30-06: I'm confused about bullet nominclature and loads...

[bison]

HNY to all - I'd appreciate some help on a couple basic things regarding loads for my 30-06. I'm trying to work up a hunting load for my M70 using IMR 4350 and Hornady Interlock 180 gr BTSP's. I'm seeing somewhat conflicting data, but may be misinterpreting it.

My Lee manual lists load data for "180 Grain Jacketed Bullet" as 49.1-53.0 grains. The Hodgdon website lists a 180 Gr SIE SPBT at 53.0-56.5 gn.

If I'm reading this right, Lee's max load is Hodgdon's minimum. From various posts I've see, it appears that several people have recommended about 55 gn of IMR 4350 for various 180 grain bullets.

Same issue for some 165 gn SP's: Lee lists 51.8-54.0 and Hodgdon shows 56.0-60.0

So a couple questions: 1) what is the right load range I should use?, and more generally 2) is load data generally interchangeable for bullets of the same weight (SP and BTSP, for example)?

Thanks!

 

[oneounceload]

I would trust the powder or bullet maker's data over anything from Lee or similar - they actually do the testing, including pressure testing

 

[MEHavey]

Hornady(6th ed) lists their 180 BTSP w/ an OAL of 3.245" (centered on cannelure) and a MAX of 54.4 gr of IMR4350. QuickLoad says that combination is good for 54,500psi and 2,670 fps -- "OK"

On the other hand, QuickLoad says that 56.5gr load Hodgdon lists at this OAL will hit in excess of 60,000psi/2,770fps -- the absolute STOPS of a 60,000psi-rated cartridge.

A 55gr/IMR4350/55,300psi load would not bother me in a modern bolt action as long as the brass showed showed no ill effects at the ejector slot,

56.5gr/IMR4350/180BTSP/3.245" would bother me in this configuration.

BREAK BREAK:
IF you seat that bullet out to an OAL of 3.400" (beyond the cannelure), the game changes. Now that 56.5gr Load of IMR4350 produces only 54,500psi -- another "OK" load. Problem is, your Model-70 may have a throat configuration which will prevent seating that particular bullet to that length w/o jamming it into the rifling. (This was the case with my own Model-70.)

Do you know the distance-to-lands for the Hornady 180-BTSP in your rifle?

 

[bison]

MEHavey - the COL to the lands is about 3.268". It's a new Model 70.

I have zero interest in pushing any limits and would prefer not to mess around too much with the COL (I don't have QuickLoad or anything that would tell me the effects of doing so). Better to keep the variables to a minimum.

So the bullet manufacturer says 54.4 gn max, the powder manufacturer (and software) says 56.5 gn, the press manufacturer says 53.0 gn. Confusing!

If 56.5 is pushing it (at 3.245"), maybe I load 5 each at 53, 54, 55, and 56 gns (or is this pushing it?) and see what groups best?

Can you pls tell me what the Hornady book says for the 165 gn SP's?

Thanks!

 

[MEHavey]

I believe the loading variations you're seeing is due to OAL variances and bullet type.
They matter when hitting a full case with no leftover room.

Hodgdon data is specifically for the 180 SMK @ 3.300" OAL.
Even then it's a 58,000psi load at Max

That said, Hornady lists:
HNDY 165 SP (#3040) flat base
OAL = 3.230 (cannelure)
IMR4350
- Min 48.1gr for 2,400fps (QL says 2,390fps @ 34,200psi for 24"barrel)
- Max 57.0gr for 2,900fps (QL says 2,825fps @ 56,400psi)

My lawyer says to work up carefully.
~~~~~~~~~~~~~~~~~~~~~~~

(For the HNDY 180 BTSP at the cannelure, I'd not pass 54.4 w/o good reason and a lot of brass reading.)

 

[NCsmitty]

So the bullet manufacturer says 54.4 gn max, the powder manufacturer (and software) says 56.5 gn, the press manufacturer says 53.0 gn. Confusing!

Yes, for new reloaders, various manuals will list differing charges for the same powders and loads. They will be different due to the type of firearm being used to develop the load, and different lot numbers of components.
Always remember to err on the side of safety, and use the lower charges listed between the differing manuals and work up from there.

Unless you are hunting moose or game weighing 500lbs and more, I would recommend the 165gr bullets for deer and general use. It works very well in the 30'06 and provides good ballistics.



NCsmitty

 

[bison]

This will be my hog gun so I wanted something with plenty of "oomph", though I'd prefer accuracy (that brings confidence in pulling the trigger). I'd tried both 165's and 180's using H414 but couldn't get a grouping I was pleased with (though this powder is great in my 270), so figured I try a different powder.

I'd tried 52, 53, and 54 gns of IMR 4350 on the 165's (as well as 50, 51, and 52 gns for the 180's) and wasn't satisfied with each.

So I think I'll try maybe 55 and 56 gns for the 165's and 53 and 54 gns for the 180's and see how they shoot. Sound reasonable?

 

[MEHavey]

So I think I'll try maybe 55 and 56 gns for the 165's and 53 and 54 gns for the 180's and see how they shoot. Sound reasonable?

Those specs are within Hornady Manual limits.

(Because of my recent experience with another brand new Mod-70/30-06, I'd be interested in what you eventually find for/as satisfactory groups.)

 

[rsbible]

I've experienced similar conflicts in the past. I was told that Hodgdon and Sierra are the only two that actually do their own pressure testing (don't know if that's true or not) and that I can ALWAYS trust the Hodgdon website first. Bottom line...I always start pretty low and work my way up so not usually a huge issue.

 

[ranger335v]

No intelligent reloader is going to take anyone's "max" load as safe. The common admonition to 'start low, only work up if...," etc. applies. Start by picking an OAL that feeds and chambers without jamming the bullet in the lands, start low and develop your charge at that length. Tweak the OAL for best accuracy after you find the best shooting combo of powder and bullet.

All loading data is generic by powder type and bullet weight so it really doesn't make any difference which manual we work with. The book makers give us the charges and OAL they used and the velocity results they obtained. Each team uses their own rifles so they get different results, if they used the same ones they would likely be very close in results. Our's is different from their's so our results will also be somewhat different. (And some books don't give a specific OAL simply because it's largely irrelivant to us as individuals.)

Quick Load and favorite manuals not withstanding, reloading is more of an art than a science. We have to find what works best for us and no one else can tell us what that will be!

 

[MEHavey]

Sierra's 180 SP(#2150/flat base) is a close match-up w/ Hornady's 180 SP.

Sierra's (5th ed) data maxes out at 55.3gr/IMR4350 for an OAL=3.300"
QuickLoad says that produces 100% case fill/54,900psi -- safe w/ ~10% margin
Again, the loadout numbers differ

But also again... the devil is in the exact details, and a careful workup.

 

[Sunray]

"...My Lee manual..." Their data comes from other sources. Usually Hodgdon. At least for Hodgdon sold powders.
"...think I'll try maybe..." Work up the load from the Starting load. Don't just pick a few and hope.