Hey boys.

I am developing loads with the 165gr interlock BTSP for my 300 winmag.I have had success with the interlock BTSP bullet in 270 win at 2950fps-3100fps{lightmag/custom factory ammo}.

I am trying to load keeping 3100fps+/- as a ceiling speed in the 300 win.If I get the accuracy I want at 3000fps then that is fast enough for me.My question is: Am I pushing too fast of muzzle speed/pressure in the magnum for this BTSP's bullet construction?I am using RL22 and Fed215 primers with the BTSP bullets.

Thanks in advance RB

You should be able to get 3100 out of a 24" barrel.
i have not heard or had any problems at 3250 out of a 26"
barrel
Dave

I think the answer to your question depends a lot on the game you intend the load for. It should do fine on animals up to cow elk, perhaps, but for larger, tougher animals, I'd switch to a double-core type like the Nosler Partition or Swift A-frame, or one of the bonded-core bullets such as the Hornady Interbond.

I see no point in using anything but super premiums for hunting..Pick your bullet wisely, use the best available,If you don't then you will sooner or later have a sad tale to tell and nobody to blame but yourself...and the cost difference in the best and the worst is minimal compared to the cost of a hunt gone south...Hornadys are great bullets at 308 and 30-06 velocities, I want Nosler, No. Fork, Swift, Failsafes in a magnum...

I plan on hunting mule deer with the BTSP.I know they work at the speed I want with the 270 win,however I don't know whether they will work at the same speed with the pressure generated by the magnum.I am not against using a premium bullet,I.E. nosler Accubond but I have great history with the BTSP and I am looking for someones experience with them and the 300 winchester magnum.

I don't shoot a .308 bore but in my .338 the 225gr Hornady comes apart pretty quick when impact vel. gets much over 2700fps. When I think that's going to happen, I'll switch to a NP. For open country, longer range shots, I think you would be fine. Fdeer size game you should be good to go.

RB: When I was hunting with my .300 Win. I fed it a strict diet of 180 gr. flat based Interlocks at 3100 fps. This load worked great on a 200 lb. muley buck at 90 yards and an antelope at 300. Both were broadside heart shots and the wound channels were remarkably similar with golf ball sized exit holes. If you are in any way leery about the bullet not holding together enough try a flat based version before you move on to a bonded bullet. In my experience the flat based Hornady Interlocks are some of the most accurate bullets made.

frontlander;I hunt open country and I will be sticking to the boatail design.I will be doing some development with the 180gr as well though.I have read other threads saying the same about accuracy of the flatbased bullets.I have had two long distance adventures in the last two seasons and I want to be able to go 400yds and will be practicing to 500yds.I am glad to here about the interlocks holding up at 3100fps.
Thanks for the info RB

I've just started to shoot them in my 300wsm and so far on paper they look pretty good. I'm alittle over 3100fps. I shot some speers 165 gr bt at 300yds and also they printed on paper pretty good. I got one box of interbond 165 gr and haven't tried they yet seems to be a longer bullet and with either r-19 or r-22 don't think there is much case capacity left for those longer bullets. I'am trying H-4350 as that may give me enought case to try the interbonds plus keep the velocity between 3000/3100fps. I thought I'd try a different barrel this time so got a broughton 5r which likes the bt bullets and it's been an experience as I usually shot flat base bullets for hunting. I started back in the 60's reloading and have never really shot many bt bullets, I did try the lvd bullets in a 6br and 6/284 I had done up with a 1/8 twist barrels and never had much luck with those rifles just me. Been shooting a 6.5/284 set up for the 142smk and has given me a better look at what bt bullets can do. Never too old to learn. Good luck

Ruttinbuck,

I hunted Mulies for over a decade with 145 gn 7mm Hot cores @ about 3100 fs, never had a problem one and frankly I'd have more faith in your load. Deer just arent that tough. In fact, I think a less tough bullet actually works better on a deer because they react to their thin hides quicker and deliver more shock before sailing away out the back door. Even at high velocities.

