Used 6.5-284 problems (buyer beware)

[MrUnderwood08]

I bought a used 6.5-284 built on a stainless savage action off Gunbroker awhile back. It came with brass and dies. Brass showed definite over pressure signs (cratered primers, multiple ejector impressions from previous firings etc). The previous owner said he was loading 50 grains 4831SC and using Berger 140 VLDs seated to a comparator length of 2.445. I verified this with his seating die since it had not been adjusted. I asked him what 2.445 length was in relation to the lands (jump/jam) and he said .015 jump. Round count around 400. Claimed accuracy capability with this load was 1.5" at 600.

I finally have some time to play with the gun but as I peal back the onion I am getting concerned. The pressure signs on the case were obvious which led me to believe he may have been shooting hotter loads than he stated. I also question the 400 shot round count. I've started to prep and load brass and decided to independently check seating depth using a Hornady Gauge. Using SMKs and Bergers I get a comparator length of 2.320-2.330... WOW. I checked this over and over wondering if I was doing something wrong. That would be a .120 jam bullet if I loaded to his specs.

So what I think I have is a Barrel where the gunsmith used a 6.5-284 WIN (Not NORMA) chamber reamer so the COAL is intended to be 2.8 instead of the 3.228. Touching the lands a 142 SMK is at an overall length of 2.988.

There were other issues that I have already addressed like the modified trigger that dropped the sear if the bolt was closed with moderate force.

He warned me that the 142s shot poorly. Makes a little sense since the bergers would tolerate the jam better. If I had to guess though based on the cases, he was shooting up around 53-54 grains 4831SC. To borrow a phrase from a friend I think this gun may make a better tomato stake than a 1000 yard Benchrest rifle.

 

[CatShooter]

I bought a used 6.5-284 built on a stainless savage action off Gunbroker awhile back. It came with brass and dies. Brass showed definite over pressure signs (cratered primers, multiple ejector impressions from previous firings etc). The previous owner said he was loading 50 grains 4831SC and using Berger 140 VLDs seated to a comparator length of 2.445. I verified this with his seating die since it had not been adjusted. I asked him what 2.445 length was in relation to the lands (jump/jam) and he said .015 jump. Round count around 400. Claimed accuracy capability with this load was 1.5" at 600.

I finally have some time to play with the gun but as I peal back the onion I am getting concerned. The pressure signs on the case were obvious which led me to believe he may have been shooting hotter loads than he stated. I also question the 400 shot round count. I've started to prep and load brass and decided to independently check seating depth using a Hornady Gauge. Using SMKs and Bergers I get a comparator length of 2.320-2.330... WOW. I checked this over and over wondering if I was doing something wrong. That would be a .120 jam bullet if I loaded to his specs.

So what I think I have is a Barrel where the gunsmith used a 6.5-284 WIN (Not NORMA) chamber reamer so the COAL is intended to be 2.8 instead of the 3.228. Touching the lands a 142 SMK is at an overall length of 2.988.

There were other issues that I have already addressed like the modified trigger that dropped the sear if the bolt was closed with moderate force.

He warned me that the 142s shot poorly. Makes a little sense since the bergers would tolerate the jam better. If I had to guess though based on the cases, he was shooting up around 53-54 grains 4831SC. To borrow a phrase from a friend I think this gun may make a better tomato stake than a 1000 yard Benchrest rifle.

Always buy a used gun, prepared to throw money at it - if you don't have to, then you are ahead of the game.

 

[expiper]

OP,,,he took his measurements with some sort of ojive meausrement tool or nut,,,,those measurements are only good to the person using that particular tool,,,,that is why if I ever do give a LOAL measurement I remind people that you gotta find your own Jam and jump lengthsi,,,,sorta like asing what does your old g/f like to do,,,it is different with every combo,,,,and remember its a Savage and they do make a cute tomatoe stake,,,Roger

 

[MrUnderwood08]

Anyone have experience with this less common chambering? What works best?

The barrel is stamped 6.5-284 N but the actual throat length does not match the CIP specs for the Norma cartridge. It was chambered with the 6.5-284 win reamer. It's not about his measurement versus mine or the tools used.

He may not even be aware that this was the case. I'm certainly not faulting him. He has been helpful. It is frustrating though. If it's already got a few hundred rounds through it I might as well rebarrel it instead of gamble on setting it back and rechambering. But it will still be a savage and I'll have 50% more into it.

 

[FatBoy]

I've had three different 6.5x284 Norma match reamers with three different throats. One was short in an attempt to chase the throat for more Barrel life, which incidentally failed. Settled on the Lapua match PTG and haven't looked back.

If you can chamber Lapua brass I doubt it was cut with a Winchester spec reamer, as the base is much narrower with win brass. If I recall, my win chamber was like .498" at the base and the Lapua is .504", it this if from a memory my wife calls "questionable".

