Pre-mil 308 Savage 99 shoots a nice group @ 125 yards (top group).

At 200 yards it turns to crap (bottom group).

Loads are 150 grn. ballistic tips running at 2810 fps. Ballistics shows a 2" drop @200 but I'm getting quite a bit more. Any ideas?

Groups look like either a scope or a bedding type issue.

The excessive drop could be attributed to a different shooting rest setup, or something else that may change POI, other than gravity.

Are you shooting with a scope?

Also, both groups are string horizontally. That could be due to strong winds, but I hope not. If not, it could be the bedding of the forend.

Also have to ask: Are you checking the alignment of the bullets in your handloads?

I'm surprised that no one has chimed in to righteously rip you for having a target backing that was made in China. (or contained a product made therein)

Scope is a Leupold 3X9 I use for load developement.

Wind was light from right to left.

No on checking alignment Of bullets.

Same rest on both groups. Range has maybe a 3 to 5 foot drop in elevation over 200 yards.

What gets me the most is the drop.

My range less the cow.



My set up but not the rifle in question.



BP...

I ran out of radical Islamist boxes.

BP...

lets see about a 2" group at a 100 and about a 5" group at 200 is about on par for one anouther I would be working on cutting the 100 group down before i worried about the 200 ,oops i see now 125 yrd for the top group than add a little wind still not that far off

What does Federal Gold Medal Match (or other match ammunition of your choice) shoot in your rifle under the same conditions?

Shot on the left at 125 yard was a called flier. None the less, why the extreme drop, about 7" and a 6" spread, at 200?

BP...

re: drop.....For practical purposes, looks like you are sighted POA at 100 yds....you should be more like 2" high at 100 to be POA at 200 with that load.

Have no idea. The only loaded ammo I buy anymore is 22 LR and .40 for CCW.

BP...

Serious comment this time: I see that you shoot across a pond, as do we. I often wonder if that creates some variable that isn't there when shooting over land (fluctuating temperature when passing over land/water/land or something).

Might go to the Hornady site and use the ballistic program there. I just ran a number thru and youir about where you should be at 200 yds. (doing it swag style on my part).

I had a rifle that stung horizontal like that once and the problem turned out to be a shifting scope base that bedding cured the problem

well than I don't call 2 shots a group ! Is this kinda groupings at both ranges consistant? is the lower group right of POI as much as it appears ? I know this will go over great for some but an old 99 ain't exatly a precision rifle how good are you looking for ? and is the 2810 chrono speed or listed ? just tring to give you more thoughts.

Is it your experience that a rifle with a scope or bedding issue will shoot good groups at 100 yards?

Really?

I don't see all that much inconsistency in the two.

The horizontal dispersion is obvious and more than reasonable. I'd solve that first and then see what I had.

Some of the 99's I've shot benefit from putting a bushing/spacer right over the screw that attaches the forend to the barrel (kind of a free float).

Not so much on takedowns, but the solid frame rifles at times have been squirrley. Once the spacer is in place, the stock still moves a bit, but isn't contacting the barrel.

Worth a try, it's easy, and cheap.

boilerpig1;
While I've not played with lots and lots of 99's over the years, one thing that I have learned to pay attention to on any rifle with a 2 piece stock is how the butt stock is bedded onto the action.

On something like a .308 level recoil rifle, if it was a 99, Ruger No 1 or Winchester/Marlin lever action, I'd be tempted to bed the front edge of the butt stock so there was a perfect fit between the front flats of the wood and the rear flats of the action.

Some I've even bedded so there is 100% contact with the flats and tang - such as a Marlin Guide Gun or a .300 Win Mag No. 1 - both of which benefited from the bedding.

While you have it apart, check to see if any cracks are happening in the butt stock too, as I've worked on at least one 99 that I can recall where a cracked butt stock caused the groups to go wacky.

Hopefully that was some use to you or someone out there sir. Good luck in getting your rifle tuned up and all the best to you in the upcoming week.

Regards,
Dwayne

[quote=boilerpig1]

Pre-mil 308 Savage 99 shoots a nice group @ 125 yards (top group).

At 200 yards it turns to crap (bottom group).

Loads are 150 grn. ballistic tips running at 2810 fps. Ballistics shows a 2" drop @200 but I'm getting quite a bit more. Any ideas? [quote=boilerpig1]


Was this result repeatable? It may be fruitful to establish that the first observation is not an odd example of one.

I would suggest repeat shooting the two groups at the two distances again, twice. Once with the original scope and mounts and again with iron sights. If the 5" drop at 200 yds is repeatable with the scope and not repeatable with the iron sights, the problem is probably the height of the scope over the bore.

I was referring to the reason behind the horizontal stringing...

The above target shows the the 2nd shooting of this load. Shots were run over a chrony both times.

BP...

I heard you on that. I have an O-ring under the forearm.

