Fine Tuning Powder Charges and Anything Wrong With My Rifle?

[falldowngoboom]

So I finally caved and got a shooting vise. I'm an okay shot with sandbags, but I wanted to rule out human error.

I loaded up some 150g Hornady FMJBT under IMR 4350 for my 30-06. Loads were 57.4, 57.7, 58.0, 58.3, 58.6, 58.9, 59.2, and 59.5. The second pic has the 59.2 and 59.5. I spaced for a moment and shot the wrong target, so the 59.2 is spread over two.

I found 58.9g to be the best load out of the group, so should I now load up in 0.1g increments to fine tune? Something like 58.7, 58.8, 58.9, 59.0, 59.1? Are 3 shot groups enough or should I have tested 4 or 5 shots?

Also, is there anything wrong with my gun that I don't have any sub-MOA groups using a vise through this range of loads?

All shots were at 100yds. with a Marlin XL7 in 30-06. Targets were 5.875" diameter (black part). Every two groups (6 rounds) I cleaned and allowed to cool for 10 min. Weather was mid 80s.

 

[30Cal]

Those aren't exactly match bullets (I think they're at the polar opposite end of the scale). 2MoA with fodder bullets is reasonable.

I typically use 1gr increments and 0.3grs when I go to fine tune. I don't think 0.1grs (especially for '06) is going to do anything useful for you.

58.1 or 58.2 looks good to me. I look for a load that shoots well that isn't picky--not interested in a 1/4 MoA load if I have to measure out every single charge in order to get it.

 

[rcmodel]

+1

In general, FMJ-BT's are the least accurate bullets made.

If you want to see how well it can shoot, get some HP or A-Max match bullets, or V-Max varmint bullets with the jacket hole on the front end.

It is also possible a vice will not give you all the accuracy your rifle is capable of.

Clamping solid in a vice can set up barrel & stock vibrations and bedding issues never present in hand-held firing off of sand-bags.

IMO: You should have spent the vice money on better bullets.

rc

 

[falldowngoboom]

58.1 or 58.2 looks good to me.

30cal, is that a typo or do you mean 58.1/58.2g works well for your gun? Thanks for the feedback.

In general, FMJ-BT's are the least accurate bullets made.

If you want to see how well it can shoot, get some HP or A-Max match bullets, or V-Max varmint bullets with the jacket hole on the front end.

RC, I guess I just assumed FMJ BT would be more accurate because they have a solid tip, as opposed to HPBT. I'd like to stay with Hornady as I plan on using GMXs for hunting, but I could switch to either BTSP or HPBT for plinking. Which would be better? For my purposes, I'd rather shoot more than pay for the extra accuracy, but maybe I'll buy a box of the good stuff just to see what the barrel can do.

It is also possible a vice will not give you all the accuracy your rifle is capable of.

Clamping solid in a vice can set up barrel & stock vibrations and bedding issues never present in hand-held firing off of sand-bags.

I was worried about harmonics, so I made sure to put my shotbags on the stock only and not touch the barrel or receiver. The clamp on the vise isn't really that great, so the grip on the forend wasn't all that firm. Vise only cost $30 after all.

 

[Ol` Joe]

I`d shoot the Hornady SP and then use the same bullet for hunting. I went with a 150 gr Hornady SP for years in my `06 for deer and never once was let down.
When I hunted moose and bear the 180 gr SP was again my choice. Both bullets are flat enough out to 300 yds in the 30-06 for the game they are designed for and accurate to boot.

 

[30Cal]

30cal, is that a typo or do you mean 58.1/58.2g works well for your gun?

No typo. Looking at your targets, I see nice groups at 58.0 and 58.3. Now that I've looked at them again, I have some misgivings. They still look good to me, but it's hard to place any confidence in a single 3rd group. I generally shoot 15 each for the first pass (three 5rd groups). You may see a half minute group in one, then shoot again and see 1.5 MoA in the next (and that's with match stuff)

Match bullets are almost always HPBT--they're the easiest ones to manufactur with a high degree of consistancy. Also, the tip of the bullet really doesn't affect where the bullet goes. You can crunch it with a pair of pliars and it'll still go to the same place.

 

[WNTFW]

"30cal, is that a typo or do you mean 58.1/58.2g works well for your gun? Thanks for the feedback."

I think he is suggesting 58.1 to 58.2 would be a good range to look at since
58.0 & 58.3 looked good to him. If you find 2 good groups look in the middle and you should find a good load that will tolerate some variance.

