Home Forums Hunting & Shooting Ask The Gunwriters 7-08 Loading Question from Big Book of Gun Gack

I've read the book (and love it it by the way!) and have run into a loading question. I've been working up some loads trying to duplicate the Federal Premium 140 grn NBT load I've been hunting with for the last few years. I checked the Big Books listing, and it shows several loads with similar bullets (1 with the NBT) all at 49 grn of H4350.

I checked Hogdon's data, and they list 48 as a compressed Max load. I started at 47 grn, and loaded up to their 48, but I'm kinda worried about moving up to the 49. I'm generally a conservative loader, looking for accuracy over velocity, but I've also read Mule Deer enough now to know he is too... So is this really that compressed of a load, and safe? I know this is a somewhat rhetorical question as I know JB wouldn't publish something pushing the ragged edge.

I'm heading to the range tomorrow afternoon to test these loads and the chronograph I'm sure will shed some light on this, but I'm still curious.

Did you read the chapter about why reloading data varies?

I think you pretty much answered your own question.

John, I don't have near the experience that JB has, but I do have a decent amount loading for the 7-08. If you're going to be dealing with compressed loads, like the H4350 example you posted, you may want to consider going to a ball powder like H414 or Big Game, as it compresses more easily than extruded powders. Just a thought......

What's your COAL? Are you matching the length of the premium NBT loads? If I recall, they are 2.72 or 2.75" OAL (going on a vague recollection). Can you load them out to 2.8" or so to free up some case capacity and still be within magazine limits and throat limitations? Just an thought.

I would think factory ammo would all be to SAAMI spec, or in this case 2.800.

You're probably right JG. I'm having vague memories going back about 12-13 years ago or so when I played around with the Federal factory stuff. I think I have box of the 140s tucked away and will have to check.

Yeah, I've got room to seat out, and magazine room as well, but the load would still be compressed. 48 grn's is mid way up the neck.

I've tried some other powders that aren't compressed and have shown some possibilities (RL-17 and 4451). Mule Deer's recommendations have been spot on so far, so when starting a load I checked his recommendation in The Big Book, and hence the question.

On one hand, I don't know why it worries me, since I know he wouldn't publish anything he thought was on the edge. The only worry is I've looked high and low for a load showing 49 grn's of H4350, but 48 keeps popping up as the max.

Thanks for the replies.

JohnChilds,

Glad you like the book!

If you check Hodgdon's data, you'll find the 48.0 grain maximum load of H4350 with a 140 uses the Swift A-Frame, a bullet that tends to produce more pressure than most other bullets. Even so, 48.0 grains only results in 49,800 CUP (Copper Units of Pressure).

This indicates the data is fairly old, since Hodgdon (and SAAMI) have pretty much switched over to electronic testing and list pressure in PSI (Pounds per Square Inch). However, I have an older SAAMI handbook which lists the maximum average pressure (MAP) for the 7-08 as 52,000 CUP. So even with the Swift A-Frame the load's pressure is well under SAAMI's listed MAP.

Hodgdon's data for the 139 Hornady Interlock Spire Point (which tends to produce less pressure than most other bullets) lists 50.0 grains of H4350 as maximum for 47,500 CUP. This indicates the maximum listed charge of H4350 is limited by space inside the case, rather than pressure. I've used the 50.0 grain maximum and it is indeed ALL the H4350 you can get into a 7-08 case and still seat a 139/140 grain lead-cored bullet. All pressure indications were mild in my rifle.

Which is why I eventually settled on 49.0 grains of H4350 as a "normal maximum." which has worked well in sdeveral rifles with lead-cored 139/140 grain bullets. That much H4350, however, takes up too much room with the 140-grain Tipped TSX, which is longer than any lead-cored 140, which is why I use Big Game with TTSX's: Big Game is much more compact than H4350.

I sincerely doubt you'll encounter any pressure problems with the 140 Ballistic Tip with 49.0 or even 50.0 grains of H4350. But 50.0 grains would probably be pretty crunchy when seating a plastic-tipped boattail, and the bullets might not want to remain seated at the same depth!

Mule Deer,

Thanks for the reply. Your info makes total sense. I'll be trying that load this afternoon.

Keep the great books coming!

Just a follow up. I shot the 49 grn H4350 load, and it seemed to have no issues. Unfortunately my chrono's battery died just prior to shooting this load so I don't have speeds to reverse verify pressure, but from Mule Deer's info above I'm sure it is fine.

The load showed some promise. The day turned erratically breezy, and the load still shot into slightly over an inch, with a nice center cluster from a 5 shot group. I'm thinking this might be the load I've been looking for.

Thanks JB for the insight!!

FWIW 50 H4350 and a flat base 139 Horn SP have been a fairly religious 2850-2875 out of Doecamper's 20" Model 7 7mm08.

Really can't expect a sweeter spot for a 7mm cup n core bullet.

GE

I tend to shoot hotter loads in stronger action guns, such as Winchester model 70s. With Remington actions, I tend to work up cautiously.

Might be my own theory, but it produces excellent results in all my rifles.

70's are stronger than 700's?

Oh, oh, this is how it starts.

I hate compressed loads and avoid them if at all possible.

Varget is your huckleberry in the 7-08. There are likely newer powders I haven't tried that are just as good. 4350 was never my favorite with that cartridge. Many ball powders are just denser than rat turd powders- not necessarily easier to "crunch". Big game and Hunter are hard not to like- if you can find them.

If you can find them is the key word! Been looking... I'd like to find both, but Big Game seems to fit more of the loads I would use.

Big Game = pixy dust in these parts...I've had the itch to try it in my 7-08 for 3 years now with no luck. I've heard some say 4451 is pretty good with heavier bullets in the 7-08, and I now have some just haven't been able to try it.

I did try some 4451, but RL-17 shot ever so slightly better. It didn't shoot bad, and could be something if I played with it, but the RL-17 slightly more consistent.

Dennis,

Would be interested in why you "hate compressed loads and avoid them if at all possible."

I'm not Dennis and I don't play him on the internet, but I prefer to avoid much powder compression for runout and seating die reasons.