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Old 03-04-2019, 12:37 PM
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Harrell tuner & 64MPR



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I'm traveling down the "tuner" road with my 64MPR. I ordered and received the tuner, did the measurements per the Purdy formula, and my MPR barrel measures 25 7/16" long, bolt in and locked using a 20 cal cleaning rod inserted from the muzzle.

My AL is 28.62"-.402 EC for a 28.218" PL, and I'm at the 450 clicks out range of adjustment so I don't have much if any adjustment left.

Tony indicates/states the tuner works best when in the middle of the adjustment range (~250??), AND that for barrels "a little longer" than 25", you will probably need a screw in weight to make the length you need for a proper tune. (I'm quoting Tony from his posting of the actual formula post or walk thru from sometime in the past).


What size weight do I need since my barrel is "little bit" past 25". If I need to provide more/additional info, let me know. TIA

Jim
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Old 03-04-2019, 03:58 PM
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You need to come out 1/4" which equals 250 clicks. It is length that matters not weight so you can cut out some circles from pieces of cardboard and glue them on.
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Old 03-04-2019, 04:43 PM
swo1
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KSS sells Riverside weight kit for the Harrell Tuner. They are stainless steel and various thickness. Here is the link:

killoughshootingsports.com/index.php/tuners.html
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Old 03-04-2019, 07:11 PM
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Originally Posted by vlnbyr View Post
You need to come out 1/4" which equals 250 clicks. It is length that matters not weight so you can cut out some circles from pieces of cardboard and glue them on.
I'm not following as to where I would glue the cardboard circles on? Any pics to show how this is done??
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Old 03-04-2019, 07:24 PM
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You can also buy weights from Harrell
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Old 03-04-2019, 08:36 PM
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Originally Posted by vlnbyr View Post
You need to come out 1/4" which equals 250 clicks. It is length that matters not weight so you can cut out some circles from pieces of cardboard and glue them on.
Man, wished I had thought of that, before I cut the barrel off and started over. Weird thing was, it ended up right at the length it was before adding the tuner the first time.

To the OP, think Hopewell.
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Old 03-04-2019, 08:44 PM
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To the OP, is this rifle bedded? if not you will not see the full benefit of a tuner.
I just bedded an MPR that the owner tried using a tuner, it was not bedded and would shoot tiny groups however it would shoot 2 tiny groups regardless of how much weight or which setting he tried.

any inconsistencies that the action fit to the stock has will cause a secondary harmonic which will cause wild shots or again the inability to tune it so you get 1-single tiny group. this example I am relating since being pillar bedded now shoots single tiny groups, no more 2 tiny groups.

also forget the PRX tuning, just use the tuner and shoot 3-shot groups, starting at 0 and go out by 5-clicks at a time, till you can get the smallest and roundest groups.
use good ammo and if you get vertical stringing which you can not adjust out, then you can add weight.
once you think you found a good setting shoot that setting for awhile, if it shoots pretty much the same every range session you are done.
but again if this rifle is not pillar bedded you may be spinning your wheels.

Lee
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Old 03-04-2019, 08:49 PM
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Quote:
Originally Posted by jpx2rk View Post
I'm not following as to where I would glue the cardboard circles on? Any pics to show how this is done??
John, is being comical forget that silly PRX, tuning is timing the barrel with the bullet's exit, you are trying to make the bullet exit at barrels same rise
the weight of the tuner will alter the speed in which it rises thus effecting where and when bullet exits at the peak barrel rise.

Lee
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Old 03-04-2019, 11:51 PM
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Quote:
Originally Posted by 52DH&R12 View Post
Man, wished I had thought of that, before I cut the barrel off and started over. Weird thing was, it ended up right at the length it was before adding the tuner the first time.

To the OP, think Hopewell.
Jorge, instead of cutting the barrel off, you do know you can unscrew it from the action don't you? When you got it off, where did you cut the barrel? The muzzle, the crown end or in the middle? How good is the loctite you use? Or is gorilla glue really all that?

Hopewell?

You crack me up

You going to the barn? Think big time, think 2 machine, think Hopewell.

To the OP, lots of ways to go about this. You've already gotten some suggestions. Try them all if you wish. Only way you'll personally know for sure which is best for your gun.

I'm not as down on the PRX as some so give it a shot if you wish. Personally only had it work on one gun, but know lots of others that have success with it. Guess you could try putting a spacer between the end of the barrel and the bottom of the bored section of the tuner body. If you want a weight set that will give you some length, Riverside has them. If you just want to test, let me know. I'll send you a complete set to try out. At least you'd know if it works before buying anything. Just shoot me a pm with your info.

I use a longer barrel and had the same issues as you. With a regular Harrel, I was down near 0 on the tuner. This was found from just doing as Lee suggested, shooting, moving a few clicks, and shooting again. Repeat until you're out of ammo or are shooting like the king of the world. I approached it differently in that I just cut weight off the tuner. Worked fine, but now am using a very very light tuner (thanks to Lee!) and it seems to be working pretty decent. In the past have used weights and saw some good things, but they weren't consistent day to day. And really, that's what I'd think people are looking for in tuning.

But Lee brought up a great point. Is your gun bedded? If not, just for giggles, get you some of that aluminum tape, take a hole puncher and put three or so layers of tape together, punch a two holes, cut out in circles (like those paper things to repair worn holes) and then stick them to your action to where the action screws enter. Will sometimes show you how the gun might benefit from bedding. Play with torque a bit to see which does best and then when you get it the best you can, stick the tuner on and give it a go. You'll probably be down near the bottom near 25 (or below) or will find something just under 100 and again from around 125-175. Will probably find something in the 250 range too. From the little I've messed with this, there are several "windows" across the tuner adjustment range. What you have to do is find the one that works best day in and day out. Not an easy task! But a fun way to spend the day!

Oh, was just having fun at George. There is a method of tuning called Hopewell. George calls my method Hopeless.

Good luck with this.

Kenny
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Old 03-05-2019, 08:33 AM
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Thanks for all the suggestions and tips.

My MPR has not been bedded but will try the suggestion of the tape on the action to see if it would help. I have played with the torque settings a bit but did not see any real improvement so did not pursue that any further.

I've read of the Hopewell method, and was wanting to try the PRX method to see if would work, or at least get me in the zip code of a tune. I've read a lot of comments (both +/-) on the PRX, guess it depends on the person trying it and the equipment on hand.

Kenny;
Thanks for the detailed tips and suggestions and appreciate the offer of the use of your weights, will send you a PM.

Jim
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  #11  
Old 03-05-2019, 10:49 AM
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The Purdy Rx got me to within five clicks of the tune and saved me a lot of expensive ammo.
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  #12  
Old 03-05-2019, 09:57 PM
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you only have 1 locking lug so stock and bedding along with recoil are critical. try a lite tuner. marty


well you don't want the barrel to droop and flex as much plus less drag.
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Old 03-05-2019, 10:15 PM
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found another lite tuner in the files. marty
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Old 03-05-2019, 10:21 PM
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so like the suhl with 1 locking lug every attempt should be made to reinforce the action so variation in pressure doesn't cause variation in action flexing which result in barrel amplitude variation so my recommendation is sturdy double strap or steel split rings. marty
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Old 03-05-2019, 10:24 PM
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suhl is in the middle, so when thinking thru this, always think of a target rifle as an entire unit. it's the sum of all.. marty


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