17 HMR groupings

mister gullible

I think as far as I know the Parker Hale is only rated for .22LR subsonic ammunition. The pressures on a .17HMR have knocked the stuffing out of any Parker Hales I've seen when using them with .17's, popping the threads and distorting the baffles causing bullets to tip off them.

I use a 22 Parker Hale on my HMR. It works well as a moderator and I have had no problems with it.

mac80

I didnt get a chance to go out and have another go, but i did inspect the mod and it looks fine.

Slug chucker

mister gullible wrote: »

I use a 22 Parker Hale on my HMR. It works well as a moderator and I have had no problems with it.

You can also prop your car up on concrete blocks as we'll but I'd rather use axel stands working underneath mine
All I'll say is the Parker Hale opens to be disassembled and cleaned, in the few I've seen after .17's they don’t open properly and when you do get them open the threads are stretched and the baffles have been damaged. I’m not a gunsmith but that says pressure problems to me. But hey I’m not the manufacturer; they say the moderator is for .22LR subsonic ammunition. So do you think the .17 HMR which is a necked down .22 magnum high velocity round would create more pressure than a .22LR subsonic round in a confined space.

Seriously I'm not having a go at anybody using a Parker Hale on a .17HMR but it's just not rated for that pressure which could lead to a life altering experience
Cheers
Slug

kakashka

It wasn't me! wrote: »

It will exert a levering force on it, yes, but depending on the stiffness of the barrel, its length, the weight of the mod, even the mod's design, it's likely that the barrel will not bend to any practically measurable extent.

And i said??

kakashka

It wasn't me! wrote: »

Hundreds of thousandths of an inch are utterly insignificant. To conduct an experiment, weigh your mod, then remove it and hang soft material of the same weight from the end of the barrel and see how the points of impact and accuracy compare. I'd want that data, plus measurement of the extent to which a barrel is bent, before I'd think about that assertion.

it's obviously not the problem here but i'd like your opinion on bedding and free floating if you believe fractions are insignificant

kakashka

ezridax wrote: »

If a moderator was able to bend a barrel there would be obvious scrape marks down the inside of the barrel as the bullet followed the bend of the barrel

You did say...please:D..i stand by what i said,i dont know the specs here and dont have that much experience with rimfire but mod will bend barrel,i'm not proclaiming to be an expert and i cant say why your POI is higher with supp on but maby something to do with arrangement of the baffles.

sfakiaman

kakashka wrote: »

i cant say why your POI is higher with supp on but maby something to do with arrangement of the baffles.

I think it may be due to the bullet causing the barrel to whip as it travels down the rifling. Any change to the whip caused by a mod or bedding would make the bullet leave the barrel on a different trajectory giving a different POI. I wouldn't think the difference would be that dramatic though.

moose112

riflehunter77 wrote: »

Moose get yourself a SAK there about 45 to 50 euro, i have one on my Marlin 17hmr over 2 odd years now. It cuts down on the crack quite abit and it wont break the bank either.. 400 euro for a rimfire mod thats made my day , if that whats he is charging for a moderator whats he charging for firearms and optics..

Hey riflehunter mind me asking where did you pick up your SAK moderator having serious problems finding one.

lucy333springer

We everyone, when I bought my CZ .17, I was told by the dealer that the rifle had been zeroed and ready for bunny eye shots, but when I mentioned about popping on the moderator, he said that he forgot about this purchase, and that the gun needs zeroed in again, (sak mod, silence of the lambs)

also, i have a brno 22lr, i'm kind of scared to think about this, but can my .17 mod fit this .22lr safely, no if's but's or maybe's

---

YES, or NO.
Thanx.

Cass

Quick answer, No.

Long answer, if the mod is designed for use on .17 a .22 bullet will be larger in diameter and will not fit through the mod. Check the specifications of the mod. Unless its designed to take up to .22 then the answer is no.

lucy333springer

Thanx,
I was kinda thinking that,
it's all the chat on here about mods and different
bullet sizes.
this night duty is hard work on the fingers:D

foxhunter

lucy333springer wrote: »

We everyone, when I bought my CZ .17, I was told by the dealer that the rifle had been zeroed and ready for bunny eye shots, but when I mentioned about popping on the moderator, he said that he forgot about this purchase, and that the gun needs zeroed in again, (sak mod, silence of the lambs)

also, i have a brno 22lr, i'm kind of scared to think about this, but can my .17 mod fit this .22lr safely, no if's but's or maybe's

---

YES, or NO.
Thanx.

If it's an SAK mod then yes it will fit they are made to do .17 to .22 mag

riflehunter77

moose112 wrote: »

Hey riflehunter mind me asking where did you pick up your SAK moderator having serious problems finding one.

Moose most dealers should be able to get them in for you no problem, try giving joe meany a ring in connolys red mills 0599775800 he might have one or be able to get one in for you. I think i got mine in athlone it was sent to be threaded and fitted by my dealer. There well worth it really cut down on the crack.

rrpc

sfakiaman wrote: »

I think it may be due to the bullet causing the barrel to whip as it travels down the rifling. Any change to the whip caused by a mod or bedding would make the bullet leave the barrel on a different trajectory giving a different POI. I wouldn't think the difference would be that dramatic though.

That's the correct answer, well done that man

Barrel flip or flap is a well known phenomenon and was one of the reasons for experimentation with shorter barrel lengths. The same reason as was suggested for floating barrels as it meant that the barrel harmonics weren't interfered with.

There certainly would be some 'bending' effect from extra weight on the end of your barrell, the amount would be very tiny, but can be calculated. However, the forces generated by the bullet as it travels down the barrel would be far greater by an order of magnitude and in fact the difference in POI is as was suggested; caused by the change in barrel flip due to the added weight of the mod.