.270 Win and 150 gr. Partitions

[Hegland]

Whatever the speed, you've got yourself a very capable load there. Good job!

 

[Silentstalker]

Antelope,

I stopped at 57 gr. for now. After wednesday I will see where I am at with pressure signs and accuracy. Its nice to know others have had success at higher gr. loads.

SJB,

I bet they are rocking out of that wsm!

Its nice to see such accuracy that is rivaling my BT loads! Thanks for all the kind comments and help! Cant wait for wednesday to try them again!

 

[Antelope_Sniper]

I was getting 2950 fps out of my 22" BBL .270 Win.
All things considered, yea, it was a pretty rocking load.

 

[Silentstalker]

Ok guys I need some more help/advice. I went out and shot today after reloading 55.5-57gr of H4831sc with the same exact seating depth as last time. Only thing that changed is that I cleaned my rifle versus last time I shot it with about 20 rounds through it to begin the session. Wind was calm and temps were a tad warmer at about 55 degrees. I fired 5 shots of a factory load to "dirty the barrel". Even at 57 gr. I had no pressure signs.

One thing I have really started to notice is 2 patterns.

#1- I quite frequently get an extremely tight 2 shot group out of shots #1 and #2. Then I get a flier of shot #3. My shot cycle is to shoot all 3 fairly quickly and let the barrel cool for 5-10 minutes then shoot 3 more. Could this 3rd shot flier be heat related or something else?

#2- My gun really seems to shoot its best groups after about 20+ rounds through the barrel.

What are your thoughts on my next step? Start over? Redo any particular load?

Here are the results:

 

[SJB358]

I'm thinking heat is getting to it by your 3rd shot. My 338 does the same thing. The first two will snug in real good but unless I wait a bunch of time to fire the 3rd it'll walk out a bit. To be honest I'm not too worries about it. You might try seating a little deeper. Might pull that 3rd shot in for you.

 

[DrMike]

That is almost assuredly related to one of two phenomena--either there is a pressure point that is walking as the rifle heats up, or you are tiring as you fire in rapid succession.

 

[Silentstalker]

So based on that assumption which I tend to agree with based on my gut and your knowledge, should I shoot really slow 3 shot groups to cool inbetween shots or just pick a real tight 2 shot group with a flier and test it against various seating depths?

Edit... Im thinking the 56 gr. load looked really good till that 3rd shot. I may start there.

 

[SJB358]

I'd wait at least 2 minutes between shots. Dry fire the rifle between show while your waiting. I use my stop watch to time my shots so I keep them even. May even need to wait 3 minutes between shots. Allow it to cool straight down between shot groups.

 

[Antelope_Sniper]

First thing you do is check to make sure your barrel if free floated.

Unless you have a pencil thin barrel, so long as it's properly floated three shot should not be a problem. After 3, set iti the rest, shoot 2-3 more groups out of other rifles, then come back to it for another group.....

2 in and one out is a classic indication that you may benefit from a reduced OAL.

That should keep you busy for the next few sessions.....let us know how it goes.

 

[Silentstalker]

I can slide a piece of paper between my barrel and stock. So I think clearance is okay. I will rotate guns and shoot slower sets of 3. I will also try the shorter coal's too. I also think as Dr. mike alluded to, the 3rd shot could be me...

More range time is good for me! Thanks again for all the great advice.

 

[Oldtrader3]

The traditional load for this bullet with IMR 4831 is 57.0 grains of powder with the 150 gr Partition. You might try going a little higher than 55.0 grains and see what your groups look like?

 

[Silentstalker]

Im shooting H4831sc. I know I could go higher up even than the 57 gr I have already done. Perhaps I will reshoot the 55.5, 56, 56.5, at current and shorter coal, and then try up to 59 grs too.

 

[hubcap]

The traditional load for this bullet with IMR 4831 is 57.0 grains of powder with the 150 gr Partition. You might try going a little higher than 55.0 grains and see what your groups look like?[/quote
Thats an awsome load. Real fast and accurate too.

 

[vodekzz]

I best load is R-22 with 150 Partition. Rl-22 58 gr. It might be too hot for some rifles be careful.
Very accurate.
Vodekz

 

[sask boy]

Well guys I have 200 150gr. ABLRs for our 270s. I have both 4831sc & lots of RL22 need starting points for both. My Son's rifle is a BDL with a 22" barrel. I was thinking 54.5grs. Of 4831sc. What about for RL22?
Starting to load this evening!!

Blessings,
Dan

 

[SJB358]

Well guys I have 200 150gr. ABLRs for our 270s. I have both 4831sc & lots of RL22 need starting points for both. My Son's rifle is a BDL with a 22" barrel. I was thinking 54.5grs. Of 4831sc. What about for RL22?
Starting to load this evening!!

Blessings,
Dan

Dan, use the data for the 150 PT/BT in Nosler's #7 for RL22. You should be able to go a little higher, but this is a good place to start.

 

[bobnob]

2 in and one out is a classic indication that you may benefit from a reduced OAL.

How does reducing oal help there? Interested.

 

[Silentstalker]

I am also curious on an explanation as to why shortening up the COAL brings in a flier? I have heard this from quite a few people but do not understand the "why".

I have loaded up several COAL's with 3 powder charges that looked promising. Hoping to get to shoot them Monday morning. Crossing my fingers my groups tighten up a bit.

 

[SJB358]

2 in and one out is a classic indication that you may benefit from a reduced OAL.

How does reducing oal help there? Interested.

Changes the harmonics of the load to bring it into sync with a node. I know someone will come back with a much better explanation, but that is what it does in my head.

 

[Oldtrader3]

You are pretty close Scotty, not sure that I could improve on your explanation.