Confused about my 270 Win Reloads

[mosinmaster]

Can you guys help me figure out my next step? All reloads are 3.405" COAL for my rifle, just off the lands.


May 1, 2019 I loaded FL sized brass IMR 4831 53.5gr, 54.0gr, and 54.5gr. I got 0.81" (53.5gr), 1.76" (54.0gr), and 2.73" (54.5gr) at 100 meters.

Ok, so I try my uncle's RCBS NS die with the two most accurate loads 53.5gr and 54.0gr and shoot groups on Aug 2, 2019. Accuracy opens up at 100 meters with both loads: 1.42" (53.5gr) and 2.71" (54.0gr). At 200 meters the 53.5gr opens up to 2-4".

I was confused and wanted to try NS with a Lee Collet Die to see if there was better performance, so I loaded up 53.5gr and shot at 100 and 200 meters today, Aug 23, 2019. Even worse accuracy, and it may be due to my unfamiliarity using the Lee Collet die. I also reloaded a batch of FL sized 53.5gr and it shot as great or better than the first loading in May.

Lee Collet Die 53.5gr 2.95" @ 100m

Lee Collet Die 53.5gr 3.72" @ 200m

Lee FL Size 53.5gr 0.79" @ 100m with 1 flyer.

So at this point I have two options. I can adjust the powder charge if NS. I've read that a fire-formed case may have increased velocity with the same weight of powder, and decreasing the powder charge may help improve accuracy. Should I try loading the NS brass at 53.0gr (1/2 a grain less) and see if the groups shrink back down to sub-MOA? At this point, I need a load for hunting season and I'm going to settle on FL sized 53.5gr and raise the elevation a bit to zero at 200m for whitetail/mule deer this Fall.

Any further suggestions?

 

[Buckmastr]

Lots of stuff going on here but you may want to seat the bullet 10-15 thou deeper and see if the 53.5 gr load improves. A chrony will help you determine how much more charge weight you can tolerate which I suspect is close to 2940fps or 55 gr in a 22" barrel

 

[8x68]

Think you might have them seated out a bit far as Buckmastr pointed out. Additional pressure could be playing a factor, or the bullet prefers a "jump" to the lands. Try listed COL (3.320") and go from there. Nosler also doesn't list using IMR4831 for the 150gr bullet. Not saying it won't work for some, just isn't listed on their website for the 270Win.

 

[mosinmaster]

Any idea why my FL sized loads shoot 1 MOA while NS loads with RCBS and Lee open up dramatically? They’re all seated the same. I agree pressure may be causing the change in group size with the NS loads. I’ll play around with seating depth as well as back off on the powder charge.

 

[8x68]

Are you letting the barrel cool between strings? Is the barrel freefloated? I'm no reloading expert just going by what I find when I have issues. I've also found different primers can affect accuracy as well. I believe Fed 210's are a pretty toasty primer.
Everything tight on your platform?
Just in case you don't have loading data from the Nosler manual for the 150gr Nosler B/T
https://load-data.nosler.com/load-data/270-winchester/
If your happy with FL sized 53.5gr group then stay with that. Load up 3 strings of five for 100/200/300m (if you have that distance available) and see what you get. Sometimes just bumping the neck back 1-2 thou works as well. Depends on what kind of accuracy you are striving for. 1" group at 100m is a respectable group for hunting. Not sure you need to neck size brass for a hunting round.
There are those on this forum whom have vast knowledge about reloading. Hopefully they chime in.

 

[9.3mauser]

That's a very light load. I would think velocities would be similar to a mild 7x57. Some rifles are happier when run close to max pressures.

 

[cosmic]

The FL die is allowing the bullet to centre in the throat. The neck sizing die causes the brass to centre in the chamber. If the chamber is not cut to be exactly concentric with the bore, then neck sizing die will cause the bullet to be off centre in the throat. Pretty fancy theory , eh?
Anyway, stick with what works. Use the FL die and continue to tune your loads. Its a mountain rifle with a pencil barrel - getting sub-moa groups at 100 y should be considered an accomplishment!

 

[nowarningshot]

This is going to sound odd. If i am revved up on caffeine, i shoot like shat. If im planning a range day, i skip my morning coffee three days.

 

[fingers284]

The FL die is allowing the bullet to centre in the throat. The neck sizing die causes the brass to centre in the chamber. If the chamber is not cut to be exactly concentric with the bore, then neck sizing die will cause the bullet to be off centre in the throat. Pretty fancy theory , eh?
Anyway, stick with what works. Use the FL die and continue to tune your loads. Its a mountain rifle with a pencil barrel - getting sub-moa groups at 100 y should be considered an accomplishment!

