Thread: 17hmr

Originally Posted by gonetropo

rossi bolt or semi ?

Bolt. I don't think they do a semi in 17.

Thoroughly recommend this for rabbits.
I have a CZ bolt action with a varmint barrel & a Savage semi A17.
I would recommend CZ or Tika and yes do put a suppressor on it !!!!
Other important thing to get right is a decent scope. You need the ability to pick out a small target at 200-250 metres so don’t skimp on the optics.
All the best

So this may or may not be informative.

I did a bit of digging and came to the conclusions that:
1: ammo quality lot-to-lot is indeed highly variable and drives precision with rimfires
2: precision expectations with .17HMR should be limited, and the ammunition is such poor quality that it is not possible to get a good understanding of precision with a particular load/lot # from 3, 5, or even 10 shot groups - 20-30 (or 50) is needed.

https://www.rimfirecentral.com/threa...204943/page-14

I shot the 3 ammo types available locally. It does appear that precision at 100m is correlated with velocity consistency - unlike centrefire cartridges at 100m, but similar to centrefire cartridges at longer TOF. I can watch the trace going in at 100 through the scope with the .17....

I think my barrel is about 14 inch for reference
20gr CCI HP - average V 2258 SD 51. Inconsistent, not good.


17gr CCI Vmax avg v 2541 SD 38, inconsistent - mean radius higher than the 20gr. No good


17gr CCI TNT HP avg v 2443 SD 33, precision acceptable (1.67moa 30rd group, probably reasonably representative of the actual cone of fire). I'll buy a bunch of this particular lot # if I can get it.


In future it is apparent that ammunition will have to be selected through large sample lot # testing.

I'll also bed the action & make sure my barrel is well-floated on the CZ but don't expect any major improvement in results considering the sorts of precision others have shown (see RFC threads) with large samples even with highly customizable rifles. Looks like .17HMR is a "1.5moa at best" true precision proposition if you get a good lot of ammo. For my use I will not bother investigating whether any sort of concentricity sorting can make any difference.

I've had Three 17hmr

CZ453 Varmint with a greystone can, fuk me that thing shot like a laser, bunnies out to 250 yards ( stupidly sold aka gave it away on here )
Browning T bolt Varmint / laminate stock HRE suppressor, was an awesome little rifle, shot ok ( was given so much shit by me old farmer mate I sold that too )
Currently running a Sako Finnfire II with DPT & 3-18 Z5 Swaro, Shoots pretty good & is a lovely rifle to use


I like the 17hmr, ammo has got very expensive, kills well for what it is & within limits & it's no 17 hornet ( which I also had to replace the hmr ) or a 223 but then you don't need to fuk around picking up brass - reloading & being rimfire they're lighter & not as loud when on lifestyle blocks etc


I'll still keep one in the safe

Got some hornady ammo in queenstown if you are looking for some

@gimp are those groups shot using a 5 shot magazine?

Originally Posted by sneeze

@gimp are those groups shot using a 5 shot magazine?

10 but yes fed from a mag

There seems to be clusters related to the mag change, possibly breaking position to reload? Rimfire I find is quite sensitive to hold position . @mudgripz might chime in hopefully.
I havn't seen the lot to lot change in HMR being any where near as relevant as with 22LR. I have a couple of different lots of the cci 17gr HP here. If you want to try then I might be catching up with R93 at easter, he could take them back

Love my CZ457 with DPT suppressor - think these are a must for these HMRs. Found the CCI A17 ammo great grouping for me - then tried the Hornady XTP - even tighter so will use that once the brick of A17 is used up.

Found grouping goes to shit quick, so carry a pull thru with me - twice thru and a laser once more...

Just needed the legs over the humble .22 LR

Originally Posted by Nasty Factory Trigger

Love my CZ457 with DPT suppressor - think these are a must for these HMRs. Found the CCI A17 ammo great grouping for me - then tried the Hornady XTP - even tighter so will use that once the brick of A17 is used up.

Found grouping goes to shit quick, so carry a pull thru with me - twice thru and a laser once more...

Just needed the legs over the humble .22 LR

Im happy to buy the A17 brick off you, I'm always trying to get the stuff and nobody stocks it anymore.

Originally Posted by sneeze

There seems to be clusters related to the mag change, possibly breaking position to reload? Rimfire I find is quite sensitive to hold position . @mudgripz might chime in hopefully.
I havn't seen the lot to lot change in HMR being any where near as relevant as with 22LR. I have a couple of different lots of the cci 17gr HP here. If you want to try then I might be catching up with R93 at easter, he could take them back

Scatter random throughout the mags. Haven't had a .17 in many years and I'd forgotten how little recoil there is, cool to watch the trace dropping in at 100m. Not much movement of the rifle. The high/low shots were often directly observable off the chrono - see a high shot and look at the chrono - yup 100fps faster.

A feller on RFC got the best 50rd .17hmr group with the same stuff at 1.375moa, but from a very heavy bench rig with a lilja custom barrel & 32x scope etc.

I'm going past a couple of gunshops this week so I'll see what else I can pick up to have a play with - cheers for the offer I might take you up if I don't find anything else on my travels.

The .17 is fun

Originally Posted by gimp

Scatter random throughout the mags. Haven't had a .17 in many years and I'd forgotten how little recoil there is, cool to watch the trace dropping in at 100m. Not much movement of the rifle. The high/low shots were often directly observable off the chrono - see a high shot and look at the chrono - yup 100fps faster.

A feller on RFC got the best 50rd .17hmr group with the same stuff at 1.375moa, but from a very heavy bench rig with a lilja custom barrel & 32x scope etc.

I'm going past a couple of gunshops this week so I'll see what else I can pick up to have a play with - cheers for the offer I might take you up if I don't find anything else on my travels.

The .17 is fun

The first two seem so and not unexpected with ammunition that dosn't suit the rifle but the third with the a more favorable load shows three distinct groups.
The only brand I saw really large es from was CCI A7. It was truly horrible . I havn't chroned any from some time now , Ill try the stuff I'm using if I get a chance.

Oh the numbers are not the actual shot numbers, just how I went round in the app. Scatter was random throughout

E.g shot 16 was actually about shot 7, and was a high value on the chrono

Be interested to see what 30 out of yours looks like on paper & chrono if you have some spare

SD of 33 = a true ES of about 200 which matches other results online

Originally Posted by gimp

E.g shot 16 was actually about shot 7, and was a high value on the chrono

Be interested to see what 30 out of yours looks like on paper & chrono if you have some spare

SD of 33 = a true ES of about 200 which matches other results online

Banging 30 rounds into paper is not something I find enjoyable or have any real ability to do consistently but I'm here now so Ill see if I can find some time on a still day. I would expect results to line up with your expectations in the 1.5 + ish moa.

Originally Posted by gimp

Oh the numbers are not the actual shot numbers, just how I went round in the app. Scatter was random throughout

Ah ok, I assumed if you were numbering shots they would be the actual shots.