BP...

If I could see a target at 200 yards and hit it with iron sights I wouldn't need to have all these high dollar scopes. To many birthdays I guess.

BP...

I've had my best luck with rebedding 99 forends by checking to see if the rear end of the forend is binding on the front of the action. In a surprising number of rifles there's considerable pressure there, and if it's on one side in particular it can cause horizontal stringing. I just relieve any pressure with a fine file rather than epoxy-bed. This essentially free-floats the barrel AND forend.

I've owned a bunch of 99's and generally expect scoped pre-million serial numbers to group 3 shots in around an inch at 100, and some have done much better.

I'd also roll your ammo over a piece of glass. If you can see the tip of the bullet "wobble" then the bullet is seated pretty crooked, enough to cause definite fliers.

Forgot to add: The tables in the back of the Nosler manual say the 150 BT @ 2800 should be 3.6" down at 200 if the rifle's zeroed at 100. Your load is dropping twice that.

boilerpig,

Your post is interesting and all, but what I'd really like is to see the obverse side of your avatar. You wouldn't, by chance, have that to share with us, would you?

I hear you regarding too many birthdays. I've got a pretty good collection going on myself, right along with age related failing eyesight.

When you get your 99 sorted out, please make a post as to what the problem was. I am interested as to the cause.

You betcha. Thanks all for the ideas.

BP...

Another thing I've noticed with my 99s, is they seem to like the forearm support to be as far rearward as possible, damn near under the action. My EG model 99s seem to be more fussy than other models. If it doesn't help, it didn't cost you nothing to try.

Also remember that a scope's reticle subtends twice as much area at 200 yards as at 100, making precise aiming more difficult. Scope parallax may also figure into the equation as well. Personally, compared to the group at 125 yards, that 200 yard group doesn't look all that awry. Maybe you could do a little impromptu test of the parallax by fixing the rifle in the rest and moving your eye side to side in the eyebox to get an idea of how parallax might be affecting you at both ranges.

I just skimmed through the replies and didn't notice anyone mention that your bullets may be unstable. If so, they get progressively worse as they go down range. At 100 yds, they hit nearly point on, and given a descent group but as they continue downrange, they become increasingly "wobbly" (technical term), which destroys accuracy.

It also really increases drag so the bullet begins to slow much faster and thus, the bullet has a longer time to drop. Thus the much lower average POI. That seems to be the case in the photo you have shown but it's hard to be sure.

I would suggest a substantially shorter bullet - but check your rifle's crown first. Might be other causal mechanisms too, but those are two easy ones to try.

The too symptoms taken together add up to a ballistic problem. I would further guess that if you shot at clean cardboard (or better clean foam board) you would find the 200 yds holes are larger, more oblong than the 100 yds holes are. That would be the third symptom to look for.

Brent,

The reason I didn't mention bullet instability as a possible cause was that the standard twist in the .300 Savage is 1-10, which is far more than needed to stabilize a 150-grain Ballistic Tip. Sierra twist calculator suggests a 1-14 twist is sufficient, and the Miller Formula (the best I've encountered) says that a 1-10 will provide a stability factor of over 2, and 1.4 is considered plenty.

MD, I do agree that it seems improbable given a standard barrel but perhaps it is a replacement barrel. There are other ways to get bullets to be unstable but they take some effort to make happen. Loading exceedingly cock-eyed cartridges, a poorly throated/chambered barrel, damaging bullets when seating/crimping, etc. might do it. My suggestion to look at the crown is another. MD, you can probably come up with 20 other ways to get a bullet flying cattywumpus as well.

The symptoms you describe are a dead ringer for the problems we so often in BPCR and esp. BPTR where we are always pushing the bullet weight to the limits over excessively long range. Faster twist barrels, shorter bullets, and sometimes more velocity (if possible) generally fixes the problem. But whether this is likely with your M99, I don't know.

I'd sure like to see some close ups of the bullet holes in the cardboard from the 100 and 200 yds targets. If they are less round at 200 yds, then bullet stability IS the problem. Finding the cause of the problem may, however, be problematic.

If I'm able to make it to the ranch this weekend I'll get you some pictures of the backboard. But I seem to remember, they were round. I saw no signs of tumbling.

BP...

If you can shoot new ones - do it on fresh cardboard, preferable with something firm behind it. Look close.

Brent,

Wiht spitzer bullets in smokeless centerfires, bullet stability actually increases with distance.

Bullet instability occurs for two reasons:

1) Air pressure on the front end of the bullet overcomes the center of mass toward the rear of the bullet.

2) The bullet enters the transonic zone between about 1100-1300 fps, which introduces weird forces.

With spitzer bullets fired from smokeless cartridges, bullet stability actually increases until velocity drops enough for the bullet to enter the transonic zone. This is because air pressure on the sharp front end decreases rapidly (with velocity) but spin slows down at a much slower rate.

