8% increase.
ADI 129gr Interlock SP:
2209 45.5gr
2213SC 48.5gr

For comparison sake I had a look at Alliant's Reloader 19 and 22 data. For the commercial action the maximum pressure is listed at 58,000psi (+13.7%).
Alliant 120gr Speer SP:
RL19 @ 51,000psi 41gr
RL19 @ 58,000psi 46gr +12.2%
RL22 @ 51,000psi 42gr
RL22 @ 58,000psi 46gr +9.5%

2209 and RL19 have a similar burn rate as do 2213SC and RL22. Is it sane to think an 8% increase 2209 (49.1gr) and 5% increase to the 2213SC (52.4gr) will result in a pressure around 55,000, but still be below 58,000psi?

Any help would be greatly appreciated.

ADI and a lot of other powder makers/ distributors will quote low loadings because there still exists a lot of older pre 98 mausers. I don't load for a 6.5x55 anymore but when I did the top ADI load was generally the starting point if that helps. What rifle are you loading for?

A modern action Sako. It's more of a question of how high is too high. I don't want to hamstring the cartridge but also don't want to get caught up chasing velocity.

Quote:

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Originally Posted by Magnetite

5% increase to the 2213SC (52.4gr)

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That should be 50.9gr.

I load 46-47 gn of 2209 behind the hornady 129 in my R8 for about 2800 fps. No pressure signs but warmish. Each rifle is different. Find the answer for your rifle load a ladder series from 44 up and look for pressure signs and accuracy nodes.

Chase accuracy not speed, that's what the swede is famed for, anything over 2600 fps will be perfectly adequate for hunting out to 3-400 ydswith that bullet. I use 2206h in my m38 sporterised with 140 gr Sierra gamekings 36 grains and 2550 fps predictable and reliable.

Increase powder charge by 0.5 for each load. Shoot a 3 shot group working your way up, rem bering to let your barrel cool down between groups. Take note of the accuracy, you should hit a sweet spot where your groups tighten up well before you reach any pressure signs.
As said above chase accuracy not speed.

FWIW I use 2209 in my Tikka and my collection of old SE’s. For the modern rifle, a tad under 45 grains behind 143 eldx pills prices 2770 fps with one hole at 100m. 139 Scenar with 41.5 gr of powder produces similar.

In the old rifles, I play with loads between 39 gr to just short of mid 40s. Velocity in the 2200 - 2500 range from memory. You don’t need huge amounts of powder to make this calibre sing.

Quote:

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Originally Posted by Magnetite

Hi, I just getting started loading for a 6.5x55 SE but I'm having doubts about some of the load data.

I will be using 129gr Interlock SP to start with and ADI AR2209 and AR2213SC powder.

The problem is determining a maximum load. Looking at ADI's data, it's significantly under pressure. ADI list maximum pressure as 46,000CUP (~51,000psi). CIP list the maximum pressure as 55,1100psi, an 8% increase.
ADI 129gr Interlock SP:
2209 45.5gr
2213SC 48.5gr

For comparison sake I had a look at Alliant's Reloader 19 and 22 data. For the commercial action the maximum pressure is listed at 58,000psi (+13.7%).
Alliant 120gr Speer SP:
RL19 @ 51,000psi 41gr
RL19 @ 58,000psi 46gr +12.2%
RL22 @ 51,000psi 42gr
RL22 @ 58,000psi 46gr +9.5%

2209 and RL19 have a similar burn rate as do 2213SC and RL22. Is it sane to think an 8% increase 2209 (49.1gr) and 5% increase to the 2213SC (52.4gr) will result in a pressure around 55,000, but still be below 58,000psi?

Any help would be greatly appreciated.

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The Hodgdon data is quite old and current AR2209 is much faster. 45.5 grains of current AR2209 gave me 2805 fps and 46 grains 2,850 fps with the 129 grain in my T3. The higher load appears to be close to or at max to me. Loads with the old AR2209 matched the Hodgdon data. AR2213SC is a bit slow for the 120 and 129 grain but works better with the 140 and 143 grain projectiles. I was using the 129 grain Hornady SST and would not use the above loads with the Nosler AB and especially not with the Barnes projectiles. There is a thread further back discussing the 129 grain loads and I wrote an article for NZ Guns recently dealing with the 120 grain.
As you have discovered the 6.5 x 55 data is all over the map but would suggest that your two suggested loads are far too high. Working up to .260 Remington velocities (a slightly smaller case) would be a good way to go.
Regards Grandpamac.

its a very forgiving case. Step up gradually and it wont give you sudden surprises. Norma brass is softer than Lapua and will stamp mark sooner.

