Range Report: Barnes XPB Part I

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Range Report: Barnes XPB Part I

Postby Hoot » Tue Jul 05, 2011 10:33 pm

Note from Hoot: I have finally repaired most of the broken image links due to changing ISP a few years ago.

Range Report Barnes 200 gr XPB

The reputation of Barnes' bullets performance has always made them alluring, but due to their cost being around $1.00 each just for the bullet, they were too rich for my blood. Good fortune provided me with several boxes of the Barnes XPB 200 and 275 grain bullets. They have been on my wish list of bullets to try in the 450b due to no other reason than I like their form factor. Having recently read of one of our members having pushed lighter bullets, that were coated with a friction reducing compound, very fast in the 450b, I was interested in also going in that direction. I had never pursued it with the lighter, more affordable, Hornady bullets that I already have because Lil Gun seemed to benefit from the back pressure that goes with resistance to the bullet moving down the barrel and these coatings reduce that resistance. I do have the capability of shot plating the big three coatings, WS2 (Tungsten Di Sulfide), MoS2 (Molybdenum Di Sulfide) and HBN (Hexagonal Boron Nitride). All reduce bullet drag and are listed in order of lubricity. HBN has been the rising star because it has no sulfur in it and if the residue is left in an un-cleaned barrel, in high humidity over time, it does not corrode the barrel. Not that we treat our weapons that way, but both MoS2 and to a lesser degree WS2 have gotten beat up for that. Also, for folks already contending with not enough case capacity for the amount of powder they need to cram into it, the reduced back pressure historically required more powder to achieve the same velocity. It is counter-intuitive as you'd initially think that more slippery equals faster. With the 450b, you usually run up against over-pressure signs before you run out of case capacity, so to me, it's no big deal if using a slippery bullet requires you to put an additional grain of Lil Gun in. Anyway, it was an added opportunity to experience the impact it has upon performance, so I included WS2, the most slippery coating in the test. I also could not resist doing a water shot to see if I could reproduce that beautiful expansion pattern we're accustomed to seeing in the Barne's Ads. The .451 XPB is designated as a bullet for loading the .460 S&W, just like the 200gr Hornady XTP.

I hadn't shot my 450b since just before last year's deer season (thanks Dad) and it was still wearing a hunting scope. So, I had to change out the scope for one more appropriate for sub-MOA accuracy testing. I have all my black rifle scopes on the same YHM risers, so changing them around doesn't require as much work as if I had to re-do the rings and everything. Still, any swap requires a re-zero. For that, I used a 5-shot flight of the 275 XPBs. They were not the focus of this test, but shooting a one grain per step group allowed me to accumulate some correlating data for QuickLoad to be used in determining loads for a future report. They also allowed me to season the bore with WS2 prior to my tests since I coated them as well. Their stat are included in the Excel spreadsheet below.
None of the 275gr loads exhibited excessive pressure signs and there was still a little capacity left in the case. They sure recoiled more than the 200s did though. :eek:

Before I get to the meat and potatoes. As promised, I did a shot using the lightest 200gr load that I tested with into milk jugs filled with water. I have used that method before with the various Hornady FTX bullets and though not as scientific as ballistics gel, it is an affordable means of testing expansion performance every one of us can use to share among ourselves with our own loads. Having seen the results from those FTX shots, all I can say is Barnes truly has this down to a science. The 200.7gr bullet weighed 200.7gr after the shot as well. In my book, that is 100% retained weight. But then, you'd expect that with a homogenous material with really thick petals. Not at all like cup and core designs with a relatively thin jacket about the same gauge as copper chimney flashing. The bullet penetrated 4 milk jugs, with the first two being totally destroyed with the resultant shock wave from impact and the latter two having just a hole in, out and in again. That could equate to penetration after the petals curled back.

Here's the porn:

Image

The front-on image is almost a work of art:

Image

Consider this. Before those petals ultimately bent back, they transitioned from slightly open, to fully extended, giving a huge internal cutting area with edges like copper Ginsu blades. I've got me one heck of a tie tack project. :wink:

WRT internal ballistic performance, I had wide-ranging velocities within a load, consistent with not enough neck tension. Next time, I'll either taper crimp these to .475 instead of .476, or throw in a light, Lee FCD crimp over the rearward cannelure. My experience with the 200gr Hornady FTXs was when used with Lil Gun, their velocities varied a lot until I laid on enough neck tension to allow it to get really cooking before releasing the bullet. I did chamber a round, ejected and examined it to measure how much the bullet pulled and it was something like.007, so I knew the tension was not totally inadequate. I suspect that the insufficient neck tension may have led to the high SDs. In some loads, I got some pretty good groups, but then I've seen before where SD did not correlate to great groups in this caliber.

