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17 HMR 3/4 scale ar15

7K views 33 replies 14 participants last post by  1biggun 
#1 ·
I wanted to do something special for my sons birthday, so I was thinking he already has some guns but what about a .22lr 3/4 scale ar15 (sp01). Then after shooting a friends 17HMR I was hooked. So here is the upper receiver almost finished (17hmr) and the .22 lr lower. I will cut a new lower and send it out for engraving. Here it is with its big cousin, an ar10 I milled



Of course there is still a lot of work to do on the upper (thread for barrel nut, final contour, ejection door and smoothing the contour of the rear(will be done after lower is cut)
 
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#4 ·
WOW!!!!!! IS A UNDERSTATMENT.

I KNOW OF A COUPLE GUYS WHO WOULD BE VERY INERESTED IN BUYING ONE. I RELIZE YOU CANT SELL HOME MADE RECIVERS BUT MAN WOULD THESE BE SOUGHT AFTER. ANY CHANCE OF A FULL SIZE UPPER OR CONVERSION PARTS OR PLANS FOR A 17 hmr. ARE YOU HAND MILLING ALL THIS OR IS IT OFF A PROGRAM? THERE ARE NOT A LOT OF CHOICES IN A SEMI AUTO 17 HMR IF YOU COULD MAKE FULL SIZE UPPERS THEY WOULD SELL! AGAIN WOW.
 
#6 ·
Guys this is done off a chinese harbour freight mill/drill, no CNC, took about 8 hours to this point.
I bored a .750 hole through the block of aluminum and then inserted a .750 steel rod. Drilled and tapped 2 screws to lock it tight. Put it in a dividing head I picked up used for $15. then just cut away everything that wasn't 3/4 scale. want to cut him a sp01 slick sided receiver. unfortunately i changed caliber after making the lower. (22lr) and went with the 17hmr. now I have to sell off the nowhere near 80% lower for 22lr or make another upper in 22.
It will be several months before I finish, lots of irons in the fire+hunting season+military commitment+family and work.

The bolt will be very similar on the front end to a ruger mkII/2245, the back end will be like an ar. To get the bolt weight I will have to go with a tube/extension just like the real deal. I will make some fiber glass triangular hand guards and butt stock for it too.
 
#7 ·
I GOTTA HAVE ONE OF THESE MAKE MINE A FLAT TOP WITH MILLED IN RAILS

WHAT MAGS ARE YOU USEING?? THE GUY WHO TAKES ME PRAIRE DOG HUNTING REALLY WANTS A 17HMR AUTO LOADER.

I REALLY LIKE HOW YOU DID THE SET UP IN THE MILL. IT GIVES ME SOME IDEAS ON HOW TO BUILD SOME OTHER PARTS. I HAVE GOOD EQUIPMENT BUT REALLY DONT KNOW HOW TO PROPERLY RUN IT. I NEED TO TAKE A CLASS OR SOME THING.


DID YOU SEE WERE THE kERNEL MENTIONED THAT THE AMT 22 MAG PISTOL HAS GROVES IN THE CHAMBER TO HELP LOCK THE CASE IN UNTILL THE PRESSRE DROPED. THAT WAY THEY COULD USE A LIGHTER BOLT. I HAVE BEEN THINKING ABOUT THAT ALL DAY FOR USE IN A BLOW BACK BUILD.

now I have to sell off the nowhere near 80% lower for 22lr or make another upper in 22.
BUILD IT UP 22 LR IS SO MUCH CHEAPER TO SHOOT. YOU COULD ALWAYS DO A
17 HMR 2 ON IT AS WELL.
 
#8 ·
the 10/22 by ruger has a 17hmr semi, and is very accurate from what I hear.

I am using marlin 571 mags, $15 at walmart and designed for the 17 hmr

I was thinking about one with a top rail....

But I have so many other projects. I am building as many receivers as possible before our next round of bans..
 
#9 ·
77/22 IS A BOLT ACTION IF IM NOT MISTAKEN. AS FAR AS i KNOW THERE ARE ONLY 3 OR 4 MANFACTURES DOING A SA 17 HMR ONE IS A 10-22MAG COPY CONVERTED TO 17HMR.

THE BAN SCARES ME AS WELL. i WANT TO GET A COUPLE OF REGISTERD AS PISTOL RECIVERS IN MY NAME FOR BOLT AK,S AND AR,S. i THINK THEY WILL BE AT THE TOP OF THE NEXT BANNED LIST.

