Author Topic: Effects of forearm variables on rifle accuracy  (Read 1423 times)

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Offline kody

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Effects of forearm variables on rifle accuracy
« on: October 15, 2010, 07:39:02 PM »
I have read many cause and effect descriptions concerning Handi-rifle accuracy and would like to hear the opinions of forum members. The subjects that have been covered have had a lot to do with the fit of the forearm. Are forearms best matched to specific barrels as barrels are to frames?  Does the type of forearm matter? Does having a sling attach point at the forward end, like the Survivor, matter? Besides looking neat what other effects go along with a Mannlicher forearm? How important is the pressure of the spacer on the receiver? How is the proper pressure determined and how can it be adjusted? There was a description of a constant pressure spacer fitted to a Handi forearm and "O" rings fitted to the attach screw point. I couldn't figure, from the replies, whether that was a good idea or not.  Proper torqueing is called for. How is the proper torque value arrived at.  I don't remember any talk of pillar mounting but bedding has been covered. I would be interested in hearing what priorities you attach to the various approaches to maximum accuracy.    Ken

Offline Swampman

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Re: Effects of forearm variables on rifle accuracy
« Reply #1 on: October 16, 2010, 01:06:44 AM »
In the calibers I shoot it doesn't seem to matter what I do the point of impact doesn't change, but that's just me.
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Offline Darreld Walton

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Re: Effects of forearm variables on rifle accuracy
« Reply #2 on: October 16, 2010, 02:09:25 AM »
Took my .45 Colt 'Classic' to the range, load was 250 gr. Noslers and 'a lot' of 2400.  Gave nice little groups as long as the receiver rested on the bag, but when we grouped it on the forend, where yer hand would normally go, the shots went almost 5 inches higher, though still in a useable group.
I told my pap and mam I was going to be a mountain man; acted like they was gut-shot. "Make your life go here, son. Here's where the people is. Them mountains is for Indians and wild men." "Mother Gue", I says "the Rocky Mountains is the marrow of the world," and by God, I was right. Keep your nose in the wind and your eye along the skyline

Offline bikerbeans

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Re: Effects of forearm variables on rifle accuracy
« Reply #3 on: October 16, 2010, 03:10:54 AM »
Kody,

If you think your groups are affected by the forestock then try shooting it without the forestock, put your rest under the receiver.  If groups are better then the barrel is being affected by the forestock.   I think at that point you get into all the "fixes" that are listed in the FAQs.  I think you probably are into the trail & error mode at this point.  I have 10 handis, 223 Rem throught the 45 cals and a 50 MZ and all are a bit different.  I have one gun that has a pillar and bedding on the forestock, installed by a professional gunsmith.  Most of my guns I  have just relieve the barrel channel on the forestock (sandpaper wrapped around an impact socket) and installed a fairly thin rubber gasket that I cut to fit the relief in the forestock.  FWIW the pillar/bedded gun doesn't shoot any better than the guns I have modified myself.  What I have found once I relieved the forestocks and installed the rubber gasket is that the guns will shoot almost as well with me holding the forestock as they do when placing a rest under the receiver and not touching the forestock.  I want my guns to shoot okay with me holding the forestock as this is the mostly likely shooting position for me while hunting.  No comment on using a sling as I don't put them on my guns.

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Offline Swampman

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Re: Effects of forearm variables on rifle accuracy
« Reply #4 on: October 16, 2010, 03:21:04 AM »
All my guns have slings and I haven't noticed any problems there either.
"Brother, you say there is but one way to worship and serve the Great Spirit. If there is but one religion, why do you white people differ so much about it? Why not all agreed, as you can all read the Book?" Sogoyewapha, "Red Jacket" - Senaca

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Offline tobster

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Re: Effects of forearm variables on rifle accuracy
« Reply #5 on: October 16, 2010, 03:53:40 AM »
Took my .45 Colt 'Classic' to the range, load was 250 gr. Noslers and 'a lot' of 2400.  Gave nice little groups as long as the receiver rested on the bag, but when we grouped it on the forend, where yer hand would normally go, the shots went almost 5 inches higher, though still in a useable group.

[/ qu

If you then shoot off-hand, as in the field, does it still shoot 5" high?

Offline necchi

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Re: Effects of forearm variables on rifle accuracy
« Reply #6 on: October 16, 2010, 04:51:41 AM »
Wow, that's alot of ??,,
I hope you've read the accurizing tips in the FAQ's, every answer is found in there.