Enough foreplay. Here's the meat:

Image

I'd bet a dollar to a doughnut that those speeds would increase an average of 30-50 fps each step if I had laid on more neck tension. That's my gut feeling anyway.

Here are some images of the more notable groups shot at 100 yards:
Note: Those are half inch grids and bullseye. "Aim small. Miss small."

200gr XPB WS2 Coated with 41gr Lil Gun (Best 3-shot group) (Best 5-shot group)

Image

200gr Plain XPB with 40gr Lil Gun (Best 4-shot group)

Image

200gr XPB Plain with 41gr Lil Gun

Image

The Barnes 200 XPB bullets exhibit textbook expansion, which is to be expected. Whether that terminal performance makes them worth the cost is a personal call. Certain loads are definitely accurate, but others were not. I will follow up with all the full size target images if there is interest. Suffice it to say, the above loads are definitely good choices. WRT using friction reducing coatings. After the first 25 rounds of WS2 bullets. Upon cleaning the bore, there was considerably less resistance to the first few patches soaked with Kroil. After the first brushing and patch, the WS2 one was for all intent and purpose, done. It took a second round of brush and patch after shooting the 20 uncoated bullets to reach the same point. I generally clean between different bullets and also fire a fouling shot. I did not include an image of the five 275gr bullet group as they were for sighting in the scope and were all over the place until I got the scope dialed in.

Notable Revelation:

Back when I first set up my upper on my RRA NM lower, I had been following gunnut's efforts in developing his Recoil Less stock and made my own closely paralleling his design, but with one heavier spring weight as opposed to two. FWIW, I believe that two, consisting of different spring strengths, are a better choice as they will act upon different frequency components in the recoil impulse. Either weight system, when combined with the muzzle brake contributed to making shooting the 450b very pleasant, or so I thought.

Another caliber I'm developing loads for is my AR15 .300 WSSM upper, which also wears a Ross muzzle brake. It throws a 150gr bullet at 3000 fps, putting the performance somewhere between a .30-06 and a lite .300 Win Mag. Out of curiosity, I shot it without the brake and the perceived recoil was much more violent. I put the brake back on and removed my shake weight. There wasn't much change in perceived recoil. When I went back to the 450b, I left the shake weight out. Whoa! The perceived recoil was much more pronounced than I recalled, even with the muzzle brake on, so I put my shake weight back in and suddenly, the 450b was once again tamed. I've said this before, but it bears repeating. My Dad has a Browning A-Bolt Presentation Grade in .270 Winchester. The recoil from it is much more objectionable than the 450b with the brake and a Recoil Less stock. If you're concerned about hunting with a muzzle brake WRT your hearing, don't use one but fdefinitely consider one of gunnut's stocks with both recoil reducers installed.

Conclusion:

As some folks have already speculated, I suspect at the muzzle velocities we encounter and given the bore size of the 450b, a muzzle brake does not do nearly as much for perceived recoil reduction as in the .300 WSSM because the recoil in the 450b is more a function of Newton's 3rd Law of Motion and it is much less dependent upon reducing the rocket effect afforded by a muzzle brake than the .300 WSSM. That's a plug for gunnut's Recoil Less stock. Shooting is believing. It will have a greater effect on perceived recoil than just a muzzle brake. Ultimately, both contribute to reducing recoil, but the lion's share of the effect in the case of the 450b goes to gunnut's Recoil Less stock.

Upcoming tests:

1) More Powder, same bullet, up to signs of excessive pressure.

2) Water shots using less powder with a grits filler (for safe chamber pressure) to check expansion at lower velocities that would be predicted to occur at 100 (1930fps), 200 (1500fps) and (not my choosing) 300 (1175fps) 300 yards. Given the velocities of the intended .460 S&W, I expect similarly pleasing results.

3) Moving on to test the 275gr XPB similarly.

