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17 HMR - Observations

7K views 19 replies 10 participants last post by  Boubound 
#1 ·
There are many threads which I have read on 17 HMR ammo and rather than pick one that might be somewhat related, I thought I would just share my experiences from last Monday's range session. This is a bit long so bear with me. :eek:

I will admit that I do not shoot my 17 HMR’s very often as I categorize them as part of my “Small Critter” hunting rimfire rifles and I have several to choose from. The 17 HMR's are intended to be on the long range end of my “Small Critter” requirements as well thus would be the initial choice for 100-165 yards using MPBR as a guide. I have 22 LR & 22 WMR rifles that are part of this category as well. At this point I only have about 500 rounds through each rifle.

With several RFC threads related to 17 HMR accuracy I decided to take my 17 HMR’s to the range Monday and do some ammo testing. I have a CZ 453 Varmint SST & a 455 Varmint both with Leopold VX I 4-12x40 Leupold scopes, which is another reason I use them on the longer range due to the 100 yard parallax setting of these scopes.

I selected a box of the following ammo types intending to shoot 25 rounds of each ( 5 groups of 5 ) and document which ammo preferences for each rifle:

CCI A17 Varmint 17 grain BT 2,650 fps
CCI GamePoint 20 grain JSP 2,375 fps
Federal V-Shok 17 grain VMax 2,550 fps
Hornady V-MAX 17 grain BT 2,550 fps
Hornady HP-XTP 20 grain JSP 2,375 fps

Note - the Hornady V-Max is the oldest ammo in the 8-10 year-old-range. The rest was acquired within the past couple of years.

At this point I need to remind myself that this is “hunting” ammo not “match” grade target ammo - just like the 22 WMR. Also note - I am shooting at an indoor range at 50 yards thus having to reduce magnification due to 100 yard parallax setting on the scopes. I know . . . these should be AO scopes.

I have never paid a great deal of attention to the fired 17 HMR cases . . . I just put them into the “fired” pile as I use them. I put the first half of the rounds through the CZ 453 encountering some frustration with group sizes, but also remembering certain ammo will work better than others in any given rifle.

I switch to the CZ 455 Varmint and found out very quickly that I had switched the scope on this rifle and it needed to be sighted in, so it took a few rounds to get that accomplished :eek: then back to the ammo testing. As I was sighting in the scope, I happen to catch the fact a few of the fired cases were splitting. Not that surprising based on the comments I have read on the RFC, however I began inspecting each case as it was fired and noticed of how many I actually found. It was not uncommon to have 1 or 2 in each group of five rounds. I will say that none of the Federal rounds experienced a split case. The Hornady ammo was about a 3 to 1 ratio over the CCI cases. (34 Hornady & 11 CCI )

Most of the splits are from the tip of the case to 1/4 down the case. The splits appear to be "random" as to position on the case in relationship to the firing pin impact point. Based on other RFC threads noting cases may be split before firing - I was not specifically looking for split cases when loading the rounds into the mag, I did not recall any problems. Also - I just checked the 900 remaining rounds of 17 HMR in my inventory and did not see any split case problems.

Okay so I am now questioning the exercise - How can one really make a decision on which particular ammo works best in a rifle, when you are experiencing split cases . . . Surely a split case is not going to give results on par with one that does not . . . Even in a hunting round. Obviously had I been using a chronograph I would have better information and potential proof that the speed from a split case was not on par with one that does not. Maybe some others on the RFC have some experience with that.

So bottom line to the RFC experts, can one expect similar performance from a round that encounters a split case and one that does not? Common sense tells me that would not be the case. :(

Secondly the potential damage from split cases - I have read threads where the rifle was damaged due to ruptured cases. Again common sense tell me this is not a good situation to just ignore. :eek:

There seems to be a two fold point of root cause - (1) the throat in the rifle is not cut properly or (2) the ammo fails due to improper annealing when the case is downsized from 22 WMR. I would say this is not a chamber issue for either rifle since the splits are rather random in position on the case.

