Chrono testing advice (Which pellets)

[Blue407]

Morning All

I've got a Compro Mk4 on order, to test my TX200 before I make any adjustments.

I currently only have AA Diablo Field .22 16 grains, once I've finished polishing, cleaning, fitted the Tinbum kit etc what pellet should I use for Chrono testing to make sure I'm under the legal limit?

Obviously want to make sure that if its ever tested, no mater what pellet they use its legal.

Thanks in advance for advice and suggestions.

[Quare Fellow]

Invest in a tin of the lightest pellets, and a tin of the heaviest pellets you can find. Do a run of each and them make sure that it's turning out no more than 11 ft/lb with any of them if you want to leave a safe margin.

[CapitalBee]

I don't own a TX, but found that pellets will affect different air rifles with regards to FPE. I tended to try RWS Hobbys as they are light pellets and will give an increased feet per second figure out of the muzzle (and often the highest fpe reading). Maybe someone could offer their experiences with TX's?

[TonyL]

Different guns, even different examples of the same model, will give different results with different pellets.
So, although time consuming, the more pellets you can test with, the better.

However, AS A GENERAL RULE OF THUMB, a springer will return higher muzzle energies with lighter pellets.
But some of the more adventurous tinkerers can have a springer set up to be different to this generalisation.

For many years, the RWS Hobby, a very lightweight wadcutter, was regarded as the best control pellet in this regard and tends to give high muzzle energy figures in many guns.

The Falcon Accuracy Plus is a lighter Roundhead which tends to give healthy energy returns in many guns.

I'd say give these two a try (plus one or two more that others may suggest) and make sure that you're safely under with the most efficient pellet. That should ensure that if the gun was used with a pellet that you haven't tested, but yet is very efficient, you should be safe.

[Waisted]

With this pellet 15.9 grain I would aim for about 560 to 570 ft/s that about 11.1 to 11.5 ft/lbs, none off the lighter pellets that I have used have gone over the limit . If you can average the speed to about 565 ft/s you will have a sweet smooth shooting gun. Hope this helps.

[gil66]

I set mine up using AA 16gr fields and none of the lighter pellets i`ve tried have so far have been over limit.
You may(will) find that it will increase a little as it beds in and settles down so build up a little on the low side(say 10.5 ftb initially) and keep checking
11.4 ftb,..as been said above,is definitely the sweet spot on mine tho consistency is the goal
Have fun,..its a great learning experience

[p.sharp]

Jsb / aadf's are the most efficient in mine, superdomes / accupell (the lightest pellet I have ATM) are a full ftlb down on jsb's. Strange things airguns.

[Blue407]

So the bottom line is that as long as the AA pellets I use test < 11.2 (Even after bedding in) I should be legal with any pellets?

Has anyone actually tested how much of a difference from lowest pellet to highest on same rifle?

[GrahamAD]

So the bottom line is that as long as the AA pellets I use test < 11.2 (Even after bedding in) I should be legal with any pellets?

Has anyone actually tested how much of a difference from lowest pellet to highest on same rifle?

Done this a few times but mainly for down field pellet efficiency (the fastest pellet does not always have the most energy when it hits the target). Posted some of the results from testing on an LGU here and currently got another batch of 5 new pellets types to test when time permits.
Been running a similar test on a Webley Alecto in .20 (not so many choices in this calibre) which has given differences of up to 15% in muzzle energy but a difference of only 6% on impact energy between pellet types.

[angrybear]

So the bottom line is that as long as the AA pellets I use test < 11.2 (Even after bedding in) I should be legal with any pellets?

Has anyone actually tested how much of a difference from lowest pellet to highest on same rifle?

I did this with my .25 Hatsan striker across 17 different pellets, some results were off the scale extreme from under 6ftlbs with Gamo PBX lead free ultra lite (13+14gn) up to 13.5ftlb with Marksman

The other 14 were all between 10.8-11.6 but because the marksman were so high I had to set it with them which put everything else well below 11ftlb.

[Blue407]

Done this a few times but mainly for down field pellet efficiency (the fastest pellet does not always have the most energy when it hits the target). Posted some of the results from testing on an LGU here and currently got another batch of 5 new pellets types to test when time permits.
Been running a similar test on a Webley Alecto in .20 (not so many choices in this calibre) which has given differences of up to 15% in muzzle energy but a difference of only 6% on impact energy between pellet types.

15% difference in muzzle energy is worryingly high, that would mean a 10.5% rifle could go over 12% with the right (wrong) pellet...

[Fluffybuck]

15% difference in muzzle energy is worryingly high, that would mean a 10.5% rifle could go over 12% with the right (wrong) pellet...

Yes. I've often said in the past that I reckon I could push half the guns on here above 12ftlb with cunning choice of pellet and test conditions.
Many people want 11.5-12ftlb and set for that level, which makes it very easy to catch them out with certain other pellets. Lack of appreciation for/knowledge of PCP power curves doesn't help.
I recall a friend had a Logun S16 serviced. It was set to 11.3ftlb with Logun's then-recommended pellet Crosman Accupell (14.3gn) by the factory and on its return to my friend I decided to test it with Logun Penetrator which in both 16gn and 20.5gn form, sent it waaaay over the legal limit even though it was indeed running at 11.3ftlb with Accupell, and I don't think the gun was illegal with the 21gn Bisley Magnums.

There can be huge and unpredictable variations in pellet performance through different guns, powerplants and barrels, although there are general trends.

The only way to have a high level of confidence that you're legal is to test with a variety of pellet weights and brands. The more variety the better. Heaviest does not guarantee highest muzzle energy in a PCP and lightest does not guarantee highest energy in a springer or rammer.
If you set the gun not to exceed 11.2ftlb (at the peak of its power curve in warm conditions if it's a PCP) with a varied selection of pellets, including the ones you intend to use, you're unlikely to go above 12ftlb with other pellets.

[GrahamAD]

Many people want 11.5-12ftlb and set for that level, which makes it very easy to catch them out with certain other pellets. Lack of appreciation for/knowledge of PCP power curves doesn't help.

More variables in a PCP to catch the unsuspecting out than a springer... air pressure, port, hammer rate, even temperature/air pressure and humidity. Seen too many times people adjusting one variable to give a "fixed" muzzle energy and often wondered if they realise they could be walking around with a FAC rated rifle or firearm pistol if given an extended test for court. You only got to fail on one pellet to find yourself in a big mess.

[TonyL]

On a related thread the other week, one of the posters suggested that maybe the trade/authorities settled on a control pellet.

Personally, I think it would be a good idea and would alleviate the biggest variable.

It was suggested that a new pellet was introduced. But maybe a single existing pellet could be chosen; far cheaper and no costly R&D for the maker.

It would then be much simpler...just make sure that your fun is safely under with THAT ONE PELLET BRAND.

You'd then still go on the search for that ideal pellet for your gun, always placing accuracy first.

I have never used/bought the Air Arms Diablo Field. But, going by their general popularity, maybe that could be the pellet for the UK to settle on?

All possible solutions would be a compromise, but, for the sake of law-abiding shooters wanting to do the right thing, to me this would seem the most straight-forward solution.