Respectfully Submitted and with thanks to commander faschisto,

Hoot
Last edited by Hoot on Thu Jul 28, 2011 9:46 am, edited 7 times in total.
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Re: Barnes XPB Range Report

Postby bushmeister » Wed Jul 06, 2011 5:25 am

Awesome! well worth the wait. That will be one cool Tie tack!
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Re: Barnes XPB Range Report Final Edition

Postby Hoot » Wed Jul 06, 2011 10:42 am

Looks like I was not limited on images and was able to finally upload the report.

As promised, here's a composite image of all the 100 yard targets, arranged by plain versus WS2 coated and by velocity. You can see both types tighten up as the velocity goes up arriving at one of the Theoretical OBT nodes. In the case of the plain bullets, they actually go past optimum one step and the group starts opening back up at the same time the slightly slower WS2 bullets tighten up. Again, in Theory the groups would continue to open up and then start tightening again if the next node's velocity can be reached before running into excessive pressure or running out of case powder capacity.

An alternate Theory is forget about OBT. Some bullets just get more accurate, the faster they go, until you run into excessive pressure or run out of case powder capacity.

Further testing may shed some light upon those Theories, though I'm sure most of us can agree that this particular caliber is somewhat on the fringe of conventional behavior. For every Theory, there is always some anecdotal exceptions. ;)

Image

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Re: Barnes XPB Range Report Final Edition

Postby commander faschisto » Wed Jul 06, 2011 10:52 am

Excellent work, as usual, Hoot-Mon! Looks like those 200s will be able to come outs da tube right quickly, if you got to 2500 with no real pressure signs. Let's hope the accuracy holds up at the higher speeds, too. Sub-MOA with something as big around as the 450b is impressive, if there is another "sweet spot" or two to find next.

Brilliant idea about the Barnes boolit tie-tack...you could start your own little cottage industry here with those things! :)
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Re: Barnes XPB Range Report Final Edition

Postby Edward78 » Wed Jul 06, 2011 11:24 am

I am looking forward to the 275 test as well I have been using the 200 grain bullet for hunting in 450B since I got her and the best load I found was with 40 grains of powder also taper crimped to .475. Its a great bullet and i plan to get a bear with it this year. Deer have already fallen to this bullet :D . Great write up as always thanks Hoot

Ed
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Re: Barnes XPB Range Report Final Edition

Postby Hoot » Wed Jul 06, 2011 11:27 am

commander faschisto wrote:Excellent work, as usual, Hoot-Mon! Looks like those 200s will be able to come outs da tube right quickly, if you got to 2500 with no real pressure signs. Let's hope the accuracy holds up at the higher speeds, too. Sub-MOA with something as big around as the 450b is impressive, if there is another "sweet spot" or two to find next.

Brilliant idea about the Barnes boolit tie-tack...you could start your own little cottage industry here with those things! :)


Now if only I could commandeer the range and install a water trap behind the 100 yard target boards, I could continue load development and capture all the expended rounds to make tie tacks. :lol:

Beats mining range lead once (if) the range dries out. This has to be the wettest year I can remember since moving here in 1976.

2500 is quite doable. What it buys us besides 50 more fps remains to be seen. I got case capacity, bullets, powder, primers and the itch for experimentation. ;)

One thing I forgot to touch on in the initial report is how drastically the brass shrunk after the first firing. Now, admittedly, I'll get some of that back when I resize, but it's discouraging nonetheless as you never get it all back. Almost like Hornady figured out a brass formula to make darn sure we don't reload these infinitely. In that lies the appeal of the .284 brass. Still, we're skirting a fine line between case walls that are too thick to chamber rounds, but which resist shrinkage a little more, versus cases that fit fine, but are thinner and more prone to shrinkage. Last year, I noted and I think I mentioned that the less powerful loads shrink the most. I suspect that is because they aren't grabbing that chrome lined chamber as tightly as the ones running higher chamber pressures. The conundrum is that it's not just how much pressure is generated, but equally important, how quickly it occurs to allow them to bite in before they get pushed back into the bolt face. It is an equation of many variables... :|

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Re: Barnes XPB Range Report Final Edition

