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Beartooth Regular
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I had an interesting experience at the range today. I've been experimenting a bit with Ramshot Big Game powder in my 30-06. With 165 gr Hornady bullets their listed max produced 2875 fps, right about what it should have. Well, I worked up to the same max charge with the 165gr X-bullet, and saw no signs of excess pressure or any difference in the cases when compared to the Hornady load.
BUT today I chronographed that load and was shocked to get an average velocity of 2990 fps. Now, some folks may think that's great, but I'm thinking I probably didn't get that extra velocity without some extra pressure. I think I'll back off just a little! But I found it very interesting that I could tell no difference in the cases and extraction was effortless. It would do no good to mic them since they've been fired umpteen times (I just keep annealing the necks).

Just passing along another reminder that different components produce different results, and you can't always tell what's going on via external pressure signs. ID
 

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Good evening,

One thing that i remember about the X bullet, is that they do need a little more distance between the ogive and the beginning of the rifling, else higher pressures will result.

These are real interesting bullets, the x'ers. I am wondering if the failsafes have any of the pressure issues that the x bullets have, as they are not completely copper, and should take a little better to being squeezed down the rifling.

well, thought i would sound off, let me know what you all think.

Steve
 

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The Hog Whisperer (Administrator)
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Yes, Barnes recommends a good 0.050" jump to the rifling for the "X", I guess to give it a good running start....

After perusing the data, it appears that the Failsafe brings up pressures just a little more than a regular bullet, but not as much as the 'x'.

As always.... double-check load data with both the powder & bullet manufacturer! A good lesson for all of us.
 

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Beartooth Regular
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Discussion Starter #4
Hi,
I didn't mention this is the first note but I did seat the bullets approx. .05" off the rifling per Barnes' instructions. The Ramshot data listed several 165gr bullets but not the Barnes X. So I started below the lowest and worked up to somewhere in the middle of the max charges listed. (It is NOT the largest powder charge shown for 165 gr bullets!) Why I didn't have the chronograph with me the first time I shot these loads I don't remember, but I sometimes am very pressed for time or am going somewhere afterwards and don't want to leave the chrony in the truck (I leave it set up on it's tripod all the time). Anyway, another eye-opener. ID
 

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I am going to use X-Bullets on a bear hunt in Maine in two weeks and I am having similar reulsts with 225 gr X bullets in my .358 BLR. They don't like to be pushed.

I have experimented with .223 X bullets in a # 3 Ruger and in .338 in a Browning bolt gun as well. Preasure was an issue and I could not get a satisfactory group from either gun.

I wound up with v-max in the .223 the harder I pushed them the better they grouped.
 

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Beartooth Regular
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Discussion Starter #6
I actually got super groups, under an inch, from all the loads I've tried with X-bullets in 30-06 and .308 and got minimal fouling of the bore. Pressure was my only concern. ID
 

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Sometimes I get some wacky numbers from my chronograph. I've found that things like light angle, light intensity, low battery, ghosts in the machine(?) can throw some strange numbers out from time to time. Once I was able to get 2960 from 270gr Hornadys and R12. I checked the load again on another day with a new battery and landed back on earth with a bit less than 2700.

In 35+ years of handloading many 30-06's with several combinations of 165/powders, I've never seen that number from a 22" bbrl.
 

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Having had once problems getting x-bullets to shoot in some of my rifles, it was solved by the Barnes recommendation of completely removing all traces of previous jacket fouling from the bore. I did this with some JB bore cleaner in short order. After that the x-bullets shoot great groups( like sub moa.) for about 20 rounds before groups open up in my .300 mag. and .270.
However this is plenty good for the full hunting season.
 

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Discussion Starter #9
I don't think there were any ghosts in the machine! We chronographed three different rifles that day and all were in line with expected results. My rifle has a 24" stainless barrel and it has often given fast velocities with published data. For instance, I have acheived over 2850fps with H4350 and the Speer 180gr spitzer using data from Speer's manual that was listed at about 2750. Generally, when I get a velocity higher than expected I back off a bit until I get to the "target velocity". (Doesn't happen much, but it has happened a couple of times.)
Oh, the load with the X-bullet not only got high velocity, it was also very consistent, with an extreme spread of only 12fps over ten shots. So I don't suspect any chonograph errors! ID
 

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Hot loads

IDshooter -

Even with the recommended .050 setback from the lands, the X's are very resistant to deformation, which has the same effect as seating to the lands with jacketed bullets. The X's are also quite LONG for their weight, and the reduced case capacity will also raise pressure and velocity. The combined effect of case capacity and deformation resistance can jump you 100 fps and add the equivalent of 4-3 grains of powder to your charge. Some powders are more responsive to pressure rise than others.

You are wise to back off, but it makes sense that you had no extraction problems. At 2990 fps, you are probably in the 54,000 CUP range with the 165s. This will not give any evidence of pressure problems, even though it is about 4000 CUP high for the '06.

There is another trick for estimating pressure problems: when working up loads, single punch all for you fired primers and mike them for diameter. When Remington 9.5s go from .210 past .217, its getting pretty hot. Over .221 and you should be getting a sticky bolt lift. Over .224, the bolt won't lift.

This only works if you have already confirmed that headspace in your rifle is good, and you seat the primers fully. For other brands of primers, make up your own data base as some primers are harder than others. If a primer seats too easily in an older case, don't use that one for pressure analysis. CCIs are slightly over .210 to start with so mike them before and after.

This technique is for trouble shooting ONLY. The correlation between fired primer diameter and pressure/velocity is poor until you approach maximum. If your velocities are high for a given charge weight, check out the primer diameters.
 

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Beartooth Regular
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Discussion Starter #11
loader,
Thanks for the info! It never occured to me to measure the punched primers. I use CCI primers so I'll have to start that new data base... IDShooter

PS- I didn't think the pressure was at a dangerous level, since cartridges such as the 270 and 25-06 operate at higher pressure than the 30-06. But I like to limit the "wear factor" and appreciate the extra safety margin, even if it is mostly perceived! Thanks again for the data.
 
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