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.
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 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.
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.
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.
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 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.
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.
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.