With its high BC and SD it neither needs speed or fancy bullets to perform well.

Thanks for all the replies.

Quote:

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Originally Posted by grandpamac

The Hodgdon data is quite old and current AR2209 is much faster. 45.5 grains of current AR2209 gave me 2805 fps and 46 grains 2,850 fps with the 129 grain in my T3. The higher load appears to be close to or at max to me. Loads with the old AR2209 matched the Hodgdon data. AR2213SC is a bit slow for the 120 and 129 grain but works better with the 140 and 143 grain projectiles. I was using the 129 grain Hornady SST and would not use the above loads with the Nosler AB and especially not with the Barnes projectiles. There is a thread further back discussing the 129 grain loads and I wrote an article for NZ Guns recently dealing with the 120 grain.
As you have discovered the 6.5 x 55 data is all over the map but would suggest that your two suggested loads are far too high. Working up to .260 Remington velocities (a slightly smaller case) would be a good way to go.
Regards Grandpamac.

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Its seems the only place to get up to data data is Alliant and Vihta Vouri. I bought the Hornady 10th edition data and was sorely disappointed. As for ADI/Hodgdon the last update was in 2000.
ADI 1996 129gr:
2209 46gr @ 2800fps w/ 18" barrel
2213 47gr @ 2800fps w/ 18" barrel

ADI 2000 129gr:
2209 45.5gr @ 2703fps w/ 24" barrel
2213SC 48.0gr @ 2689fps w/ 24" barrel

Was this the 129gr thread you were referring to? https://www.nzhuntingandshooting.co....estions-25692/

Would the best bet be running off velocity instead. Killing testing at a maximum velocity of 2900fps w/ 23" barrel for the 129gr provided there are no pressure signs prior?

Also what length barrel is your T3?

Quote:

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Originally Posted by Tahr

Norma brass is softer than Lapua and will stamp mark sooner.

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I'm using once fired Norma (from the same rifle) to start with. Even though it's softer does it make any practical difference?

Just start at adi max data or creep up a little from 260rem data as has been suggested. All will be sweet

I had a look at how pressure and velocity increase in relation to charge weight in both the 260 and 6.5x55. Looks my initial figures where too high. Assuming a linear relationship (I know it's not but there's only two data points) and target pressure of 58,000psi (the same as the 260).
New maximum charges:
2209 47.5gr @ ~2800 w/ 24" barrel
2213SC 50.5gr @ ~2800 w/ 24" barrel

I will be reducing them by 10% and working up in 0.5gr increments.

Sounds about right. What's the rifle? I've a Ruger 260 and a husky 1640 6.5 on the way.

Greetings Magnetite,
I have replied to my own thread so you should find it on page 1 now. Extrapolating from my own results with a standard T3 Lite barrel (570 mm I think) 47.5 grains of AR2209 would give you about 2,900 fps with the 129 grain and is likely too hot. I chronographed 50 grains of AR2213SC behind the 129 grain at 2,800 fps so 50.5 grains should give you about 2,830 fps. The 1996 data you quote appeared in their pamphlet in 1986 and the AR2209 in 1984.
Regards Grandpamac.

I finally found a place to do some testing.

I've only tested the 2209 so far. I stopped at 45.5gr which was doing 2842fps from a 580mm barrel with suppressor. This matches up with the ADI max load and .260 Rem speeds. If anyone's interested here's the results (4 shots each charge):

Grains fps SD ES
42.5 2693 23.3 52
43.0 2726 12.6 28
43.5 2750 10.4 19 (only 3 shots)
44.0 2761 16.8 39
44.5 2780 9.9 24
45.0 2805 9.5 22
45.5 2842 21.8 43

~43.3gr and ~44.8gr will be worth looking at. I'm not sure if it's worthwhile testing lower loads. I didn't get any pressure signs but it seems like testing higher loads would be asking for trouble. Thanks everyone's suggestions.

2209 is a good choice for your bullet and barrel imo. But i would stop at 44.02grains and choose the 143gn eldx for hunting. I kinda dont see the point of light projectiles whatsoever unless your gun hates heavies (like my 243).

