284 accuracy issues

[distantfoe]

I've spent the last week trying to get a 284 to shoot groups better than 1 moa. The rifle specs are:
Brux #5 barrel @ 26" 9twist
surgeon rlr action
Mcmillan htg stock pillar bedded
Nightforce 5.5-22 nxs scope

I've reduced neck tension from .002 to right at .001, varied torque on the action screws, and tried several powder bullet combinations at various depths with no yield in accuracy. (from +.020 to -.130)

I've shot a few small groups but when I go back to verify the group, it opens to moa+.

 

[wbm]

What powder and bullets are you using? You have a great barrel, receiver and stock so I am thinking the problem is with the ammunition.

 

[distantfoe]

I've tried both H4350 and H4831sc with 175 smk's and 168 berger vld's.

 

[wbm]

When you shoot a 5 shot group with a cold barrel can you tell any difference in the second 5 shot group from a warm barrel. Also when you say it opens up to 1 MOA is it because of a flyer? Good article below for the .284.

http://home.earthlink.net/~rfrailey/sitebuildercontent/sitebuilderfiles/284loaddata.pdf

 

[distantfoe]

My first 2-3shot groups are slightly better than moa but groups open up with each successive group. I typically wait close to 10 minutes between groups. 50% of groups are triagular shape and the other 50% are erratic/inconsistent.

 

[RDavies]

Have you tried the rifle/scope with a different barrel?

I have had a 284 which would not get better than 1 moa, but the barrel was a dud.
284s with 9" twist usualy love the combination you have been using. I have found .003"neck tension works best with this combination, but that is realy only fine tuning.
I have had a few 284s play up, but after lots of testing and head scratching, found it was the scope let go.

 

[FroggyOne2]

I have had two .284's and what I have found is that they can be very finnicky at times. With the first one, I found that RL17 was the powder to use, with a moly'd Berger 180VLD jumping the bullet 60K. Also using the Hornady 162 AMax with RL17 worked as well with the bullet seated 10K above the neck/shoulder joint. Then the second time around, using the 175SMK using again RL17 worked. It took a good bit the first time around of about 400 bullets finding a load that worked. The second time around wasn't so bad, only about 50 to get it worked out, more than likely because I already had a hint as to what powder to test with. Then I moved on to the 7mm SAUM, it was much quicker finding a load that worked. Going with Danny's data, in the matter of 25 rounds, I had a load. So I would say that some more playing around with it is in order. Some other powders to explore are N160 and RL17 for starts.

 

[Keith Glasscock]

I've been to that rodeo recently. I'd suggest that you start with the scope. If you have another available, put it on and see if things get better (while you are there, check all of the screws!).

If no better, then pull the action out of the stock and check the bedding for problems. Do the dial indicator test if you can to determine if the bedding is stress free.

If no luck there, talk to your smith. Something, somewhere is wrong - could be a barrel (been there, done that).

While Froggy has a great deal of experience with the 284, I've come to believe that a good barrel will hold around half MOA with anything you feed it. Having inconsisencies in group sizes of any significant magnitude is a warning sign of mechanical problems (including the rest setup).

 

[hogan]

I would look at your scope rings. Swap a prove set and see if results don't improve.
Might also take caliper/mic to your base, if Picatinny slotted.

First .308 I built had Badger Ord flat base and precision dealer was out of BO rings, but talked me into Leupold mk4. Gun shot terrible. Returned the mk4s and got BO and was shooting sub .4" at 100 and sub .67" at 200 all day long. The .300win mag with quality pic rail would never shoot at distance, turned out the rail spacing was off by .005" on one side when I compared with my other 700 LA bases. Near Mfg is really some superbly crafted gear, if you need a recommendation...