Look at the Optimal Charge Weight site if you have not seen it yet.. (looks like you already did).
http://optimalchargeweight.embarqspace.com/

I have shot my best groups off of the ground. I'm not as good off of a bench. Prone is better when there is no bench or a bad bench. I tried a rest on a bench once. Not good for me. Some guys are obviously quite good at it, "Benchrest"

 

[Ky Larry]

My CZ-550 in .30-06 seems to like 165gr bullets better than 150 gr. It likes Hornady 165gr SST's with 56.5gr of IMR-4350. Will shoot .5 MOA from sand bags.

 

[falldowngoboom]

I`d shoot the Hornady SP and then use the same bullet for hunting.

Unfortunately (or fortunately) I've decided to use copper for hunting, so I have to pick a lead bullet for plinking and adjust to copper when I hunt.

As a side note: at a recent DFG clinic, I was shown x-rays from a study in colorado where they shot 37 mulies with lead bullets and x-rayed them before field dressing. They found the impact area (probably a 6-8" diameter circle around point of entry) contained hundreds of tiny lead fragments, most of them much, much smaller than BBs. This was regardless of the bullet being recovered or not. It was really eye-opening and the main reason I switched to copper. Just an FYI.

No typo. Looking at your targets, I see nice groups at 58.0 and 58.3. Now that I've looked at them again, I have some misgivings. They still look good to me, but it's hard to place any confidence in a single 3rd group.

Yeah, I thought 3 shot groups might be a bit skinny to judge with. I'll go with 4 or 5 next time. Reason I asked about the typo is that my best groups are actually 58.9 and 59.2. It's hard to tell, but I measured them out (using calipers on the pic I took) and they're 1.18" and 1.51" respectively whereas the 58.0 and 58.3 are 1.74" and 1.48" respectively.

If you find 2 good groups look in the middle and you should find a good load that will tolerate some variance.

Look at the Optimal Charge Weight site if you have not seen it yet.. (looks like you already did).

Yup, I think I've read through that twice. It's very helpful.

My CZ-550 in .30-06 seems to like 165gr bullets better than 150 gr. It likes Hornady 165gr SST's with 56.5gr of IMR-4350. Will shoot .5 MOA from sand bags.

I've heard that 165g tend to shoot better too many times now to ignore. I'm definitely gonna try some. They're kind of a bit much for my purposes (deer & pig) but if they shoot better...

 

[Slamfire]

Hornady FMJ's will shoot well under the right conditions. I don't think you are there. And your rifle may not be the right rifle.

I suspect they will shoot better with 55.0 grs IMR 4350, because I use to shoot a lot of 168 SMK's with that charge.

But, if you want match results, you better shoot match bullets.

I have shot 168 Hornady match, Nosler match, and Sierra match out to 600 yards. They are all good bullets.

Buy a box, and start at 55 grains IMR 4350, work your way a grain at a time, and see if you hit a sweet spot.

You can always refine later.

 

[smokey262]

I would stop cleaning so frequently too. Most of my rifles take a few shots to settle down after being cleaned.

 

[1911Tuner]

Also, is there anything wrong with my gun that I don't have any sub-MOA groups using a vise through this range of loads?

Probably not. Getting from 1 MOA to3/4 MOA through load development is twice as hard as getting from 1.25 MOA to 1. Getting to 1/2 MOA is twice as hard as getting to 3/4...and without some mechanical tweakin' on the rifle...almost impossible. If your criteria is to maintain that same MOA potential at 200 and 300 and 400 yards...the undertaking is garguantuan. Many rifles that will shoot MOA at a hundred and two hundred will fall apart at 300 and beyond.

Gilt-edged accuracy doesn't come from any one thing. It comes from several small things being right and stacking up...each one complimenting the other.

I think that fretting over useful accuracy is pretty much a waste of time unless you're a bench rest competitor or taking after prarie dogs across large expanses in Montana.

If you take a 7-shot group that spans one inch at a hundred yards...that group size only gives the rifle credit for the two worst shots. The others will be closer to the center. If you find the geographic center of that group, the worst two shots will be 1/2 inch from the center. I can't see a half inch at a hundred yards without 12 or 15X magnification...much less hold to it.

 

[tango2echo]

For load development I like to shoot atleast four 5 round groups. Even better, shoot 4 fives on two different days. Separate loads by .5grs to get close, then .2grs to refine.
(example: 45.0, 45.5, 46.0. 45.5 shoots well, so load 45.3, 45.5, 45.7 in second batch. 45.5 is still best. To refine further try the same load with slightly more or less bullet seating depth.)

