Bipod for F-TR?

seblambang

seblambang

seb
Gentlemen,

Can someones explain if a bipod with coaxial/joystick feature can be used (=legal to use) in F-TR?

I can't find specific rules about bipod in the F-TR rules, only it shall be a bi-pod (=with two legs).

Okay, I plan to make it if it's ok/legal to use.
(It's just my newest idea.....well, not a secret anymore now).

The idea is to add joystick feature on a common bipod.

That means adjustment is/will be by the joystick (not rear bag squeezing)

Pro? Cons?

Thanks you in advance,
seb.
 
To copy from NRA website, Section 22. F-Class Rifle Rules.... http://www.nrahq.org/compete/RuleBooks/HPR/hpr-w22.pdf

3.4.1 Rifle Rests

(b) F-Class Target Rifle (F-TR) Rests - A bipod and/or sling are the only allowed front supports for the F-TR
rifle. The rifle may be supported by a bipod and/or sling and a rear support which provide no positive
mechanical method for returning it to its precise point of aim for the prior shot. Subject to:
(1) The bipod and/or sling and rear support may not be attached to each other.
(2) The use of any form of a table is prohibited. Separate flat boards or plates not exceeding the
dimensions of the individual rests by two inches are allowed to be placed under the front and/or rear
rests. In the case of a bipod, the board or plate may not exceed the width of the bipod by 2", nor be
more than 12" front to rear. See Rule 3.4.1(a)(1).
No leveling screws or protrusions are allowed on these boards or plates. They must be flat on the top
and bottom.
This discipline is a modification of high power prone shooting, not a form of bench rest and should not
be construed as such.
Disabled competitors may apply to the NRA Protest Committee for appropriate dispensation.
The intent of this rule is to prevent the use of a table type device.
(3) A bipod is a device with no more than two legs that touch the firing point. It must be rigidly attached to
the forend of the rifle. The bipod may have rigid or folding legs, and may be adjustable to compensate
for the uneven surface of the firing point.
(4) No portion of the rifle’s butt or forend shall rest directly on the ground or any hard surface. A rear
rabbit eared bag, small sandbag or a gloved hand may be used to support the rifle’s butt. Any rear
support employed shall not be attached, clamped or held to the rifle in any manner. The rear support
may not be fixed to or protrude into the firing point. Mechanically adjustable rear support is not
allowed.
(5) Any number or type of objects may be placed beneath the bipod or rear support, to compensate for
variations in height or slope of the firing point.
(6) The bipod and rear rest may be adjusted after any shot to compensate for rest movement or settling.
A sling may be used in conjunction with the rest(s), but its weight will be included in the rifle’s overall
weight (Rule 3.4.(b)).


In Section 3. Equipment & Ammunition
3.3.2
(b) Bipods may be attached but not utilized.

"may be attached but not utilized"... What does this mean?


seb
 
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seb,

You've went beyond the F-Class Rules with your question about Rule 3.3.2, which when read in it's full form answrs the question you asked......

 3.3.2 NRA Any Sight Match Rifle/Tactical Rifle - Same as NRA Match Rifle Rule 3.3 except there is no restriction as to sights. The following restrictions will apply:
(a) No person firing an any sight rifle under 3.3.2 will be allowed to compete with any other group of shooters who are also firing. A competitor using any sight rifle under Rule 3.3.2 will only be eligible for awards in their own division.
(b) Bipods may be attached but not utilized. Ammunition will be restricted to no larger than .35 caliber.

It covers using a Tacticl Rifle with an attached Bi Pod as a Match Rifle in the Any Rifle/Any Sight Class, not F-Class.
 
Does this rule even apply to F/TR ( F/ Target Rifle)? I believe the last sentence excludes F/TR but correct me if I am wrong. There is "NO" Tactical in F/TR...

Roland
 
My mistake & ignorance. I think I have 'mixed' the rules, i.e. section #3 for tactical/match rifle into the F-TR.

Thanks you for the replies,
seb.
 
If the new Sinclair is legal then a joystick one should be. I have a extra Shadetree joystick I have thought about rigging just like you are thinking. Just really don't want to give up any weight on my gun. Seb how lite do you think you could get the joystick unit down to. Ease of operation would be your only gain.
 
sdean,
Thanks for your response.
I 'aim' 400 grams max (less than 14 oz) for the 'coaxial unit'.
Technically it can be done/no problem, it's basically an extra small/miniature of my current coaxial unit.
From my rough sketches it's about 1" thick x 1 3/4" tall x 4" long.
Another 13 oz or so for the legs/feet & upper attachment. Total weight about 1.6 lbs. Yes, the lighter the better for this purpose.