Might also try a bottle of Barnes CR-10 and recondition your barrel once all traces of copper are removed. Did the rifle ever deliver precision? Maybe your crown was damaged? As far as load data, try Sierra's match load for your bullet weight as a starting point. There are many variables to consider, but strikes me that your results are so poor that it means a major component is out of kilter. Perhaps whoever built your gun or smithed your barrel has a borescope to inspect same and could do a chamber cast? If you have a Wilson case gauge or RCBS Precision Mic, what sort of before/after results are you seeing when compare virgin fired cases?

Start with the rings and then base, if confident barrel has been well-maintained. Hope you find your problem lies there. Good luck.

 

[LongRanger]

I have it third hand from my gunsmith from Boots Obermeyer from the US Givamint that the Givamint gave up on the 284 as a military weapon due to inconsistent accuracy. Whether the string is true or false, my findings and that of several top F shooters bear out the Givamint findings. I must in fairness also state that some top F shooters are/were very successful with it.

Lord knows, I gave the sucker a fair trial. Three Krieger barrels and almost 4K rounds had me really questioning whether I knew diddly about reloading after 60 years of doing it. I developed several loads that would shoot laser accurate one day and then, the next day, spray the hillside. And believe me when I say I worked the problem from all angles...different scopes/different actions
different brass/powders/bullets/seating depths, neck tensions/neck thicknesses/time of day/weather for day and I don't know a what all. Seemed like everything would work once and give a nice 1/4 moa group only to fall flat the next day.

To save my sanity, I killed the effort last month, trashed all the dies, bagged up about 30# of brass for the salvage yard and am now sleeping better without the labor of going to sleep or waking up with another "what if" plan of attack.

Frank B.

 

[wbm]

To save my sanity, I killed the effort last month, trashed all the dies, bagged up about 30# of brass for the salvage yard and am now sleeping better without the labor of going to sleep or waking up with another "what if" plan of attack.

Man's gotta do what a man's gotta do! ;D

 

[jsimonh]

I have it third hand from my gunsmith from Boots Obermeyer from the US Givamint that the Givamint gave up on the 284 as a military weapon due to inconsistent accuracy. Whether the string is true or false, my findings and that of several top F shooters bear out the Givamint findings. I must in fairness also state that some top F shooters are/were very successful with it.

Lord knows, I gave the sucker a fair trial. Three Krieger barrels and almost 4K rounds had me really questioning whether I knew diddly about reloading after 60 years of doing it. I developed several loads that would shoot laser accurate one day and then, the next day, spray the hillside. And believe me when I say I worked the problem from all angles...different scopes/different actions
different brass/powders/bullets/seating depths, neck tensions/neck thicknesses/time of day/weather for day and I don't know a what all. Seemed like everything would work once and give a nice 1/4 moa group only to fall flat the next day.

To save my sanity, I killed the effort last month, trashed all the dies, bagged up about 30# of brass for the salvage yard and am now sleeping better without the labor of going to sleep or waking up with another "what if" plan of attack.

Frank B.

As someone who is currently building a .284, this thread is discouraging! and I havent even got my barrel yet.

 

[Maurice]

Had my rifle rebarrelled in .284 - 32" trueflite/barnard/mastin laminated stock with NXS5.5 - 22.

Ran through 100 Berger 180gn hybrids in Lapua brass with CCI primers, ADI 2213sc, but best I could get was around the 1 MoA mark. I really expected better, considering the cost of the Bergers.
Switched to SMK 180 gn with seating depths from touching, to .005, .010, .015, .020.
Groups started at >2in, but at .015 had shrunk to .5 MoA & at .020 to .265Moa.

Went with .015 on the basis that the barrel would wear into the tighter node as the season progressed. Incidentally , also had to change to Win brass, as I could not get the extra 150 Lapua to make up the 250 I needed for the for the season.
Interestingly , I could get less powder in the Win brass than in the Lapua (6.5/284 necked up), - running 55gns at 2848fps.
As always, if this is of use to you, start your powder loads about 10% lower than mine and watch for pressure!!

 

[Erik Cortina]

Is it a tight neck chamber? Have you checked for enough neck clearance?

N550 and Hornady 162 AMAX or 162 BTHP work great in 284.
Start at 48.0 gr. and work up. Put bullet in the lands.

