Which air rifles have choke - and why?

[Artfull-Bodger]

I meant the front sight mounts on the hw99s and other break barrel rifles .

Yes I know mate, the grooves are crimped on which causes a slight raising of the surface which you can feel with your fingers, if you look at the direction this process is done you can see how the force pushes the steel up and out not down and in, also if you measure the choke position on grooved and non grooved barrels, oddly enough it's in the same place, the grooves don't cause the choke it's part of the barrel making process.

[bighit]

Yes I know mate, the grooves are crimped on which causes a slight raising of the surface which you can feel with your fingers, if you look at the direction this process is done you can see how the force pushes the steel up and out not down and in, also if you measure the choke position on grooved and non grooved barrels, oddly enough it's in the same place, the grooves don't cause the choke it's part of the barrel making process.

I have edited my second post, but as I say that is not where I originally read it.

[Artfull-Bodger]

I have edited my second post, but as I say that is not where I originally read it.

They seem to have missed the rather important fact blanks are made without grooves, then machined to fit the particular model, the choke is at the end of the barrel, so are the grooves, so they seem to correlate this as being as a result of the groove crimping, yet the choke position is the same whether the barrel is grooved or not, so ask yourself a simple question , why would HW make choked barrels (sold as such WITHOUT grooves http://silco.co.uk/products/-BARREL-...CH-CHOKED.html ) if just crimping the end of the barrel creates a choke effect?

[bighit]

They seem to have missed the rather important fact blanks are made without grooves, then machined to fit the particular model, the choke is at the end of the barrel, so are the grooves, so they seem to correlate this as being as a result of the groove crimping, yet the choke position is the same whether the barrel is grooved or not, so ask yourself a simple question , why would HW make choked barrels (sold as such WITHOUT grooves http://silco.co.uk/products/-BARREL-...CH-CHOKED.html ) if just crimping the end of the barrel creates a choke effect?

I don't know I don't make them. I only shoot them.

[Antoni]

First thing I was told about air rifle rifling was that the initial burst of pressure engaged the pellet's skirt firmly into the rifling.

My HW80K's barrel-end has been crimped for a foresight. I'll try the pellet push-through trick to check for extra friction at the end, but from what's been said here, that wouldn't prove the 'internet myth' of it causing choke (if there turns out to be a restriction on mine), because I don't know whether it was choked before-hand.

All the same I'll check it for excessive restriction as was mentioned in case it might be contributing to my poor grouping.

Reducing pellet fussyness?

There must be someone on here that has a confident understanding of why air rifle barrels can be had with chokes. Or is it just a marketing thing?

[bighit]

First thing I was told about air rifle rifling was that the initial burst of pressure engaged the pellet's skirt firmly into the rifling.

My HW80K's barrel-end has been crimped for a foresight. I'll try the pellet push-through trick to check for extra friction at the end, but from what's been said here, that wouldn't prove the 'internet myth' of it causing choke (if there turns out to be a restriction on mine), because I don't know whether it was choked before-hand.

All the same I'll check it for excessive restriction as was mentioned in case it might be contributing to my poor grouping.

Reducing pellet fussyness?

There must be someone on here that has a confident understanding of why air rifle barrels can be had with chokes. Or is it just a marketing thing?

Tom gaylords view on it

A choked rifle barrel squeezes the bullet or pellet slightly just before it leaves the muzzle. This is only an analogy, but it’s like pulling hard on a dog’s leash — it gets his attention and focuses him. In the case of the bullet and pellet, it stops any minute fluttering that may be happening inside the bore.
In my experience, it does work. Here’s what I know. First, the great barrel maker, Harry Pope, always choked his barrels. He first drilled the holes in the barrel blank undersized, then reamed the bore to get a choke of half a thousandth of an inch (0.0005-inches or 0.0127mm). His choke was an even taper down the full length of the barrel; and for the life of me, I can’t comprehend how he did it. Most barrel makers have a transition point where the bore tapers more or less abruptly from one size to the smaller size. This transition is very smooth, and the choke is seldom more than a thousandth of an inch, so it doesn’t disturb the bullet or pellet that much.
Pope’s barrels are legendary. One of them put ten lead bullets into 0.20 inches at 200 yards! And a great many of them will put 10 shots into a half inch at 200 yards, although Pope never guaranteed that level of accuracy.
But what about today’s barrels? Are they choked and does it help? Yes and yes are the answers. But not all barrels are choked — and even those that are choked may not be so intentionally.
Here’s a true story. When AirForce Airguns was switching over to Lothar Walther barrels in the early days, they tried barrels with and without chokes. Lothar Walther was capable of making barrels without chokes; but in their conversations with AirForce, they asked why they wanted unchoked barrels. After testing, AirForce decided it was well worth the additional cost to have all their barrels choked.
In the three years that I worked at AirForce, I tested every rifle that was returned to the company for inaccuracy. That must have been 20-30 rifles, in all. Every time one came in with such a complaint, the first thing I did was clean the barrel with J-B Non-Embedding Bore Cleaning Compound, and the next thing I did was shoot a group with the clean barrel. In all that time, I only had to shoot a single group with each barrel to produce a 5-shot group that ranged between 0.25 inches and 0.375 inches at 23 yards (which was the longest straight distance I had inside the old factory). Then, the rifle was packed with the target that I signed and dated and returned to the customer. Case closed.
Only once in three years did I find a barrel that I couldn’t get to shoot. It was an 18-inch .22-caliber Talon barrel that I’d cleaned several times. It just would not group better than 0.75 inches at 23 yards. It stumped me until I pushed a pellet through the bore with a cleaning rod, starting at the breech. There was no choke! Somehow, this barrel had slipped through the Lothar Walther manufacturing process without getting a choke, and it would not shoot.

[bighit]

another tom gaylord post

Lothar Walther chokes their barrels, too
A second endorsement comes from Lothar Walther, the German company that is well-known for making fine airgun barrels. They can supply their barrels with or without a choke, but their choked barrels out-shoot their unchoked barrels by a significant margin. They tell that to anyone who does business with them.


http://www.pyramydair.com/blog/2005/...ifle-accuracy/

[ballisticboy]

In all that time, I only had to shoot a single group with each barrel to produce a 5-shot group that ranged between 0.25 inches and 0.375 inches at 23 yards (which was the longest straight distance I had inside the old factory). Then, the rifle was packed with the target that I signed and dated and returned to the customer. Case closed.

I find it amazing that anyone who is supposed to be an "expert" should regard a single five shot group size as being adequate proof that a barrel is performing satisfactorily.