Pressure 260 Rem load

[rharfo]

Just got a Nosler M48 in 260 Rem. Rifle shot a .3 ,3 shot group after two sight in shots. Load was from nosler manual. 45.0 grains of IMR 4350. 130 Accubond, match LR Fed primer. Fed once fired brass. Had a slight stiff bolt lift and extractor mark on case. Same load in converted Ruag brass showed no signs of pressure. Do I back off in the Fed brass? Back off in the Ruag brass too?
I have about 7 pounds of imr 4350 and since it's grouping good I would like to stay with it. Primer change?

 

[26Reload]

Sounds like it shoots well...but hot...wheres the speed

 

[rharfo]

My chrono went back to magnetospeed and then corona hit and I've never heard back from them. So no speeds yet.

 

[rharfo]

It's might be a shooter

 

[26Reload]

Back the load down some and see what it does.....

 

[scottishkat]

What's the weight of the Ruag brass compared to Federal? Fill the Ruag case with water and do the same with the federal brass and compare the 2. If the Ruag brass holds more water you need to back down a little. Less capacity = more pressure more pressure = more velocity. Your chrono will tell you the same.

What temperature was it outside when you were shooting I 4350 increases pressure every degree above 70F.

Nosler data indicates 47gr of water with a 130gr seated to 2.800.

Good luck and shoot straight y'all.

 

[rharfo]

Case filled to top with water.
Fed: 53.7,54.7,54.3. Same case checked 3x
Ruag: 54.2,54.3. Same case checked 2x.
Never did this so bare with me.
Fed brass weight: 179.6,178.3,178.2,178.3. -4 Fired cases
Ruag brass weight: 174.1,175.1,174.6. -3 Fired cases.

outside temp was 50 and damp when I shot the initial loads.

 

[RT2506]

Well first off you broke the first rule in hand loading. You started with a MAX listed load. Then you broke another rule. You changed components in a load with no drop in powder charge.
You should choose which ever components you want to use and stick with them. If you want to use the Federal cases I would back off 2.5 grs and work up in .3 grs at a time to see what your groups are and pressure signs are since you don't have a chrno. No two rifles are exactly the same so what was OK as a MAX in the Nosler test rifle may not and seems like is not the same as YOUR rifle. If you are having sticky bolt at 50* then at 80 or 90* you may rupture primers etc.
Since there seems to not be that much difference in case capacity between your case makes it could be that the Federal are softer and thus expand and flow more and grip things better. Cases could have different neck wall thickness. Also from what my buddy and I learned way back when the 260 Rem came out which was before you could get 260 Rem. cases is that using 308 Win cases necked down left the neck pretty short from what a trim to 260 is supposed to be. That changers neck tension. We found that 243 Win necked up worked best.

 

[JMW67]

Just got a Nosler M48 in 260 Rem. Rifle shot a .3 ,3 shot group after two sight in shots. Load was from nosler manual. 45.0 grains of IMR 4350. 130 Accubond, match LR Fed primer. Fed once fired brass. Had a slight stiff bolt lift and extractor mark on case. Same load in converted Ruag brass showed no signs of pressure. Do I back off in the Fed brass? Back off in the Ruag brass too?
I have about 7 pounds of imr 4350 and since it's grouping good I would like to stay with it. Primer change?

my advice to you is get you some Peterson or lapua 260 brass back off powder charge 2.5gr. and work back up in .2gr increments the reason I say buy this brass is it will last many firings and you will not have to rework load a lot. As temp increases be careful with imr 4350 as it is temp. sensitive and your pressure will increase as the weather warms up good luck with it the 260 is a great round

 

[rharfo]

I've loaded some rounds at 43.0 vs the 45 max.
I've got 7lbs so I'd like to find some use for the IMR 4350.....
Hope to shoot Monday.

 

[JMW67]

I've loaded some rounds at 43.0 vs the 45 max.
I've got 7lbs so I'd like to find some use for the IMR 4350.....
Hope to shoot Monday.

the imr 4350 is fine for the 260 just keep in mind that you don't want to work up a hot load on a cool day and shoot it on a hot day as you could very well be over pressure

 

[scottishkat]

Rharfo did you check the water weight of the brass with the extractor marks? Be interesting to see what that will tell you. Looks like the federal brass is a good bit heavier. If you can resize the case body without the neck you can mark a 130gr at 2.800 oal and put the bullet In a case to the mark weight the water left and see if it's less than Nosler data.

43gr may produce the same velocity but you'll only determine that when you get your chrono back. Dropping back a grain will probably be plenty. Always check capacity if you can when using max loads with nosler data it's one of the reasons data varies so much. I note that berger does not give a case capacity and max is 40.3gr and swift says 44 with Remington cases.

Any time the data gives a case capacity you should check or just work up to a grain less. As has been suggested pay attention when shooting max loads of I4350 on hot days the temperature sensitive powders can change velocity and point of impact.

I really like H4831 and H4350 in the 260.

Good luck and shoot straight y'all

 

[CaptnC]

I would stay away from Federal brass. I've had problems with it before myself. I shoot a lot of range pickup brass and was loading a box of 50 6.5 Grendel brass when I noticed two cases were up in the neck. With Benchmark powder it is a compressed load in the 6.5 Grendel so I'm used to seeing a lot of powder in the cases. Normally I can lightly tap the cases and the powder level goes down.

But not these two, so I stopped to find out why. Turned out I had picked some federal cases.

I did load them with a reduced load and ended up with the same velocity but the ES and SD were not acceptable.

Also Federal cases have a ton of shavings around the flash hole. I've broken two flash hole tools trying to clean up the flash holes. I ended up just using a drill...it was too much for me.

 

[rharfo]

Shot the 260 today. 65 degrees. The Fed case with 43.0 grains showed no pressure and excellent accuracy.