6mm Sierra 100gr pro hunter.

[Tikka_prs]

I'm at a loss as to what to try next with these bullets. I tried working up a load in my 243 with the 100gr pro hunters over n160 today. Everything I try gives me crazy pressure and even blew the primer out of a couple of rounds.
I have a load worked up for 100gr ppu bullets which is using 40.6gr of n160 seated 30 thou of the lands. It gives me 2840 fps. I started seeing pressure signs at 41.8gr with this load.
Today I tried the sierra's, I'd looked at the vhit app which shows speer grand slams as the only 100gr bullet with a max charge of 39.8gr of n160. I knew I could use 40.8gr behind the ppu's so I thought I'd start with the Sierra at 38gr and work up. I loaded 3 round groups going up in 0.2gr steps up to 40gr.
Fisrt round of 38gr gave a speed of 3040fps with ejector swipe and a blown primer!!! So I pulled all of the other loaded rounds. I then backed off to 37gr, gave a speed of 3004fps and crazy pressure signs again.
Backed off further to 36gr, gave 2940fps but still crazy pressure signs. At this point I thought maybe I had a mix up with powders so I loaded up my ppu load with the same powder and it shot completely as expected, consistent speed and no pressure signs.
I've seated the sierras 30 thou off the lands so it can't be excessive pressure from jam. The only thing I can come up with is the ppu's measure 0.2425 on my micrometer but the sierras measure 0.2435. Could that extra 1 thou really be so tight to the barrel that excessive pressure is being created?
Anyone any thoughts?
Maybe I should just stick to my original ppu load.

 

[308tikka]

Brass different, primers different, copper on bullets different, different shape bullet.

use a different powder.

 

[Tulloch]

I use RE19
I get amazing results , here is the load I use

42gr RE19 , I get 3065fps with a 2.1 SD

Cci 200 or 2br pimer or Fed premium large primer

Federal brass

You need to watch the pressures with Vhit

If you decide to use RE 19 42gr is a little higher than book weight but its a slow burning powder so less pressure I had the same issue as you with H4895 and a couple of Vhit powders so moved to RE19.

Start at 41 then 41.5 then 42 and 42.5 and see what your groups are like rais and drop .2 as you see fit.

Hope this helps

 

[Tikka_prs]

Brass different, primers different, copper on bullets different, different shape bullet.

use a different powder.

Same brass freshly prepared, same primer, everything the same except for actual bullet and seating depth.

Its looking like I will need a different powder for them at the moment.

 

[vpk999]

I had a very similar experience with 95grain Nosler Ballistic Tip #39534 with Viht N160 and Reloder 15. According to quickload, everything should be fine, but pressure signs, high speeds and a couple of blown primers. I backed the powders right off and now they shoot fine at 3000fps. I checked the weight of them and the diameter and everything was fine. Yet I use the original powder charge with other 95grain brands without any issues.

 

[Cottis]

Quite simply back off the charge weight until you get a load shooting around the 2850fps mark which also gives you the accuracy you require.

Forget what the PPU bullets are doing.

Pressure is pressure. You either have not enough, enough or too much. Back off until you have enough. Pro hunters and N160 are a good combo.

For what its worth, i shoot the same load. I cannot remember without looking exactly what the chargeweight is but i encountered ejector swipe and sticky bolt at chargeweights i expected to be fine so ended up around 36grains. The load shoots superbly

Good luck with it. It is easy to take load data at its word but it is only a guide.

 

[hendrix's rifle]

I'm at a loss as to what to try next with these bullets. I tried working up a load in my 243 with the 100gr pro hunters over n160 today. Everything I try gives me crazy pressure and even blew the primer out of a couple of rounds.
I have a load worked up for 100gr ppu bullets which is using 40.6gr of n160 seated 30 thou of the lands. It gives me 2840 fps. I started seeing pressure signs at 41.8gr with this load.
Today I tried the sierra's, I'd looked at the vhit app which shows speer grand slams as the only 100gr bullet with a max charge of 39.8gr of n160. I knew I could use 40.8gr behind the ppu's so I thought I'd start with the Sierra at 38gr and work up. I loaded 3 round groups going up in 0.2gr steps up to 40gr.
Fisrt round of 38gr gave a speed of 3040fps with ejector swipe and a blown primer!!! So I pulled all of the other loaded rounds. I then backed off to 37gr, gave a speed of 3004fps and crazy pressure signs again.
Backed off further to 36gr, gave 2940fps but still crazy pressure signs. At this point I thought maybe I had a mix up with powders so I loaded up my ppu load with the same powder and it shot completely as expected, consistent speed and no pressure signs.
I've seated the sierras 30 thou off the lands so it can't be excessive pressure from jam. The only thing I can come up with is the ppu's measure 0.2425 on my micrometer but the sierras measure 0.2435. Could that extra 1 thou really be so tight to the barrel that excessive pressure is being created?
Anyone any thoughts?
Maybe I should just stick to my original ppu load.

Literally just worked up a load like yours, 40g of n160, federal 210 primer, norma brass, 2.650 coal. Sub half inch group at 100, with 2 other loads giving 0.8-0.9 inch. Match made in heaven!

 

[hendrix's rifle]

Out of interest, what's your coal?

 

[Mach IV]

I have been pondering on this and I am with Hendrix's Rifle, are you sure you are 30thou off the lands? Have you checked with the Prohunter?
I did a quick ladder test with my new to me .243 yesterday.
Federal Classic brass (necks skimmed and case length checked 2.040), COAL 2.650 (which is 40 thou of the rifling measured using a 100gn Prohunter).
N160 at 38, 39, 40 and 41g all good, no signs of pressure. I could have gone higher but it was an exercise to just check everything was behaving normally and as expected.

 

[Shotgun572013]

Hi all . Anyone had any issues with 100/95gr Nosler partitions with RL 19 or Viht N160 ? Another member was asking if the 100 grain will stabilise in a 1 in 10 twist ? Thanks in advance