Accuracy issues

[Ketch]

Hey everyone, I’m new here and in desperate need of help. I’ve been reloading for my Remington 700 ADL in .308 1/10 twist. For approximately 3 years. For three years I’ve thought I’ve had my load dialed in. I’m using hornady brass, CCI Large rifle primers, 41 grains of IMR 4895, and 165 grain Sierra game king boat tail hollow points. I’m also using a Vortex diamondback 3.5x10x50 scope. At one hundred yards, on most days I can hold a sub MOA group. Last week I had my first opportunity to shoot out to 200-300 yards.

At 200 yards I had 14 inch drop and a 10 inch grouping with three shots. At 300 I wasn’t even on paper and I had two targets stacked on top of one another. I initially thought my loads were just to light. I went out and bought hornady 165 grain SST superpeformance and headed back to the range.

The results were 2 inch groups at 100 that were very inconsistent and 3 inch groups at 200 that were hitting 2 inches right. 300 was about an 8 inch group and 11 inches in drop.

I’m shooting off bags and taking my time with the whole process. Before my firearm skills come into question, I’m an army veteran and current LEO. I shoot weekly and can hit golf balls at 25 yards with iron sights using my Sig P229 chambered in 357 sig, so I have a fairly good grasp on proper shooting.

Would using a heavier bullet be helpful or am I missing something.

Ive received advice on other forums stating it could be copper fowling. I have not cleaned the barrel in about 60 or more rounds since my groups were holding tight. I’ve also been advised to check all of screws to make sure they were on correctly.

Any help would be appreciated.

[Bart B.]

Something about the rifle may have changed.

Was the rifle taken apart after your first successes?

Is the barrel at least 1/8 inch clearance to the fore end?

[std7mag]

Being good with a pistol does not a sniper make.

Having said that, i do thank you for your service! And from what i've seen locally, your one of the more dedicated with your pistol regimen.

While your shooting decently at 100 yards, when you start stretching the distances all kinds of tiny things can make a huge difference.

I'd first start by removing the scope, and making sure the base screws are torqued correctly. Typically 20-25 inch lbs.
Then re-install the scope torquing the rings. Typically about 20 inch lbs.
Next, or first, doesn't really matter, check the torque of your action screws.

After tbat is your load development, or your technique. Or both.

But check your screws first. .

[RC20]

Something has changed. Check your action screws, then your scope screws, remove the scope if needed to check the base.

That or you have a load bust. Severely undercharged or the wrong powder.

Depending on which book, your load is 2500 fps which while mild is not a rainbow 22 trajectory.

or your technique

Nothing is going to make it drop 14 inches at 200 technique wise.

Low velocity due to a powder issue could.

Cases should look like smoked by a candle.

[Ketch]

Nothing with the gun has changed

[Ketch]

I’m going to check the screws and clean her top to bottom tonight, I’ll post pictures of my groups tomorrow and post them

[scatterbrain]

Ketch, what's the trigger pull like, if you expect small groups at 200 to 300 yards you need a good trigger. And, if you zero at 100 yards what are you expecting to see at longer ranges?

[cdoc42]

I'm looking at my old Sierra manual and for their .308 diameter, 165gr HPBT, the "bullet path"with a velocity of 2300 fps and sighted in at 100 yards, shows a drop at 200 yards of 6.62" and 23.32" at 300 yards. That's the slowest velocity they show. Anything faster, the drop are less.

I checked a Hornady manual and their 165gr BT Spire at 2300 fps also drops 6.2" at 200 and 21.7 at 300 yards. They show slower velocities and at 1600 fps a 100 yard zero shows a drop of 14.8 inches at 200 and 49.0 inches at 300. That matches what you're telling us. Could your load be this light?

The Hodgdon manual lists 41.0 gr of H4895 for a 165gr bullet delivering 2525fps at the low end of the recommended loading.

Your second report of poor grouping is with a different bullet and I assume factory loads. So the velocity is removed as an issue and you are at least on paper at all distances. It might just be your rifle doesn't like SST rounds. I have a .270 that puts 150gr spires into 1 inch and less (sometimes, = me) groups but with 130gr or 140gr SSTs I could throw a handful at the wall and get the same groups.

But I agree with all others who advise checking all screws. I had a Kimber 6.5 Creedmoor that absolutely would not deliver anything that looked like a good group. One day I fired a shot and the scope hit me in the head -the recoil drove it backwards through the rings!!!!!

