cz hmr.17 "too long"

[trapper25 0]

just bought a cz hmr.17 didn't realize how long it was with the sak mod i,ve got the number of a good gunsmith who can shorten and screw cut it, but will it affect its accuracy? dont want to wreck an otherwise great rifle!

[martin 332]

Hi Trapper,I just had 4" taken off my Browning rimfire,and,there was absolutely no decrease in accuracy.So,as long as you get a good gunsmith to do it it will be fine..............................martin.

[trapper25 0]

Hi Trapper,I just had 4" taken off my Browning rimfire,and,there was absolutely no decrease in accuracy.So,as long as you get a good gunsmith to do it it will be fine..............................martin.

cheers martin how much does it cost for chop and screw cut ?

[Deker 3,453]

Hi Trapper,I just had 4" taken off my Browning rimfire,and,there was absolutely no decrease in accuracy.So,as long as you get a good gunsmith to do it it will be fine..............................martin.

cheers martin how much does it cost for chop and screw cut ?

 

Thats a Browning... seeing as a barn door usually presents a problem for them its hardly surprising taking 4 inches off will not make any difference!!!! (only joking)

 

From memory the CZ full length barrel is 22 1/2inches. The normally supplied screw cut barrel is 20 inches. Taking 4 inches (or there abouts) off it will have an effect on accuracy but it will be very minor, you can also expect to reduce the power by around 2%-3%. For most uses you will not notice the difference but you will obviously have to re zero it.

 

Cost wise for this job is very difficult, many people charge £100 for a screw cut, remember cutting the barrel will need a new crown as well as screw cut, and the rifle will also have to be re proofed! If you get all that done for £100 I recon you have done quite well, could possibly go as high as £200.

 

Deker

Edited November 23, 2007 by Deker

[mileoff 0]

I had the same problem with a 22 brno. I chopped 8 '' off and machined it up in a lathe to 16'' barrel and recut threads.

A lot of people won't do the work without reproof thats where your money will go

If you know somebody with a lathe then your halfway there

Worth the effort in my case now far better for lamping, vehicles, trees etc.

[Guest baldie]

Nowhere in the firearms act, or gun barrel proof laws, does it state that a weapon has to be reproofed if shortened and screwcut. The proof house has lost two cases it brought against gunsmiths who refused to reproof.One being jackson rifles, the importer of t8,s, and the other, the owner of the gunshop at Barnett.The act states a gun must be reproofed "if the integrity of the barrel strength is compromised" or words to that effect.That is open to interpretation by the individual gunsmith.

Shortening a barrel should not affect its accuracy at all, apart from make it better, due to it being recrowned carefully, and not by a machine with dull tooling etc.If its any less accurate, you need to be asking questions of the chap who did it!

.17hmr,s dont want shortening too far otherwise you will lose velocity, that makes the round as good as it is, although i,ve shortened them as far as 14" for one customer. I would say 16" is about right, infact thats what cz,s are now available at.

.22 rimmies are good at 14" although we do a lot at 12.5".

Price? £65 , shorten, thread, and recrown.

[Deker 3,453]

Nowhere in the firearms act, or gun barrel proof laws, does it state that a weapon has to be reproofed if shortened and screwcut. The proof house has lost two cases it brought against gunsmiths who refused to reproof.One being jackson rifles, the importer of t8,s, and the other, the owner of the gunshop at Barnett.The act states a gun must be reproofed "if the integrity of the barrel strength is compromised" or words to that effect.That is open to interpretation by the individual gunsmith.

Shortening a barrel should not affect its accuracy at all, apart from make it better, due to it being recrowned carefully, and not by a machine with dull tooling etc.If its any less accurate, you need to be asking questions of the chap who did it!

.17hmr,s dont want shortening too far otherwise you will lose velocity, that makes the round as good as it is, although i,ve shortened them as far as 14" for one customer. I would say 16" is about right, infact thats what cz,s are now available at.

.22 rimmies are good at 14" although we do a lot at 12.5".

Price? £65 , shorten, thread, and recrown.

