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Beartooth Regular
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1,177 Posts
Discussion Starter #1
Finally got to do some load work with the BTB 358 WLN+P gas checked bullet in  the 357 Maximum. I had a 10" Contender bbl in 357 Mag rechambered to the Max. This gets rid of the "forcing cone" throat in the Mag and replaces it with what can be described as a gentle tapering Ball Seat type throat arrangement.

I'm really getting to like this barrel very much as it's a snap to resize cases and develop loads for it. Also, recoil is very manageable and a surprising amount of power can be obtained from the 10" bbl. I see this cartridge as a great woods round out to 100 yds or so in the Contender.

Getting to the loads, I utilized WC680 Surplus powder with Federal 205 Small Rifle primers and Remington cases. This powder has exhibited 2 distinct burning rates of lots out there so some caution is in order to begin load development with it. Turning to my Hornady manual, both WW 680 and AA1680 loads were listed with WW 680 loads showing lighter powder charges than the AA1680 in the Max for comparable velocities. So, I elected to use the WW680 charge weights to give me some leeway with the Surplus lot I had. It turned out that the WC680 I have is apparently a slow lot and in fact is much more comparable to AA1680 that I also have on hand.

I started with 19.5 grs of WC680 on up to a top charge of 23.8 grs as listed in the Hornady manual for WW680. Velocities were quite inconsistent and unburned powder flakes were present in the barrel on up to the 23.8 gr load. Velocities ran from 1280 FPS on the low side to 1500 FPS at the 23.8 gr load. The interesting part is that these loads were still quite accurate even though the powder and velocities were very inconsistent. Accuracy averaged a ragged 1.5" hole at 25 yds. Black smudges also appeared on the outside of cases with soot actually backing up at the breech plate showing very low pressures relatively.

My next visit to the range was with heavier charges of WC680 starting at 24.5 grs on up to a compressed charge of 28.0grs. The 24.5 to 25.5 gr loads exhibited the same sooting and unburned powder residue in the barrel. Then, things started to change with the 26.0 gr loads. I noticed a distinct jump in velocities from about 1680FPS to 1713 FPS with the 26 grain load. Also the powder residue just started to lessen. At the 26.5 gr loading (1722 FPS) things started to improve more with extreme spreads starting to lessen considerably. This first slightly compressed loading started to tell the real tale loud and clear. Powder residue dropped to about a quarter of what it was with previous loads. Cases were sealing off well in the chamber. Also, extreme spreads dropped to 25-30 FPS. The 27 to 28 gr loads showed steady velocity increases and powder residue dropping to slight to nothing. The 28 grain load showed less pressure than my full up WW296 loads do with a lighter bullet from primer appearances and other indicators. The velocity averaged 1850 FPS with an extreme spread of about 10-15FPS. Accuracy looks to be extremely good at less .8" at 25 yds with the 2X scope I have on this 10" bbl. albeit I was not shooting for accuracy but more for pressure and velocities at this session.

To review, it appears this ball powder likes to be somewhat compressed at least in the Max in MY bbl. The performance exhibited by it clearly demonstrated that fact. Once it was, ballistics settled right into a predictable outcome. Regarding the 180 gr WLN+P, this bullet almost appears to be made for this round as it's crimp groove in my rechambering is positioned perfectly for the throat length. And yes, with this powder at least, a moderate to heavy crimp must be applied to aid ignition. Actually, all loads were taper crimped with an older CH taper crimp die I have just above the crimp groove. The wide driving band area on this bullet allowed this. This die tapered the case mouth perfectly into the side of the bullet imbedding it into the lead like a pseudo Factory Crimp die. A taper crimp in this way is quite firm, moreso than a roll crimp in the crimp groove in my opinion. A Redding profile crimp being even better as it is a combination of the 2 crimps.

I could have went to higher charge weights but I really don't like to compress more than is reasonable in my estimation with ball powders. Carried to an extreme, they will become like a solid mass thus affecting consistent burning progression. Sort of like lighting a fuse instead.

Originally, I experimented with AA2200 powder but found it to be too slow in this cartridge. My thanks to Johann Loubser over at Accurate powder for some excellent advice and a very correct prediction on that experiment too. LOL.

A note or two on the scope and mount is in order. The scope base I'm using is a Leupold double dovetail. Originally, Leupold rings were installed on it. After having scope slippage problems, I opted to try the newer Signature rings from Burris on the Leupold base. I've found these to be excellent rings with terrific gripping power with one caveat. After you first install the scope in them, Check back in few days or so and retighten the ring halves again. I've found the plastic inserts take a "set" to the inside surfaces and the rings will loosen. After retightening them a few days later, they are still good and snug. So watch for this little condition to develop with them. The Bushnell Trophy 2X handgun scope has held up very well and is an excellent value for the money, surprisingly so actually. All my barrels wear the Trophys and I've never had any problems with them. A 2X6 variable on my 358 Bellm has been pounded with a few hundred rounds and it is still going strong with no point of impact shift whatsoever or nothing detectable at any rate.

Again, if you are in the market for a woods range cartridge for deer, black bear and the like or more, look into the Max. It's really an under-rated cartridge for hunting and didn't deserve it's fast "death" shortly after introduction by uninformed "experts". The 180 gr WFN+P at 1850 FPS from a 10" bbl is nothing to sneeze at either. A nice little carbine in this cartridge would be a great application for it too.

I look forward to further experimentation with this barrel.


Regards
 

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Beartooth Regular
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2,146 Posts
Dang Contender!
    That's a smokin' load from 10" of barrel! I would think that would be useful on most anything except a really big bear, certainly ideal for whitetails and black bears. Good work, man!
     I still think I need a better job so's I can play more....              IDShooter
 

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Beartooth Regular
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1,177 Posts
Discussion Starter #3
Ain't it the truth. So many guns/barrels so little time and money. (grin)

I tell ya, I'm impressed with this cartridge in the 10" bbl. I'm not saying it's a 44 mag but, it has quite a bit less recoil, is real easy to load and experiment with. No custom dies. The BTB 180 looks awesome in the cases too. Like it was made for this cartridge as I said. Taper crimping into the driving band also allows me to use the crimp groove as a 3rd lube groove as the bullets came with it full of lube anyway. Absolutely no leading at these speeds and pressures. This is a 48,000 CUP cartridge.

As you said, this bullet should penetrate into next week.

Also the smaller head and case diameter furnishes less backthrust on the breach area of the Contender.

It will also do 1900 FPS+ with a 158 gr bullet.

The WC680 Surplus is a boon for anybody with this cartridge or the Super Mags.

The Contender makes a great pure handloading platform for experimentation.


Regards
 
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