.300 Win Mag Test Results/ Barnes 180 gr. TSX--and Question

Hello: I am preparing for my first African hunting trip. I'll be hunting plains game in the Eastern Cape province of the RSA this coming June. My primary rifle for the trip will be a Winchester M70 Super Grade chambered in .300 Win Mag, topped with a Leupold VX 3i 4.5-14 x40 in Warne rings and bases.

I am developing a load using Barnes 180 gr. TSX bullets and IMR 4350 powder. My goal is 3000 fps and sub-MOA groups off the bench. I have the velocity nailed with 69.3 grains (the max load out of the Barnes manual), but I am not presently satisfied with the accuracy of the load. My groups are averaging 2.3" at 100 yards. Here is the data I have collected. During both ranges session so, far, the air temperature was about 27 degrees Fahrenheit. The velocity numbers are based on a 10 round average for each load.

Day 1
66.0 grains = 2931 fps
67.0 grains = 2880 fps

Day 2
68.0 grains = 2844 fps
68.5 grains = 2888 fps
69.0 grains = 2984 fps
69.3 grains = 3009 fps

I didn't really measures group size the first day, but for the second set up loads, group sizes at 100 yards were as follows:

68.0 grains: 2.137", 2.553"
68.5 grains: 2.830", 1.780"
69.0 grains: 3.990", 1.774"
69.3 grains: 2.229", 1.768"

Average group size across all 8 groups is 2.38". All the loads except the 69.3 were seated to 3.340", which is what it says in the Barnes manual. For the 69.3 loads, I measured the chamber with the Hornady gauge and seated .050" off the lands for a OAL of 3.427". Those rounds are too long to fit in the magazine, and there doesn't seem to be much difference in accuracy.

I am wondering what I can do to improve the accuracy of my loads at this point. In excess of 2 MOA is not acceptable. For testing, the gun is sandbagged in place on a benchrest. I shoot an average of .6" groups from the same set up with my Remington 700 Varmint in .308, using Sierra MatchKing bullets, it it isn't me.

Do I need to try a different powder? Should I continue experimenting with the seating depth?

Any help is much appreciated.

 

I would not be happy with that result either.

Do you have a box of TTSX you can try? My rifle shot the TSX like a shotgun pattern.
The TTSX, sub MOA.
I can't argue with the result.

 

Mike,

Most of the rifle in my house are M70's and I also have the same rifle your working a load for. What I have with most of mine, and it may just be my rifles, but that the TSX/TTSX copper foul quite quickly in my barrels. I don't doubt this could vary for you. But consistently what I read about those who love the Barnes bullets and those who don't is that a clean barrel is essential for accuracy with these bullets.

Take a close look at the muzzle end of your barrel in/with good light. If it looks like a nice new shiny penny in color, it's time to get that copper out. That may take your sub 2" groups down to sub 1" groups all on its own and you'll have your load developed.

For whatever it's worth, my .300WM SG really like H4831 with the 180's and 200's. It won't always give the best velocity, but it gives the best accuracy in my rifle. 200gr loads were in the 2800-2850fps range for mine. So I'd guess that it would get pretty close to 3000 with the 180's.

 

I would seat them deeper. I know Barnes says .050” but a lot of guys are getting better accuracy seating them deeper. I have a 257 mag that shoots them touching at 100 yards seated deeper.

 

Your rifle could be telling you it doesn't like the Barnes TSX and no amount experimenting will change it. What twist is your barrel? I would try Brickburn's suggestion and if you get the same results, try Sierra Game Kings, Berger Hybrids, Hornady interlock or interbond or one of Nosler's hunting bullet options. As far as your goal of 3000fps, I would shoot for an accurate load before being concerned about reaching a certain velocity. With your caliber, 100 fps isn't going to make any difference with plains game at any range out to 500 meters plus. Depending on your expected furthest shot, I would try for .5 moa at 100 and see if it is still .5 moa to at least 300. Good luck on your safari.

 

I have loaded ttsx for a 270 so this is definitely a 2 cents worth of advice/theory: It seems the rifle has a long throat so I wouldn't try to use it as a reference. I know they like a lot of jump so I think there are no concerns about being too far from the lands. In fact I would try seating deeper. The other thought I had is that the 180 is a very long bullet. Perhaps a 165 would work better? @Divernhunter has worked a lot with Barnes so he may good insight.

Good luck!

 

Thanks for the replies. I will get a box of TTSX and give them a try. I have some 175 grain Sierra MatchKings on hand, so I think I will load some of those up as well and see how they group. I am sure I do not have a copper fouling problem. The rifle is brand new with exactly 70 rounds through it. I cleaned it thoroughly after the first thirty rounds, and again yesterday after the next forty. I am using Butch's Bore Shine, which seems to do pretty well.

I am interested in opinion on whether crimping will adversely affect accuracy. I am using a roll crimp on these loads, given the magnum caliber. Is that an issue? It seems like it wouldn't matter as long as it is consistent, but most of my prior loading for accuracy has been with no crimp.

 

I don't crimp anything, not even .223 AR rounds. I'm shooting a 28 Nosler with 195 grain bullets, no crimp. Crimping changes seating pressure which could cause it to be inconsistent. I would NOT crimp.