 

 

Come on Baldie...."Shortening a barrel should not affect its accuracy at all, apart from make it better, due to it being recrowned carefully".....you are getting a little carried away there...lets assume the crown was ok to start with...shortening the barrel will then ALWAYS effect the accuracy, not necessarily very much I grant you, unless you take it to extremes, and, as you say it will also reduce power. Thats "one" of the reasons why rifles have longer barrels than pistols, you are very well aware that a .22LR pistol will not be as accurate as a .22LR rifle (or deliver the same power even with identical cartridges). CZ as you rightly say offer a 16" barrel on some of their rimfires for the simple reason that the loss of power and accuracy from the original 22 1/2" barrel (they now have 3 different barrel lengths on their rimfires) is relatively small, it starts getting disproportionally worse the shorter it goes after this, particularly with the HMR. Then there is this bit "if the integrity of the barrel strength is compromised"...shortening a barrel may not effect the strength of the barrel but anyone can see that cutting a chunk of barrel away to create a thread must reduce the strength at that part of the barrel. Anyway, I really don't know what all the reproofing laws are about so I don't know at what point you MUST get it reproofed. Seems that every dealer tells you it needs to be done after being screw cut though. Your price of £65 for shorten, thread and recrown sounds very competitive but I take it that does not include re proofing.

 

Now then.....could do with some help/advice from someone such as yourself. I have a Tikka T3 Lite stainless in .223, twist is 1-8 and the rifling is very fine. I always thought this seemed a bit tight as all the formulas I could find led me to believe 1-12 would be more appropriate. Just been on Tikka website and find they now list .223 with 1-8 and 1-12 twists, what the **** is going on, and what if anything would you suggest ammo wise for either and both of these twist rates for hunting and target.

 

Second... been looking at the .204 Ruger and just asked for help in the "ammo/reloading etc" forum I get the impression you may have some views/experience with this, any input appreciated.

 

Cheers

Deker

[markbivvy 6]

had my cz cut from 18 to 14 inch, i cant see a difference in accuracy, and if its slower

the rabbits aint ducking quick enough.

[Guest baldie]

Bloody "ell" Dek, i,ve just come in from the pub

We shorten many a std ruger barrel [10/22] which are strictly average as std....you would not believe how well they shoot after shortening/recrowning, almost up to match std...i shit you not.

Its down to factory crowning buddy.There,s not a lot wrong with most, but they cant match a hand cut crown, on a freshly squared and threaded barrel....its absolutely mint, and shoots that way, only drawback is, its vulnerable to damage, and must be either braked, moderated, or taken care not to be knocked.I dont crown my own barrels, i just cut them absolutely square.The crown is there just to protect the rifling from your average user.

 

Yes, there is velocity loss, but comparing a pistol and a rifle isnt fair, it has to be one or the other, or "similar " lengths.

I,ll give a good example. I shot an Anschutz x1v carbine for a couple of years, the 14" carbine. Absolutely excellent rifle, killed a shed load of rabbits with it, and it would put 5 winny subs in a quarter inch regular at 50 yards. Decided i wanted to upgrade, and bought an anschutz silhouette rifle , the better match 54 action, in a beautiful stock, designed for shooting the turkeys, piggies, rams , etc....it has a 24" barrel [i think] couldn,t hit shit with it.Eventually realised it was my technique, or rather lack of "follow through" which was unneccessary with the 14" carbine, but vital with the longer barrelled gun.Sorted my shit out, and voila! excellent groups again. The moral of this story, is not that short barrels are more accurate, just that they are much more forgiving, and easier to shoot well. Its no secret, that our best selling barrel, by far, is the 12.5" volquartsen carbon fibre barrel...it produces the results most require, with less user input.

 

Proof.

They didn, t give a shit about screwcutting, moderators etc, until they lost a huge amount of buisness after the pistol ban.

This subject isnt covered in the proof act, because mods didnt, exist all those years ago.

The end of a barrel is the "safe" end, regarding pressure.Plus, the ring of steel, offered by a screwed on mod, negates the few thou, turned off to form a thread.The owner of "gunshop" at barnet , was prosecuted for COUNTERBORING a 10/22 barrel, and fitting baffles to make an INTERNAL moderator.That would be a compromise in most peoples book....but he won the case.

 

Tikka,s . hmmmn. The 1 in 8" twist will shoot owt from 55 grains up to 77 grains....its shouldnt but it does, and i cant explain it.My speedy wont stabilise owt under 60 grain bullets. They offer both twist, to cater for the varmint weight bullets shooters [40-55 grain] and the 1 in 8 to cater for the target men, with their 69- grain bullets.

 

Half the dealers in the country dont reproof, we are one of them, on the screwcutting issue, all others, we reproof, eg action work, new guns etc.

 

Send me a pm Dek, on your questions for a .204, its a great cartridge. I,m off ta bed.