A .30 caliber 150-grain Ballistic Tip is not only not nearly long enough to be marginally stabilized in a 1-10 twist, but when started at 2800 fps it won't be anywhere near the transonic zone until close to 1000 yards. And even if the barrel is a replacement, I sincerely doubt it would have a 1-14 twist, since they're almost unknown in .30 caliber centerfires--and 1-14 would still be plenty to stabilize the 150 BT.

I copied the photo of the target and blew it up and three of the four bullet holes at 200 yards are perfectly round. The other hole shows a slight opening on the right side that looks like an irregular tear in the cardboard, rather than an oblong shape to the hole.

Yeah, there are reasons other than twist for bullets to be unstable as they leave the muzzle, but if a 150-grain Ballistic Tip from a .300 Savage is stable at 100 yards it will be stable at 200. The same applies to a worn crown. Crooked-seated bullets aren't unstable, they just leave the muzzle with their base at a slightly different angle than straight-seated bullets.

Which is why my money is on a forend bedding problem.

MD, you are probably right. But I don't think so. I do absolutely agree that the twist should be enough to stabilize that bullet. No doubt.

I understand 1 and 2 and yes, they are not a factor here.

I cannot even come close to seeing enough detail in that target to say anything about what bullet holes are perfectly round and which ones are not. It is hard enough when looking at a target up close and in person.f If they are keyholing sure, but then most of the bullets would be missing altogether.

But one thing is for certain - unless the two groups are unique flukes of chance. And that is that accuracy as is rapidly, very rapidly, declining with distance. Those bullets are becoming ever more inaccurate while they are flying and long long after they leave the muzzle and any influence of the forearm bedding etc. If your forearm hypothesis is correct, and the rifle shoots 3MOA at 100 it the forearm can't cause it to shoot 6 MOA at 200 because by the time the bullet reaches the 100 yds line, it has long forgotten the forearm per se. It can only be less accurate if something is happening to the bullet out there in the middle of the range. That leaves just the bullet's intrinsic properties and the environmental conditions such as wind.

If wind conditions etc, do not factor in, then the group size at x00 yards should be reasonably x times the group size at 100 yds. No news to you there, but this is dramatically larger. I would doubt that any environmental variables (e.g., wind) changed sufficiently to cause that increase in group size above this expectation or the OP would have mentioned that.

So, it's got to be intrinsic to the bullet itself. And that means stability, regardless of what the numbers say. I disagree that you can launch a wobbly bullet and expect it to be stably wobbly such that the "cone of fire" or MOA of accuracy would be maintained. It is knuckleballing out there and when it does that it's shedding velocity fast (thus the huge drop from the expected center of the group). And the big increase in MOA group size.

I don't know how the forearm would cause that group to drop like that, nor how it would induce a larger MOA. I just don't see a mechanism. So, I'm sticking with my story - besides, I've been there, done that too many times.

But maybe you are right. Maybe we will find out. It would be interesting to know.

I had a 338 Lapua that would not stabilize one particular 325 grain VLD rebated boatail. When this happens horizontal stringing is the least of your troubles.

This may get me in trouble....but I don't think there is anything wrong with the rifle or the load.A lot of the analysis being made(good suggestions!)are based on two groups,and assume the OP is holding perfectly each and every time(Not dumping on the OP, just being realistic).

Three of the four shots in the 125 yard group are trending "right"( and those three are not strung and the group is pretty good)....this right tendency will be exagerated at greater distances and shows up in the lower group..I bet the horizontal stuff is due to alignment and the forend of that Savage rolling around in the bags and bouncing off the firm bags as he fires.There may also be cant in the scope or the way the OP holds the rifle that we can't see.

As for the lower impact, I think he just has to take it back to 100 and zero so that he's a full 2" high above that white dot.POI should come in at 200 or close to it.I'd also do what another poster suggested and get the forend off the bags back more to the receiver.Might also try a soft towel under there to try to minimize freaky bounces off the rest as the rifle recoils.

Bob,
No doubt there is a bunch card houses being built on the shaky foundation of just one pair of groups. Seeing that pattern repeat with the same load, the same everything sure would shore up some foundations.

Brent: What I'm thinking....hell I get downright suspicious if things fall together too good right off the bat..

I confirm and reconfirm over about a year before I'm firmly convinced

Looks like the 200 yds while not great, is as expected, roughly 2x the size of the 125 yd group.

I suspect the barrel has seen better days.

I love shooting mysteries like this - just not when they are with my rifles.

The problem the OP has is one that I chased for a long long time before I finally figured it out with some of my long range target rifles. I spent a lot of time and money before I figured out the problem wasn't me. It wasn't the rifle, it was the bullet.

