Bearing surface and pressure

[Mogollon Hunter]

Decided to try out some hornady sst 154 gr bullets in my 28 nosler because they were available and I figure at the very least they'll do good on some yotes and possibly coues. I don't see any load data on this bullet with us 869 which is all I've been able to find and I want to use my current charge for the 168 vld hunting as a starting point given the weight difference but I'm concerned by the difference in bearing surface length. Hornady sst I measured at .558" and the berger is at a stated .417". Would you guys with more experience be concerned by this or would you go ahead. Just trying to maximize point blank range with this load and minimize component waste finding a decent load.

 

[WildRose]

Decided to try out some hornady sst 154 gr bullets in my 28 nosler because they were available and I figure at the very least they'll do good on some yotes and possibly coues. I don't see any load data on this bullet with us 869 which is all I've been able to find and I want to use my current charge for the 168 vld hunting as a starting point given the weight difference but I'm concerned by the difference in bearing surface length. Hornady sst I measured at .558" and the berger is at a stated .417". Would you guys with more experience be concerned by this or would you go ahead. Just trying to maximize point blank range with this load and minimize component waste finding a decent load.

Greater bearing surface with equal loads produces much greater pressures so be conservative and work up.

 

[asd9055]

Decided to try out some hornady sst 154 gr bullets in my 28 nosler because they were available and I figure at the very least they'll do good on some yotes and possibly coues. I don't see any load data on this bullet with us 869 which is all I've been able to find and I want to use my current charge for the 168 vld hunting as a starting point given the weight difference but I'm concerned by the difference in bearing surface length. Hornady sst I measured at .558" and the berger is at a stated .417". Would you guys with more experience be concerned by this or would you go ahead. Just trying to maximize point blank range with this load and minimize component waste finding a decent load.

I would start with Gordons Reloading Tool or QuickLoad to get an idea!

 

[QuietTexan]

Are you somewhere in the ballpark of low to mid 90gns for charge weight with the 168?

Drop 10%, run it back up, go past if you can. 10-15 rounds, keeps your face arranged correctly, and you can even shoot it as an OCW and see if there's an obvious vertical node in there with the different bullet.

 

[Mogollon Hunter]

Are you somewhere in the ballpark of low to mid 90gns for charge weight with the 168?

Drop 10%, run it back up, go past if you can. 10-15 rounds, keeps your face arranged correctly, and you can even shoot it as an OCW and see if there's an obvious vertical node in there with the different bullet.

Sitting at 94 grains for for the 168, it gives me about 3300 fps out of my bergara 26" barrel. Never done the ocw test, gonna have to read up on it. Started reloading fairly recently.

 

[Mogollon Hunter]

I would start with Gordons Reloading Tool or QuickLoad to get an idea!

This needs to be used on desk top right? I went ahead and registered but it might be a bit till I can make use of it.

 

[asd9055]

This needs to be used on desk top right? I went ahead and registered but it might be a bit till I can make use of it.

I have only ever had DOS/Windows systems. Both Work on my systems, desktop and laptop windows. Model first the load you are now shooting to learn and calibrate and the. Try the new load you are trying to figure out. As always start low work up

 

[QuietTexan]

Sitting at 94 grains for for the 168, it gives me about 3300 fps out of my bergara 26" barrel. Never done the ocw test, gonna have to read up on it. Started reloading fairly recently.

OCW can roughly be described as look at the target as you shoot the loads, and look for sequences where successively increased charge weights don't alter POI very much - in the vertical AND horizontal. Very simple to do because you don't need a chrono to do it, just a series of progressively heavier charge weights (and a range longer than 100 yards if you're currently stacking groups too small to distinguish differences between them).

In your case you have to shoot the charge weight increments back up to be safe with the new bullets, so as you do it mark up a copy of the target numbering each shot in the sequence and look for any three shots that hit the same POI - you might find a velocity window with a tight dispersion just shooting up to a new max load, regardless of the muzzle velocity statistics that a chrono would show you. I'm stepping on his method a little bit by only shooting one shot at each charge instead of a group of 3, but his logic of examining POI in two dimensions holds. Basically I'm trying to score you a freebie while doing the smart thing and working back up.

Home

If you're looking for absolute top speed then the ladder test of matching low vertical dispersion with stable velocity would be more useful, but if you do that and it doesn't work (at the speeds you want or in general) then the best option is change components. Kind of tough to do voluntarily right now.

Creighton Audette’s Ladder Test

Creighton Audette came up with a method for developing precision rifle handloads that has been refer...

precisionrifleblog.com

 

[Mogollon Hunter]

the best option is change components. Kind of tough to do voluntarily right now.

It's tough to select ones to start with right now haha! Which reminds me, found some 7.62 nato spec primers at the lgs today, think they're worth picking up? I've read that they're equivalent to large rifle magnum primers

 

[Mogollon Hunter]

OCW can roughly be described as look at the target as you shoot the loads, and look for sequences where successively increased charge weights don't alter POI very much - in the vertical AND horizontal. Very simple to do because you don't need a chrono to do it, just a series of progressively heavier charge weights (and a range longer than 100 yards if you're currently stacking groups too small to distinguish differences between them).

In your case you have to shoot the charge weight increments back up to be safe with the new bullets, so as you do it mark up a copy of the target numbering each shot in the sequence and look for any three shots that hit the same POI - you might find a velocity window with a tight dispersion just shooting up to a new max load, regardless of the muzzle velocity statistics that a chrono would show you. I'm stepping on his method a little bit by only shooting one shot at each charge instead of a group of 3, but his logic of examining POI in two dimensions holds. Basically I'm trying to score you a freebie while doing the smart thing and working back up.

Home

If you're looking for absolute top speed then the ladder test of matching low vertical dispersion with stable velocity would be more useful, but if you do that and it doesn't work (at the speeds you want or in general) then the best option is change components. Kind of tough to do voluntarily right now.

Creighton Audette’s Ladder Test

Creighton Audette came up with a method for developing precision rifle handloads that has been refer...

precisionrifleblog.com

Also thank you for the write up and advice

 

[QuietTexan]

More than welcome sir, this is a good group here.

I would buy them. Never a bad idea to have components around to use

Honestly start saving a sleeve of every primer you can get and a pound of any useable powder you can find and eventually you'll have a nice backstock to test things out with. That's half the fun of this to me, taking something that's being contrary and finding the right set of components to make it work.

 

[Mogollon Hunter]

Thanks for the replies and insight fellas, I really enjoy being able to ask questions here and recieve insight within minutes. Thinking I'll start at 88 grs as my pet load with the 184 f-open hybrid berger is 90.1 grs and the bearing surface is within approximately .016" with the f-open at a stated .542". Will likely update this thread with my results in the coming weeks.

 

[Mogollon Hunter]

Got the rounds loaded, probably gonna end up pulling some bullets.

 

[QuietTexan]

But. But.... But those cannelures.

I have a ton of SSTs in 308 cal and use them in 30-06 and 300 RUM. Always makes me twitch not using the cannelure The things we let bug us for no good reasons astound!