Load Too Hot??

[TenshiWingusu]

Hey Everyone,

This is my first post here so be nice, I did do a lot of searching for the answer already but didn’t get much.

I have a R700 Sendero SFII in 300 Win Mag, it’s a 1/4 MOA rifle when I use the 208 A-Max over some RL22 but the 208 has been sold out EVERYWHERE so I was forced to use SMK's mainly the 200 HPBT

Alliant's Site has a 200gr Speer SP which is nothing like the SMK but close enough to start to; it lists it at 73gr of RL22 and a MV of 2852 fps out of a 24 inch tube.

So I loaded a few strings working my way up. At 72.5gr I started to get an average MV of 2963 fps out of my 26 inch barrel ( Fed. match magnum primer, unfired Winchester case, and an OAL of 3.43" I didn’t want to shoot a compressed load and I have a long throat) my gun flattens and craters every primer so that doesn’t help me much and the bolt lift was pretty normal.

Is it too hot?

That load shot the best group of all the strings so I’d hate to not use it.

Thanks for the help!

 

[Greg Langelius *]

Re: Load Too Hot??

If you're not sure, it is. I know that's not all that helpful, but I think that what you're really talking about is your peace of mind.

On a more practical level, the lack of bolt drag suggest more optimism, but if pressures are your concern, I'd try working the load downward in small increments until you find the next lowest 'best accuracy' node.

It's my personal belief that the slowest velocity that delivers both good accuracy and at least 1300fps at the target is the best load for the rifle.

With the .308 and those heavier bullets, that's a pretty narrow margin; and may not, in fact, be fully achieveable. In which case, I would nudge the acceptable 'at-target' velocity downward to 1200fps, and certainly not less than 1175fps.

This is why I no longer shoot .308 for LR. IMHO, the .260, .280, and .30-'06 are all superior for that task, mainly because they can deliver that 1300fps without running at marginal overloads.

The more pressure you cram on in the bore, the more beating the bullet takes before it exits, and the more copper fouling one has to deal with as the string of fire progresses. Neither is good for scores or bore life.

With the .300WM, a VERY versatile chambering, you can get what you need with the pressures still just loafing along. Larger charges of slower powders can still produce a respectable load density percentage, and hey, that's a good thing. Going for the licketysplit velocities is not good for anything, really; and that includes your physique, too. If you beat 'you' up, you have a tired shooter trying to get those good scores for you. Loaf it, you'll like it more.

Greg

 

[alf]

Re: Load Too Hot??

Nosler shows 72.5 at 2960 as max for comparison.

Primer appearance is't always reliable by itself.

A good test is to rechamber a fired piece of brass. If the bolt has quite a bit of resistance, you're already there.

 

[TenshiWingusu]

Re: Load Too Hot??

Great guys thanks for the help, what does the Nosler manual show for the 190 SMK's max load? I have a 600 yard shoot next week and I’m scrambling to try and find something that is going to work well and not blow up in my face.

 

[BCP]

Re: Load Too Hot??

Here are some 300 win mag loads:

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=348736&gonew=1#UNREAD

I see a couple people using an almost identical load to yours so you're probably fine. I have that same rifle and am chicken though so my 180 nosler loads go about 2850fps.

 

[alf]

Re: Load Too Hot??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tenshi Wingusu</div><div class="ubbcode-body"> what does the Nosler manual show for the 190 SMK's max load?</div></div>

Nosler isn't gonna pimp someone else's product......

Sierra shows 72.7 of 22 with their 190's.

 

[samnev]

Re: Load Too Hot??

Just MHO but if your flattening and cratering primers I would back off some. Why take a chance of a problem happening. Primer condition isn't ALWAYS a danger indicater but usually tells you your in thr danger zone.

 

[TenshiWingusu]

Re: Load Too Hot??

my gun flattens all primers, low load, high load, factory ammo. primer metal isnt what it used to be.

 

[jrob300]

Re: Load Too Hot??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tenshi Wingusu</div><div class="ubbcode-body">my gun flattens all primers, low load, high load, factory ammo. primer metal isnt what it used to be. </div></div>

Tenshi,

I have a 300WM also. It used to flatten primers, not matter what also. I just bought a lot of Win. brass and now, I can't seem to get it to flatten the primers. Even when I get stiff bolt lift. The difference? The pockets on the Win. brass are a lot tighter than the Fed./Nosler brass I've been using. My guess is the primers are not moving in the primer pocket as easily.

Primer flattening in a Magnum rifle is not a good way to look for pressure.

Heavy bolt lift, brass does not rechamber easily. Those are the two biggest clues to me... time to back off.

John

 

[TenshiWingusu]

Re: Load Too Hot??

Thanks everyone for your help. I would have had some nice load data for the 190 SMKs but the thunderstorms in central FL were bad this morning

I think the 200SMK load will be fine. The brass rechambered fine and I had no stiff bolt lift. (famous last words...)