Now I have this Marlin lever rifle that seems possessed by an entirely different sort of devil. I've got some "fixes" in the works but not much confidence that they will actually work. Time will tell, but I'm still not sure if it is the rifle, the bullet, the load or maybe even me (naw, not possible :))

Say, boilerpig, when you were shooting these two groups, did you rest the rifle at the same spot for each group? If not, that could explain the drop from 100-200 yds.

looks like a hard trigger pull ,or a flinch...

Check the action screws.
Get someone else to shoot a group.
JW

Perhaps I missed it. Once it is confirmed that the unexpected large drop is repeatable, simply remove the fore arm and shoot the rifle rested on the receiver to either indicate or rule out the fore arm as the culprit. Be advised that the POI may change with the fore arm removed though.

Brent,

You need to do more research on the science of bullet stability. I would suggest Bryan Litz's book as a starter.

One thing is certain: The two groups do not provide enough information. If we just eliminate either the left or right shot in the bottom group, the other three shots would be about as relatively accurate as the top group at 125.

The drop is more of a puzzler. Even a very bad chronograph reading (and I have seen cheap chronographs give readings as much as 10% off over the years) wouldn't explain that much drop.

The scope may also be the culprit. In fact unless a scope has really been proven on another rifle, I tend to suspect the scope first in most problems with smokeless rifles.

On Savage 99's the forend would be second on the list.

I have a 99 that does the same thing, or did. I found out I was doing a couple things it didn't like. First was it didn't like being shot off the type of rest the OP showed, or even sandbags. If I hold the forend with my hand, then put the back of my hand on either type rest it shoots tighter groups. The second thing I was doing that made it look like I had too much drop at 200 was in trying to be more precise at 200 I found I was holding the gun tighter, and worse, putting a lot of cheek pressure on the buttstock. With no cheek pressure the drop between 100 and 200 is about 2/3 that with cheek pressure.

With 99s I've always found them particular off the bench, so I always try to shoot them free recoil, with the front rest almost at the receiver (as somebody else mentioned). Don't pull them into your shoulder, don't lay on them with your cheek, don't get a death grip on the forend, and don't rest the forend on anything remotely hard.

I have Marlins and Winchesters also, that are much easier to shoot off the bench. For some reason though, the 99s always end up going hunting while the Marlins and Winchester stay home...

No, groups, esp. these do not provide enough information. But they do provide more info than you give them credit for. The biggest hint is in the biggest effect - the large drop from 125 to 200. I might know more about bullet stability than you think.

The "puzzler" fits better with my hypothesis than yours. I can't ignore, so what can explain that and, at the same time, the apparent decrease in accuracy?

Why would the scope be an issue? True, it may not be working properly, but why would it work more improperly at 200 than 125? AND why would it cause that drop?

I agree the differences in accuracy are not THAT much off from what me might expect do to just range alone but they still are more than we would expect. And I cannot "just eliminate" data without a reason either (too much like the guy that shoots subMOA all day long - except for those fliers).

And that still leaves the drop issue. I'm count that as a real issue and not some fluke of course but then that's presupposed by the entire discussion.

Stability in a 30 caliber at 1 in 10 twist is definatel not the issue


Geez

kc,

Interesting!

I tend to use softer rests than many shooters, especially with lighter rifles, and many 99's are pretty might. In fact these days I often drape a folded-up towel over the front rest, because I've found the point-of-impact from shooting over the towel duplicates the POI when shooting the same rifle over a daypack--which is how I often shoot at longer ranges in the field.

It took me a couple years to figure out how to shoot 99s off a bench. I almost sold a 250-3000 because it patterned instead of grouped; went from about 5 inches to 0.75 inches at 100 between load development and learning how to shoot it. Like my shooting mentor told me, "sometimes it's the loose nut behind the trigger"...

I forgot to mention - thanks for the towel suggestion. I'd read it in one of your posts (or articles?) some years back, and have used it successfully on other hard cases.

Brent,

Scopes can do all sorts of weird things--including erratically going from one POI to another between strings of shots. They can also start stringing shots horizontally, as in the second group. The mounts themselves may even be involved.

Your theory is based on assumptions about bullet stability that are wrong. Yes, it's coommonly believed that bullet stability declines at longer ranges, but I already outlined the reasons that isn't happening here. You just refuse to believe them, even though they've been proven over and over again.

Plus, if bullet stability were the problem, both groups would have fliers in all directions, instead of being basically strung out horizontally.

As jwp pointed out, marginal bullet stability is definitely not the problem here, and just because you've induced it with too-long bullets in your rifles doesn't change that. A 1-10 twist in a .300 Savage will stabilize a 200-grain spitzer started at 2200 fps.

Yes.

BP...

Thanks. That can be excluded.

I know you asked an important question,but my eyes keep wandering back to your avatar for some reason ,and I cant seem to remember what the hell this thread is about!!!