280ai 175 eldx and RL26 pressure?

[Jimmyfish]

Hi guys,
I'm celebrating NZs ease in lock down with my first trip to My Cook to try find a Thar.

I have been struggling for consistent accuracy with my Tika t3 280ai 26inch 1/9 twist. and the previous owner found his best load was 59gn 2213sc behind a 160 accubond traveling at 2850fps around .75in at 100m.
I've fiddled with the 162 eldx on top of n560 and 2213 with poor groups when speed gets above 2900.
Which led me to think of using the 175eldx and keeping the speed down around the 2850 that the barrel likes with the 160abs.

Well today I loaded a single shot ladder with RL26 behind the 175s jammed .005
58.0gn 2874 fps
58.5gn 2910 fps
Didnt go any higher as this is already plenty.
So the two questions I have are:

1 do these speeds seem excessive for the charge? (charge was weighed on two sets of scales)
2 thoughts on primers? Normal bolt lift on both rounds.

Many thanks

 

[lancetkenyon]

The primers look OK to me.

RL26 usually yields better speeds than a lot of other powder choices. 58.0 & 58.5gr should be in the higher end before pressure. Speeds seem fine, I run a 175 Berger @ 2976fps w. RL23 in my 26" 1:9" .280AI.

If you are in New Zealand, I assume you are in your winter right now. I have no clue how warm it gets in NZ in your summers, but be careful if you are near a max load in cooler temps, RL26 can go over pressure if you hit 85°F.

 

[Jimmyfish]

Well loaded up a few more 175 eldx at 58.5 of RL 26 and shot them today. Finally something my rifle likes.
Avg 2870 fps and .5inch at 100m. Then put the velocity and estimated drop from Hornadys ballistic app into the leupold rangefinder... ranged the 390 yard gong, dialed the drop and fired two shots.

I'm not mucking with it any more.

 

[Dmagna]

I shoot the 175 elite hunter out of my 280ai Just shy of 3000. I didn't like rl26 in my 280 because it would always cause a flier. I switched to N565 and never looked back. It's a great powder. The 175 eldx didn't agree with my 1-9 twist.

 

[Dmagna]

Also nosler just changed their brass, so keep that in mind. The new brass is stamped NOS instead of nosler. Peterson is where I am going to go when I destroy what I have.

 

[L.Sherm]

I had the same problem that Dmagna had with 26.

 

[Jimmyfish]

That's interesting..
I'll leave it for now as I'm heading into the hills this Friday and haven't got time to explore any other combos.
I have tried n560 behind 162 eldxs but haven't tried n565.

 

[fightthenoise]

I've loaded for 4 different ELD bullets in 4 different barrels and they all grouped best at 0.020" off the lands in the seating depth test

 

[BoatTail]

Side question. The Vihtavuori N5XX series of powders I have heard is not temp sensitive but can find it qualified as such from the vendor. Do some of you have that info?

 

[Jimmyfish]

Well the 175 Eldx on top of RL26 did the job at 600yds on a 12.5 inch Mt Cook Tahr.
Went through both shoulders and recovered under off side skin.

 

[Dmagna]

Side question. The Vihtavuori N5XX series of powders I have heard is not temp sensitive but can find it qualified as such from the vendor. Do some of you have that info?

VVn565 and N570 are very temp stable.

 

[Kmccord]

Very nice, are those Tahr very good for table fare?

 

[VLD Pilot]

Hi guys,
I'm celebrating NZs ease in lock down with my first trip to My Cook to try find a Thar.

I have been struggling for consistent accuracy with my Tika t3 280ai 26inch 1/9 twist. and the previous owner found his best load was 59gn 2213sc behind a 160 accubond traveling at 2850fps around .75in at 100m.
I've fiddled with the 162 eldx on top of n560 and 2213 with poor groups when speed gets above 2900.
Which led me to think of using the 175eldx and keeping the speed down around the 2850 that the barrel likes with the 160abs.

Well today I loaded a single shot ladder with RL26 behind the 175s jammed .005
58.0gn 2874 fps
58.5gn 2910 fps
Didnt go any higher as this is already plenty.
So the two questions I have are:

1 do these speeds seem excessive for the charge? (charge was weighed on two sets of scales)
2 thoughts on primers? Normal bolt lift on both rounds.

Many thanksView attachment 197647

Give reloader 23 a try

 

[Deleted member 107796]

I don't see any extractor marks from excessive pressure. I would bet your bolts' firing pin exit hole is chamfered like my Winchester 70 in 7wsm and always leaves craters to some extent.