I plan to contact both CCI & Hornady for their input and will take some pictures as best I can of the split cases. At this point the 17 HMR’s have slipped a bit on my appreciation list. :confused:

As to the groups ( those that were well behaved ) were slightly less than 1/2" and certainly acceptable for hunting small critters. I would anticipate at or near MOA groups at 100 yards but that needs to be proven. :bthumb: The Hornady Varmint Express 17 grain, CCI A17, & Hornady XTP 20 grain did okay in the 453 while the Hornady Varmint Express 17 grain & CCI Game Point 20 grain showed better groups in the CZ 455.

I'll let you know what I hear back from the ammo vendors.
 
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#2 ·
Is one rifle causing more splits than another? Could you have a headspace issue? Ruger changed out the bolt on my American because of frequent splitting. Having said that cracks on some batches of ammo have been reported. Even so, the chamber still seals with the rear of the case and you can still get good accuracy even with cases splitting here and there. When everything is working right, splits should be rare in the 17hmr.
 
#3 ·
Addition Testing of 17 HMR Ammo

I did some additional ammo testing this time with my Magneto Speed V3 chronograph. I bought the chronograph months ago and not used it thus far, so I thought this would be a great time to break it in. It's a really solid function and easy to use chronograph, especially at a range since you don't have to wait on anyone else to set it up or take it down and it never missed a single shot. I give it an A+ rating thus far . . . however that is based on one ( 3 ) hour usage mounted on a varmint barrel. That rating may change with a tapered sporter barrel, which I will put on my list.

Anyway on to the 17 HMR testing - I only used ( 4 ) different types of ammo this time - I left out the Federal as my rifles did not seem to appreciate it.

CCI A17 Varmint 17 grain BT 2,650 fps
CCI GamePoint 20 grain JSP 2,375 fps
Hornady V-MAX 17 grain BT 2,550 fps
Hornady HP-XTP 20 grain JSP 2,375 fps

I only brought one rifle since I knew this would take some time, so the CZ 455 Varmint with a Leupold VX I 4-12x40 was selected, set on about 7x since I was shooting at a 50 yard target indoors ( no AO & a fixed 100 yard parallax ). I did a detailed cleaning on the barrel after the first round of testing.

I inspected each round prior to loading and after it was fired for splits, then placed the case back in the box so I could keep track of them against the spreadsheet data. It took almost 3 hours to go through the 170 rounds shooting 5 round groups.

I have a spreadsheet with the captured speed of every one of the 170 rounds, but will not bore anyone with the details of each round, but rather give you a summary of each ammo type and then some observations.

Series # 1 # of Shots 50 Type - Hornady Express VMax @ 2550
Min 2391 Max 2656
Avg 2591 Std Dev 51
ES 265 Split Cases ( 4 )

Series # 2 # of Shots: 20 Type - Hornady XTP 20gr @2375
Min 2418 Max 2537
Avg 2484 Std Dev 69
ES 119 Split Cases ( 2 )

Series # 3 # of Shots: 50 Type - CCI A17 Varmint @2650
Min 2554 Max 2904
Avg 2774 Std Dev 88
ES 350 Split Cases ( 16 )

Series # 4 # of Shots: 50 Type - CCI Gamepoint 20gr @ 2375
Min 2314 Max 2575
Avg 2505 Std Dev 44.5
ES 261 Split Cases ( 1 )

I realize this is a small sample test using only a single box (50) rounds for each of three of the ammo types and (20) rounds of the fourth type, however one has to start somewhere to begin to understand what is taking place. The previous 200 rounds seemed to have a similar pattern, but I do not have the data to back that up outside of the count of split cases. BTW - I have about 500 rounds through each rifle at this point.

I was hoping to build a solid case documenting that severely split cases were indeed producing a much slower velocity and therefore the point of impact would be affected spreading out the group. However, looking over the velocity of the (23) split cases - over half of them were near or above the average for the group. So the data doesn't support that line of thinking.

