Controlling muzzle jump at the bench.
- Thread starter SuperCub
- Start date
dude on youtube done it, i watched a vid yesterday, he was a bit painful to listen to but did a heap of tests with the rifle resting- on the barrel on a branch, on the barrel on the bag, on a branch but no barrel touch, hand over top of barrel no pressure, hand on top of barrel alot of pressure .e tc etc
it tend to show downward pressure and or pressure bottom of barrel would kick groups up considerable-
bla bla.
it tend to show downward pressure and or pressure bottom of barrel would kick groups up considerable-
bla bla.
Licensed to kill
CGN Regular
- Location
- Peace Country Alberta
Stock architecture has a significant impact on muzzle jump(and felt recoil). You can make a big difference in muzzle jump with pitch as well as drop at comb/face and heal. You can make better or much worse.
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Melvin of Ula, nula, whatever you want to call the company fame would full length bed the rifle.
I’d wager you can’t see a difference when shooting how it’ll be shot in the field. Is there a point shooting from a bench and working up loads, looking for mythical nodes, magic seating depth, accuracy you can’t use…..
- Location
- Western Manitoba
Probably Texas gun maker Melvin Forbes - I think he started or was involved with NULA
I am a bit with you on your second part. Two "games" - bench rest and hunting - similar, but not the same. As I discovered, my store bought hunting rifles are not "close" to my target rifles. So it is a waste of my time to try to make my commercial hunting rifles or my ex-military rifles to shoot like they were target rifles - they aren't.
Many "reloading" discussions do not seem to recognize the duality - trying to load using techniques that probably are "normal" for bench rest competitions, but likely a waste of time for hunting purposes.
If you "lost" a competiton because your 10 shot group was 0.010" larger than the winner's group, probably you want to look at your stuff. If you "miss" a 10 MOA kill shot when hunting, it is probably not the gear that is the issue.
I do not know why - but I do it - I want to be sure that any "miss" while hunting is on me - not the gear. I can sight in, I can hand load, I can bed the action, I can test for accuracy - in my hunting guns. So, if I "miss", about all that really is left is "me", that day, unless I deliberately want another excuse to use. And there are many critters out and about that I have fired shots at - so I "missed" my share, for sure!!!
- Location
- Western Manitoba
Part of hunting, in my opinion, is "trigger time" and "missing" what you aimed at. You make changes to hit. My son was about 12 or 14 at the time (now in his late forties) - using his Mom's 243 Win - I used my 308 Win - we placed clay pigeons (circa 4" diameter?) on the 100 yard rifle backstop - then standing free hand would shoot at them from beside the 100 yard tables - at the start, take five shots and still all five pigeons there. Then it became common to get 3 out of 5 - I do not recall 5 out of five shots, but that would have been note worthy! And we were just dumb Prairie schmucks hoping to get a deer that Fall - I understand there are shooters who can do 1/2 MOA offhand - I once owned a Schultz and Larson Model 61 Target 22 rifle like was used in World's (?) "free rifle" competitions - 10 shooters tied at 400 each - after 4 positions shooting - and I had the 50 meter targets - same as they were using.
Rifle recoil should be looked at as two phases. Firstly the phase where the bullet travels down the barrel which is the time when the rifle accelerates backwards. Secondly once the bullet has left the barrel. The first phase will dictate accuracy as the balance of the rifle and the way it is held can alter the launch angle. As long as the rifle accelerates backwards due to the bullet accelerating down the barrel we will see a rifle rotating around the centre of gravity. It is the centre of gravity in relation to the centre bore of the rifle. If the COG is well off the line of the bore the launch angle changes from your point of aim. To fix this one can firstly find out where the COG is, then correct by using different components. Mostly the COG is well below the centre bore leading to shots going high. The rifle will be sensitive to the way it is held. The fix is to reduce weight below the centre bore line and increase weight above the centre bore line. Lighter stock, heavier scope and / or higher mounted scope. Once the COG is on then centre line of the bore then holding the top of your scope or tight vs loose hold will not effect accuracy. Even the torque of the rifle will then stay on aim point.