 

[macca09]

Maurice,
When you say "seating depths from touching, to .005, .010, .015, .020", is that jam or jump??
What load/powder type did you use when you were doing this??

thanks

 

[Baron B58]

jsimonh I am with you in that I also recently built a 284 and then you read posts like the one from Longranger; very discouraging indeed. I am a very black and white person though and just cannot accept that a rifle will shoot the one day and not the next; scientifically speaking this just dont make sense. If this is indeed the case why would only a 284 do this and not a 308 for example. What type of design flaw can be present in the 284 that would make it possible for the cartridge to shoot the one day and not the next? what makes the whole thing more confusing is the fact that the 6.5-284 is based on the same case and has been used with great success in countless F class matches and I have never heard those shooters complaining about it other than for barrel life. Charles Ballard and company win national championships with this round; surely that wont be possible if it is a inaccurate and unreliable round !! Because of what I said above I think I will persevere with my 284 project and hope that it will keep making a comeback.

 

[bozo699]

That's superstitious hog wash, the .284 win can be a very consistently accurate round I don't care what the (Giviment) or anybody else says, there's to many winners that have won with it and still are. Also many other 7mm cartridges have been winners. My factory 40+ year old Savage 99 .284 win shoots between 3/4" and 1" yesterday, today, and it will tomorrow and the next day also, my factory Tikka T3 in 7mm-08 will shoot 1/2" three shot groups every time I shoot it. I have a 6.5*284 f-class and a 6*284 1K BR rifle and both of them shoot under 1/2 moa out to 1000 yards and I am sure if I build a plain .284 Win it would as well and so will yours if you have quality equipment and get every thing tuned.
Wayne.

 

[Raptor]

I have a 284 with a Broughton barrel on it and its the most accurate rifle I own.

I built it on a short action because I had a 260 built and it was the most inconsistant rifle I ever shot. It would shoot .3s one group and .7s the next. You just never knew what it was going to do.

I had the barrel pulled and had the 7MM 284 barrel put on it and now its a hammer.

If that had of been the fist 260 I had built I would have probably been soured on them. However it was the 3rd 260 barrel on that action and all the others had shot great!! No one could really give me a good reason why the rifle was so inconsistant. So sometimes you just get a turd and you have to start over.

 

[bozo699]

I have a 284 with a Broughton barrel on it and its the most accurate rifle I own.

I built it on a short action because I had a 260 built and it was the most inconsistant rifle I ever shot. It would shoot .3s one group and .7s the next. You just never knew what it was going to do.

I had the barrel pulled and had the 7MM 284 barrel put on it and now its a hammer.

If that had of been the fist 260 I had built I would have probably been soured on them. However it was the 3rd 260 barrel on that action and all the others had shot great!! No one could really give me a good reason why the rifle was so inconsistant. So sometimes you just get a turd and you have to start over.

Absolutely.

 

[jonbearman]

Could the chamber be out of square and parallel to the bore. If ,when chambering something moved or the tailstock wasnt trued to the spindle bore,it would pull off to one side using any type of reamer holder. As a machinist,I would do the easiest and change the scope and make sure the base is square and true as well. Next I would have the smith that did the work,chuck up the barrel and certify the chamber is right.Next bore scope and make sure that nothing is building up in the barrel that you might have missed. Try some 162 grain sierra's if you havnt already. Is the bedding reaching out past the recoil lug,if so remove enough to make the barrel a true freefloat. I hope this helps. Any smith that wont recheck his work regardless of what is at fault would be the guy I would never do business with again. Thankfully most prominent smiths will do it as part of pride of quality workmanship. I am seriously thinking of doing a gun in this caliber,and sincerely hope you find out what the culprit is. Call the barrel maker as he or she may have some good suggestions to help eliminate some of your headaches. Good Luck and be safe above all. Remember light speed isnt the avenue to accuracy. Maybe a lower charge would reveal a node that works for your combination.