.22 ignition problems?
While shooting over a crony I saw that the average deviation from one rifle to another rifle was almost double. Why would one rifle deliver a more consistent FPS than the other rifle? The ammo used was out of the same box.
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PHASE OF THE MOON?[:D]. NO TWO RIFLE BARRELS HAVE EVER BEEN MADE THE SAME, YOU CAN HAVE 2 RIFLES COME OFF THE ASSEMBLY LINE NEXT TO EACH OTHER AND THEY CAN PREFORM WORLDS APART. INSIDE BARREL FINISH/UNIFORMITY WILL HAVE A GREAT DEAL TO DO WITH S.D., YOU MAY FIND ANOTHER TYPE OF AMMO THAT WILL GIVE YOU OPPOSITE RESULTS. 0 -
First of all:
What loadingsystem do the two rifles have - By that I mean Bolt-action, lever action, semi-auto?
How long are the barrels?
Different lengths of barrel can have quite noticable qualities and show significant differences.
You say it's two rifles - there might not be as much difference between them.
As Mike said - no two barrels are alike.
This covers the way the barrels are made.
If it is two different manufacturers, the process of making the barrels can be so much different - the tools used or even the cooling used to lubricate/cool the drilling and cutting of the barrel have a lot to say
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The inside surface of the barrel can be very different - you might not be able to see it, but at the high speeds gasses and projectiles travel at - even a dirty barrel or nonpolished barrel will show lower velocities.
Barrels can seem crude or uneven if you look very closely to the surface.
You can even take two identical barrels - from the same productionline and they will still show differences.
This is due to tollerances of the finished barrels.
How much was the difference you measured?
The rifles - Make, model and how are they loaded and what is the measured barrel length.?
It's hard to say what could have caused it without knowing this.
Don't do anything that I've allready done - That'd be just plain STOOOOOOPID.
The only way to get stoned??? - Whisky on the rocks offcourse.!!
Wanna see somethin' scary.?? Click here...0 -
I don't understand...your reply's. It is not the FPS that is different, that much I know about, it is to be expected.
It it the variation of the FPS between the rifles. One rifle shoots a very small Standard Deviation. The other rifle has a much wider deviation. That is what I don't get.
Both Rifles are bolt action and have simular barrel lengths.
The Anschuta 1422 showed a 54 FPS std deviation
The Marlin showed a 186 FPS std deviation.
Do you think it could be a weak firing pin spring in the Marlin causing the difference??0 -
The rifling lands on the Marlin are further from the bullet than they are on the Anschuta, thus more elapsed time (bullet jump) for deviations to occur, and occur to a greater degree.
If that WAG sounds intelligent, it is only by accident.[^]0 -
Bpost1958:
I suspect that the Marlin has a weak firing pin spring, as you postulated.
Weak springs in .22 rimfires are not uncommon. They're most often found in older .22s but can occur in new .22 rifles too.
A weak spring will give erratic ignition, from strike to strike, resulting in the disparity you noticed.
Also, out of all the calibers out there, the .22 rimfire )Short, Long, Long Rifle, etc.) exhibits the greatst disparity in preferences and dislikes.
When I buy a new .22 rifle or handgun, I also get a box of every type of ammo I can find: Remington, Winchester, Federal, Aguila, Eley, CCI, etc. I also buy standard, high velocity and hollowpoint versions from each manufacturer.
Firing at 25 yards for either rifle or handgun is plenty far to weed out the good groups from the so-so. Then, in the case of rifles, the ammo that produced good groups is fired at 50 yards. This separates the ammo further. Usually, the 50-yard test results in only one or two types of ammo that the rifle likes.
It's tedious work but you end up with a load matched to your rifle or handgun.
Use nothing but standard bullseyes, fire 10 shots of each type of ammo at each target, then write the rifle, serial number (in case you later get an identical rifle) and ammo type directly onto the target. Then, file them away. This is the easiest reference method.
Each gun is an individual. .22 rimfires are the most individualistic of the lot.
"I see an ugly cat. Smoke. The smell of brimstone. Holes in parchment. The ugly cat grins." --- The Prophesies of Gatodamus (1603-1666)0
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