If your shooting a tikka I'm getting out standing results with 143 eldx in front of norma brass fed 210m and 44.8 of 2209 validated at 2720.
I cant shoot any better than that load

Sent from my SM-G950F using Tapatalk

Quote:

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Originally Posted by Magnetite

I finally found a place to do some testing.

I've only tested the 2209 so far. I stopped at 45.5gr which was doing 2842fps from a 580mm barrel with suppressor. This matches up with the ADI max load and .260 Rem speeds. If anyone's interested here's the results (4 shots each charge):

Grains fps SD ES
42.5 2693 23.3 52
43.0 2726 12.6 28
43.5 2750 10.4 19 (only 3 shots)
44.0 2761 16.8 39
44.5 2780 9.9 24
45.0 2805 9.5 22
45.5 2842 21.8 43

~43.3gr and ~44.8gr will be worth looking at. I'm not sure if it's worthwhile testing lower loads. I didn't get any pressure signs but it seems like testing higher loads would be asking for trouble. Thanks everyone's suggestions.

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Greetings Magnetite,
Looks like your rifle gives a little more velocity than mine with your selection of components. I note that you are using a suppressor which some suggest gives more velocity so perhaps this is part of it. Low standard deviation and extreme spread don't always result in greater accuracy so testing for accuracy is probably the next step. To me 45 grains and 45.5 grains looks like a good place to start. Your velocity is in line with the .260 Rem so your pressures should be a little lower. John Barsness suggested that the 6.5 x 55 needs about 2 grains more powder to equal the .260 Rem velocity at about the same pressure (probably a little less) so I think you are in safe country with either 45.0 or 45.5 grains of AR2209. I wouldn't bother with the lighter loads. Both the 129 grain Hornady Interlock and SST are pretty soft projectiles so don't run the pressures up as much as some of the harder projectiles, especially the Barnes.
Regards Grandpamac.

I did check the group sizes at 100yards but I don't trust them entirely as the wind was up.

Grains 42.5 43 43.5 44 44.5 45 45.5
Max Spread 1.172 0.988 1.290 1.926 1.337 1.496 1.136
Group Height 0.961 0.985 1.283 1.817 1.108 1.462 0.872
Vertical Offset -0.785 -0.105 -0.529 0.332 -0.325 0.610 -0.249

The plan is as follows:
Work up a load with 2213sc. Shoot best load from 2209 and 2213sc and compare. Then move on to seating depth testing.

I botched some of those numbers. Corrected below:

Grains 42.5 43 43.5 44 44.5 45 45.5
Max Spread 1.172 0.994 1.287 1.926 1.326 1.496 1.135
Height 0.961 0.991 0.648 1.817 1.174 1.462 1.039
Vert Offset -0.785 -0.108 -0.200 0.332 0.318 0.446 0.503
Mean Rad 0.496 0.442 0.580 0.696 0.625 0.506 0.47

Greetings Magnetite,
I tried 49 and 50 grains of AR2213SC behind the 129 grain SST which gave 2,720 and 2,780 fps respectively. You may get a little more. As far as your accuracy figures go you could shoot that string again and get completely different results. For accuracy testing the average of three, three shot groups would give you a better idea.
Regards Grandpamac.

Obligatory disclaimer: What you put in your chamber is your business. Some of these loads are over ADI's maximum.

2213SC powder 4 shots each charge:

Grains fps SD ES
46.0 2475 29.9 63
46.5 2486 34.1 73
47.0 2538 29.3 58
47.5 2570 3.7 8 (Several chrono errors in this group)
48.0 2603 15.6 37
48.5 2632 9.7 23 (ADI Maximum)
49.0 2645 13.3 32
49.5 2677 8.4 19
50.0 2709 10.3 23
50.5 2749 8.3 18
51.0 2769 14.7 34

Attachment 148939

It looks to me that 49.5-50.5gr should be pretty good. The node seems to be a bit wider than the 2209 but you sacrifice 100fps. I didn't see any pressure signs and it's under expected velocities. I not sure what I should call maximum. What's everyone's thoughts on the 2213sc vs 2209 data?

2209 data for easy reading:

Quote:

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Originally Posted by Magnetite

Grains fps SD ES
42.5 2693 23.3 52
43.0 2726 12.6 28
43.5 2750 10.4 19 (only 3 shots)
44.0 2761 16.8 39
44.5 2780 9.9 24
45.0 2805 9.5 22
45.5 2842 21.8 43

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Attachment 148942

I’ve always been a group or ladder shooter when looking for new loads. However following Erik Cortina I would now look more closely at ES to zero in on the node.