You're correct about ease of operation. But one of the more important goals for me is 1) it would/must be more comfort to use compared to a conventional bipod. When you shoot prone with one/another hand squeezing rear bag (under the arm-pit), the muscle works harder (whether the muscle in the arm or around the fingers) - compared to the arm in the front using a joystick.
(You can try it... pretend to shoot prone with another hand under your arm-pit squeezing rear bag, for several minutes. Then compare with the arm in the front using a joystick. I guess that you would agree with me).
It must also be able to withstand rough/heavy recoil, etc.

seb.
 
how are you going to keep the joystick from moving with all the shifting the F-class guys do, I have a neo and it is great but have not tried it on the ground, waiting for counterweights,

remember the F-class do not shoot free recoil

Jefferson
 
Seb if you can build one at 2 lbs then put me on the top of your list.It would help me stay in a more consistant position -short arms- then reaching for my new Sinclair. I hold my gun fairly hard so I use both hands on the buttstock anyway. I really like my Sinclair but if it had a joystick I think I would like it better. I would think some might try to limit stuff like this in FTR but probably be hard to do. Just human nature to push the envelope and to innovate. I play by whatever rules they have. There is a club shoot by me where you have to use a harris type bipod and magazine fed just to stay away from this stuff. It is fine with me I have a gun to fit that too. I just like to shoot.
Stephen
 
Jefferson said:
how are you going to keep the joystick from moving with all the shifting the F-class guys do.

remember the F-class do not shoot free recoil
Click to expand...

That's the challenge Jeff, how to make a joystick bipod that works & works well. As I said in the earlier post, it must also be able to withstand rough/heavy recoil/bouncing etc.
I think it can be done. I'm quite optimist with it.
I must be able to make a prototype next month and will check how it works in Bisley UK.

, I have a neo and it is great but have not tried it on the ground, waiting for counterweights,
Click to expand...
Thanks you so much for being a loyal customer! (I know you bought many stuffs from Uncle Paul, also remember with the hat you gave me a few years ago? I still keep it!)

Cheers,
seb.
 
Stephen,
2 lbs is plenty, my aim is less than that.
Thanks, but later on that. I will only produce it if it works superbly as expected.
seb.
 
OK, I have not yet shot F class, but there is something wrong here, at least to me.

How can one adjust a bipod if you're holding the bag with the left hand and your right is on the trigger. As I said, I've not yet shot this class, I don't even have a bipod, but the physical configuration just don't seem right. But then again, what do I know.

Someone enlighten me.

Thanks,

Roy
 
Okay, I have made a rough prototype today.

The mini 'coaxial unit' is done, it weighs approximately 380 grams with/including the joystick. (I'm very happy with the result, it works very well also).
I think I still can reduce the weight of the coaxial unit by about 15-20%, still plenty meat on the 'body' that can be machined out.
The coaxial unit/top would handle 20 lbs rifle with ease, so it's 'already very enough' for 17 lbs F-TR rifles.

Now with the legs.... I made two rectangular solid bars of about 1/2" thick x 1-3/8" wide x 8" long (still heavy approx 600 grams for a pair). It's just/still a very rough legs and not adjustable in length, only to see how the 'bipod' works on a rifle.
BTW, the legs are foldable & each leg is secured with one bolt only (M6x1.0 adjustable handle/lever screw). It can be folded to the front or to the rear (total 180 degree). The whole unit + the joystick measures about 2" thick x 5" wide x 9" long when folded.
The 'footprint is about 15" wide. This is at the lowest setting, it will be much wider when done with the adjustable legs. It will be wider when taller.

I put the "bipod" (with "...") on one of my rifles this afternoon. The stock can accept a Harris bipod, I just removed the sling nut & use a screw.
I tried to 'shoot' in prone, operated the stick etc, also to twist the 'bipod' to any angles and found no any movements. It feels very solid & rigid. (that's why I'm very happy).
I also tried to put my whole weight (160 lbs +/-) on the bipod (stood on the 'bipod') and found no flex etc. (So if the adjustable legs can withstand more than 60 lbs it will be great).
I'll make new (adjustable) legs to be less than 400 grams, next Monday/Tuesday.


I have 2 questions at this time...:

1). Any inputs for the height? ... lowest & highest?.... 6" to 9", or 6" to 10", or ...?
For me the 'comfort zone' is about 8" to 9", but it's just me.
Considering shooting uphill & downhill.

2). Also any inputs with how to attach/secure the bipod on the stock?...such as the Anschutz rail or Weaver style, or?
Never have other bipods rather than the Harris here. Also never make a bipod before.
Probably some photos showing the underside of the fore-arm? so I can see it clearly how your bipod is secured to the stock/forearm.
I want to make a universal "head/attachment" & tilt-able or rotate-able (but can be locked), if possible.

Your inputs & photos will be much appreciated.

Thanks you in advance,
seb.

PS: I'll take some pics of the prototype unit in a few days/next week.
 
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Seb,

I'll take some measurements for height/width/adjustment range, and some pics of the attachment points if someone doesn't beat me to it. Might be a day or two, though.

Monte
 
I would not have the Anschutz as the only means of attachment as there are some FT/R socks with a very thin forearm and to mill out a 3/8" deep slot would weaken this area too much. We just had a stock in and we had intended on installing a Anschutz rail and decided that it probably would have split the stock. We went with a short stub of Picatinny rail for attaching the bipod.
 