I know this is a LOT of shooting, but if you want the ultimate in accuracy it is necessary.

I shoot off extra large, heavy sandbags. Never found anything better. The lead sled takes the sting out though.

Very good point 1911Tuner, just like racing. It takes 10% more Horsepower to go 1% faster (and usually 100% more money!)

t2e

 

[Ben Shepherd]

Brand new rifle you say? Don't worry about about dime sized groups with it until you've put better than 100 rounds down the tube. The barrels still breaking in and accuracy will jump all over until the barrel's broke in. I've seen it many, many times with factory mass produced rifles.

That doesn't mean they don't settle down and shoot very well to excellent most times, it just means they are mass produced, and won't shoot like a custom barrel that costs as much as your whole rifle did right out of the box.

Also, every 10-15 shots as you're braking it in, check all your screws/mounts. Make sure nothing is showing the potential to shoot loose.

 

[falldowngoboom]

Actually, I've shot nearly 300 rounds through it at this point... I'd just like to get it consistently shooting sub MOA at least.

 

[243winxb]

is there anything wrong with my gun that I don't have any sub-MOA groups.- I'd just like to get it CONSISTENTLY shooting sub MOA at least.

Sub MOA never going to happen with most factory rifles. Internet groups, Yes, real world groups NO. Consider yourself lucky if you can average 1 1/4" or under, shooting 4 groups, 5 shots each @100 yards. Its all in the barrel, you can bed the action, make custom ammo, use the best of scopes. But its still all in the barrels. In a hunting gun, the rifle must hold Zero week in, week out. This is most important. http://www.chuckhawks.com/practical_accuracy.htm Just check the gun tests in the American Rifleman, see how many rifles shoot under MOA.

 

[oneounceload]

Yeah, I thought 3 shot groups might be a bit skinny to judge with

I'll disagree with this philosophy for a medium caliber hunting rifle. For 15 shots, I would rather shoot 5 3-shot groups than the other way around. Most hunting shots are done in 1-3 shots anyway. I always fired a fouling shot first, then fired the three shots within a 30 second to one minute time frame to make it close to the actual scenario I might find myself in.

I would also try Barnes' all copper bullets. Once I had the bullet/load combo, I would leave my scope alone if I was going to shoot something completely different for "plinking"


Now, if you're talking BR or a varmint rig, then 5-shot groups make more sense

 

[1911Tuner]

5-7 shot groups are for proving accuracy...and preferably 7. 3 shot groups are for zeroing.

 

[R.W.Dale]

I'll second the comments above that FMJ-BT bullets are a complete waste of the ability to handload. I will not buy them anymore

 

[1911Tuner]

I'll second the comments above that FMJ-BT bullets are a complete waste of the ability to handload.

And I'll have to disagree...depending on the bullets. Pulled 147 grainers from mil-spec ball are pretty dismal. Hornady's 150 grain FMJBT bullets are accurate enough for practice out to 300 yards if shot from a good rifle. In .308, I like 47 grains of 748...metered, not weighed...for speed of assembly. Cut the charge to 46 grains in NATO brass. Not a top-end load, but it doesn't need to be.

 

[kelbro]

165gr bullets have consistently shot better in my 30-06 and 308s. You might give a little heavier bullet a try.

 

[JDGray]

Get better bullets

Sub MOA never going to happen with most factory rifles.

I disagree. It depends on the ammo, shooter, weather or not your shooting off a rest or bipod. I couldn't have lucked upon 2 centerfire rifles that just happen to be sub MOA shooters. My AR15 has put 10rds inside an inch, and my Savage .308 on a bad day will stay in an inch, normally .600" for 5 rds. However, to get sub moa, I shoot handloads with match bullets. That same AR15 has shot 2" 50yrd groups, with FMJ junk bullets.

 

[30Cal]

Actually, I've shot nearly 300 rounds through it at this point... I'd just like to get it consistently shooting sub MOA at least.

If you can't get it done with a 168gr Sierra, then it's probably not going to happen; at least not until you pump some more money into the rifle.

 

[R.W.Dale]

If you can't get it done with a 168gr Sierra, then it's probably not going to happen; at least not until you pump some more money into the rifle.

I wouldn't be so quick with this blanket statement. I've had 30-06'es and other 30 cal rifles in the past that absolutely would not shoot boat tail bullets worth beans Even matchkings. But thew same rifle would shoot little bug holes with flat based hunting bullets.

Before you condemn a rifle you need to try a few projectiles that differ dramatically in shape and weight. Each rifle is it's own individual with it's particular likes and dislikes