I was "not" able to track each round as to point of impact against the captured velocity of each round, however common sense would say the point of impact would be affected when the velocity falls off by 200-300 fps within a group of 5 rounds.

Most of the groups are slightly under .5" @ 50 yards and certainly adequate for hunting small game ( gophers, rabbits, squirrels, rats, and selected annoying birds). I'm sure with a bit more magnification & AO on the optics those groups could be improved. But again I remind myself this ammo is all designed for hunting not "match" target shooting.

My CZ 455 Varmint 20.5" barrel seems to prefer 20 gr ammo, but after the first couple of groups and the barrel warmed up a bit most of the 17 gr groups were respectable.

The necks of 17 gr rounds show a lot of fouling & powder burns - the 20 gr rounds are much cleaner for both CCI & Hornady.

This time around CCI A17 had most of the split cases. (16 out of 50 = 32%) which seems :eek: very high to me. One could expect this particular round to generate the higher pressures and if the case neck is indeed the weak area it's apt to split and todays testing seems to support that.

I did sent an email to CZ Customer Support based on the input from my initial test, but have not heard anything back from them as yet. I will follow-up with a phone call and share the results of my second round of testing as well.

I have not yet contacted CCI or Hornady but will see if they have any comments.

Another task is to speak with a gunsmith to determine what methods are available to check the chamber throat & head spacing, but I would prefer to not incur expenses to prove the ammo or rifle is the problem, however I need to move this forward.

I feel the barrel (excluding the chamber throat at this point) is decent for the $ since we are seeing some fairly decent groups and when I look at the details of those ( 5 ) shot groups the velocity is very consistent. I see no reason to replace the barrel at this time.

I'm very concerned about the fact that we are seeing so many cases having close to 1/2" splits in them with "scattered" documented reports of firearms being damaged due to more severe split case issues. I am certainly not willing to let my grandsons shoot them at this point. :eek:

I will update again when I hear back from CZ, the Ammo makers, and input from a gunsmith.

Thanks
 
#4 ·
Your numbers are similar to those I've obtained.
The other problem that affects accuracy is inconsistent bullet seating.
With the cartridges in the tray a quick look will show non-conforming bullets
seated more and less than the average. Rolling a cartridge on a flat surface
will show tip wobble about the axis of rotation. Not something you want to see.
For less than 50 yard usage the effects are minimal,
at 200 yards poi can be 3 to 5 inches from poa.
 
#5 ·
Jala - very good point and one I was going to add to my list of actions along with weighing & taking some overall measurements compared to the 17 HMR spec. That could account for the 17 gr rounds having more fouling if the shoulder isn't up to spec. I have a concentricity gauge which I have used on "match" grade centerfire ammo and was absolutely shocked as to how much "wobble" there was on both the case neck and bullets. :eek: I never experienced that much with any of my own reloads and would certainly be disappointed if I produced a product lacking in quality to that extreme.

Thanks for the reminder . . . :bthumb:

One other thing I forgot to mention - In the Hornady Extreme package of 50 rounds, I found different colored ballistic tips - the Hornady VMax product is usually a bright red and I found about a half dozen or so "dark" what I would call maroon colored tips. :confused: I think I read somewhere the Hornady VMax bullets are used in many 17 HMR products and for each vendor, CCI uses a different color. But to mix different colors within the same sealed package would be yet another strike against quality control in the manufacturing process. Either that or the dye used for the Ballistic Tip doesn't hold it's color very long. :) :D That's not to say the bullets are not of the same quality as I think the Hornady VMax has a pretty good reputation and the color is no big deal as long as it performs well.
 
#6 ·
The dark tips are caused by lubricant from the manufacturing
draining down from the brass onto the bullets.
A conversation with customer service at CCI explained the cause
and stated it was only a cosmetic difference.
Wipe off the cartridge and the red tip is still there.
 
