Interesting results from die comparison

[tddeangelo]

Talking with Scotty, I got to wondering if my Hornady dies for me 300WSM might not be part of what the rifle has seemed to elude shooting truly consistent, good, groups for me. It has, to date, shot an exceptional group, but then mediocre groups when trying to confirm that the load that shot so well would do so again.

Case in point.... I worked on a load of 68.0gr RL19 under a 180gr PT, OAL set to 2.890". Initial run gave me a group somewhere around a 1/2" and I was thrilled. Subsequent groups to verify printed more like 1.2"-1.5". This has been the story with this rifle since I got it.

So, with the Cabela's near me running a sale for 15% off RCBS dies, I got a new set of RCBS dies for the 300WSM and decided to run a little experiment.

First the data, then the target pic.

Actually, let me give the setup first. I used the load mentioned above.... 68.0gr RL19, 180gr PT, and OAL of 2.890". I used Federal 215 primers out of the same pack. I used Nosler brass out of the same age/number of loadings batch. Trim length was set to the same (I forget it offhand, but I measured them to be sure of consistency).

I full-length sized 6 brass, primed them, and loaded that load, all done on the RCBS dies. I used a Sharpie to record load data and which die maker's set was used, and I did this on the case itself to avoid confusion.

I then did the same for 6 more cases, using the Hornady dies.

I use an old Lyman beam scale, which I verified/reset to zero every three charges.

I measured EVERY round for OAL and they were consistent.

Yesterday, I went to the range. I fired all 12 in groups of three, allowing the barrel to return to (to my touch at least) ambient temp before firing another group. I also ran all rounds over the chrono.

Results of two groups of 3 per die maker:

RCBS- Ave. Velocity = 2919fps, group size average = 0.975 (including a called pulled shot). Vel spread = 13 fps

Hornady- Ave. Velocity = 2874, group size average = 1.25 (including all shots, no called pulled shots), Vel spread = 44fps.

Granted, I would need a LOT more data to conclusively prove anything, but this was really surprising and eye-opening data for me. The marked increase in consistency in velocity was interesting.

Target pic:

I shot the RCBS loads on Dots #1 and 3, Hornady on 5 and 7. Of interest....Hornady produced the smallest group AND the largest, but that's the kind of thing I've been seeing from this setup. RCBS produced two decent groups, with #3 having the called pulled shot (left, high). Even so, it wasn't pulled hard or far, and to keep from potentially "rationalizing" that shot away, lol, I included it in the data.

For those curious, Dots 2, 4, and 6 were shot with my 300H&H, decreasing OAL by a quarter turn on the seating stem on the die. Looks like Dot 4 has the best "compromise" there, with that group measuring a touch over an inch. I still have work to do on that rifle, though. The bolt lifted hard on the last portion of the lift, which that rifle does just in general, but it shouldn't be THAT difficult to open the bolt, and I was not thrilled with how it was. It seems this rifle gets that issue very quickly and well before max charges are reached. Even so, that was moving a 200gr AB at 2700, which isn't shabby.

I may restart the whole process with the same 180PT I'm using in the 300WSM. Makes bullet stocking a lot easier for me if they both run the same thing, anyway, and that might give me a better experience with that rifle. At any rate, there's work to be done there yet.

The torn-off section was not me hiding bad groups, lol...that was my dad's section of the target where he'd shot his 243 at our range session, and he kept the targets. As some keen-eyed observers will notice, I've used that piece of cardboard before to hold targets. My wife laughs at me....I don't toss cardboard I use for target backing until it looks like someone machine gunned it....twice. I can say, though, that one particular piece of cardboard that I used for a LONG time on the rifle range did succumb finally when I used it to pattern turkey loads.

 

[BK]

Yeah, turkey loads will do that.

Do you have access to a concentricity gauge? I would be curious whether you were having runout issues with the Hornady dies or bullet pull issues. I wouldn't have even thought that if it weren't for the marked increase in velocity.

It would be interesting to try the test again with Redding dies, like mine.

 

[Wondermutt]

At the time we bought our last sets of dies, we could only get Hornady dies for our 7mm-08's. We experienced the same thing as you. We recently switched to RCBS and the groups got more consistent. So look like the hornady will be going down the road...

 

[DrMike]

Interesting observation, Tom. I'm not convinced it is statistically significant at this point, but it is sufficiently suggestive that it would make me want to explore further.

 

[AzDak42]

Interesting observation, Tom. I'm not convinced it is statistically significant at this point, but it is sufficiently suggestive that it would make me want to explore further.

While the methodology to isolate down the number of variables is fairly sound, I'd have to agree. I think that the sample size is just too small to be statistically meaningful. You'd have to repeat this test a number of times and with a couple of rifles, before I'd want to make a statement about the dies.

- If the Hornady die is well used, is it clean? Additional friction inside the die can cause you to have to use more force and a less consistent motion on your press arm. (I was running a 50 round batch of 95g SMK .243 Win and after 20 rounds realized I was fighting the press. I pulled the dies, cleaned them, and then did the rest of the batch. I had far better accuracy out of the last 30 than the first 20...)

- Dies are not perfect, either are chambers. What this could tell you is that your RCBS die more closely matches your particular rifle's chamber. Sort of depends where in the reamer life your chamber was cut and where the tooling was when it made your die...

The only great news is this...

The only way to find out is to go reload and shoot more.

 

[SJB358]

I responded to your other post Tom, but I think you are on to something, if anything, the RCBS dies seem to be shooting more consistently for you, overall. You have shot so many groups with the Hornady's that I think you have plenty of data with them dies. A few more with the RCBS's would net you some more.

