Stabilising the rear bag

[M12LRPV]

I've been shooting F-Class for a little while now and have realised that i'm having issues with the rear sandbag.

I wasn't really aware of it until I shot on the super center at the rail and tram OPM last weekend. That beautiful white dot showed up all of my handling faults

Having come into it from rimfire benchrest, i'm using the pedestal rest and rear sandbag combination. I'm used to the stability that this combination offers when set up on the bench.

What's annoying me is that in f-class the rear bag sits on the shooting mat and the "give" in the mat destabilses the bag. I've got some pieces of timber that I use for elevation but they don't alter the situation, it's still unstable.

Are there any tips or tricks to make the rear bag more stable?

[VickiMcc]

get the bag off the mat. If you can get hold of a piece of steel a bit bigger than your bag about 10mm thick and put a spike in each corner so you can anchor it in the ground it will give you a much more stable platform. The only drawback is that it takes more time in setup as you have to align everything to the target, but thats just a minor thing compared to the benefits you get

Paul

[johnk]

I'm with Paul. Th reason why I wear elbow pads is because I don't have a mat anywhere near my bag - which didn't stop me buggering up at Lower Light when my no-as-flat-as-it-should-be bag bottom pivoted on a high point on the mound.

I kind of like the donut underbags as an alternative to a hard base for the bag. My thinking is that you can generate a degree of levelling that way - and it's a tad less resistant to slippage, maybe.

If you have to have a mat way up there, do like some do & have a cutout made in it for your bag.

John

[AlanF]

...get hold of a piece of steel a bit bigger than your bag about 10mm thick and put a spike in each corner...

Just be aware that some ROs may question spikes - my steel plate has angle iron at the corners which were pointed, but as a result of a tip-off, I cut the points off so they don't penetrate the surface more than a few mm. It still does the job of providing a stable and level base, which is what the rules for F-Open rear bags intended. I use a piece of carpet with a hole cut in it for the rear bag.

Alan

[Cameron Mc]

...get hold of a piece of steel a bit bigger than your bag about 10mm thick and put a spike in each corner...

Just be aware that some ROs may question spikes - my steel plate has angle iron at the corners which were pointed, but as a result of a tip-off, I cut the points off so they don't penetrate the surface more than a few mm. It still does the job of providing a stable and level base, which is what the rules for F-Open rear bags intended. I use a piece of carpet with a hole cut in it for the rear bag.

Alan

Al, that is the reason I don't use a plate under the rear bag. I watched an RO stop a shooter using one. It's the old story, the rules don't say you can't use it, but........
Cameron

[VickiMcc]

20.1.1.15 A rear rest must use a sandbag as the only contact with the rifle. Any number of simple
objects of any material may be placed underneath the rear sandbag to stabilise it or make
allowance for variations in slope of the mound.



Pretty clear i think . You can use 50mm spikes in a front rest providing no mound damage, why not the back plate??


Paul

[AlanF]

Al, that is the reason I don't use a plate under the rear bag. I watched an RO stop a shooter using one. It's the old story, the rules don't say you can't use it, but........
Cameron

Well I'm prepared to risk it. I actually drafted the F-Open rules on rests and the intention of the packing under the rear rest is clearly stated (see Paul's post above). My plate is a very simple object designed to do exactly that, stabilise and allow for uneven surfaces. JohnK, you saw it when I left it on the mound when you were RO at the 2008 Nationals. Were you confused by its complexity?

Paul,

Technically, they could get you on spikes because they aren't specifically mentioned. However at the last NSW Queens there was a protest about a spiked (approx 50mm long) wooden rear packer used by an F-Std shooter - it was dismissed. Its just a matter of how much the RO of the day understands the F-Class rules.

Alan

[M12LRPV]

Thanks for the ideas guys.

I'm probably going to have to give the steel plate a miss because the missus and I share gear and she's complaining about the weight of all the gear as it is.

The idea of cutting out a section of the mat is probably the easiest option.

Spikes and timber might be the go too but i'll have to figure out how to level it without running afoul of an overzealous official.

Because the subject of the rules came up I read through them again. It's interesting to note the difference in the latest SSR's between the F-Open and F-Std rules for rear bags...

F-Open
20.1.1.15 A rear rest must use a sandbag as the only contact with the rifle. Any number of simple objects of any material may be placed underneath the rear sandbag to stabilise it or make allowance for variations in slope of the mound.
20.1.1.16 The contents of front and rear sandbags shall be a dry, finely (<5mm) divided substance such as, but not limited to sand, or grain, packed loosely enough so that the bag can be visibly deformed with the fingers.
20.1.1.17 A front rest may be mechanically adjustable for both windage and elevation. A rear rest must not be mechanically adjustable. Rests may be adjusted before each shot.

F-Standard
20.2.1.5 Rear Rest:
Rear rest will not be attached to the front rest, and will consist of a sandbag filled with, but not limited to sand, gravel, grain or other suitable material, in contact with the rifle’s butt, with any number of packers consisting of any material under the sandbag to allow for height adjustment and inconsistencies in the firing mound.

It seems that for F-Std there is no requirement that the objects be "simple" or even that the objects can't be mechanically adjustable

[AlanF]

...It's interesting to note the difference in the latest SSR's between the F-Open and F-Std rules for rear bags...

There was no request for collaboration when the F-Std and F-Open rules were rewritten by two different groups in 2006. As far as the current F-Open rules go, they were deliberately modelled on the ICFRA rules, with some minor differences.

Alan

[timothi3197]

I use a third size besser block(one of the ones you user on an endwall)as a packer for my rear bag and rest it directly on the ground(when I am serious I never use a mat), it is rock steady. If it is too high I use half a red house brick. If it is still too high I have a piece of 3" steel plate with 1/2" of concavity machined between all four corners.

I have been accused of cheating for this however- but there is no rule against it. My defense was that in each case they were made of a single pure piece of material with no moving parts and didn't pierce the top layer of soil on the mound so therefore were packers and not mechanical items. Then there was some crap about unfair advantage?????? Fair go I am shooting with an outfit worth less than $1200 including scope and accessories and a home made (and unpainted raw steel front rest). The objections wouldn't have occurred if I were finishing in the bottom half of the field.

Technically I am eligible for a disability pension and could use a bench but don't- so they can all go and make love to their cats as far as I am concerned.

[M12LRPV]

Truth be told i'm surprised at how few people have tackled this issue...

On the weekends at Malabar I haven't noticed a single shooter with anything other than a simple timber base for their bag.

I suppose it's because most of them are ex elbow shooters and are used to holding the rifle rather than letting the bags do the work.

[johnk]

I suppose it's because most of them are ex elbow shooters and are used to holding the rifle rather than letting the bags do the work.

The game's been going formally for a dozen or so years now, & longer than that experimentally. Give shooters the credit for maybe having thought out what works for them, eh?

[John E]

I don't think I'll be able to sleep tonight, worrying about all this crap!!!

John

[M12LRPV]

I suppose it's because most of them are ex elbow shooters and are used to holding the rifle rather than letting the bags do the work.

The game's been going formally for a dozen or so years now, & longer than that experimentally. Give shooters the credit for maybe having thought out what works for them, eh?

I'm not criticising. Just honest observation. Different background = different technique.

Don't shoot the messenger.

I don't think I'll be able to sleep tonight, worrying about all this crap!!!

John

Huh?

[timothi3197]

I don't think I'll be able to sleep tonight, worrying about all this crap!!!

John

Relevence to thread? Or just a CRAP comment?