#7 ·
On Monday the 13th I did another round of 17 HMR testing to obtain additional information for my Split Case Project. This time I used my CZ 453 Varmint SST ( no modifications ) shooting at an indoor range @ 50 yards. The scope was a Leupold VX II - 4x12-40mm ( no AO ), thus had to back the scope off to about 8x to get the best target image. I was using a red or green 1.0" dot with a 1/4" black square center for the point of aim. This is an indoor range which is a bit on the dark side down range and the make-shift bench is not totally solid. I was using my Caldwell Rock Jr front rest & a small Protector rear bag as bench space is limited. I tested ( 4 ) different types of ammo shooting 125 rounds in 5 round groups. I used a MagnetoSpeed V3 chronograph to capture the velocity of each round, which I have downloaded into a spreadsheet. Here I will only supply the summary information of each group & added in split case counts, average group size, lot #'s, and the ammo type for each group.

3rd Round of Testing - 08-13-18

Group 1 # of Shots 25 Hornady Express VMax - 17 Gr @ 2550
Min 2529 Max 2787 Lot - C03P07
Avg 2616 Std Dev 62.6 Number of Split Cases ( 2 )
ES 258 Avg. Group Size - .292

Group 2 # of Shots 25 Hornady HMR XTP - 20 Gr @ 2375
Min 2387 Max 2547 Lot - M02P20
Avg 2433 Std Dev 30.9 Number of Split Cases ( 2 )
ES 160 Avg. Group Size - .371

Group 3 # of Shots 50 CCI A17 - 17 Gr @ 2650
Min 2498 Max 2890 Lot - ? (Last 50 of 200 Round Box)
Avg 2756 Std Dev 87.9 Number of Split Cases ( 18 )
ES 392 Avg. Group Size - .431

Group 4 # of Shots 25 Federal V-Shok TNT HP - 17 Gr @ 2550
Min 2575 Max 2653 Lot - J14X23
Avg 2604 Std Dev 20.1 Number of Split Cases ( 0 )
ES 78 Avg. Group Size - .313

Similar results with this set of testing:

I did take out a few (called) flyers due to the jerk behind the trigger in an attempt to keep my groups as reasonably accurate as possible. I had some challenges from the kids with their AR's :Blasting_ generating bench vibration and cases flying my direction from time to time. :eek:

The CCI A17 "again" :mad: had over 30% case splits which I am going to take up with CCI. It has the largest extreme spread (nearly 400 fps) however I still do not find anything unique in the velocity of the split case rounds versus those that did not. This was the last of this box of 200 which was purchased fairly soon after it initially hit the shelves. I did buy a new box of 200 to do more testing with just to see if that makes any difference.

I find it interesting the Federal ammo has no failures (in either rifle). :( I will ask CCI if there is anything different about the Federal build process.

I did some sample case measuring, weighing of full loads, measurements of cases before & after shooting and found some variation but am sure that was not enough to point to a case that had potential to or why a case did split. I think one would need to take cartridge & case measurements of every round before & after shooting it and be able to document where the bullet impacted on the target. I'm just not setup for that.

My objective was to see if I could corrilate split cases to flyers, but thus far I have nothing but my unproven theory a split case could be a cause for a flyer. I would have bet money before I started my effort . . . that split cases would be show lower velocities, but thus far I have found nothing to support that. :confused:

Again . . . no failure to load, fire, or eject across the board in either of the CZ actions. I am reasonably satisfied with the accuracy for hunting small critters as the average group sizes (including my mistakes) would have taken the critters I would be hunting. I just don't like shooting ammo that splits cases :eek: :eek: :eek:
 
#8 ·
I was getting regular splits in my Ruger American Predator until Ruger replaced the bolt. I get occasional splits now but nothing that I worry about. The rear of the case can still seal the chamber as long as the crack doesn't go much past half. Cracked necks can't cause a gas leak but may contribute to flame cutting if regularly in the same spot. I suspect you have some bad ammo for the A17 that is out of the "norm" for hardness. Can you check that next? Checking the same ammo in both rifles is a good way to minimize the possible cause being an out of spec chamber or large head space. rc
 
#9 ·
RJ, your chronograph numbers show the same variations in MV spread as mine.
Anything from 60 fps to 400 fps ES from a box of 50.
CCI does not provide adequate quality control to produce anything approaching match ammo.
No surprise on the neck splits either. They still have problems with the neck sizing process.
 