 

Pheroze has it nailed. Divernhunter is very experienced with Barnes and he is offering the same advice. Barnes bullets are long because lead is 26% more dense than copper so to get the same weight the bullets must be made longer. Stability isn't determined by bullet weight but length. Pheroze, Larry4831, hog patrol and Brickburn offer very good suggestions.

1. use the TTSX
2. drop the weight 165 is plenty. Barnes shoot better when driven fast
3. seat them deeper. start with the Barnes COL. If you look at Barnes factory ammo you will see they are deep
4. don't crimp Barnes specifically advises against crimping

as for max loads I would heed Hogpatrol's advice. 100fps will make zero difference but the risk of a stuck cartridge, blown primer or worse will ruin your hunt

BTW depending how rough your bore is you may wish to clean it more often say 15-20 rounds. I use wipeout. If it comes out blue I repeat till the blue (copper) is gone. on badly fouled guns it may take 3 cleanings

 

ok here is my 2 cents
1st i dont shoot mono metal bullets for all of the issues you are running into aka they are long, they fould up the barrel, tricky to get to fly right, the long bearing surface increases the pressures as you crank up the speed, etc and sorry offer no advantage over a premium bonded core lead bullet. a 180 or 200gr nosler AB will shoot under 1moa all day with RL22 at 3000fps and def get the job done on the critters. an easy load to work up.
that being said try a diff powder 300 win mags REALLY like RL22 and if you just gotta shoot monometal then you need to use somekind of copper remover to clean the barrel and you better have a bore scope as it isnt easy to get that copper mess out of a rough factory barrel

 

Another option for heavy coppering barrels is JB Borepaste or Iosso Bore cleaner.

 

What is the inherent accuracy potential of the rifle? And if it is capable of <1" @ 100- what load? How does it shoot a comparable lead core premium like an A Frame or Woodleigh?

As to jacket fouling?... I've found the banded solids like the TSX to be no more or less fouling than conventional jacketed bullets. The original, smooth shanked Barnes X bullets were horrendous for fouling, poor accuracy and pressure spikes. The modern banded monumental brass and copper bullets by the various manufactures are like the difference between night and day with the early smooth shanked Barnes X. I've also found, without exception, the modern banded designs to be as accurate if not more accurate than the conventional heavy jacketed and bonded premium bullets. They have been very predictable for pressure vs velocity and it has been easy to develop accurate hunting loads with them. My experience with the banded monometals includes 30, 338, 416 and 458 calibers. I crimp all my hunting ammo. The Lee collet type Factory Crimp Die is the best to use. I have had no issues crimping any of the monometals. And in heavier recoiling rounds in magazine rifles, it is almost imperative to crimp to avoid bullet "setback". And in doubles, it may be necessary to crimp to prevent bullet "pull".

I have avoided the more modern smooth shanked monometals on purpose- so no experience with them.

 

Try the Peregrine bullets out of RSA and you'll not see the fouling you do with the TSX's.

 

I shoot a 300H & H, so a little less powder. Mine preferred Reloader 22, so you might want to try a different powder. As some have already said, some barrels don't like TSX. If that is the bullet you really want, I would try another powder.

 

I don't doubt your experience. Some see the copper fouling issue to greater degree than do others. I believe to at least be in part a function of the barrel diameter to which the specific rifle was cut. If you look around enough, many have had the same experience I've had. It happens in nearly all of my rifles, I think I have one or two it hasn't been an issue.

For others who see it, it's a slow enough process, meaning it takes more shots than what is anticipated to be taken on a hunt. And so even though they'll see the accuracy drop off eventually, it doesn't affect their hunt. So they clean the barrel well before the hunt and then afterwards.

 

May also be one of those things where once it is written and talked about enough, people start looking at their bores more carefully and "suddenly" notice the copper fouling. I simply can't tell much difference between the amount of fouling left comparing conventional jacketed bullets and the new banded monometals. For me, it takes just as long to get all the copper out after shooting 10-20 rounds of regular jacketed bullets as it does after shooting 10-20 rounds of banded monometals. Plus, some bores simply foul more readily than others, no matter the type of bullet

 

Mike Delta Foxtrot I have been loading a 300 win mag savage for quite some time and my rifle literaly hates tsx 2.5-3.2 moa but when I load ttsx at67 grains of h4350 running at 2970 fps I can get .7 to .5moa at the bench I have not found any more copper fouling with barnes in the last 10 years than I find with sierra or horady early ,beore the bands fouling was horrible go to the ttsx and I think you will be much happier good luck and have fun

 

This is just my 2 cents. I own 2 300 win mags one is Sako a7 roughtech the other is T/C venture. As reading the original post I see that you are using IMR 4350 in my experience with my guns is that 4350 done better with lighter bullets 150 to 168 gr. I like and my guns like heavy for caliber bullets in the 190 to 212 gr range. I've had good success with ELD X, Sierra gambling, Nosler accubond. H1000, RL 23, RL 26, and IMR 4831 all shot pretty good with the nod going to H1000 and To Rl 23. Had to work with seating depth to get my loads fine tuned. I did find my best accuracy was near max loads. Hope you get it shooting to your liking.

 

Butches Bore Shine work very well if you follow the directions

 

That should be Sierra gameking.