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Old September 19, 2012, 02:06 PM   #1
Tom68
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7mm-08 Load Data puzzle

Would like to solicit some opinions regarding broad mis-match in published load data.

I am using IMR-4350 and 140 grain Nosler BT.

Speer #14 lists data for their 145 grain bullets. I am aware that it is okay to use load data for a slightly larger bullet, but never okay to do the reverse. Speer shows a min load of 44 grains, max load 48.0 grains, and does not even state that the load is compressed.

Hodgdon Basic Reloading Manual dated January 2009 lists data for a 140 gr. Swift SP: Max charge is listed as 46.5, and shows being compressed. Since they do not list a minimum charge, a 10% reduction would have the starting data at 41.85 grains, which I'll round up to 42.

Unfortunately, Nosler does not list load data for this bullet using IMR 4350, but they do list data using H-335, which is another powder I'm going to try. However..... Nosler's max load in H-335 is 40.0, while Hodgdon's data (again, using the Swift bullet) maxes out at 37.5 grains...another significant difference. Hodgdon's max charge barely clears Nosler's minimum for this powder.

Now, I always use at least two published references before developing any load, and I'm accustomed to seeing differences in load data: some of the differences are rather easily explained, such as using bullets from different makers in the exact same weights, due to the differences in construction, length, bearing surfaces, etc. Other differences are probably attributed to differences in measuring pressure, calibrations of equipment, and so on. Either way, I've not seen differences of this magnitude before, and it has me puzzled.

I've already loaded up to 47.5 grains of the IMR 4350 (haven't yet started the H-335, wanted to get a jump on getting opinions before I completely finish). Just like Hodgdon's data indicates, the load started compressing at or near 46.5 grains: at 47.5 it was difficult to seat the bullet at the maximum listed COAL of 2.800": I didn't even bother trying 48 grains: that much would just about have the case overflowing even with a very slow pour into the funnel.

I'll be firing these from a Ruger M77 that I have complained about before on this forum: 6 boxes of factory loads that would not group less than 1.5", most closer to 2" or more has me trending towards selling the rifle, but I borrowed a set of dies from a buddy to try handloading to see if it is worth salvaging. And, of course, I will be looking for overpressure signs as I work up, and will cease at the first positive sign.

Please reply with your thoughts, and especially your experiences with this combination. And... feel free to volunteer your favorite powder in this cartridge: I'll admit that I was a little overwhelmed by the wide selection of powders for which there is data, and I had six of them on my shelf.
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Old September 19, 2012, 03:48 PM   #2
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That doesn't seem to broad to me, well within 10% of each other. Either way, it makes sense to do the load up in your rifle with your components. Only way to know for sure anyways. Although I wouldn't have chosen 4350 for 7mm-08, as even with a 140gr projectile it seems a bit on the slow side for the case capacity.

Good luck.

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Old September 19, 2012, 05:24 PM   #3
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I have been using IMR 4064 with good results.
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Old September 19, 2012, 05:58 PM   #4
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I'm looking at the Nosler Manual 5th Edition. It lists the 140 grain BT and IMR 4350 powder
7mm-08 Remington. 140 BT, IMR 4350.
Start load, 42.0 grains for 2600 fps
Max load 46.0 grains for 2840 fps. They also say that the max load gave them the best accuracy.

I once had a Remington Model 7 in 7mm-08 that shot factory Core-locts so accurately that I never reloaded for it. It would keep them inside a half-inch all day long. I lost that rifle during a divorce and the subsequent financial dynamics and I'll admit that I miss the rifle a whole lot more than I miss the woman.
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Old September 19, 2012, 06:20 PM   #5
Brian Pfleuger
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Hodgdon data is pretty known for being MAX when they say max. That Speer data out of line.
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Old September 19, 2012, 07:56 PM   #6
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I'm looking at Nosler #6 ed. It's the same as their earlier manuals. 140 bt with 46 gr. max imr4350 100% load density.

I once owned a nicely accurate 708... it shot nearly everything that was around 140 grains in weight well with good ole ww 760, a ball powder that fits well in that size case.

My rifle was a Remington though, please don't be offended if I suggest that, perhaps your problem indeed has more to do with your rifle instead of your ammo.

