Range Report - .338 WM - Ruger M77, Sauer 90

[gitano]

I'm continuing with this thread and today's range report because it 'closes the loop' on the load workup for the Sauer 90 and 225-grain Accubonds.

You may recall that Accurate 2495 shot the best among the three tested powders of RL-17, I3031, and 2495. You may also recall that I didn't have any H-4831 when I tested the above 3 powders, but I wanted to try it because it had worked well for me in the past. So today I went to the range with 9 rounds: 3 loaded down 0.3 grains from the previous "good" charge of 2495; 3 loaded up 0.3 grains from the previous "good" charge of 2495; and 3 rounds loaded to the 'right' timing with H-4831. I was pleasantly surprised.

Here is the H4831 load:


Vertical spread is 0.93". Horizontal spread is 0.468". Euclidean max (max spread) - 0.935". I like it.

Here is the group from the "high" load (+0.3 grains) of the 2495:


Vertical spread is 2.16". Horizontal spread is 0.563". Euclidean max is 2.164". Not good.

Here is the group from the "low" load (-0.3 grains) of the 2495:


Vertical spread is 0.67". Horizonal spread is 0.14". Euclidean max is 0.67". Now THAT I LIKE! There's the load!

That is the charge I will put behind a box of 225 Accubonds to be shot from the Sauer 90. :D

Paul

[sakorick]

Whew! For awhile there, I was thinking.......oh never mind. My Dad told me not to try to think when I wasn't used to it! That 4831 load looks real good H4831.......yes? Did you Chrony that load?

[farmboy]

Now that this is setup for all to see and I know we all get this but it always surprise s me how much the group size can change with so little powder difference. Basically a two inch group to a half inch group with less than one percent change in powder charge.

[gitano]

Yeah, Rick, it's Hodgdon's 4831. I had planned to use the chronograph today, but I was "shooting for group", and didn't want it nagging the back of my brain with "I wonder if the chrony effected the group size".  Next range session I'm going to just get it "on target" (it's still too high and just a skosh left of where I want it to be), and I will chrony then. QuickLOAD puts that H4831 load (70.0 grains) at 2675 f/s. I'd bet good money it was within 50 f/s of that figure.

The "high" charge (56.3 grains) of Accurate 2495 produces the highest pressure (57,544 PSI) of all of the charges, but has the lowest case capacity (87%) and burns 100% in the barrel after only 9.3" of bullet travel. H4831 is relatively "low pressure" at 53,982 PSI, but it's already at 105% of case capacity. There's no going "up".

The "properly timed" RL-17 load has REALY low pressure at 49,765 PSI and filled only 93% of the case. But... I 'liked' the way the 2495 shot. Today's "-0.3grains down" group is the smallest I have fired with this rifle. It's pressure is theoretically 55,800 PSI and the MV is supposed to be 2616 f/s. That's only 10 f/s off the "ideal" I was trying to get of 2625 f/s retaining 2000 ft-lbs at 300 yd with an impact velocity of 2000 f/s and has a total vertical deflection of less than 12". The 2616 muzzle velocity retains 1987 ft-lbs at 300 yd, has an impact velocity of 1994 f/s, and has a total vertical deflection of 12.3". Close enough when it shoots 0.68 MoA. :D

You're right, farmboy. Personally, I attribute a bunch of that to the 'timing', but in the end, the cause isn't as important as the group size! The original charge was 56.0 grains. I went down to 55.7 grains and up to 56.3 grains. The total distance between the high and low charges was 0.6 grains, or 1.1%.

Paul

[gitano]

Interesting to me how the maximum dispersion with 2495 is always in the vertical dimension. Even in the "bad" group above, the horizontal spread is only half a MoA. That is not true for I3031 though, in which the max spread is in the horizontal. For RL-17, neither direction is significantly different from the other. I'll have to think about that. A sample size of 3 for the H4831 is too small to draw conclusions from.

Paul

PS - After some thought:
Since the  rifle is capable of very small horizontal dispersion, AND since the total dispersion (combined vertical and horizontal), is very small - 0.67 MoA - part of the increased vertical dispersion could be due to changes in MV.

Paul

[gitano]

For those interested:

The initial load for Accurate 2495 was 56.0 grains. The overall length was 3.345". The estimated muzzle velocity was 2627 f/s. The estimated max chamber pressure was 56,657 PSI. The bullet's estimated time to exit the barrel was 1.274 milliseconds.