Seb,

The Sinclair Gen II and Gen III pods that I measured were approx. 16.5" wide, with a height adjustment range from ~5" to ~10" (from the top of the pod/bottom of the stock to the deck).

The Centershot pod that I measured went from ~4.5" high to a little over 9" high, and from about 16" wide to just about 20" wide.

As for pics... without disassembling them, which I'm not willing to do, I don't think my cell phone pics would help that much. General idea is a standard ratchet lever for tightening (similar to the Pod-Loc available for the Harris bipods) that snugs things up to where they won't move. The handle on the Sinclair is much larger (~2x) than the one on the Center shot, and the bearing surfaces that it tightens are much bigger/ more solid. When it locks, it ain't moving, period. The Centershot is not nearly as rugged, but once snugged down I've never had it move either.

Regarding the Anschutz rail vs. picatinny... if a stock is so thin in the fore-end that inletting a rail would potentially spit it, I 'd say get a better stock as that one will likely flex too much. Maybe not. At any rate, its not really any harder to mount a section of Anschutz rail to the outside of the stock than it is a section of Picatinny rail... Picatinny is nice in that you can find quick-release lever systems for removing the bipod when in transit between firing points. Even if they have parking access behind the firing line, its still a PITA to try and stuff a gun with a wide bipod attached in the vehicle. If you have to carry it between yard lines, doubly so. My experience with a Picatinny QR mount (GG&G, supposed to be 'good stuff') was that it started coming loose under repeated use and I kept having to get a tool out to tighten it back up - at which point the whole tool-less quick-release bit becomes somewhat pointless.

YMMV,

Monte
 
Thanks you for the inputs gentlemen!

The prototype is almost done... the mini coaxial unit works & weighs as expected (probably exceeds my expectation- if I can say this). The legs are now adjustable in length (can stretch-out), also rigid enough for 30 lbs weight on the top when full stretched-out/at the highest setting. I'd probably need to make an extra light 'bracing' for the legs to be able to withstand, say a 80 lbs weight on the top without any flex...but maybe not needed for a standard F/TR rifle...(?).
The 'footprint' is about 15" at the lowest setting 6" tall....it's about 21" wide at the highest setting 9" tall. I think it's very stable already.
I'll make a set of 'ski-feet' & 'half ball' feet tomorrow. (the feet must be compatible/interchangeable - to see which one works better for various/uneven ground surfaces). I'll also make the top attachment tomorrow. I have found the Anschutz rail measurements (both the European & American version), I have had some weaver/picatinny rails...so the head-attachment would be no problem I guess. My only problem is the total weight... the whole unit still weighs approximately 820 grams (29 oz +/-) today, without the feet. I need to think how to reduce the total weight (especially with the legs) without sacrificing the stiffness/rigidity of the whole unit. I have a couple designs with the legs anyway, I just don't have time to make several type legs at this moment.
The mini coaxial unit (it's "the heart" of the bipod) is now about 340 grams (12 oz +/-)...it's quite compact & light already...I have reduced the weight today. Without some 'meat' on the sides of the coaxial unit for securing the legs, it can be smaller & more light.... probably can be done with the other leg design. --- I am hoping the whole unit to be no more than 25 oz, with all metal construction. (most parts are from alum aircraft grade 7000 series).
I'll take some pics for more inputs....probably tomorrow or the day after tomorrow....very tired now, just back home from my workshop.... Again thanks, seb.
 
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The prototype is almost 100% ready now. I have polished it, too.
The 'head' attachment can accept Weaver/picatinny & Anschutz rail (both European or American/Win style), or by a screw directly into the stock (i.e. ex. sling nut).
It's the first model. I'll make other models (with different legs) when I have time / after the European F-Class.

Some photos as promised....

At the lowest setting - 6" tall... can withstand weight around 80 kilograms (175 lbs +/-) on the top w/ almost no flex.
View attachment 13145
IMG_5056.jpg


From reverse angle... spare feet (as an alternative to the 'ski' feet, probably when sighting-in on a bench top), about 1.5" diameter, convex neophrene bottom
View attachment 13147
IMG_5057.jpg


Upside down... legs are from solid alum machined
View attachment 13148
IMG_5062.jpg


At the highest setting 9" +/-...can withstand about 30 kgs weight on the top w/ very minimal flex. Can withstand 80 kgs but w/ more flex.
View attachment 13149
IMG_5053.jpg


When folded... shown w/ weaver style attachment (just a cheap aftermarket stuff, still have no time to make a custom one)
View attachment 13150
IMG_5065.jpg


What do you think guys?.... input or critique, please.

It weighs 740 grams total. I think I can make it under 700 grams next time.
It can be used in 'up for up' or up 'for down' mode, just like my other rests.
It has a built in uplift also... quite smooth even with 15 kgs +/- weight on the top.

All the best,
seb.
 
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