This is very plausible...and another thing you might be varying is the bullet/neck tension by using the different dies from different manufacturers. I would back-track to what worked best at under a MOA and maybe play with the charge a bit but for sh!ts & giggles but have a bunch of the MOA rounds loaded up and ready for the season...at 200 yrds you could still head-shoot a deer ( not that I'm recommending that shot placement mind you).

 

[tigrr]

My 270 didn't like 150 NBT bullets at all. Bought some 130gr Nosler ballistic tips and I found it shot a 3 shot group under a half inch. Deer and bear fall easily to 130 gr bullets. Some groups were down to the .25"
Don't get stuck on one powder either.
Clean the gun between sessions as well. Get a copper fouling remover and get rid of the green.

 

[mosinmaster]

The FL die is allowing the bullet to centre in the throat. The neck sizing die causes the brass to centre in the chamber. If the chamber is not cut to be exactly concentric with the bore, then neck sizing die will cause the bullet to be off centre in the throat. Pretty fancy theory , eh?
Anyway, stick with what works. Use the FL die and continue to tune your loads. Its a mountain rifle with a pencil barrel - getting sub-moa groups at 100 y should be considered an accomplishment!

Thanks I have come to that realization!! I can put the first 3-4 shots in under an inch at 100meters with the FL 53.5gr. I'm going to abandon the NS now for hunting season and stick with that FL load. Maybe tinker once the season is over.

 

[mosinmaster]

My 270 didn't like 150 NBT bullets at all. Bought some 130gr Nosler ballistic tips and I found it shot a 3 shot group under a half inch. Deer and bear fall easily to 130 gr bullets. Some groups were down to the .25"
Don't get stuck on one powder either.
Clean the gun between sessions as well. Get a copper fouling remover and get rid of the green.

Which copper fouling remover do you recommend?

 

[r204]

I shoot alot of nosler bullets like Varmageddons,Bts and accubonds and I have always found they shot there best with 10-30 thou jump from the lands.
I use Sweets 7.62 to remove copper fouling. I will clean all the powder fowling with Butches bore shine first. then I put a patch through with Sweets let it sit for 5 min then dry patch . Repeat intill the dry patches come out clean with no blue on them. Then I will run another patch with Butches followd by a couple of dry patches.

 

[pete dobinson]

My Kimber Mountain Ascent shoots better with a fouled barrel. Don't over clean. I get better accuracy with hot loads. I use 130 gr TTSX and 60grns of H4831. Velocity is 3100 fps. 3 shot groups is all you need, don't overheat the barrel. All rifle's are different but this is what works for me in my light weight Kimber and my Ruger #1 270 win.

 

[mosinmaster]

My Kimber Mountain Ascent shoots better with a fouled barrel. Don't over clean. I get better accuracy with hot loads. I use 130 gr TTSX and 60grns of H4831. Velocity is 3100 fps. 3 shot groups is all you need, don't overheat the barrel. All rifle's are different but this is what works for me in my light weight Kimber and my Ruger #1 270 win.

FL or NS or Shoulder bump?

 

[pete dobinson]

Full length resizing.

 

[pete dobinson]

After thought, I full length resize because my chamber is tight, if I partially resize the cartridge wouldn't chamber. I prefer the cartridge to have a little resistance when I close the bolt and I was getting phenomenal accuracy until I got a notion to clean the lug recesses out. Now when I chamber a round there is no resistance and the accuracy fell off so now I have to get it back to where it was. So back to partial resizing. Don't over clean. This is from my experience, other's may vary.

 

[Buckmastr]

My Kimber Mountain Ascent shoots better with a fouled barrel. Don't over clean. I get better accuracy with hot loads. I use 130 gr TTSX and 60grns of H4831. Velocity is 3100 fps. 3 shot groups is all you need, don't overheat the barrel. All rifle's are different but this is what works for me in my light weight Kimber and my Ruger #1 270 win.

Yes try a 130 ttsx. My model 700's like them a lot.

 

[mosinmaster]

I just clean the carbon fouling out after each range session. I haven't done any copper fouling removal yet as I don't think it has built up to a critical level yet and accuracy is repeatable with the 53.5gr FL load.

 

[pete dobinson]

I just run a patch through the barrel and I won't run a brush through it until the accuracy falls off.