Handloads that salvaged my Rossi 243

[Pacolyptic]

Seems a lot of people have bought various models of Rossi single-shot break-action rifles in .243 (mine was a 3-barreled Rossi Trifecta), and while similar Rossi rifles in other calibers shoot just fine, the models chambered in .243 are frequently plagued with abysmal accuracy. I've seen quite a few threads where Ross .243 owners gave up after trying various factory ammo and got 5"-9" spreads at 100 yards, and a mention or two of people who found a handload that dialed it into acceptable accuracy.

So I just got mine from the land of horrible groups down to 1.25 MOA at 100 yards. Good enough that I'm taking it hunting this season (I'll be woods where the shots are sub-100 yards). In the hopes of saving others some time and frustration, here's the whole ordeal.

Quick observation: Ignore every "good load" people have posted online for .243 in their Tikka, Remington, etc. These Rossi guys are tricky because:

1. They have a short barrel (16").
2. They have a 1-in-10 twist.

The recipes for longer barrels don't hit the sweet spots, and a lot of those recipes use 100gr bullets which most people say won't stabilize well with a 1-in-10 twist.

So I started the same way as everyone else - I tried factory 243 (Win Powerpoint, Remington Core-Lokt, Federal Powershock) and got craptacular results. We're talking 5" groups. I already handload for my other guns, so I immediately decided to work up a load to see if it's the gun or the ammo.

Since I mainly reload 30-06, I already have IMR 4350 powder on hand. Turns out to be a well-regarded powder for .243, so I decided to start with that. Also, because of the twist rate and my intended use (deer hunting), I went with the heaviest bullet a 1-in-10 barrel should be accurate with - the consensus of the all-knowing internet seems to be 85gr.

So I decided to do all testing with IMR 4350 and Sierra Game King HPBT 85gr bullets.

Round #1 - Ladder, IMR 4350, CCI 200, Win brass, Sierra GK HPBT 85gr, 2.741"

Using the ladder method, I worked up 5 batches. Trying to cover ground quickly, I used 0.5gr increments:
39.0
39.5
40.0
40.5
41.0
41.5

I also tried the conventional wisdom of seating the bullets just off the lands.

PROBLEM: These Rossi's have long throats. Seems like I'd need a 5" long bullet (exaggerating a bit) to reach the lands. So I seated the bullets as far out as I could while feeling they wouldn't fall out.

So COAL was 2.741" and no idea how far it still was from the lands.

The results for Round #1 were confusing as heck. The batch at 39.5gr produced a nice 1" group, but a step above and below spread out quite a bit. So I immediately loaded a couple more batches - this times at 39.3, 39.5 and 39.7. The results were horrible - this time I got a 1.7" group from 29.5 and the others were really wide. Made me wonder if I had messed up in my loads somehow, though I've been successfully reloading for years and had worked up greats loads for my other rifles this way.

I scratched my head, went home, and read way too much stuff on the internet. Eventually, I got into the barrel harmonics threads and the OCW threads and decided to change my approach this time.

Round #2 - OCW, IMR 4350, CCI 200, Win brass, Sierra GK HPBT 85gr, 2.625", crimped

So, after a small hiatus (*cough* 3 years *cough*), I got the Rossi out again. Thank God for log books! I decided to change my approach and try the OCW method. Google it if you don't know it - I'm definitely using this approach for all future load development.

With OCW, you first find a sweet spot in charge weight where POI isn't really affected much by a modest change in charge - doesn't matter if it groups well, just want to know that the POI doesn't change. Once you've found a sweet spot for charge weight, you dial in the group size by varying COAL.

So this round was all about finding the charge weight. I also tried a higher max charge than I did in my first round - I had seen so many different max charges from different sources that I went pretty conservative that first time. This time, I went with a max of 45.0gr and carefully watched for signs of pressure.

PROBLEM: It really is a mystery why there's such a discrepancy in max charges for .243. It also seems that, in general, older sources listed higher max charges, so maybe the powder formulation changed for IMR 4350 in the not too distant past(?). Anyway, I found sources listing max charges past 45.0 but I wasn't going to push it.

Also, since I knew I wasn't anywhere near the lands on bullet seating before, this time I decided to pick a COAL that seemed in-line with what different reloading manuals listed for this bullet - hence 2.625" COAL. And I crimped every round using a Lee Factory Crimp Die (LFCD).

This time, my five batches were:
43.2
43.7
44.1
44.6
45.0

Also, this time, I used my smartphone to take pictures My results made one thing obvious - I didn't need to go up in charge. If you know OCW, you know the spread isn't the important part in this picture - the triangulated POI is the important part. Still, except for the first batch, the groups were really, really wide.



So I decided to redo the first phase of OCW, this time with a lower range of charges.