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Old September 19, 2012, 09:14 PM   #7
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oldscot, no offense taken... I've been led to believe that M77's are rather hit or miss as far as accuracy goes, and I just may have a really pretty rifle that doesn't shoot too well. OR...it may be the amateur (eh, that would be me) who mounted the scope. That's another thing I'm going to check tomorrow before going to the range, as the bases may not be completely tight.

As far as the 4350 goes, I'm betting that I don't wind up firing the last two charges on account of excessive pressure signs, and that I re-claim that powder and try something else.

Was really hoping for a magic solution with on-hand powders as I haven't yet found a real need for faster burning powders; I load .270 Win more than anything else and my rifle likes H4831SC, RL-19, and IMR 4350. I do have some Varget on hand, and I'll be trying WC 844 tomorrow in addition to the 4350. Also have some WC 846 on hand as well as W760, but for some reason I naturally gravitate towards stick powders. If tomorrow's a bust, I'll still have a few options before dropping another $25 on a jug of powder.

A question for the guys who like ball powder in this cartridge... do you use a magnum primer? Hodgdon's data doesn't call for it, but Speer does. I used a WLRM primer for the WC 844 loads, and would also do so with the 846, W760, or H-380.
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Old September 19, 2012, 09:30 PM   #8
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The "magnum primer" for ball powders is an interesting topic. Several years ago the military found that normal primers in M80 ball ammunition could have a slight "delay" in lighting off WC846 powder.

This was a concern for use in electric motor driven miniguns used on some aviation platforms. The firing rate is so high that a delay could be disastrous. So the primer was changed to the current milspec "magnum" primer.

So there you have it, a standard primer will light off ball powder, but there can be a delay measured in microseconds. Some folks who hunt in the cold report failures to ignite, but I haven't any first hand data or .gov reports to fall back on for that.

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Old September 19, 2012, 09:36 PM   #9
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Out of curiosity, I ran the load info in QuickLoad to see what it thinks.

With default values, it thinks a Nolser 59992 140gr BT bullet over 48.0gr IMR4350 would be 111.9% case fill, produce 66,616psi and 2,949fps from a 24" barrel.

Using the Nosler bullet, it agrees with Hodgdon that 46.5gr (technically it thinks 46.6gr) would be max load, at 58,623psi and 2,855fps.

However, using the Swift bullet from Hodgdon's data, QL thinks max would be quite a bit higher, at 47.9gr

In any case, you'd probably have to use a wooden dowel and hammer to get enough 4350 in the case to rise to dangerous pressures.

If you're curious, QL thinks that RL-17 (45.5gr max) would give excellent velocity and 100% case fill, 99.97% powder burn, an exceptional 31% efficiency and 2,940fps from a 24" tube. RL19 and 4831SC are too slow, 110% compressed charges don't get you within 200fps of RL17.
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Old September 19, 2012, 09:57 PM   #10
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Differences in bullet construction.

I am not surprised at the differences in load data for the different bullets. While they are both "cup-and-core" construction, they have much different cups.

I once used Speer data with Nosler BT bullets (not yet having a Nosler manual). Loads that produced 3,000 fps with 130 grain Speer bullets produced 3200 fps with the same weight Noslers. I am sure that the difference was pressure, rather than magic.

But my M77 showed NO signs of pressure. I think that says more about the construction of the Ruger than my skill as a reloader at that point in my career. ANyway, I figured a steady diet of 3200 fps 130 grain Noslers would soon eat the barrel of my .270. So I bought a Nosler manual and found that their loads for their bullets produced nearly the same velocities as Speer's data for the Speer bullets.

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Old September 20, 2012, 08:03 AM   #11
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I'm not going to get into the powder selection/load, but will throw this out...

Unless I misread your posts, your "load workup" is consisting of a single bullet- the Nosler 140 grain BT...

Now, I've only been reloading for a few years now, but for a half-dozen centerfire rifles, including my long-range 7-08...

Your assessing the ultimate accuracy of the rifle, based on it's performance with a single bullet is a mistake, albeit that it's with different loads and powder combinations.

Could very well be, that your rifle doesn't like the 140 Nosler...

Could also be, that the rifle is somewhat inaccurate- a "hardware" issue, as it were. Barrel, action, who knows...

