Started loading 300 win mag

[Thebear_78]

Preacher the havak is no heavier than the b14.


Sent from my iPhone using Tapatalk

 

[PearsonRidgeMan]

Then, after fire-forming brass I used 200 grn AB loaded the following loads (which I checked out results while fire-forming the brass to get a feel for the loads).

Sorry, I didn't include the velocities. Here they are. These are 3-shot groups. I'm targeting for a min vel of 2750 fps and max of 2850 fps. Prefer 2850 fps.

H4831SC 70.4 grn, WW Western Case, Fed 215M, 200 AB = 1.26" @ 100 yd
2842, 2857, 2855. Avg: 2851 Var: 15 fps

H4831SC 70.5 grn, WW Western Case, Fed 215M, 200 AB = 1.85" @ 100 yd
2830, 2861, 1861. Avg: 2851 Var: 21 fps

H4831SC 70.6 grn, WW Western Case, Fed 215M, 200 AB = 1.26" @ 100 yd
2842, 2818, 2772. Avg: 2811 Var: 70 fps

H1000 75.0 grn, WW Western Case, Fed 215M, 200 AB = 2.40" @ 100 yd.
2783, 2795, 2783. Avg: 2787 Var: 12 fps

 

[PearsonRidgeMan]

To: SJB58 et al. The cartridges are now set at approx 3.340" OAL. (I use the Hornady ogive method. See my Aug 24 post. ) At that OAL my bullet is resting 0.22" off the lands. For a hunting load (i.e., loading out of the magazing) I'm not sure IF I can get the bullet 0.050" off the lands.

 

[desertcj]

.220" off the lands is a long ways? Will your magazine not allow you to seat bullets out farther? Your rifle either has an exceptionally long throat for some reason or I suspect you may have measured the cartridge base to rifling incorrectly somehow?

 

[SJB358]

.220" off the lands is a long ways? Will your magazine not allow you to seat bullets out farther? Your rifle either has an exceptionally long throat for some reason or I suspect you may have measured the cartridge base to rifling incorrectly somehow?

That is pretty common for the 300 Win to be honest. They have a 3.4 mag box and most 200 Accubonds will touch at 3.6" roughly.

To: SJB58 et al. The cartridges are now set at approx 3.340" OAL. (I use the Hornady ogive method. See my Aug 24 post. ) At that OAL my bullet is resting 0.22" off the lands. For a hunting load (i.e., loading out of the magazing) I'm not sure IF I can get the bullet 0.050" off the lands.

Seeing your targets, I would try sinking the 200 AB another .010" shorter and see how that affects your groups PRM. They look very predictable at the 70.5 charge of H4831. If it were mine gun, that's what I would do and see what happens.

 

[PearsonRidgeMan]

One of the reasons I asked about load data was I've not done much adjusting of seating depths and its one thing I'd like to try to see (for myself) how it affects precision.

I measured my magazine (which is a trick due to design) with a Mitutoyo digital caliper and I get at least 3.52" of magazine space.

So, I like the idea of seating my bullets out further. I'm thinking of loading 3 at +0.010", 3 at +0.020", and 3 at +0.030". OAL would be 3.350", 3.360", and 3.370". I'll set the actual length with my 30 cal bullet comparator. (I think that's what you were saying "sink the bullets .010" shorter". Did I understand you correctly ?

 

[desertcj]

.220" off the lands is a long ways? Will your magazine not allow you to seat bullets out farther? Your rifle either has an exceptionally long throat for some reason or I suspect you may have measured the cartridge base to rifling incorrectly somehow?

That is pretty common for the 300 Win to be honest. They have a 3.4 mag box and most 200 Accubonds will touch at 3.6" roughly.

To: SJB58 et al. The cartridges are now set at approx 3.340" OAL. (I use the Hornady ogive method. See my Aug 24 post. ) At that OAL my bullet is resting 0.22" off the lands. For a hunting load (i.e., loading out of the magazing) I'm not sure IF I can get the bullet 0.050" off the lands.

Seeing your targets, I would try sinking the 200 AB another .010" shorter and see how that affects your groups PRM. They look very predictable at the 70.5 charge of H4831. If it were mine gun, that's what I would do and see what happens.

I've never loaded for a 300 win mag specifically. Holy cow that's a ton of jump though! I don't think I've ever heard of that much free bore except maybe the old(And maybe current?) Weatherby rifles/cartridges. I'd be trying to load them out as long as the magazine box would allow.

 

[PearsonRidgeMan]

desertcj : Yah, I know. But some of the guys at the Gun Club say exactly what you said "Never heard of that much free bore EXCEPT for maybe the Weatherby rifle cartridges." Then they added, "Measure your free bore with the Hornady gauges and see if Weatherby put that much 'jump' in the 300 WM as they do in the 300 Wthby Mag. I guess they do. I double, triple checked my msmt and asked several of the experienced reloaders at the Club and they all said I was measuring correctly. Sooo, here we is.

Hey! Thanks for your feedback. I've been shooting for a long, long time, but reloading only a few years. The PRM

 

[flyingagg]

The most I have heard on a 300 Win Mag is 0.120" off the lands. But I am just starting to load this caliber. My 300 WBY has about 0.150" or more freebore.

 

[SJB358]

Me personally I’d try some a bit shorter by .010 increments. Mean if you’re at 3.340 I’d try 3.330 and 3.320 myself before going longer.

Winchester’s aren’t the same freebore as a WBY, they just made their chamber when Bullets weren’t nearly as sharp pointed as we have today so the blunter bullets of the past filled up the throat, hence why Nosler has a 180 Protected Point Partition. It was made for a 300 Win Mag and to be loaded out in that cartridge.