The "Final" load is 55.7 grains. The overall length remains the same. The estimated muzzle velocity is 2616 f/s. The estimated max chamber pressure is 55,798 PSI. The bullet's estimated time to ext the barrel is 1.283 milliseconds. (That's 9 microseconds or 9 MILLIONTH of a second slower than the 56.0 grain charge. So fairly 'close'.)

When I get measured muzzle velocity values I'll post a trajectory table based on the average.

Paul

[gitano]

What's wrong in this picture?


Paul

[gitano]

I'm sure many would see it PDQ, but I don't want to wait for responses so...

Notice a case head to the left of the die and a close look in the die reveals the ragged edge of a headless case. This head just "popped" off, leaving the case body in the die. Grrr...

Here's the 'strange' thing; This is a "Neck Only" (NO) sizing die. I wondered if the Sauer could handle neck only resizing so I tried one case, and it chambered fine. :huh: So I continued with the Redding NO decapper/neck sizer. About the 5th case, this happened. So I wrestled around a bit with it. Then I went to YouTube looking for a BROKEN case remover. There are lotsa folks posting on YouTube that don't know the difference between a "stuck" case and a "broken" case. Potterfield has a video about removing a broken case from a single shot rifle using CerroSafe. I didn't want to go to all that trouble.

I knew that I would need to "get something in there and expand it", but I really didn't want to make a broken case extractor unless there was no other option. I thought maybe I could 'tap' the case body and pull it out so I got my SAE tap and die set out and looked for a tap that would fit inside the case but not hit the walls of the die. The 1/2-20 die was the one I finally settled on.

Being very  careful to get it started properly, I slowly cut some inside threads on the case, watching closely that I never touched the side of the die. There wasn't much 'meat' between the OD of the tap and the OD of the case and ID of the die. I got 8 threads in before I felt 'that was far enough'.


Pulling on the tap didn't work, primarily because there really isn't anything to 'grab onto' on the end of the tap. It was becoming clear that I was going to have to screw something with a 'head' on it into the case. I hadn't looked at the size of the tap before I started using it, I had just found one that 'fit'. If I was going to have to look for a bolt in my shop or worse yet, go buy one, I needed to know the thread dimensions I had just cut. Turned out they were 1/2-20 - half inch/20 threads per inch. I was pretty sure I didn't have anything like that on hand. :lipsrsealed:

I futs'd around for a bit looking for something that might work, but there really wasn't anything. DRAT! So I started to reassemble the die so that I wouldn't misplace any pieces until I got a 1/2-20 bolt. As I was screwing the decapping stem back in the top of the die it occurred to me that its threads looked a lot like 1/2-20. Hmm... I unscrewed what I had screwed in, unscrewed the expander ball, inserted it into the case and gave a twist. It fit. I screwed it all the way in and tugged on it. The case didn't budge. I needed more leverage or more muscle. Since the geometry of things limited the leverage, 'muscle' was the only option left. (Leverage IS "muscle", but when I say "muscle", I mean directly applied force, not indirectly applied force.)

I screwed the expander ball back on the stem that was now sticking out of the TOP of the die. Once tightly on, I took a brass drift punch and 'hammered' the decapping rod. The case came out 'easily' wit a couple of taps.




You can see the squarish expander ball. That made it easy to use a punch to apply 'muscle'. You can also see the threads telegraphed through the case. Like I said, there wasn't much meat left beyond the diameter of the tap. One can feel the 'ridges', but no marks on the die walls.

So, "all's well that ends well" - sorta. There are a couple of 'things' to note here:
1) This was a NECK sizing die. WHY did the BODY of the case get stuck, and sufficiently stuck so as to require "pounding" to extract?
2) Why does a "neck only" (at least in name) sized case chamber in the Sauer chamber when I had so much trouble before with full length resized cases?
3) When one of these cases is chambered with the muzzle of the rifle pointed down - below horizontal - it chambers fine. When attempting to chamber the same case with the muzzle pointed up - significantly above horizontal - IT WILL NOT CHAMBER.

That's a problem, and it's not a "case" or "headspace" problem. It's a bolt problem. I'm going to have to take the bolt apart and see what's going on. Sumpin' ain't right. I'm thinking the "headspace" issue isn't an issue. Setting the shoulder back too far (so the case can chamber) has the effect of causing premature head separation. Exactly what has happened.