I understand that you had unsatisfactory results with factory loads, but you didn't say whether it was one type, or six different, or if they were "match grade" factory loads. Getting MOA results, from non-match ammo like FGMM or Black Hills is not likely from a factory stick.

But I would certainly try different bullets, in different weights, from different manufacturers. FWIW, the current barrel on my 7-08 likes the 150 SM over H4350. Factory 20" barrel, sub-minute accuracy.

I'm putting a new faster twist barrel today on my 7-08 to shoot the 162 Amax- hopefully. Will it like the bullet? Dunno- only time will tell.

Try some different bullets...
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Old September 20, 2012, 07:59 PM   #12
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Tom68 - Don't give up on it too quickly... we all want rifles that shoot like a dream right out of the box, but some weapons are just picky. You are right to check and recheck every component of the system, but keep working on your loads as well.

Another personal antedote... I have a nicely accurate Remington 700 ADL in 6mm Rem, but it wasn't always so. In fact, in all the years I've owned it, it has only shot three loads really well. Everything else I've put through it was mediocre to poor at best. But, oh, those loads it likes, it's really satisfying to see those groups.
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Old September 20, 2012, 10:28 PM   #13
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OK, range results are in...

albeit a very limited outing, but it did show some promise.

The attached picture is quite the outlier... out of 3-shot strings of 16 different charges and two powder types, I got 3 sub 1" groups, including this dandy .211" group. Could have been a fluke--as in even a blind squirrel gets a nut every now and again--but I did get two others at similar velocities that indicate some hope. Most of the others, however, were over 1"...and 1.5"... but believe me, that is FAR better than the 2" I was getting from six different factory rounds (Winchester Silvertips, Remington standard, Barnes, Superformance, Federal Premium, and I now have forgotten the other).

What I am seeing, and future testing may validate this... is that the rifle has nodes in the very low velocity range. The .211" group had an average MV of 2276 fps; the other two were slightly faster (.371" @ 2455 Avg MV, and .611" @ 2533). Of the 16 groups there were others hovering around the 1" mark, and they were all less than 2500 fps as well. ANYTHING in this bullet/powder combo fell apart as MV passed 2600, and though I pushed it up to 2800, it kept getting progressively worse.

tobnpr, you are correct in reading that I have begun this process using a single bullet type. I select a bullet for a specific purpose (Alabama Whitetails--they don't get very big around here) and then try to find a powder/primer combination that works well with that bullet. If it doesn't come together, I'll switch and start over... but I do NOT feel that I have to pay big $$ for premium bullets to harvest the kind of deer we have in my area.

But... being that this isn't my primary hunting rifle, I do have time to continue working on it... and my next step will be a faster stick powder, and some more experimentation with the WC 844. I was working in 0.4 gr increments, so I probably will go back to the same load I got results with before, and also try 0.2 gr on either side of that. Beyond that, it'll be a different bullet.

On sticking with the Nosler 140 gr BT... one wonders just how that would perform at 2276 fps?
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Old September 20, 2012, 10:34 PM   #14
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Well, I get a lot of criticism for it but I always like my guns to shoot like they're meant to shoot. If I wanted a 30-30, I'd buy one. I wanted a 7mm-08, so I bought one. 2,200 doesn't cut it for me, whether the bullet performs or not.

Just a thought, but if those expensive premium bullets,work, they're not nearly as expensive as punching 100 holes in paper with the "cheap" bullets trying to make them work.
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Old September 20, 2012, 10:45 PM   #15
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both good points.
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Old September 21, 2012, 06:23 AM   #16
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IMO, I don't consider the Nosler Ballistic Tip as a "cheap" bullet. Yes, it is cheapest in Nosler's hunting lineup but it is a well made bullet for whitetail.

I would rather start with one Nosler (pick your favorite brand/weight for intended target) bullet and change the powder selection till I find one that shoots well out of the rifle. I've always had good luck with Nosler bullets (also Sierra, Hornady, Berger and Barnes).

The toughest part of finding the right load is knowing your shooting abilities and your rifle capabilities. The reloading part is less complicated.
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Old September 21, 2012, 07:56 AM   #17
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Quote:
but I do NOT feel that I have to pay big $$ for premium bullets to harvest the kind of deer we have in my area.
Heck, Tom, you're absolutely correct.

