Wierd Pressure Spike with 2015BR/70 Sierras/6BR

[Bradley Walker]

Hey I tried 2015BR with 70 grain Sierras (as it is one of my favorite powders in 223) and I got some very weird behavior in my 6BR.

It went from blacking the case (like it was under pressure) to making extractor marks. There was no pressure good spot. The bullets were jumping 20 thou.

I was using CCI 450 primers. Too hot for this fast powder? I have never seen anything like it. The CCI 450 works great with R-15 (which of course is substantially slower).

I found 2015BR to basically be the 1/2 grain faster N133. It will out will out shoot N133 in my 223's and 223 AI's in fact.

 

[Varminator]

30.5 gr 2015 Sierra 70gr BlitzKing Moly 2950fps out of a 15"BBl
XP-100 Custom in 6BR 14 twist. Max load, into the lands. Golf balls at 250yds Burris 3-9 old pistol scope.
Custom scope mount for silhouette by Chad Bicket.
This is my go to round suggested to me by Chuck Bicket, I only weigh every third or fourth throw from a Redding BR3. Shoots good from my 10 twist rifle as well but in the rifle I get better accuracy with H-335 and Data 73 and the 75gr VMax.
Mark

 

[Bradley Walker]

What primer? I was using a mag primer. I figure these might be too hot for fast powders.

 

[Varminator]

The primers I've tried are CCI450, CCIBR and Fed gold metal match. All of which provide similar results.
The old data on the AA site showed 30.5 as a max load so I only went to 30.8 and stopped there. Try H335 or if you can get some Data 73 try that, though it has basically disappeared but someone might part with some, it is very similar to AA2230 but is faster. The H335 seems to burn the cleanest of all as long as you keep the loads stiff/hot. If you have an 8 twist you will get better results from heavier bullets like the 87VMax and RL-15 or IMR4320 the 87VMax shoots well in my 8 and 10 twist and also my 9.25 twist .243. I was never able to get good results with the 8 twist and the 70-75gr bullets with my 6Dasher.
Have you tried H335 in your .223? I like 25+ gr with the 60gr VMax depending on the lot.

 

[Bradley Walker]

Just shot H322 tonight with the 80 gr Fowlers.

It blew away everything I have tried so far.

Looks like anything between 29 and 30 would just hammer... looks like 29.6 was the magic load in the cool air, but there was little distinction in any of the groups from 29 to 30, the powder is not "peaky". I did switch to Fed 205M just to be sure the primer was not too hot.

6BR
29.6 H322
205M primer
+15 into lands after touching
Fowler 80 grain moly coated

Looks like several groups in the high 1s. Calm cool air about 55 degrees at 100 yards.

The R-15 appears to be very temperature sensitive with this bullet, as the loads that shot 3 weeks ago when it was 75 degrees plus will not shot shoot now without fliers (they appear to be below the node now). I shot the R-15 all the way up to 33 grains with no pressure (and they shot pretty good--- I saved them for foulers when it was hot and now they are not over pressure). These loads would should show extractor marks last month.

So, I guess I have a lot to learn about these faster powders.

The H322 gives low recoil, burns super clean, and shoots little teeny bugholes. I will have to see if it is temperature sensitive as it warms up.

I will also say this... I am just trying to learn how to shoot benchrest. I just purchased my first benchrest this year, and this is my first real benchrest rifle. I will tell you one thing... I shoot hard hold. I cannot shoot free recoil at all. I come from a highpower background, I like a hard cheek weld, and the gun in my shoulder. I have no clue how to shoot with the gun just floating on the rest and rear bag. I guess I suck, but I am shooting better than I ever have from the rest after I gave up on free recoil. Even after I bought the cool front and rear rest that goes with my stock.

I will try the cci 450 with the same load and see what happens.

 

[Bradley Walker]

It appears that 29 gr H322 won the day, but I think the second group was actaully shooting better and the group only opened up due to shooter error.

 

[NorCalMikie]

Try the same load that was causing you problems with the bullets jammed into the lands about .010.
On my Savage rifles a load will show pressure signs with the bullets jumped and no signs with the same load and the bullets jammed. ???

 

[Bradley Walker]

Maybe that is it.

Yah, this jamming thing is new to me, but it does seem to work on my new rifle.

 

[NorCalMikie]

Might be as simple as that! But make sure you make "only one change at a time" or you'll end up chasing your tail and not knowing what changes made the difference. (been there, done that)
Or at least you got more trigger time. ;D
Set the bullets to a longer OAL and see what happens. Won't cost you anything to try.