Load for 270 too hot?

[catorres1]

I am working up a new load for my son's 270. 140 ABLR. They are loaded out quite a bit farther than book length, also only bumped shoulder back, so minimally resized.

Not actually concerned about getting max velocity, but as I did load development, the SD's and ES's kept getting smaller and smaller. My final load, which was .5 grains higher than book had some of the lowest SD's and ES's of any load I have made (which is not saying much, but still).

There was no sticky bolt, but I noticed the primers had a slight edge around the strike point, what I would assume is cratering. You can't really see it without a magnifying glass, but you can feel it if you scrape it with your fingernail. BTW, the primers are WLR's, I've noticed they seem pretty soft.

Velocities were also very slightly (15 fps) faster than book max for this load, which also concerns me. Usually, I load up to book max velocity if there are no pressure signs, but in this case my case capacity is increased, no doubt, so I think I should be able to get a bit more.

I would not bother thinking about this load if it were not for the great SD's and ES's. And were it not for the feel of the primer, I would not worry, as extraction was just like the minimum loads.

Thoughts? Thanks!

 

[MudRunner2005]

I would say that you're just now starting to see pressure signs...

This is from my .25-06 AI at the range during load workup..

This is how you KNOW you've gone too far.

 

[catorres1]

Whew! Yeah, I think I might back off that load just a bit! Ha! I thought of trying to post a pick of my primers, but nothing would show in a pic. So what do you think? Should I load up some more and see how they group?

 

[Hatrick]

In my 270, fireformed, neck sized, 55 gr imr4350, 130 gr combined technology, winchester primers flattened more than cci but shot better. I chauked it up to softer primers.

 

[MudRunner2005]

Whew! Yeah, I think I might back off that load just a bit! Ha! I thought of trying to post a pick of my primers, but nothing would show in a pic. So what do you think? Should I load up some more and see how they group?

Make sure you're not jammed into the lands. That can cause pressure spikes. I'd set them about .015" off the lands (with a proper gauge) and then re-test that load.

Also, trying the Federal 210M primers might be worth a shot. I use either Federal or CCI primers. Never cared for Rem or Win primers.

Also, with the 140's, you might want to give a slower powder a try... I use IMR 7828 SSC in my .25-06 AI with Berger 115's.

 

[catorres1]

Yeah, I am not jammed, I set length with the hornady tool and then double checked to make sure it was not hitting. I am .015 off the lands as I remember, at least. For powder, running 4831. Hoping its just soft primers, I'm going to run them again along with .5 grains under (which would be book max) and see where the accuracy lies. If they are the same or close, I'll go slower.

 

[benchracer]

Many factory rifles will exhibit primer cratering well below max pressure. The typical firing pin hole is oversized enough to cause this. Absent other pressure signs, I don't believe the cratering is significant.

 

[Trm82]

I am working up a new load for my son's 270. 140 ABLR. They are loaded out quite a bit farther than book length, also only bumped shoulder back, so minimally resized.

Not actually concerned about getting max velocity, but as I did load development, the SD's and ES's kept getting smaller and smaller. My final load, which was .5 grains higher than book had some of the lowest SD's and ES's of any load I have made (which is not saying much, but still).

There was no sticky bolt, but I noticed the primers had a slight edge around the strike point, what I would assume is cratering. You can't really see it without a magnifying glass, but you can feel it if you scrape it with your fingernail. BTW, the primers are WLR's, I've noticed they seem pretty soft.

Velocities were also very slightly (15 fps) faster than book max for this load, which also concerns me. Usually, I load up to book max velocity if there are no pressure signs, but in this case my case capacity is increased, no doubt, so I think I should be able to get a bit more.

I would not bother thinking about this load if it were not for the great SD's and ES's. And were it not for the feel of the primer, I would not worry, as extraction was just like the minimum loads.

Thoughts? Thanks!

They don't make a 140 ABLR , do you mean 140 accubond ?

 

[catorres1]

Quite right, 140 accubond, not ABLR!

 

[Rich Coyle]

catorres1,

Maybe I'm more carefree than some of our .com friends here. I fail to see the problem. If I can get eight or ten firings from a single brass, I couldn't care what a book says about the load.

If you have older reloading books you will find some loads considerably hotter than today's lawyer proof loads.

 

[ranger3]

If you're shooting these in the same temperatures as you will be when you are hunting I wouldn't be too concerned this is a condition that you might see just because you're at a peak load. I have a load in my 270 that is way over booked on the amount of powder using a nine and a half Magnum primer and it is just fine you wouldn't take it out on 85 degree day but I don't hunt on an 85 degree day. That is why I now only use temperature in sensitive powder.

 

[Gord0]

My .300 win craters primers with factory loads. It even craters them very slightly with low to mid level book loads... I would say that you are fine with the load you are running.

 

[catorres1]

Awesome, thanks guys. FYI, it was probably 90 degrees outside when shooting...Texas...here we have Game of 'Thorns'..Winter is NEVER coming....
Working on loading more of 'em up to see how they group. Hope it's on the money, I am running out of time for my trip to Colorado....need another 3 months!

 

[4xforfun]

I am working up a new load for my son's 270. 140 ABLR. They are loaded out quite a bit farther than book length, also only bumped shoulder back, so minimally resized.


Thoughts? Thanks!

This is where the trouble of over-sizing happens....bumping the shoulders. Bump them back to much and you find yourself in hot water.....IE ...headspace issues!! There is no other way to over-size your brass.

Tod