I don't think anyone would argue that point.

You certainly don't need half-minute accuracy to hit the vital zone on a whitetail. I don't even hunt, but I get that

But, you said you were getting as good as minute and a half from factory ammo- that can always be improved with handloads, at least to the extent of minute of angle, if not better- based just on my experience...

So I don't understand, why you say that you're considering ditching a rifle that will probably hold minute accuracy when you find the right load/bullet combination, when that level of accuracy is perfectly fine for your intended use.

Anyway, I still stand by my opinion of trying different bullets- from different manufacturers, and different weights.

I've been there, and done that, too many times and know that if your rifle doesn't "like" the bullet- and we never know why- you often can't "make" it shoot by trying a dizzying combination of powders and loads.

My experience tells me that the "right" bullet is more important... and sometimes when you find that magic bullet, accuracy is far less sensitive to powder choice and load. Just one guy's opinion, YMMV.

And as an aside, I like Nosler's bullets... a little less expensive than SMK's and can shoot well.

The Custom Competition is one of the "go to" bullets in my son's 700 bolt .223.

Carrying that logic forward, we tried the 123 grain Custom Competition in his 6.5 Grendel AR.

LOUSY accuracy, compared to the 123 Amax. I've still got a partial box if anyone wants them...

Are they an inaccurate bullet? Heck no.

They are inaccurate out of this particular rifle.

You CANNOT pick one bullet, and be guaranteed it will shoot well out of any rifle- I don't care how many types of powders, primers and brass you try. Sometimes, it just doesn't work.

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Old September 21, 2012, 08:19 AM   #18
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tobnpr, I agree with you on all points.

What may or may not have been clearly expressed before, is that yesterday was the first time this rifle had ever shot anything better than 2", with 6 different factory loads, some of them being "top shelf". With results like that, I initially felt that I really had reason to question whether the rifle would ever accurately shoot anything.

So, with yesterday's results, I'm no longer considering writing off the rifle--it definitely has potential. But I will keep working on components to see if I can find a combination that shoots at least 1" consistently within acceptable 7mm-08 velocities (with a nod to Brian).

So many projects, so little time... I've still got my son's .308 that I haven't tamed. It'll shoot Federal Fusions, and nothing else that I've tried, including Federal GMM and Hornady Match. But, I back-burnered that project, since he at least has an accurate load to hunt with this season... But, that is a topic of another thread I started last year...
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Old September 22, 2012, 01:27 AM   #19
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Before you write the rifle off, be sure to check the action inletting and fore end. Rugers are notorious for having over-torqued action screws, and nearly any brand of rifle can come with defects in the action inletting.

My M77 Mk II was no different. I spent the first few years with that .270, chasing demons that I couldn't identify. Some of the best groups it printed were in the 3-4" range. I was always frustrated after a test session.

But, things changed tremendously when I realized I had been over-torquing the action screws, and that the front screw had been tightened so far at the factory that it crushed some of the wood. I also cleaned up a few wood chips that had been pressed into the stock so firmly, they appeared to be attached, but were causing the action to seat poorly against the stock. That, combined with sanding a couple little 'bumps' of resin in the barrel channel (laminate stock), turned the rifle around.

Now, I fully expect that rifle to shoot sub-MoA with a decent load. If it doesn't meet those standards, the load goes back to the drawing board.
With a good load, the rifle will shoot right around 0.5-0.6" groups, any time I have a steady rest. (The shooter is the biggest limitation, in getting things any tighter than that. )

Installing a Timney trigger and sear really help the shooter tame things, due to bad habits created shooting so many heavy-triggered milsurps. But I can't say that it really had any effect on the rifle... It just helped cover up my own bad habit.



As far as your 140 BT goes... I'd definitely be looking at a different powder, if you don't like the velocity of those good groups.

If you want to be sure it's the rifle, and not the bullet; I'd suggest giving some Remington Core-Lokts a try (the component bullet, not the ammunition). I've never found a rifle that wouldn't shoot Core-Lokts fairly well. It may be a "bargain basement" bullet that looks like crap, but, for some reason, they tend to be very forgiving and can produce some pretty decent groups.
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