My current deer load is a 115 gn .257 BT @ 3100 fs

I'm going the opposite way by adding mass and slowing down for a "soft" 7mm Rem Mag load, using 175gr SP Hornady Interlocks @ ~ 2850-2900 fps. This should be slow enough to not blow up on contact, soft enough to expand decently, and carry plenty of momentum to perforate a whitetail/muley at a "raking" angle (thanks Elmer) if necessary. I'll use 175gr Partitions for a "hard" elk/moose load.

Call me a stubborn old fart but I've definately developed a preference for heavy, flat-based SPs. Although they usually group very well, I don't like the tendancy displayed by boattails and poly-tipped bullets to expand too rapidly, lose cores, and not penetrate big game when hit at close range. I like heavy for caliber bullets, especially in magnums, because they maintain momentum better than lighter bullets. I could go to a somewhate lighter bonded bullet and flatten out the trajectory and maybe gain extra "energy" but I'll stick with old tried and true technology and use heavy, flat based SP Interlocks or Partitions, pending on rifle and/or game hunted. This is just my humble opinion, your mileage may vary.......

I would recommend against it. In my experience, Hornady Inerlocks start to fail at around 2800 fps give or take. The bullet depicted ont he far right is a 180gr Hornady out of a 300 Weatherby. I recovered the bullet from an impala shot at 80 yards slightly quartering towards me on the point of the shoulder. Bullet found in the offside ham weighing approx 80 grains. Given the caliber, bullet weight and animal size, that bullet should have zipped right through. I switched to Partitions for the 300. Other bullets shown are 300gr 375 A Frames. jorge

ruttinbuck,

Even in Northern New England the bear season is open at the same time as the deer season is. Thus one would want to be prepared for both.

The thing about asking a question like this is pretty soon the suggestions get bid up and up.

I use Hornady 139gr boattail interlokts in my 7mm rem mag, at 3200fps muzzle velocity, never recovered one from a deer.

I've used a number of Interlocks 7mm , 25 caliber , 6mm at muzzle speeds of 3000+ to 3200 they work just fine on deer/lope size stuff . Far as that goes , they worked just fine before they even had the interlock . The same goes for flat base Speer Hot Cores. These bullets usually punch clear thru on rib shots if you keep off the shoulders.....



Jorge , I would hardly call the Hornaday in the picture a failure.........from the description of your shot it sounds like the bullet made it thru the shoulder and penetrated a considerable distance and still held together , although I'll grant you it shed quite a little weight .......to be expected I think........maybe too soft for big stuff and maybe more destructive than needed for the smaller stuff but the impala must have died or you wouldn't have the bullet ??

One thing to keep in mind, too, is that Weatherby, the self-proclaimed high-velocity "experts" have been having Norma load Hornady as the standard bullet in their (Weatherby's) factory ammo for decades, now.

Doesn't mean InterLocks are perfect, but something to consider, nonetheless.

RSY

I stopped using standard bullet about 10 years ago. I shot a blacktail buck (120 lbs.) at a measured 172 yards. The cartridge was 8 m/m Mag. Bullet was 220 gr Spire point loaded to 2890 fps. The deer was steeply quartering away. I shot him behind the ribs aiming for the off shoulder. The bullet hit no bone, but shattered on impact. The sheer horsepower downed the animal(hit a bit high and close to the spine), but it required a finishing shot.

These bullets were supposed to be designed for the 8 mag and heavier game. I realize this was only one animal and one bullet it, but it convinced me to use premium bullets on game.

Slinger: Point taken, but the fact that a 180gr from a 300 Weatherby failed to pass through an 80 lb impala is indicative that the bullet might have failed on a bigger animal like an eland. I use 139gr Hornadys out of my 7 Wby Mag also with great success on deer, but I would definetly NOT use them on elk sized game. Partitions, A Frames, Xs etc work much better at higher velocities and I'm not about to scrimp on bullets on a 10k plus hunting trip. At impact velocities of 2700 fps & below Hornadys are great bullets but at the sppeds mentioned in the original post, I'd be careful, very careful about shot placement. jorge

Thanks for the info Guys.I will continue on my load developing path.Start shooting the 165gr BTSP this week.
Regards RB