Round #3 - OCW, IMR 4350, CCI 200, Win brass, Sierra GK HPBT 85gr, 2.625", crimped

This time I did 6 batches, and they were:
41.1
41.5
41.9
42.3
42.8
43.2

The results were pretty interesting! First, I expected a much lower POI with the lower charge weights (hence the reason I put the bullseyes so high on the paper). The other thing was that I wasn't sure if these results meant I had 2 sweet spots or zero sweet spots:



In a textbook OCW exercise, you'd expect to see 3 or more charge weights with similar POI. The increments I tested are about 1% apart in charge weight, which is what OCW recommends. However, if you buy into the whole barrel harmonics thing that OCW is based on, having a relatively short barrel like this Rossi, you will have narrower sweet spots than a typical rifle. So it can very well be the case that I found 2 sweet spots (41.5 and 43.2).

Seeing how crazy the groups opened up above 43 grains before, I decided to pursue the 41.5 charge weight for the next round. And, to give some buffer to charge weigh sensitivity, I split the difference between 41.1 and 41.5 and decided to use a charge of 41.3 for the next phase.

Round #4 - OCW, 41.3gr of IMR 4350, CCI 200, Rem brass, Sierra GK HPBT 85gr, crimped

For the second phase of OCW, I varied the COAL. If you're wondering "you crimped these rounds so does it matter?", I had the same thought, and again I turned to the infinite wisdom of the internet. The crimp helps ensure consistent starting pressure for all rounds, however changing the COAL does change the volume (and hence the pressure) and also the gap the bullet has to jump to reach the lands which many, but not everyone, believes affects accuracy. So I decided to still try it.

Interestingly, it made a difference:



I made batches in 5 COALs:
2.660
2.650
2.640
2.610
2.600

If you're wondering why I have the big gap between 2.610 and 2.640, it's because my earlier round used 2.625, so testing 2.620 and 2.630 didn't seem like they'd offer as much insight as just trying another step out in each direction.

The COAL of 2.650" definitely had the tightest group. It's tempting to think I had a flyer in the first group, but I honestly didn't notice any problems in my technique, I shoot a fouler before these tests too. So it is what it is.

Also, for those still awake and reading this far into my post, you may have noticed I switched from Win to Rem brass for this round. Like I originally posted, I tried both Win and Rem factory ammo originally. And after the first couple rounds of testing, I had reloaded all the Win brass and already had the Rem brass ready to load. Given the benefits you get from OCW, switching from Win to Rem brass shouldn't make a difference so I put my faith in my new found reloading voodoo and it seems to have worked out just fine.

Give the similarity in group size that I got with 2.650", 2.640" and the previous round of testing at 2.625", I'm pretty comfortable saying I've got a wide COAL range to work with (with LFCD crimping) which frankly makes me happy. Getting consistent COAL down to +/- a few 0.001" while reloading seems to consume a lot more time than it should, at least for me.

So this is the recipe I'm going to use from now on:

41.3gr IMR 4350
85gr Sierra GameKing HPBT
2.640" COAL

And I can use whatever brass and primer, and be a little off in the charge weight or COAL and still expect to get decent results - about 1.25 to 1.50 MOA from a 16" barreled cheap Rossi. I can live with that.



Other details about my tests:

All these tests were done at an outdoor range, light-to-zero wind, 100 yards, off a bench with sandbags. I didn't use a rifle rest, and I can shoot sub MOA with other rifles this way - I bet that my pulse on cheekweld contributes about 0.25 MOA or so variation in POI though.

Also, other than Round #1 three years ago, all the other rounds were shot within a few days of each other and outdoor temps were 45F-55F.

Lastly, for Rounds #2, #3, and #4, I shot foulers before each round of testing, I made sure I waited at least 2 minutes between shots, and I didn't clean my barrel until after completing each round of testing.

Well, hope this was helpful for someone!

 

[Legionnaire]

Great write up! Tagging for future reference.

 

[41 Mag]

First off I want to applaude you for sticking with it and working yourself a decent shooting load. I myself have had and still have a rifle or two that I have set aside for a short hiatus.

That said I wouldn't put much thought or faith into the following,

and a lot of those recipes use 100gr bullets which most people say won't stabilize well with a 1-in-10 twist.

I have been shooting a .243 of one form or fashion since 1970, and in all of them I use(d) 100gr bullets for hunting with no issues getting them to shoot good or group well, other than the normal, finding where they like to run. Usually with a powder like Hod, or IMR 4350 it is right in the area you were working something in like the 38.5 to 41gr range.

My last work up was a couple of years back using the 100gr Nosler Solid Base over some of the then new Hodgdon Hybrid 100V powder. I worked them up in a Sako I purchased second or more hand for the oldest grandson to use to hunt deer and hogs with. Here is the target I shot while working up those loads,

I cleaned the barrel at around 20 shots or so, and the bottom right sticker was my fouling shot target. The bottom left are the two final loads with the two flyers there were caused by the barrel heating up after the third shot, and slightly rubbing the stock. I have since relieved some wood and the groups are basically one hole now.