 

[jonbearman]

You can make a chamber cast or your smith can and see exactly what you have. Get the barrel scoped to see if the throat is burned out. The good news is you can call Jim at Northland supply and get a barrel cheap to replace it if it is ruined. His number is:1-763-682-4296

 

[MrUnderwood08]

I've had three different 6.5x284 Norma match reamers with three different throats. One was short in an attempt to chase the throat for more Barrel life, which incidentally failed. Settled on the Lapua match PTG and haven't looked back.

If you can chamber Lapua brass I doubt it was cut with a Winchester spec reamer, as the base is much narrower with win brass. If I recall, my win chamber was like .498" at the base and the Lapua is .504", it this if from a memory my wife calls "questionable".

Fatboy... That makes sense. I'm glad you chimed in. If it is a 6.5-284 Norma with a intentionally shortened throat what are my best options for loads.

1. Should I be looking at lighter bullets?
2. Use the Berger at Jam Length?
3. Stick with 140 class with a small jump and sacrifice the case capacity?

Will jamming the bullets deep increase pressures significantly and could this explain the condition of the brass? What affect does jamming this deep have on throat erosion and accurate barrel life.

I have 60 pieces of brass charged with fairly stout loads of 4350 (48gr) and 4831SC (50gr) that I was going to use to test the bergers and SMKs. Don't want to proceed if pressures are going to be through the roof.

Daniel

 

[racesnake]

The best way to see what you have is to 'scope it. Do you have a scope or do you know someone who does? This will save you a lot of grief!
Dave

 

[Patch700]

I would think it safe to assume the reason for the bto discrepancy would be the method of achieving those numbers. If you were simply using hornady's method (a modified case and sliding a bullet forward) and the previous owner was perhaps marking a bullet with a sharpie or polishing it with steel wool to see witness marks then that may explain some.

With respect to the chamber being a winchester variety it would indeed be quite smaller in the base region , I wouldn't count on the throat length being the deciding factor as to whether it is a Norma chamber vs Winchester as it is entirely possible someone spec'd a short throat Norma chamber for whatever reason. (Opted to shoot light bullets)

What you may be experiencing is an abnormal amount of carbon in the throat area and this is wreaking havoc with both your bto measurement and seating depths.

If it were mine I would grab a 7mm brush along with some carbon remover and thoroughly scrub the throat and neck area of the chamber. .. Then re-run your bto measurements.

Be forewarned , 50 grains of h4831sc with a 140 class bullet can be VERY hot in the event you do indeed have a short throat...

Good luck.

 

[FatBoy]

Edit: this is prefaced on the rifle not being chambered to feed from a short action magazine. If it's that short, all bets are off and I would find a local smith with a 6.5 throater and lengthen the throat to the point where the bearing surface is above the doughnut area with .0015" jump.

I would say work up your favorite 139-142gr bullet as normal. If Lapua brass fits I would go to 47.5 h4350 and jump .0015". If your rifle is worth a shit it will shoot this load or one real close. I almost always end up between 48.4-49gr with a 210m. Of course, work up but be warned you are about half way through that barrel so don't take 200 rounds figuring it out.

This is assuming a 1:8 or 1:8.5 twist. If it's a 1:9 you may need to go lighter, maybe a 130 or possibly 136.

As stated before, clean the crap out of the throat. If there is a carbon ring that may be why the rifle was sold. I like to use the brush with a carbon buster then I short stroke with JB. This is blasphemy with nice cut rifle barrels, I know. It's the only thing I've found to bring the accuracy back once I start to get sufficient fouling to start damaging the jacket and giving me off call shots.

 

[JamesnTN]

My 6.5-284 is a 1-9 twist and shoots the 140 class bullets really well. It even got me two world records back in the day shooting clinch river 147 grain bullets.

Now I will say when it's 20* out those bullets will not fly straight at all.

 

[338 Mollett]

Like Racesnake said scope it you could have carbon build up.50g of h 4831 is not a hot load.

 

[Terry]

Cratered primers and ejector marks are common with Savage target actions. I have several. They all do it, even with moderate loads.

 

[Judd]

There seems you learned a few things the hard way. Anyone that buys a fire breather like a 6.5-284 with the expectations it's gonna shoot is pretty naive.

Very few used guns are sold here or anywhere on the Internet that will shoot. Always plan on rebarreling. Think about it, if it shoots someone that knows the gun and have shot against it and been beat will buy it.

Good luck...I'd order a new barrel.

 

[Pinsnscrews]

How much will you take for the barrel?

No sarcasm intended, implied, i can take the barrel and have it set back and have a new chamber cut to a smaller cartridge.