I'll report more on the subject when I have more to report. At this point, all of the resized cases chamber (with the muzzle pointed down), and I will prime them, charge them, and seat bullets tomorrow.

Paul

[farmboy]

Good thinking. How many times has that brass. Been reloaded? What brand? You might want to have a really close look at that whole lot of brass.

[gitano]

I think these pieces have only been reloaded 3 times. Maybe 4. I strongly suspect that the shoulder is being set back too far with the resizing die. There is one other case showing signs of impending head separation. Honestly, as long as I don't get a case stuck in a CHAMBER because the head pulls off, I don't really care about head separations. They are NOT the "danger" that too many people have been lead to believe. By the same token, if you pull the head off of a case in the field - and especially the 'remote' field - you are outta luck and out of a rifle 'til you get 'back'. However, since these loads are not even "warm", it is unlikely that a case body would get stuck in a chamber even if the head comes off. In other words, I'm not worried about it.

Head separation isn't a brass issue, it's a rifle (headspace) and die set-up (shoulder set-back) issue.

Paul

[farmboy]

This is the nub of the tight spec issue. In my opinion you almost need to treat your 338 ammo like two different calibre s because of the resizing differences. I may be wrong but you might want to start with a different lot of brass that you use in the 90 and use the ones you have in your ruger a total pain. If it was me I would want different head stamps or brass and nickel so I would not get mixed up.  The problem then becomes you are then doing what I said before you are basically loading for two calibre s so to speak.

[gitano]

For all other rifles I own of the same caliber (mostly chambered in .308 Win), what you suggest above is required. However, that's not the case between the Sauer and the Ruger. I can put shells back and forth between the two. I cannot do that with ANY other pair (or more) of similarly-chambered rifles I own. I think what I am going to do for the time being is keep the 225 Hornadys loaded for the Ruger and keep the 225 Accubonds loaded for the Sauer. I loaded 25 of the Accubonds today. Usually I don't bother noting brass 'type'. For the most part, after the first firing there isn't too much difference between manufacturers. I noticed that among the brass I have been using in the Sauer there are two headstamps - Remington Peters and Federal. After all were reloaded I weighed every cartridge to the hundredth of a grain. The max spread was 4 grains including both types. Within types, the max spread was 2 grains. That's pretty good and pretty close for fully loaded cartridges. Next time at the range I will get MVs.

Paul

[farmboy]

Are you going to load for the sauer with the shoulder set back more than the ammo you load for the ruger?

[gitano]

It is important to note that I do not "neck only" resize any of my cartridges any more. I did not find that technique to produce more precise ammo and it certainly meant I had to 'watch' what ammo went with what rifle. Tomorrow, I will fire one cartridge from each rifle and swap them back and forth. There is no doubt that full-length resized cartridges fit both rifles. No surprise there, and that's the point of no longer neck-only sizing. I will measure the cases before and after firing, and see if there is significant 'growth' in either one.

News at 11.

Paul

[farmboy]

I have never neck sized I have thought about it over the years but never bought a die to try it. I always thought and may very well be wrong here, that was a practice for loading bolt guns. Thought it would not work to well in a falling block. Not to say all my rifles are falling blocks but I have a group of them that are as well as levers. The only place I see a little tighter groups being handy are on the varmint rifle s. A lot of people will find my method of reloading wrong but I will say here what I have done. I start with a bullet I want to load look up loads in a half a dozen manuals and get a range of powder charges. I load one at each step of powder charge. I look for pressure signs. If I get to the top before load and I am happy with what the primer looks like I load five and shoot a group. If I am happy I just stay with that load if not I try less powder and shoot another group. The easiest load development I ever did was that method and my 17 REM the first group I shot was at 5/8 of an inch extreme spread. Good enough I never tried anything else I just loaded that way and shot varmints. I recently have been looking at tested pressures with different powders for a given speed if two powders give about the same muzzle velocity I try the powder first with the lower pressure. I have been loading 223s with h414 lately I have the vtr shooting the best it has so far with a load of 414 with a 55 grain bullet. Still not a hundred percent happy though I want smaller groups. I bought some heavy bullets that I am going to try next. That rifle has a fast twist and I am thinking heavier bullets may shoot better it hates 50 grain bullets. Back on topic looking forward to your field test result s.