In the second phase after the bullet has left the barrel, the rifle is traveling at max speed backwards and being stopped by the shoulder. In this phase the shape of the stock or mainly the position of the stock to shoulder contact will dictate what the rifle does. If the contact of the recoil pad to shoulder is below the COG then the rifle will flip muzzle up. Bit like a car hitting a tree on one side, it will spin around. This part will not effect accuracy but you will loose sight picture and might get a fright when the scope comes close to the eye. The first phase of recoil is somewhere between 1 and say 4mm travel depending on rifle weight and cartridge. In this distance the shoulder pad position is not yet going to effect much as the shoulder/pad is soft. I have been setting up my rifles since over ten years using a rifle balance. Not all rifles can be balanced to centre bore due to design or only using iron sights etc. Artillery has been using balanced guns since 1920's. Crucial for their accuracy.
edi
In the second phase after the bullet has left the barrel, the rifle is traveling at max speed backwards and being stopped by the shoulder. In this phase the shape of the stock or mainly the position of the stock to shoulder contact will dictate what the rifle does. If the contact of the recoil pad to shoulder is below the COG then the rifle will flip muzzle up. Bit like a car hitting a tree on one side, it will spin around. This part will not effect accuracy but you will loose sight picture and might get a fright when the scope comes close to the eye. The first phase of recoil is somewhere between 1 and say 4mm travel depending on rifle weight and cartridge. In this distance the shoulder pad position is not yet going to effect much as the shoulder/pad is soft. I have been setting up my rifles since over ten years using a rifle balance. Not all rifles can be balanced to centre bore due to design or only using iron sights etc. Artillery has been using balanced guns since 1920's. Crucial for their accuracy.
edi
Do you even handload?
There is nothing mythical about nodes, ES, SD, seating depths or best accuracy from a rifle through testing from a bench.
Please share what is your methods for sighting, testing and shooting a sporting rifle.
That depends.
I had always thought I was experiencing basically normal overal muzzle jump and everything seemed fine no problem. I recently purchased a MDT Oryx chassis for one of my rifles and immediately began having really bad muzzle jump issues. I did my research and discovered my shoulder was contacting the recoil pad at a point to low below the center bore line. I've adjusted and that was definitely the problem. I now make a conscious effort to contact the recoil pad with my shoulder higher up when shooting all of my rifles and it has made a world of difference preventing muzzle jump even in situations where I didn't realize that there was a muzzle jump issue.
Yeah, it's retarded. The only way I can shoot of a "shooting bench" properly, is modified prone.
i think this is it here.... channel "stone labs" , title- winchester m70 308 barrel contact accuracy experiment.Gotta link for that?
- Location
- Western Manitoba
As was pointed out to me, Melvin Forbes was from West Virginia - Ultra Light Arms (ULA) and then New Ultra Light Arms (NULA). I was getting him confused with gun maker Charlie Sisk, who was from Texas.
Yes, it depends on your rifle. If your rifle is properly built and bedded pretty good chance you are fine.
So answer me this. You zero a rifle on the bench. Then you find that your zero is different in field positions. Is that the rifle?
So I was at the range yesterday with the 358. Had three different loads (of 4 shots ea) that showed promise before. Shot the 3 batches with my hand firmly over the front scope ring. This method does a great job of controlling muzzle jump and is quite easy to prepare for the shot with little movement in the scope. All shots were fired off the front rest with a rabbit ears bag in the rear.
Results .... The original vertical stringing was completely eliminated but the loads were now showing horizontal dispersions up to about 2.5". Not sure if this is a win or not.
Maybe the technique needs to have less pressure applied to the front ring. Another option is to shoot the rifle off front sand bags with the forend held by hand instead of holding the forend while using the mechanical rest.
Thoughts?
Results .... The original vertical stringing was completely eliminated but the loads were now showing horizontal dispersions up to about 2.5". Not sure if this is a win or not.
Maybe the technique needs to have less pressure applied to the front ring. Another option is to shoot the rifle off front sand bags with the forend held by hand instead of holding the forend while using the mechanical rest.
Thoughts?
Hmmm I wouldn’t call that a win, if you need to find out what pressure she likes and then need to find out how to duplicate that same pressure every shot… all my rifle are shot the same way even the 6lbs one when at the bench, metal adjusting support with cradle bag and a sand bag at the rear with a rabbit hears bag on top, I make sure the forehand is resting firmly on the front rest and that the front sling swivel stuff ain’t in contact with the rest, the back is the back, I get behind the rifle as square as I can and bring the rifle into my shoulder pulling with my hand that is on the forehand not my trigger hand. About that trigger hand I try keeping it relax but with a consistent grip making sure I don’t do any torquing what so ever and that is also really important through out the entire firing process. Light rifle need a light touch including cheek weld, you don’t want to push your face onto the stock. Front bag has to be coushy! That is what I do and my shooting did improved quite a bit!
At my range we have these heavy shooting blocks for benchrest. These are basically wooden blocks with carpet glued on top as padding. I have my own shooting bags, but these blocks are really great and I use them as often as not. If I'm shooting a hunting rifle, I'll wrap the sling under the block and rest the block against the sling swivel stud. Works quite well. Basically any barrel hop is limited by the additional 5-6lbs of wood pulled upwards by the sling.
Obviously, this is only useful for some benchrest fun, zeroing and load development, but nonetheless it works well.
Obviously, this is only useful for some benchrest fun, zeroing and load development, but nonetheless it works well.