It’s not a big deal really. Plenty of 300’s have shot fine with the long jump into the rifling and Accubonds usually thrive with some minor tweaking.

 

[flyingagg]

Scotty,
I just measured my New Heaven Model 70 Classic 300 Win Mag, I get 3.023 to lands using the Hornady O.A.L. Gauge and Bullet Comparator. I measured with Barnes 180 grn TTSX and Nosler BT 150 gr. I also Measure Factory Ammo form Hornady and Federal and I am getting about 0.200" of the lands.
You have a few model 70's. Am I doing something wrong?
Thanks
ASD

 

[SJB358]

Scotty,
I just measured my New Heaven Model 70 Classic 300 Win Mag, I get 3.023 to lands using the Hornady O.A.L. Gauge and Bullet Comparator. I measured with Barnes 180 grn TTSX and Nosler BT 150 gr. I also Measure Factory Ammo form Hornady and Federal and I am getting about 0.200" of the lands.
You have a few model 70's. Am I doing something wrong?
Thanks
ASD

I’m not sure what you mean by 3.023 to the lands? But the .200 from the lands with factory ammo makes sense to me.

 

[desertcj]

Scotty,
I just measured my New Heaven Model 70 Classic 300 Win Mag, I get 3.023 to lands using the Hornady O.A.L. Gauge and Bullet Comparator. I measured with Barnes 180 grn TTSX and Nosler BT 150 gr. I also Measure Factory Ammo form Hornady and Federal and I am getting about 0.200" of the lands.
You have a few model 70's. Am I doing something wrong?
Thanks
ASD

I’m not sure what you mean by 3.023 to the lands? But the .200 from the lands with factory ammo makes sense to me.

I think he's measuring ogive length with the bullet comparator. 3.023" base to ogive. What is the overall length of the cartridge when you're measuring 3.023" base to ogive?

 

[flyingagg]

Maybe I am using the wrong nomenclature. I think I mean the "Throat Length". It should be the equivalent of the bolt face to the lands using the Hornady modified case, Hornady O.A.L. Gauge, Hornady Bullet comparator and a Bullet of the appropriate caliber. My Model 70 30.06 id 2.742", my Model 70 300 Win Mag is 3.023".

 

[desertcj]

What is the measurement from the case head to bullet tip when you have the 3.023"? Will it fit in the magazine? You need to be at least .005" shorter than 3.023" with your assembled ammo but you could possibly gain a ton of case capacity here and I've never shot bullets with the amount of jump you're talking about before. I'm trying here, but you need to answer some basic questions....

 

[flyingagg]

Desertcj,
I don't think you understand what I am saying. What do you call the length from the bolt face to the lands where the Bullet ogive just touches them? Some call it Throat Length. Its the base number you use to calculate how much off the lands your loaded round ogive is.
What is your method of measuring this? I use the appropriate Hornady tools. I was just surprised to see on the 300 WIN MAG, some factory ammo was 0.200" inches off the lands.
I load my 30.06 at 0.010" off the lands.

 

[desertcj]

I understand what you're saying. You just haven't mentioned a few measurements. You've said 3.023" base to ogive. I get it, I know what your talking about. What is the TOTAL length of the cartridge with the base to ogive measurement at 3.023" and does it fit in your magazine box? How long of a cartridge can you fit in the magazine box? Did you mention 3.520" for the magazine box?

If you have the room to load longer, I see no reason to be loading the bullets .200" off the lands. Sometimes .100" up to .125" off the lands will show the best accuracy but I can't see needing more jump than that. All of my best loads are .005" off the lands...

 

[flyingagg]

I started thinking about this when Pearson mentioned about being 0.22" off the lands. I have not started loading this caliber yet. A friend told me he loads 215 Berger Hybrids to a 2.904 CBTO. That makes the COAL to be 3.703". This would not fit in my magazine. I will double check with him. Just out of curiosity I checked two brands of factory ammo I have, one Federal and one Hornady. These are COAL 3.33", fit in the magazine. CBTO is about 2.820, a full 0.200" of the lands. I was surprise and since Scotty is the Win M70 expert I was asking what he thought, maybe I was doing something wrong. I might have to have have some gunsmithing work if I want to load longer bullets.
I have another M70, same model, era and factory, but unfired, this one measures a full 0.100" shorter.

 

[desertcj]

Now we're getting somewhere, but you still haven't said what the COAL is with the CBTO at 3.023"? Or what length will actually fit in your magazine box. I'm going to bow out of this but hopefully you understand what I've been trying to get at? You might not be stuck with the .220" bullet jump...

 

[SJB358]

Now we're getting somewhere, but you still haven't said what the COAL is with the CBTO at 3.023"? Or what length will actually fit in your magazine box. I'm going to bow out of this but hopefully you understand what I've been trying to get at? You might not be stuck with the .220" bullet jump...

I think what he means is from the base of the cartridge to the beginning of the leade is 3.023, there is no bullet involved with his measurement so there is no way to provide a COAL, if I am understanding him correctly.

Ag, I am not totally surprised about the two rifles being different in throat, although, .1" is ALOT of difference, and more than I have ran across, but I don't think its crazy. 300 Wins have been around since 1962, so there are probably alot of worn reamers that were used. Typically, in my experience, a 200 AccuBond encounters the rifling around 3.575", or a bit less in a normal run of the mill 300 Win.

Jump to the rifling isn't a real bad thing at all times, but sometimes it leaves you without much option for load tuning.