#10 · (Edited)
Al the Instigator strikes again.


Aways watching, always waiting for the opportune moment.
He takes careful aim, fires off a scathing one liner,
then fades quietly back into the undergrowth.
Another successful sniping operation concluded.

The 17 wsm is a Winchester product.

The CCI A17 has a black tip also.
 
#11 ·
Hornady splits

I have been shooting a stainless Marlin 917VS for about 5 years. Only used Hornady ammo, 17 gr. Rifle shoots great, three shots in a dime at 100 yds off bench on a good day, BUT starting a year ago I started getting split necks on fired casings, and my rifle would not extract these. Had to pry out of chamber with a pocketknife or in worst case, bump out with cleaning rod from the muzzle. I bought 10 boxes of ammo from a guy just after I got the gun. Now, 5 years later, splits seem more frequent. Would say maybe 1 in 5 rounds. Accuracy still good, though. I just bought a new box of this ammo to try out, to see if problem shows up in the new stuff. I still have 4 boxes of the original 10.
 
#15 ·
17 HMR QC in the Mfg Process

Most guys I talk to about split case necks on 17 HMR ammo (and there have been many) . . . state they "never" have experienced any. I would have said the same thing for several years as I never examined the cases closely. They simply ejected out of the action on the ground and I would police them up into a bag and dump them into a large plastic container. :eek:

About a year ago while expanding my knowledge via the RFC is when I first learned about split case necks and started to examine my fired cases more closely. Also shooting at an indoor range over the winter months and using a chronograph, lead me to capturing each fired case and examining them. I could not believe the number of hairline & larger cracks near the case mouth & shoulder I discovered. I was also examining the cases prior to loading in the magazine to eliminate that possibility.

I dumped out a large plastic container where I collect my fired cases and was amazed at how many cases had cracks in them. I would say on average somewhere in the 10-15% (or more) range of the rounds I have shot over the last 10 years. As noted in my tests upwards of 30% in a box of 50.

The split cases may or may not have anything to do with accuracy of your groups. As jala points out it's the QC of the mfg process that is more to blame. I have shot 17 HMR in 5 different rifles so I find it very hard to believe that all (5) rifles have "bad" chambers. A CZ 453 & 455 and a Steyr Zephyr are the current (3) rifles I am using.

My 17 HMR's certainly shoot accurately enough for hunting . . . it's just that with improved QC on the part of the mfg, it could be so much better. :confused:
 
#18 ·
To get optimal accuracy out of my 22LR ammo, I weight sort to +/- .05 grains. This stops my OH **** sudden flyers for me. Yesterday I shot a 160 shot prone F-Class 22LR rifle match using SK Pistol Match ammo. Out of the 100 shot initial portion of the match at 50 yards, I dropped only one point with 78 X's. The dropped point was due to a bad wind call on my part. The target used was the NRA A50 target. This was all with weight sorted.

Due to this practice, I have started weighing my 17HMR rounds. I shoot Hornady 17 grain V-Max exclusively. The weight variations are LARGE, but I was able to get enough for a match out of a box or 2 that meet the +/- .05 grain standard to 22's. This coming week I will take my Anschutz 1717 to the range and see what I can do in the 50 yard IBS target. Also I'll check for split necks.
 
#19 ·
I hope weight sorting works for you.
I've attempted it with 22lr, 22wmr and 17hmr with no improvement to the results. 500 rounds each time.
No, let me amend that, it let me pull 22lr with no powder in the cartridges from bulk Federal.
Shooting outdoors off a bench with a barrel block rig, it didn't help my results.
Still had mv spread, still had strays, good luck.
 
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