Postby Texas Sheepdawg » Wed Jul 06, 2011 12:17 pm

Hoot, I'm wondering.... If Gunnuts A2 stock is giving these reductions, how much better does his A1 stock perform? IIRC, didn't I read in his thread "Recoil and what to do about it", that his A1 stock was performing even more effective than the A2 stock? Not to say the A2 was deficient, it is a great stock, (and next on my parts to order list), but I'm curious. I can personally vouch for Gunnut's A1 custom stock and even have video of the A1 in action.
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Re: Barnes XPB Range Report Final Edition

Postby Hoot » Wed Jul 06, 2011 12:38 pm

Edward78 wrote:I am looking forward to the 275 test as well I have been using the 200 grain bullet for hunting in 450B since I got her and the best load I found was with 40 grains of powder also taper crimped to .475. Its a great bullet and i plan to get a bear with it this year. Deer have already fallen to this bullet :D . Great write up as always thanks Hoot

Ed


All in good time Ed. I have a couple more iterations with the 200s, then on to the 275s. This is like living a dream as normally, I can't afford the likes of Barnes. In my next test, I'll overlap the hotter loads back into the upper end of these loads. I suspect that a more firm crimp could boost the MV of possibly the 40 gr plain bullet load, up darned close to 2500. For sure the 41gr load. Not knowing how close I already am to the maximum (IMHO) safe chamber pressure with the current set of loads, raising the neck tension may be all it takes to reach that point even before I advance to the next stage of hotter loads. I hate pulling down loads. The bullets are never quite the same and these are not bullets to waste, even on cool tie tacks. :lol:

Water shots are always fun, but we're not supposed to do anything at our range besides shooting paper targets. As a member of the Board of Directors, I'm supposed to set a good example. Wearing the Rifle Range Coordinator's Hat does afford me unlimited access and it's a matter of timing my water shot visits to coincide with no one else being there. That puts the weekends off limits due to all the working stiffs coming there most often then. I've gotten quite good at dropping the tail gate, setting up the workmate and getting a couple of water shots off in record time. It's hard to explain the wet spot when someone saunters in shortly thereafter though. If you have young kids, you've probably already had practice at this. ;)

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Re: Barnes XPB Range Report Final Edition

Postby Hoot » Wed Jul 06, 2011 1:27 pm

Texas Sheepdawg wrote:Hoot, I'm wondering.... If Gunnuts A2 stock is giving these reductions, how much better does his A1 stock perform? IIRC, didn't I read in his thread "Recoil and what to do about it", that his A1 stock was performing even more effective than the A2 stock? Not to say the A2 was deficient, it is a great stock, (and next on my parts to order list), but I'm curious. I can personally vouch for Gunnut's A1 custom stock and even have video of the A1 in action.


Gosh, you have me at a loss Robin. I haven't kept up with John's product line or closely watched the thread recently. I will have to re-familiarize myself before I can answer that one.

I do know the recoil impulse from Alliant 2400 and Lil Gun sure don't feel like the same time component. I was just speaking from my gut when I said about two differently timed springs in parallel, assuming that was the purpose of two compartments. Not simply two masses with the same springs in parallel for added mass. John has a lot more expertise on the subject than me. I just took a hip shot based upon a real loose understanding of his work and it hit pay dirt when I cobbled up my own interpretation, so I stuck with it. If I wanted to commit resources to some sensors and a data interface, I could probably speak from a more informed point of view.

Before John put his time and money into the subject and shared his data with us, I had always looked upon recoil reducers as snake oil. Out of a propriety, I did not pursue it in the open forums when it was obvious that he was bringing a product to market. The technology works and John's products are testimony to it. I suspect the state of the art can always be advanced and no doubt, John is busy working to that end. I'll go back and catch up on where he has taken it.

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Re: Barnes XPB Range Report Final Edition

Postby pitted bore » Wed Jul 06, 2011 1:36 pm

Hoot-
Thank you for the report. I'll read it again, and may have some follow-up questions.

Do you have any photos of your current milk-jug setup? I recall that you had some problems blowing apart an early model that was nicely constructed of wood. I'd like to see what your present rig is like, and take advantage of your hard-won experience. Recommendations for muzzle-to-jug distance would be appreciated also.

I ask because it's time for me to try a test with the Barnes 160-grain GAP bullet. Yesterday at the range the chronograph read 3200+ fps with Enforcer powder, and I'm curious what would be the result of a water test.

I've also got techniques for lengthening brass, and as a result for trimming it. I'll try to post those soon.

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