[Ketch]

I wish I could figure out how to post pictures with my phone.

On my hand loads:
There has got to be a velocity issue, that I’m sure of. The recoil between that and factory loads are significantly different.

For the factory loads:
I shot these same rounds a few weeks ago and had a decent group and consistent hits. Now the same rounds have a much larger grouping and are only getting worse. She’s getting cleaned tonight, shot at 100 tomorrow, and then on Tuesday will get a 200 yard test if the 100 goes well. I’ll keep you posted.

[RC20]

I would suggest a cross check of the load method, ie how are you weigh your charge and a cross check of that method and accuracy.

Wrong primers?

note: A scope can go out between one shot and the next and its a possibility but not likely but should not be taken out of the mix to question. .

[603Country]

One thing at a time. Check the scope mounts, clean the bore with a serious copper cleaner, and maybe swap out the scope. I’ve had a few scopes go bad over the years, and when my rifle bores get real fouled, the groups loosen up and ‘relocate’ slightly. Some rifles are worse about it than others with fouling effects.

[AgedWarrior]

Making sure everything is properly torqued and a good bore cleaning can only help and eliminate potential problems. But I suspect your load might be on the low side, even though it seems right with the Sierra data (next to latest data) which indicates a max charge of 41.9. This is comparatively very low when compared with Hodgdon data (w/Hornady bullets) and still middle to low compared to Hornady, Speer and Nosler which all suggest a velocity around 2500 +/- 50. But, you are using Sierra bullets, so their data is preferred, at least to start with. Have you ever checked actual velocity of your load? How are you measuring powder charges? Your own comments suggest a light load compared to factory...might be shooting a bit more of a rainbow arc than you thought. Hopefully cleaning and insuring everything is properly tightened will tighten up your groups some, then you can work on the load.

[RC20]

One thing at a time. Check the scope mounts, clean the bore with a serious copper cleaner, and maybe swap out the scope. I’ve had a few scopes go bad over the years, and when my rifle bores get real fouled, the groups loosen up and ‘relocate’ slightly. Some rifles are worse about it than others with fouling effects.

Agreed on one thing at a time but the process is quick.

A fouled bore is NOT going to produce a 14 inch drop at 200 yards, even if its been shot with black powder.

[Ketch]

The crazy with drop was only with my hand loads, so for the time being, those are not going to be used.

The issue I was having that is more troubling was why, with factory brass, that I was shooting good with, is their all of a sudden a major issue. I just got done using some bore cleaner and about 300 patches through her, tomorrow I’ll take her out to 100 and run some tests

[jmr40]

According to my manuals you are almost 2 gr BELOW the recommended STARTING load. You need more powder for several reasons. #1, that load is so slow that it is dropping fast at longer ranges. Some 30-30 loads would be faster.

41 gr is the starting load for H48895, but 42.7 is the starting load for IMR4895. Plus, I think there are better powders for 308. Cold temps will effect any powder and you could see significant velocity loss in cold weather. Either of the 4895's are pretty sensitive to cold weather. Other powders are much less so.

#2, if you don't have enough powder in the case you get inconsistent powder burn; that means inconsistent accuracy. The most accurate loads have enough powder in the case that it doesn't have any room to move around. If there is a lot of empty space in the case you may see a big difference in muzzle velocity between each round. That may not show up at close range, but will make a difference at longer ranges.

In my experience the Superformance ammo is not very accurate. And not really much faster than my hand loads. But getting 3" groups for your 1st time at 200 yards isn't bad at all. That tells me there is potential for good accuracy with good ammo.

[RC20]

I can see the issue develop with a bad hand load and severe fouling then ruining other good known factory loads.

I would strongly recommend Carbon Killer 2000 (CK2k in my world) - its by far the most effective carbon cleaner (and endorsed by Unclenick as well).

What I have worked out is most effecive (it will do it cold) is to shoot and warm up the barrel (5 quick shots) and then soak a nylong brush (hold it better) and run thorugh. I use an eye dropper.

Then runit through and out the bore and soak the brush again with the eye dropper or dispenser (it works in getting max fluid and minium drip)

Pull it back through and run it 5 full cycles with the last one out the bore again.

Soak the brush and pull thorugh and run a pacdh through. This will come out filhty and likely a bit of fluid out the bore. Repeat (usualy 4 cvycvles) until yhou get a damp patch but no carbon (aculay is a tad bluinsh uinder good light). Then a dry patch.