Quote:

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Originally Posted by Dicko

I’ve always been a group or ladder shooter when looking for new loads. However following Erik Cortina I would now look more closely at ES to zero in on the node.

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I like Erik's explanations, and I've cobbled together some form of hybrid method. First off I'm assuming Erik is correct with the charge determines the combustion characteristics (ES/SD) and the seating depth determines harmonics. It seems to me when developing a load your either going for precision or stability. Erik is obviously going for precision, where as the ladder/OCW test are looking for stability. I think with the small sample sizes using SD is preferred. If the samples sizes were larger ES would be preferred.

Using the 2209 data as an example:

Having thought about the data some more it looks like the best way to asses the loads for precision is using the mean ±2SD to estimate the ES for a given charge (IIRC 2SD should cover 95% of the probabilities). Initially it looks like 44gr may be good with the best ES of 17fps. However when using SD the estimated ES(eES) is 67fps. Choosing 45gr with the worse ES and tighter SD gives a better eES of 38fps.

Now with searching for stability like the ladder/OCW test, it seems the best assessment is to look at two charges next to each other. To do this I take the mean of the higher charge +2SD and subtract the mean of the lower charge -2SD. This gives attempts to simulate an under charge on a cold day and an over charge on a hot day (I don't know how much variance this will give but I think 0.5gr should be fair). The ladder/ocw method as I understand it would select the flat spot in the curve (either looking at velocity or vertical shift doesn't matter). This is 43.5-44gr. Using the above method this gives a shifted ES(sES) of 67fps. However the SD of 44gr isn't that great. Looking at 44.5-45gr even though it isn't a flat spot the sES is 63fps which is better.

One final caveat is because we are dealing with small sample sizes I think that the chosen charges will need to be verified. I don't know who said it but I tend to agree with: 3 shots with show you a bad charge not necessarily a good one.

As for my selected charges here they are in order of preference:
2209 44.8gr ~2790fps
2209 43.8gr ~2755fps
2213sc 48.8gr ~2640fps
2213sc 50.8gr ~2760fps

An interesting point I noticed there may be a shared node at ~2750fps with both powders.
Also if anyone has a better understanding of statistics please chime in (I'm not a statistician by any stretch of the imagination).
Let me know if this makes sense or is closer to the ramblings of a lunatic.

Magnetite,
Years ago I got a distinction for biometrics. However I am pleased I didn’t read your post last light half gorged on Shiraz!

While I’m not totally sure I followed your path as you walked it it think you arrived at the right place.

If I followed Erik right after testing for ES and in particular two loads a increment apart worth low Ed he then drill into the space just under the higher load to check precision and then works on seating depth if needed.

Stability I think is determined upfront by powder selection? Burn rate and temp stability. All being equal slow burning and higher case fill% more stable. Your experience may differ?

The other powder to try in the Swede with 140s if available is RL22. It can be rocket fuel in some cases. I really like RL powders despite the supposedly greater temp sensitivity.

Quote:

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Originally Posted by Dicko

However I am pleased I didn’t read your post last light half gorged on Shiraz!

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The ancient Persians would debate an idea twice: sober and drunk.

I was combining two ideas with stability. Tolerance to temperature, I think that all powders will be affected by temperature just to what extent will vary. And the other idea is tolerance to charge variation. I intend to throw the charges which hopefully should be ±0.1gr. As for my experience: none. I'm just going off what I've read while I gather my own.

I was planning to try RL19 and RL22 but availability pushed me to ADI. The other nice thing with Alliant is they have data for modern 6.5x55s.

Magnetite,
Sounds like you’re all over it. Between 09, 13sc, 19, 22 and possibly 23/26 and VV 560? ( pm @Thar for his 6.5 Swede loads) you have all the obvious powders for some outstanding loads.

Rl22 at 48.5 behind at 140 SST was a real accurate load in my Rifle.

I got round to some accuracy testing and was surprised at the results. Both were 6 shot groups at 100m. I played around with the seating depth for both powders but settled on using the same for each. Each ring on the target is 1 MOA.