One thing I have had conversations with folks about who were using the newer single shot type rifles, other than maybe a Ruger #1, is that they are really position sensitive with regard to where you set them on the rest when shooting. Most them forward or back a couple of inches and it would change everything up. I remember my late friend had one of the Handi rifles in .243 back when they first started getting popular, and we had a time with it trying to get something to shoot. It was similar to what was mentioned, I would shoot a decent group with it sitting on the rest in one place then he being shorter armed would slide the rest back a little and the groups would spread out. Not saying this is what might be going on with yours just that since then I have spoken with a few folks who saw that same issue, with similar type rifles.

 

[Pacolyptic]

Good advice

41 Mag - good points. I actually would prefer 100gr bullets so I'm gonna try this again sometime with them just to see for sure. It'd be a better deer load that way. And wouldn't be the first time the Internet was wrong on something

About how the gun is supported, I heard that too. I should've mentioned it, but I did the first round three years ago with bags under the fore-end, about where the rifle sling stud is located. After readings comments about it during that hiatus, I did all the later tests using sandbags positioned just in front of the trigger guard, so the gun is supported under the receiver. Being so short, it was actually pretty balanced that way. So I can rule out the support in the recent tests, but yes, I agree it may have contributed to the inconsistent results I got originally.

 

[243winxb]

243 Winchester MARGINALLY STABLE 10 Twist-100gr.

A 10 twist with a Sierra 100gr #1560 with bullet length of 1.067" is marginally stable out of a 16" barrel. For the Sierra 85gr #1530- 42.0gr of IMR 4350 with CCI BR2 primer in Win or Rem brass- OAL 2.645" to 2.660" has worked well in 18 1/2" to 27 1/2" barrels with 10 twist for me. Note: I have seen a couple Rossi rifles that needed the crown on the muzzle redone.

 

[Buck13]

Neat. You are a gentleman and a scholar!

As always, I'll preface this comment by saying I'm no statistician, nor much of a shooter (accuracy-wise), but I'd be cautious about over-interpreting 3-shot groups. Certainly your Group 2 target looks like what you say. On the Group 3 target, without many more shots, I'd be tempted to say you have one big sweet spot. Those groups all look similar enough to me that I'd suspect that there is simply one boo-boo in 42.3 gr batch. I know *I* would probably jerk the trigger at least once in 18 shots! Not that it's worth firing an entire box of bullets just to resolve this issue, since you have got a good result!

 

[243winxb]

243 Win Barrel Twist rate 10

http://www.bergerbullets.com/twist-rate-calculator/ The length of the bullet is more important than the weight. A 100 gr flat base/round nose* bullet would be a better choice with a 10 twist barrel. Hogdon data at maximum velocity still shows that bullet stability is marginal.

 

[Pacolyptic]

243winxb - With a username like that, I'm guessing you've shot a few 243 loads in your life. I'm definitely bookmarking that calculator. Looks really handy, and 'marginal' sounds far enough from 'good' that playing with the 100gr bullets is starting to fall farther down my to-do list. I appreciate you sharing that recipe too - especially since you noted it works well in rifles of varying barrel lengths. I'd like to find a load that has that sort of near-universal performance. That'd let me add another 243 to my gun safe without having to worry about starting from scratch. Gotta admit, I'm taking a liking to this caliber.

Buck13 - A gentleman and a scholar? I thought all us handloaders are voodoo charlatans Just wait to see how tight my groups get after I swing a dead chicken over my shooting bench.

 

[243winxb]

243 Winchester

I'm guessing you've shot a few 243 loads in your life.

Yes a few.

Ruger #1 Varminter​

Win M70 Heavy barrel​

Win M70 Douglas target barrel​

Sako L579 Forester heavy barrel, beavertail forearm​

Savage 99 Lever action​

Remingtons in 600, 700 varmint, 40X​

Most all are now sold or traded. The most accurate were the 40X, Sako, and Douglas barrel rifles. The least accurate (sorry Ruger owners) was the Ruger #1 & Savage 99. When working up the Sierra 100 gr hunting load for my son in the Rem 600 carbine, accuracy was not near as good as the 85 gr Sierra. But ok to 100 yards for deer. After 40 years, maybe its time to test the 100 gr again? Still have the same box of 100 gr bullets.

 

[gamestalker]

This is evidence that most rifles can be made to shoot with the right load.

Good job!

GS

 

[243winxb]

10 twist Barrels

This is evidence that most rifles can be made to shoot with the right load.

Not really "OK" , but more like, well there loaded, i am not pulling them. 3" groups at 100 yds are ok for a large target like a deer using the 100 gr bullets.