Helps if you have at least a Lyman boroscope at home. I would shoot 5 more quick ones and repeat until its just a bit of carbon with the 5 shots.

The warm barrel helps the process but it can be done cold, takes longer. It gets it completely clean. While my barrel all shoot good clean, some feel fouling shots may be needed and sometimes 10 or 15. I have not seen that but ...............

According to my manuals you are almost 2 gr BELOW the recommended STARTING load. You need more powder for several reasons. #1, that load is so slow that it is dropping fast at longer ranges. Some 30-30 loads would be faster.

My book says its a 2500-2600 fpm and mid to upper mid load. Will look at another book in a bit.

[T. O'Heir]

41 grains of IMR4895 is 1.7 below the current start load. Nothing to worry about. Differences in manuals can be more.
IMR4895 is not as consistently accurate as IMR4064 with 165's though.
"...The results were 2 inch groups at 100..." I'd think the rifle doesn't like that ammo much. Good enough for deer though.
"...check the screws and clean her..." First. Check the tightness of the stock screws as well.
Sounds like you may have a bedding issue. It got a wood stock? If so, is the barrel channel sealed? Any wood sealer from any hardware store will do.
Where is the thing sighted in at 100? Where are you holding at 200 and 300? How's it shoot with the 4895 load at 100?
A 165, zeroed at 100, will typically drop 4" at 200 and 14 to 15 at 300.
When zeroed at 200, it'll drop 8.4" at 300.

[Ketch]

I cleaned out the rifle took her to the range and shot at 100 with multiple strings of 3 rounds, letting the barrel cool between strings. The factory ammo was performing better, but still only holding a 2 inch group at 100. Just for giggles, I took three shots with my hand loads and they were a MOA group. So I think it’s safe to say that my hand loads are definitely set to the rifles liking but just underpowered. (Looks like I’ll be experimenting with powders and a chrono this year). As far as the factory ammo goes, it will be good enough to hunt with, just not as perfect as I’d like.

My trigger isn’t as light as I’d like it but I. An make it work. I understand that has something to do with my groupings, just not to the degree I was seeing with my handloads. The factory groupings were just as I would expect them to be.

Anyone have any good chrono recommendations

[Ketch]

My book says its a 2500-2600 fpm and mid to upper mid load. Will look at another book in a bit.

That’s what my book says as well, I’ll have to get a chrono to verify.

[olddav]

Just as an off the wall suggestion, you may have a Carbon ring in your chamber. I have a Shilen barrel and groups were opening up. Scrubbed the chamber to remove carbon ring. Groups returned to normal. I would never have thought of this if I had not read Tony Boyer’s book.

I had over 300 rounds through the barrel. I tend to clean the chamber more often now.

[Bart B.]

How much runout do the bullets have? Are the cartridges pretty straight?

[cdoc42]

Are you seating your bullets to "COL" (Cartridge Overall Length) measurements supplied in the reloading manual or are you seating them with a comparator that measures overall length from the first bearing surface of the bullet (generally thought as the "ogive") to the base of the case?

[Unclenick]

I would use Carbon Killer or, if you don't plan to shoot over the winter, you can just put Gunzilla in and let it sit a few weeks to get the carbon out. After that, get some Bore Tech Cu++ and get the barrel good and wet and let it sit 20 minutes, push a dry patch through and repeat until the really dark cobalt blue stops coming out. Then you'll have a clean gun and can be sure that's not a contributing factor.

[Mike / Tx]

Anyone have any good chrono recommendations

There are several that run around $100-200, that work just fine. There are also some that are a bit higher depending upon your taste or budget.

I personally have used the Chrony brand since they came out. They fit my budget at the time and have been plenty good enough to keep me on paper out to 800+ yards.

I understand your frustration. I went through a similar issue with a 25-06 years ago. I'd zero it at 200, then next trip to the range it would be 3-4" high at 100 and about off the top of the target at 200. Turned out the stock was the issue. It kept warping and putting pressure on the underside of the barrel. Wasn't much but it was frustrating until I figured it out. It sports a nice laminate now and hasn't lost its zero in over a dozen years.

Good luck

[Ketch]

I’m seating them to OAL, I don’t have the gauge that measures lands yet, but prior to these issues she really liked that setup