PRICE IS RIGHT ON THE MAGS
 
#11 ·
WELL THEY HAVE THE CONVERSION THAT USES THE ORIGINAL BOLT AND MAGS OF THE 10/22 YOU JUST CHANGE THE BARRELCHAMBERED TO THE 17 MACH 2
 
#12 ·
biggun, you are correct, its a 10 22 in 22mag that can be converted and add a heavier charging handle for more weight. I called my friend and had him pull it from the safe..
IT WAS MY UNDERSTANDING THAT RUGER HAD PLANED TO RELEASE THE 17HMR-22 BUT GOULD NEVER GET ALL THE BUGS OUT OF IT, SO THE NEVER RELEASED THERE VERSION (TO BAD). SOME CONVERSIONS ARE REPORTED TO WORK GREAT SOME ARE NOT GOOD. HOW DOES YOUR FRIENDS SHOOT???? THE RUGGER 22 MAGS ARE DISCONTINUED AS WELL AND GO FOR WAY TO MUCH $$$$ IMOA.

Accelerator Rifle
THERES THESE BUT iVE HEARD BAD THINGS
FOR OVER A GRAND YOU CANGET A RUGER COPY NICE GUN
Rimfire Sports & Custom: Volquartsen Lightweight Semi-Auto .17 HMR Rifle

REMINTON HAS ONE WITH MIXED REVIEWS
Remington Model 597™ Magnum LS HB

AN THIS ONE. INTERESTING
Magnum Research
 
#16 ·
any chance you want to sell a set up like this??

id be in right now....

or maybe an 80% receiver that needed holes and such drilled?
 
#18 ·
Gunter,
so what your saying is the bolt mass should be around 15 oz or 425 grams. So 4140 at .750" is 56.666 grams per inch means 7.5" (+ a little) The bolt length in the upper is only about 4" so I need to add tungsten and use a functional buffer tube.

Do you know a spring weight for the 10/22mag?
 
#21 · (Edited)
I got the 15 oz weight from your earlier post, it does seem kinda heavy. I fixed a Remington 597 in 17hmr for a friend a while back. The bolt for it did seem suprisingly heavy for its size. Since you probably can have more than the 2" of bolt travel that the other 17hmr's have, can you use a lighter bolt and a rubber bumper? I found link to a guy who makes custom 10/22 mag bolts for the 17hmr and his are 17 oz.
 
#23 ·
Going from the old notes when I was trying to add weight to a 10/22 LR bolt:
The amounts for 1 cubic inch of material:
Steel = 4.6 ounces
Lead = 6.5 ounces
Tungsten = 11.1 ounces

I take that you are using .750 round stock for the bolt. If I did the math right I come up with the same 2 ounces of weight per inch of bolt length using the value for steel from above.

With the 17HMR I feel that there are two problems to deal with. 1. Is keeping the bolt closed during firing. For me just changing the hammer spring to an extra power spring took care of the mushrooming case heads. More pressure to move the hammer rearward helped keep the bolt closed.

2. Is keeping the bolt speed down during recoil. One way is with a heavy bolt. Another is to use one of these
to help slow the bolt down. They can be found at McMaster-Carr or probably any industral supply and come in initial force required to depress the plunger from .25 lbs to 16 lbs. One placed in the receiver so that the plunger sticks up into the bolts path will slow the bolt as the bolt presses the plunger down. The only draw back is that the bolt must keep it pressed down during the cycle stroke. If it pops up infront of the bolt the recoil spring might not have enough umph to press it back down. Some guys were using these on the 10/22s to help with problems 1 and 2.

I don't think that I have a standard 22mag spring left. The one I have made up is a standard 22mag with about an inch of another recoil spring added to it. I think I can find the trigger scale and get a reading if you want.

ETA: It's called a spring loaded detent...DOH!
 
#24 ·
that is an idea. I found a site that has 3/4" diameter tungsten discs for soap box racers. I could stack these on the buffer to get the weight right and just use a ruger 10/22mag recoil spring. Start heavy and remove until I have function. My boy is only 4 (turning 5) and I dont want him struggling with a loaded gun and stiff bolt. (he does well with 410 bolt shotgun and a 357mag rifle) so the detent might not be a good idea for him but is def. out of the box and worth thinking on. ER Shaw is sending the barrel early next week and the aluminum for the lower went out today, so things are moving. Just need to get a positive weight on that bolt.
 
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