44.8gr 2209, ES: 35mm, 1.2MOA
Attachment 152011

50.8gr 2213SC, ES: 21mm, 0.7MOA
Attachment 152012

Initially thought that 2209 would be the way to go, but needless to say I will be running 2213SC in the future.

Quote:

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Originally Posted by Magnetite

I had a look at how pressure and velocity increase in relation to charge weight in both the 260 and 6.5x55. Looks my initial figures where too high. Assuming a linear relationship (I know it's not but there's only two data points) and target pressure of 58,000psi (the same as the 260).
New maximum charges:
2209 47.5gr @ ~2800 w/ 24" barrel
2213SC 50.5gr @ ~2800 w/ 24" barrel

I will be reducing them by 10% and working up in 0.5gr increments.

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Pressure and velocity do not run hand in hand. A lower velocity load may have higher pressure, or even a pressure spike, for a number of reasons.

I use 44.6 2209 with both 143eldx and Sgk 140 sbt. 0.4- 0.6 moa @ 300m. S&L classic dl.2750fps mv.

Quote:

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Originally Posted by Jhon

Pressure and velocity do not run hand in hand. A lower velocity load may have higher pressure, or even a pressure spike, for a number of reasons.

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Just some clarification on my prior statement. It is specifically referring to two cases with similar volume (<10% difference) running the same powder. Correct me if I'm wrong but unless you have an under fill situation (below book minimum) or are seeing pressure signs the relationship is close to linear. I know there are some powders which are notorious for pressure spikes but I believe 2209 and 2213SC aren't.

PS: Also haven't jammed the bullet into the lands, or compressed the load.

Quote:

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Originally Posted by Woody

I use 44.6 2209 with both 143eldx and Sgk 140 sbt. 0.4- 0.6 moa @ 300m. S&L classic dl.2750fps mv.

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What barrel length?

24"

Quote:

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Originally Posted by Magnetite

Just some clarification on my prior statement. It is specifically referring to two cases with similar volume (<10% difference) running the same powder. Correct me if I'm wrong but unless you have an under fill situation (below book minimum) or are seeing pressure signs the relationship is close to linear. I know there are some powders which are notorious for pressure spikes but I believe 2209 and 2213SC aren't.

PS: Also haven't jammed the bullet into the lands.

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To be honest mate I'm quoting something I learned elsewhere rather than by experience. The point made was that pressure can vary widely and separate to velocity for a number of technical reasons. That is, you cannot rely on an increase in powder that gives a linear increase in velocity to also give a linear increase in pressure. This is the key issue of going beyond published data. If the published data gives a velocity that one would like to improve on, and the indicated pressure is below published max for the cartridge, folk tend to assume a few steps above published load data will increase velocity and pressure at the same relative rates. This is not necessarily the case. While US liability realities might mandate large margins for error, we clearly go beyond published data at our own risk. Without being able to see what happens to pressure there is a real risk of crossing the line if we assume a linear relationship. Of course we still do it. Hopefully with a piece of string operating the trigger lol. I made the comment because I think its important to acknowledge in a forum, where the risk lies. There is no telling who will come along and read a thread and get the wrong end of the stick. Hope you don't mind. Watching with interest. J.

Norma brass.

Quote:

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Originally Posted by Woody

I use 44.6 2209 with both 143eldx and Sgk 140 sbt. 0.4- 0.6 moa @ 300m. S&L classic dl.2750fps mv.

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Same rifle, same accuracy, 140 AMax or Berger or SST, N560, 2840fps
Bloody wonderful.

If it wasn't illegal to only own one gun, this would be my only one.

Quote:

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Originally Posted by Jhon

I made the comment because I think its important to acknowledge in a forum, where the risk lies. There is no telling who will come along and read a thread and get the wrong end of the stick. Hope you don't mind.

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I don't mind at all. Hopefully I have been clear enough (In my first post I mentioned it's over max and again when I posted over max data).

Quote:

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Originally Posted by Jhon

The point made was that pressure can vary widely and separate to velocity for a number of technical reasons. That is, you cannot rely on an increase in powder that gives a linear increase in velocity to also give a linear increase in pressure.

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When venturing past max, my new approach is to cross reference with Gordon's Reloading Tool and data from previous testing. But yes it is very much at your own peril.

I don't know of this helps anyone, but I'm getting an average of 2620 FPS with 129 Hornady interlocks in a 21" barrelled '96 Husky using 46grs of 2209.

Roger