Like I said, I would deprime cases with a decap die, then pull the decapping unit. That may be your culprit as well. I started to get inconsistent groups as well, till I started annealing hard brass. Then, it flipped a switch and seems to have really helped with everything, consistency and accuracy.

 

[Guy Miner]

Check bullet runout from both sets of dies.

I think perhaps the most important thing a set of match grade dies does, is to seat the bullet straight. Really straight. Also believe that's vital for accurate rifle loads.

 

[tddeangelo]

I agree that the sample size is too small to make any broad statements about the dies.

However.....I have not seen the kind of consistency from the Hornady dies as the RCBS seem to be producing.

I'm going to load up some more for the RCBS and run them in order to dial in the scope with the last minor adjustments, and probably load up my hunting ammo for the year on those dies. Maybe in the late winter/spring when I get back to shooting for something to do, I'll run more side-by-side comparisons.

It's important to note here that there will likely be 100 questions I can't answer about this whole deal, but I thought I'd at least post what I found with those groups for others to have the data and draw their own conclusions.

The Hornady dies were bought new when I bought the rifle. I degreased the parts when bought, and the rifle's round count stands at 181 rounds, with 40 being factory ammunition, so the dies have produced 135 rounds (181-40-6=135...accounts for factory ammo and the 6 rounds of RCBS-made ammo).

Also bear in mind I am not seeking to shoot a match with this rifle. I'm simply looking to produce consistent accuracy of MOA. If it will always shoot a half-inch group, hey, that'd be great, but an 1.0-1.1" rifle will be fine with me, and really, is even more precision than is needed for a hunting rifle in most situations.

What you see in the Hornady groups is quite typical, however, in what I've experienced over the lifetime of this rifle (using those dies) thus far. That would be why I'm headed into my 2nd hunting season with it still trying to totally nail down a good load for it. I think I have it now with the RL19 load I'm running. More groups will tell the tale, but it looks promising.

 

[DrMike]

FWIW, I've used dies from most manufacturers (Hornady, RCBS, Redding, Forster, Lyman, Lee and C&H). All brands have produced acceptable ammunition. Each had to be set up carefully and the technique refined to fit the particular die. Some have appeared to be more consistent than others, but all worked. There have been instances where selected dies have had flaws that were revealed during use; in honesty, I can't declare that one manufacturer showed a greater tendency to produced flawed sets than another. It is possible that you have a set of Hornady dies that is out of spec, but I wouldn't take that to mean that Hornady makes an inferior product to RCBS. I've had RCBS die sets that were unacceptable when Hornady die sets were working very well.

 

[tddeangelo]

DrMike, no doubt. And also why I have not made any statements or generalizations about one maker vs the other. Simply that, in this case, with this rifle, in my situation, the RCBS dies I own are seemingly more consistent in the ammunition they produce than the Hornady dies I own for the same caliber. That's about all one can draw from this data.

More my point in posting was to get ideas moving on this rifle, and also for others to see so they can be aware of such possible situations when reloading. Sometimes we overlook a "variable" we didn't think of, such as the dies. I know I didn't think about them till Scotty and I were talking about reloading, and I suddenly realized that the WSM was the only round I load for that I have Hornady dies.

 

[AzDak42]

It's an interesting point, and maybe a point of last resort if someone just can't match up a rifle to any of their hand loads.. We always look at the easy ones.. primer, powder and seating depth, but don't give a lot of thought to the dies themselves. This may be even more true for those of us that only full length resize..

I'm tempted to grab a few redding sets just to see how they do with similar loads.

(And 100 rounds is usually enough to get me to clean out my dies.. I use graphite on the case mouth and I find that it can build up in that time period.. (And I really like the Hornady one shot cleaner/lube for this..)

 

[DrMike]

AzDak42, I clean my sizing dies after every loading session. I use Hoppes No. 9 and a tight fitting dowel with a patch to swab out the dies, ensuring that they are thoroughly swabbed afterwards with dry patches. These may, or may not, be sprayed with brake cleaner and swabbed again, depending upon need.

 

[FOTIS]

This is indeed very interesting. I would love to see this further investigated.

 

[dlove]

I had similar results with runout on the hornady dies. I solved it with more case lube. those dies need a lot more lube than the other brands. a little hornady unique on the expander will help a lot.

 

[tddeangelo]

I use OneShot to lube my cases. I never gave much thought to cleaning them out, but I guess I should do so.

As for a "last resort", lol....I look at this way- This cost me $28 (sale at the time on dies), which is far less than the cost of the components I've blown into the bank at the range trying to get this consistency from the first set of dies I bought. Is it always the answer? Assuredly not. But I thought it was interesting, none the less.

 

[AzDak42]

AzDak42, I clean my sizing dies after every loading session. I use Hoppes No. 9 and a tight fitting dowel with a patch to swab out the dies, ensuring that they are thoroughly swabbed afterwards with dry patches. These may, or may not, be sprayed with brake cleaner and swabbed again, depending upon need.

You sir, are a bit more dedicated than I am. I wonder how they'd do in the sonic cleaner?

 

[DrMike]

They'd likely work just fine in a sonic cleaner. You would, however, want to ensure they were thoroughly dried afterwards, however.

 

[dlove]

if you are using one shot for rifle cases, can you run this test again with cases resized with unique? I would be you will see a different result. .....and unique is about 100 times cheaper than one shot. one $5 tub will do a few thousand rounds.

 

[tddeangelo]

I'll look at ordering some. I think Scotty had once recommended Imperial and I meant to get some of that.....

 

[dlove]

the reason I ask is that I was using one shot when I was having horrible problems with my .270 win and hornady dies. now, it shoots better than .5" all day.