There is no single fix to a forearm that magically makes a handi shoot better, some it helps-others it won't. I've used a variation of the RTV bedding method in two and it's helped alot.
For proper pressure and screw torque it's a matter of experimentation to find what your rifle likes, some will use a torque screw driver purchased at a modest cost,,I went with the set screw in the bottom of the lug, all I need do is turn the screw down till it stops. ( the set screw cost 49 cents )

Basically the forearm work is much like any rifle when you hear about barrel whip and bedding. ALL barrels move when fired, it's about finding a balance of several "rifle" issues, the neat thing with the Handis is all of it can be done at home and with "tinkering" groups can shrink. As with all most all guns "handloading" for these things can make a huge differeance.  ;D
found elsewhere

Offline guns-o-fun

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Re: Effects of forearm variables on rifle accuracy
« Reply #7 on: October 16, 2010, 05:02:21 AM »
As noted here and elsewhere, there are a whole bunch of variables that play into accuracy with these guns, which is often the case with guns that have a two-piece stock.  Mic McPherson advises bedding behind the spacer to make the forend sit more tightly against the receiver - and several other "fixes".  And then there is all the stuff in the FAQs.  I have found that the forend type can even be a factor - I had problems with my 500 S&W handi until I shortened the barrel and put on a choate stock set.  Simply free-floating the barrel in that case did not help.  In other cases it does.  These guns are just not that predictable - but I still like them because you can experiment and often come up with a good fix.  My handis all now have dedicated forends that have been tinkered with in various ways.

Offline moorepower

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Re: Effects of forearm variables on rifle accuracy
« Reply #8 on: October 16, 2010, 05:15:36 AM »
I would wager that the tighter the barrel fits, the less of an impact the forearm bedding makes on accuracy. If you can't rest the rifle near the screw, it is kind of hard to shoot in the field.

Offline gcrank1

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Re: Effects of forearm variables on rifle accuracy
« Reply #9 on: October 16, 2010, 06:30:04 AM »
You have to decide how you are going to be holding or resting the rifle in actual use, then stick to that while sorting out the best accuracy. It will do you no good to have a 'one ragged hole shooter' off a rest at the action if you are still hunting and holding offhand at the mid forestock.
FWIW, I like the simple o-ring to hold the forestock a tad away from the barrel and only tighten the screw a tad past snug. Havent had one come loose yet and all seem to shoot about the same (must be me).
Consistency in hold and at recoil impulse is often an overlooked variable in the equation..
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Offline moorepower

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Re: Effects of forearm variables on rifle accuracy
« Reply #10 on: October 16, 2010, 07:09:03 AM »
My 17 furball and my .223 with just o-rings with 0 pressure on the screw shoot the same either way, but the barrels are both fit way tight.

Offline guns-o-fun

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Re: Effects of forearm variables on rifle accuracy
« Reply #11 on: October 16, 2010, 12:13:23 PM »
There is no doubt in my mind that the tightness of the barrel fit is important.  I have seen this in practice with a 25-06 barrel that I fitted.  Had it on a receiver that was very snug and it shot very tight groups.  Unfortunately, it popped open after every shot - which it should not do of course.  Tried all the standard fixes - nothing worked.  Have it on another receiver that is not as snug now - no pop open!  Dang it!  Oh well -this is going to be a dedicated receiver, so I think I can recapture the great accuracy by doing a little glass bedding to the sides of the lug.

Offline kody

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Re: Effects of forearm variables on rifle accuracy
« Reply #12 on: October 17, 2010, 11:16:26 PM »
Thanks to all of you who have shared your views. I have read the FAQs. Because of all of the various bits of info there ,most of which is pretty well scattered, led me in a lot of different directions, I decided to put the question in one place ,while mentioning as many of the scattered reports  as I could remember. Your answers now have shown me that there are many and varied ideas on the subject and,while no one offered a prioritized step list it was clear that there are a few major points to start with. This did confirm that my own trial and error, following what I believe were the strongest arguments put forth by the respondents, should be the route to take and I thank you all again for your help.   Ken

Offline Darreld Walton

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Re: Effects of forearm variables on rifle accuracy
« Reply #13 on: October 18, 2010, 03:25:41 AM »
Took my .45 Colt 'Classic' to the range, load was 250 gr. Noslers and 'a lot' of 2400.  Gave nice little groups as long as the receiver rested on the bag, but when we grouped it on the forend, where yer hand would normally go, the shots went almost 5 inches higher, though still in a useable group.

[/ qu

If you then shoot off-hand, as in the field, does it still shoot 5" high?

Sorry, I can't say.  That day, we were pressed for time at the range, and I didn't get to use the little carbine offhand, and a recent medical 'procedure' has kept me incapacitated for the last week or so, and for the foreseeable future.
I told my pap and mam I was going to be a mountain man; acted like they was gut-shot. "Make your life go here, son. Here's where the people is. Them mountains is for Indians and wild men." "Mother Gue", I says "the Rocky Mountains is the marrow of the world," and by God, I was right. Keep your nose in the wind and your eye along the skyline

Offline tacklebury

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Re: Effects of forearm variables on rifle accuracy
« Reply #14 on: October 18, 2010, 01:39:14 PM »
Hope you get feelin better soon Derreld, bad time of year for medical issues.  8(
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